GB2637949A

GB2637949A - Control of vehicle thermal management systems

Info

Publication number: GB2637949A
Application number: GB2401638.8A
Authority: GB
Inventors: Santirso Recio Pablo; Beadle James; Afrasiabian Ehsan; Comissiong Rhys
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2024-02-07
Filing date: 2024-02-07
Publication date: 2025-08-13
Also published as: GB202401638D0; WO2025168787A1

Abstract

A method 600 of controlling a thermal management system (100, fig. 1) of an electric vehicle (200, fig. 2). The electric vehicle comprises one or more thermal customers, each having a respective target operating temperature range. For each thermal customer, a respective thermal indicator indicative of whether the respective thermal customer is above, below, or within its target temperature range is obtained 602. Information for a plurality of operating modes is obtained 604 comprising, for each mode, a respective thermal criterion for each thermal customer indicating whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range. One or more compatible operating modes are then selected 606, based on a comparison between the thermal indicator(s) and the operating mode information; and an output indicating the selected one or more compatible operating modes is indicated 608. A control system, computer readable instructions, a computer readable medium and a vehicle are also claimed.

Description

CONTROL OF VEHICLE THERMAL MANAGEMENT SYSTEMS

TECHNICAL FIELD

The present disclosure relates to a method and control system for controlling a thermal management system of an electric vehicle. Aspects of the invention relate to a method, to a control system, to computer readable instructions, a computer readable medium, and to a vehicle

BACKGROUND

The temperature of certain components of electric vehicles may have a significant effect on the efficiency of operation of those components For example, when the temperature is cold, chemical reactions in traction batteries may be in hibiled, and in extreme cold the battery electrolyte may freeze, significantly increasing losses in the battery. Conversely, as the temperature of a traction battery increases, resistive losses in the battery may increase. Thus, it may be beneficial to maintain the traction battery of an electric vehicle within a certain range of temperatures. Similarly motors, electronics, and other components of the vehicle, along with the vehicle cabin for human comfort, may have desired temperature ranges in which they should ideally be maintained However, managing the temperature of components in the system may draw a significant amount of power from the traction battery, for example when powering a resistive heater, which itself may reduce the efficiency of the use of electrical power provided from the traction battery and therefore reduce the range of the electric vehicle It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a method for controlling a thermal management system, and an associated control system, computer readable instructions, computer readable medium, and vehicle, as claimed in the appended claims.

Disclosed arrangements provide a method for controlling a thermal management system of an electric vehicle, the method comprising receiving operating state information indicative of an operating state of the thermal management system, the operating state information indicating, for at least one component of the electric vehicle, whether the component is above, below, or within its target operafing temperature range, selecting one or mcre operating modes of the thermal management system that are consistent with the operating state information of each of the at least one component; and providing an output indicating the one or more selected operating modes.

For example, thermal customers of an electric vehicle may each have a respective target operating temperature range. A thermal indicator indicates whether a respective thermal customer is above, below, or within its target operating temperature range. A thermal criterion indicates, for a respective operating mode of the thermal management system, and for a respective thermal customer, whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range. Compatible operating modes are selected based on a comparison between the thermal indicators and the thermal criteria. An output is provided indicating the compatible operating modes.

Accordingly, operating modes consistent with the operating state of the vehicle may be efficiently determined.

The operating state information may indicate thermal demands of each of the at least one component (e g, whether the component is to act as a source, a sink, or is available to act as either), and an operating mode may be determined to be consistent with the operating state information if thermal demands of each of the at least one component is satisfied in the operating mode (e g, in the operating mode, thermal energy is removed from each of the at least one components that is to act as a source, and thermal energy is supplied to each of the at least one components that is to act as a sink) An aspect of the invention provides a method for controlling a thermal management system of an electric vehicle, the electric vehicle comprising one or more thermal customers, each thermal customer having a respective target operat ng temperature range, the method comprising obtaining, for at least one thermal customer, a respective thermal indicator indicative of whether the respective thermal customer is above, below, or within its target operating temperature range; obtaining operafing mode information for a plurality of operating modes of he thermal management system, the operating mode information comprising, for each operating mode, a respective thermal criterion for each of the at least one thermal customers, each thermal criterion indicating whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range, selecting one or more compatible operating mode, among the plurality of operating modes, based on a comparison between the at least one thermal indicators and the operating mode information for each operating mode, and providing an output indicating the selected one or more compatible operating mode Each operating mode may indicate a configuration of the thermal management system, each configuration defining thermal connections between the one or more thermal customers. Each operating mode may indicate an arrangement of the thermal management system, wherein the arrangement indicates an operating state of each element of the thermal management system.

Advantageously, operating modes compatible with the operating state of he vehicle may be efficiently determined. The compatibility may be based on determining modes that provide thermal energy to components that are below their target operating temperature range and extracting thermal energy from components that are above their target operating temperature range As such, the thermal indicator may indicate whether a temperature of the respective thermal customer is above, below, or within the target operating temperature range of the thermal customer. The thermal indicator may indicate whether the respective thermal customer is operating above, below, or within its target operating temperature range.

The electric vehicle may include a set of components having respective target temperature ranges, with the components in the set of components being thermal customers. The thermal management system may be arranged to control temperatures of the thermal customers, e g to cause the thermal customers have respective temperatures that are in respective target temperature ranges. As such a thermal customer may also be referred to as a controlled component or control target, as the thermal customers may be viewed as components of the electric vehicle that are ultimately controlled by the thermal management system. In some examples, the thermal customers are not components of the thermal management system, but are in thermal communication with the thermal management system Accordingly, thermal customers may be distinguished from other components of the electric vehicle.

In some examples, obtaining a thermal indicator for a thermal customer comprises obtaining operating state information indicative of an operating state of the thermal management system, the operating state information comprising the at least one thermal indicator.

In some examples, selecting one or more compatible operating modes comprises determining, for each operating mode, whether the operating mode is a compatible operating mode based on the comparison between the at least one thermal indicator and the operating mode information Accordingly, a current operating state of the electric vehicle may be obtainec, and an operating mode selected taking into account the current operating state In some examples, the operating mode information includes a lookup table including the at least one thermal criterion Accordingly, the comparison may be carried out for all operating modes (of the plurality of operating modes) As such, each of the operating modes may be assessed for compatibility with the thermal indicators. This reduces the likelihood of suitable operating modes, e.g., which a-e potentially more efficient, being overlooked In some examples, the one or more compatible operating modes are selected in dependence on each thermal criterion in a compatible operating mode being determined to satisfy the respective thermal indicator for each of the at least one thermal customers of the thermal management system.

For example, an operating mode may be a compatible operating mode when, for each of the at least one thermal customers, the thermal indicator of the thermal customer is consistent with the operating mode's thermal criterion for the thermal customer, wherein an operating mode is consistent with a thermal criterion if any of the thermal indicator indicates that the thermal customer is above its target operating temperature range and the hermal criterion indicates that the operating mode is compatible with the respective thermal customer being above its target operating temperature range, the thermal indicator indicates that the thermal customer is below its target operating temperature range and the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being below its target operating temperature range, and the thermal indicator indicates that the thermal customer is within its target operating temperature range and the thermal criterion indicates that the operating mode is compatible with the respective therma customer being within its target operating temperature range.

Accordingly, determining whether an operating mode is compatible with the thermal indicators may be performed in a simple and efficient manner.

In some examples, each respective thermal indicator comprises a high indicator if the respective thermal customer is above its target operating temperature range, a low indicator if the respective thermal customer is below its target operating temperature range, or an in-range indicator if the respective thermal customer is within its target operating temperature range.

In some examples the high indicator, low indicator and in-range indicator may be mutually exclusive, such that at any particular time, each of the at least one thermal customer is associated with no more than one of the high indicator, low indicator and in-range indicator In examples, each of the at least one thermal customer is associated with exactly one of the high indicator, low indicator and in-range indicator at any particular time.

Accordingly, the state of each thermal indicator can be represented simply, in a manner conducive to performing the comparison with the operating mode information.

In some examples, each thermal indicator comprises a field to store one of the high indicator, the low indicator and the in-range indicator Accordingly, the state of each thermal indicator can be represented efficiently, in a manner conducive to performing the comparison with the operating mode information.

In some examples, each of the high indicator, low indicator, and in-range indicator may by indicated by a respective symbol. Accordingly, the high indicator, low indicator, and in-range indicator may be efficiently stored and represented.

In some examples, the high and low indicators may be numbers having opposite signs, and the in-range indicator may be zero. For example, the high indicator may be a positive number, the low indicator may be a negative number. In some examples, the high indicator is the low indicator is '-1"_ -1' This may provide an intuitive representation of the high and low indicators that is convenient for use in computational methods.

In some examples absolute values of the high indicator and low indicator may indicate a target rate of thermal energy transfer. For example, the high and low indicator may be indicative, respectively, of a thermal energy excess or a thermal energy deficit in the associated thermal component In some examples, the high and low indicator may depend on a difference between a current temperature of the thermal customer and a target operating temperature of the thermal customer Accordingly, information about a target thermal energy transfer may be intuitively and efficiently represented by the high and low indicators, in a manner that is conducive to performing the comparison with the operating mode information.

In some examples absolute values of the high indicator and low indicator may indicate an amount of thermal energy to be transferred For example, the high and low indicator may be indicative, respectively, of a thermal energy excess or a thermal energy deficit in the associated thermal component. In some examples, the high and low indicator may be indicative of a difference between a current temperature of the thermal customer and a target operating temperature of the thermal customer.

Accordingly, the state of each thermal indicator can be represented intuitively, in manner that is conducive to performing the comparison with the operating mode information.

In some examples, each thermal criterion has a first state if the operating mode is compatible with the respective thermal customer being above its target operating temperature range, a second state if the operating mode is compatible with the respective thermal customer being below its target operating temperature range, or a third state if the operating mode is compatible with the respective thermal customer being within its target operating temperature range.

In some examples, the first state corresponds with a high criterion, the second state corresponds with a low criterion, and third state corresponds with an in-range thermal criterion. In some examples, each of the high criterion, low criterion, and in-range criterion may by indicated by a respective symbol.

The first, second and third states may be mutually exclusive, such that for a given operating mode, a thermal criterion is associated with no more than one of the first, second and third states. In examples, each thermal criterion is associated with exactly one of the first, second and third states for a particular operating mode.

Accordingly, the state of each thermal criterion can be represented in a simple manner that is conducive to performing the comparison with the thermal indicators.

In some examples, each thermal criterion comprises a field to indicate e store information indicative of) one of the first, second and third states.

Accordingly, the state of each thermal criterion can be represented in an efficient manner that is conducive to performing the comparison with the thermal indicators.

In some examples, the high and low criteria are numbers having opposite signs, and the in-range criterion is zero. For example, the high and low criteria may be positive and negative, respectively. In some examples, the high and low criteria are ',I" and "-1" respectively Accordingly, the state of each thermal criterion can be represented intuitively, in manner that is conducive to performing the comparison with the thermal indicators In some examples a thermal criterion is consistent with a thermal indicator if the thermal criterion is a high criterion and the thermal indicator is a high indicator, or if the thermal criterion is a low criterion and the thermal indicator is a low irdicator, or if the thermal criterion is an in-range criterion and the thermal indicator is an in-range indicator.

Accordingly, the state of each thermal indicator can be represented intuitively, in manner that is conducive to performing a comparison the thermal information and indicator.

At least one of the thermal customers may be designated as a thermal storage component. A thermal storage component is a thermal customer to be used to store excess thermal energy when the thermal storage component is within its target operating temperature range Accordingly, excess thermal energy may be stored in a thermal storage component, reducing energy waste due to excess thermal energy transferred to an environment of the vehicle (e g to the air outside the vehicle via a radiator) In some examples, the at least one thermal storage component includes at least one of a battery or an electric drive unit Accordingly, a traction battery or an electric drive unit may have sufficient heat capacity and a sufficiently broad target operating temperature range to allow thermal energy to be stored until requested by other components of the system.

In some examples, when a thermal customer is above its target operating temperature range the thermal customer is to act as a source of thermal energy, when the thermal customer is below its target operating temperature range the thermal customer is to act as a sink of thermal energy, and when the thermal customer is within its target operating temperature range the thermal customer is either available to act as a source or a sink of thermal energy, or to act as neither a source nor a sink of thermal energy Accordingly, a temperature of the thermal customer may be brought closer to target operating temperature range if its temperature is outside of that range. Further, some thermal customers may be used to store thermal energy while within their respective target operating temperature range.

In some examples a thermal customer (e.g. a first thermal customer) may be designated as a thermal storage component. When a component designated as a thermal storage component is within its target operating temperature range, the component is available to act (i e, is optionally useable as) as a source or a sink of thermal energy.

In some examples, the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range if. the thermal customer does not act as a source or sink in the operating mode; andlor the thermal customer is determined to be useable as an optional heat source or optional heat sink in the operating mode.

Accordingly, when the thermal customer does not act as a source or sink in an operating mode, the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range, and when the thernal customer is determined to be useable as an optional heat source or optional heat sink in the operating mode the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range.

A thermal customer is usable as an optional heat source or optional heat sink in an operating mode if transfer of thermal energy to or from the thermal customer is indicated as allowable in that operating mode when the thermal customer is within its target operating temperature range (e _g_ when the thermal customer is not requesting a transfer of thermal energy in order to meet a thermal target associated with the thermal customer) For example, when the thermal customer is within its target operating temperature range and designated as a thermal storage component In contrast, a thermal customer that is above or below its target operating temperature may be considered as an obligatory (or required) heat sink or heat source, respecfively. This is because a transfer of thermal energy is required in order to bring the thermal customer within its target operating temperature range, and the thermal management system should ideally provide the thermal customer's requested thermal energy transfer, if possible Accordingly, some thermal customers may be used to store excess thermal energy, rather than transfer the excess thermal energy off the vehicle. This may improve efficiency, for example by allowing stored excess thermal energy to De supplied from the thermal customer to a component having a deficit of thermal energy, instead of generating heat to meet the need of the component having the deficit In examples, a thermal customer (e _g_ a second thermal customer) is not designated as a thermal storage component (or is designated as not a thermal storage component) When a component designated as not a thermal storage component is within its target operating temperature range, the component is to act as neither a source nor a sink of thermal energy. In some examples, a cabin of The electric vehicle is not designated as a thermal storage component.

Accordingly, not all of the thermal customers are required to act as thermal storage components Accordingly, in compatible operating mode, thermal customers that are too hot may be cooled and thermal customers that are too cold may be heated. Further, thermal customers that have capacity to be warmed or cooled may be used as either a heat source or a heat sink The operating mode information may include, for each operating mode, an indication of an arrangement of the thermal management system in the respective operating mode, wherein identifying an arrangement of the thermal management system identifies a respective operating state of each component of the thermal management system in the operating mode, and wherein the operating modes include a first operating mode and a second operating mode, the second operating mode having the same arrangement of the thermal operating system as the first operating mode, a first thermal criterion of the first mode indicates that the first operating mode is one of (i) compatible with the respective thermal customer being above its target operating temperature range, or (t) compatible with the respective thermal customer being below its target operating temperature range, and the first thermal criterion of the second mode indicates that the second operating mode is compatible with the respective thermal customer being within its target operating temperature range.

The thermal transfers to and from components of the thermal management system may be identical in the first and second operating modes. The first and second operating modes differ in their indicated compatibility. As such, potential operating modes that are inefficient may be omitted from the plurality of operating modes of the operating mode information. That is, the operating node information may include multiple operating modes that correspond with the same arrangement of the thermal management system Operating modes corresponding with the same arrangement may differ in the indicated compatibility_ This may allow impractical or inefficient potential operating modes to be omitted from the operating mode information.

The arrangement may, for example, identify a valve position of each valve of the thermal management system, whether a heater of the thermal management system is on or off, whether a chiller of the thermal management system is on or off, etc That is, physical settings of the thermal management system may be the same in each mode having the same arrangement of the thermal management system.

In some examples, the method comprises obtaining the output indicating the selected one or more compatible operating mode, selecting a recommended operating mode from among the compatible operating modes, the recommended operating mode to be implemented in the thermal management system, and providing an output indicating the recommended operating mode.

Accordingly, a recommended operating mode may be selected from the compatible operating mode. Further, the selection of compatible operating mode may be performed before any evaluation associated with the selecting operation Accordingly, such evaluation may be unnecessary for operating modes that are not determined to be compatible In some examples, selecting the recommended operating mode comprises evaluating each operating mode from among the compatible operating modes and selecting the recommended operating mode based on the evaluating. In some examples, for one or more of the compatible operating modes the evaluating comprises at least one of assessing an energy cost associated with the one or more compatible operating mode, assessing whether thermal energy transfers requested by components are achievable in the one or more compatible operating mode In some examples, evaluating an operating mode uses more computing resource than comparing the at least one thermal indicator and the operating mode information for the operating mode.

Accordingly, the (relatively) computationally demanding evaluafion of an operating mode may be avoided for operating modes that do not provide heat to components that request thermal energy and remove heat from components that have excess thermal energy.

In some examples, the selecting comprises evaluating each operating mode from among the selected one or more operating modes, and evaluating each operating mode comprises obtaining an energy cost associated with one or more of the operating modes.

Advantageously, it is possible to select an operating mode of the thermal management system taking into consideration an energy cost associated with the operating mode. This facilitates energy efficiency, e.g. by allowing an operating mode with a low (or lowest) energy cost to be selected.

In some examples, for one or more of the compatible operating modes the evaluating comprises at least one of assessing an energy cost associated with the one or more compatible operating modes, assessing whether thermal energy transfers requested by components are achievable in the one or more compatible operating modes.

Taking energy costs into account when selecting an operating mode may allow improved efficiency, for example when compared with temperature-based selections. Assessing whether target thermal energy transfers are achievable when selecting an operating mode assists in re-aining performance of the thermal management system at a desired level.

In some examples, the energy cost of an operating mode comprises at least one of an actuator energy cost value representing an energy cost associated with operating the thermal management system in that operating mode, an energy cost associated with the battery, a thermal energy cost associated with the electric drive unit, and a thermal energy cost value representing an amount of thermal energy transferred off the electric vehicle in that operating mode The energy costs may be associated with a component may take into account operating parameters, or predicted operating parameters, of the component in the operating mode. For example, where the operating mode would lead to a temperature increase of the battery, a change in internal resistance and associated losses may be determined or estimated to obtain an energy cost associated with operating the battery in the operating mode. Similarly, torque losses in the electric drive unit may be calculated to determine or estimate an energy cost associated with the electric drive unit.

Accordingly, an energy cost for each potential operating mode of the thermal management system of the electric vehicle may be evaluated and a mode may be selected based on this (e g having a lowest energy cost, such that the most efficient operating mode to meet the required thermal transfer requirements of the components of the electric vehicle may be selected). In particular, the energy cost may include both the cost of operating the thermal management system, for example energy required to operate a compressor, and also a thermal energy cost value representing an amount of thermal energy lost from the electric vehicle, e.g. via a radiator to the environment. Thus, the method is able to select an operating mode for the thermal management system that retains as much thermal energy as possible while meeting the required cooling and/or heating requirements of the components, leading to increased efficiency overall In some examples, the actuator energy cost value associated with an operating mode is representative of at least one of: an energy cost of operating a compressor according to that operating mode; a valve actuation energy cost associated with that operating mode, a vehicle drag cost associated with operation of a heat exchanger according to that operating mode (e g vehicle drag associated with active vane management), an energy cost of operating a pump according to that operating mode, and an energy cost of operating a fan according to that operating mode. The actuator energy cost may be indicative of at least one of an ongoing energy cost of operating the electric vehicle 200 in the operating mode, an energy cost of changing from a current operating mode to the operating mode.

Advantageously, the method is able to take into account a range of energy costs associated with the operation of the thermal management system, including energy costs associated with transitioning the thermal management system from a first operating mode to a second operating mode, e g valve actuation costs In some examples, the method comprises obtaining operating state information that indicates the thermal energy transfers requested by components, the thermal energy transfers requested by components indicating target rates of thermal energy transfer to or from respective components requesting thermal energy transfers, wherein thermal energy transfers requested by components are achievable in a compatible operating mode if, in the compatible operating mode, rates at which thermal energy is transferable to respective components correspond with the respective indicated target rates of thermal energy transfer Accordingly, it is possible to take into account whether or not an operating mode is likely to bring the thermal customers towards their target operating temperature ranges in an acceptable time scale In some examples, the method comprises comprising obtaining operating state information that indicates the thermal energy transfers requested by components, the thermal energy transfers requested by components indicating amounts of thermal energy to be transferred to or from respective components requesting thermal energy transfers, and thermal energy transfers requested by components are achievable in a compatible operating mode if, in the compatible operating mode, amounts of energy transferable to respective components correspond with the respective indicated amounts of thermal energy Accordingly, it is possible to take into account whether or not an operating mode is likely to bring the thermal customers towards their target operating temperature ranges.

In some examples, the components requesting thermal energy transfers have respective target operating temperature ranges, and thermal energy transfers requested by components are achievable in a compatible operating mode if, in the compatible operating mode, the amounts of energy transferable to respective components result in the respective components having a temperature in their respective target operating temperature ranges.

Accordingly, it is possible to take into account whether or not an operafing mode is likely to bring the thermal customers towards their target operating temperature ranges.

In some examples, the method comprises obtaining operafing state information that indicates target thermal energy transfers of components, and assessing whether thermal energy transfers requested by components are achievable in a compatible operating mode comprises: obtaining a thermal energy balance value based on aggregating the target thermal energy transfers of components in thermal communication in the compatible operating mode, and determining, based on the thermal energy balance value, whether the target thermal energy transfers are satisfied in the compatible operating mode Accordingly, the selection of the operating mode may be based on whether or not, or how well, the operating mode satisfies a thermal energy transfer requirement.

In some examples, operating mode information includes, for each operating mode of the plurality of operating modes, state iidications that indicate respective functional states of components of the thermal management system in the operating mode, and the evaluating of each operating mode from among the selected one or more operating modes is based on the state indications for that operating mode.

Accordingly, details of the operating mode may be included in the operating mode information, along with the thermal criteria.

In some examples, the state indication of an operating mode comprises, for a component of the thermal management system, at least one of whether the component of the thermal management system is on or off in the operafing mode; a duty cycle of the component of the thermal management system in the operating mode Accordingly, details of the operating mode may be determined. For example, and energy cost associated with operating in the operating mode may be determined by summing individual energy costs associated with components of the thermal management system that are indicated as being on. In some examples, a duty cycle of a component in an operating mode may be indicative of an energy cost associated with that component in that operating mode.

In some examples, each operating mode is associated with: a respective coolant configuration of a cooling system of the thermal management system, wherein each coolant configuration defines a direction of flow of thermal transfer fluid to at least one component of the cooling system, and a respective refrigerant configuration of a refrigerant system of the thermal management system, wherein each refrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system Accordingly, it is possible to configure coolant and refrigerant systems of the thermal management system to appropriately manage temperatures in the vehicle. In some cases, providing configurable flow in the configure coolant and refrigerant systems may allow efficient movement of thermal energy among components to meet the thermal demands of the components In some examples, the cooling system comprises, or is in thermal communication with, at least one of a traction battery; an electric drive unit, a radiator, and a coolant heater.

Accordingly, it is possible to take into account various combinations of cooling system configurations and refrigerant system configurations. According to embodiments, it is possible to efficiently assess each operating mode, even when the number of possible combinations of coclant and refrigerant configurations becomes large In some examples, each operating mode is further associated with a respective functional state of a thermal link component of the thermal management system, the thermal link component being switchable between a first functional state, in which the thermal link component provides thermal communication between the cooling system and the refrigerant system, and a second functional state, in which the thermal link component does not provide thermal communication between the cooling system and the refrigerant system Accordingly, the functional state (e.g. on or off) of a thermal link component, such as a chiller, may be taken into account in addition to combinations of cooling system configurations and refrigerant system configurations According to embodiments, it is possible to efficiently assess each operating mode taking into account the state of a link component, even where this leads to the number of operating modes becoming large Examples may provide a control system for controlling a thermal management system of an electric vehicle, the control system comprising one or more processors collectively configured to receive operating state information indicative of an operating state of the thermal management system, the operating state information indicating, for at least one component of the electric vehicle, whether the component is above, below, or within its target operating temperature range, selecting one or more operating modes of the thermal management system that are consistent with the operating state information of each of the at least one component, and providing an output indicating the one or more selected operating modes.

Examples may provide a control system for controlling a thermal management system of an electric vehicle, the electric vehicle comprising one or more thermal customers, each thermal customer having a respective target operating temperature range, the control system comprising one or more processors collectively configured to obtain, for at least one thermal customer, a respective thermal indicator indicative of whether the respective thermal customer is above, below, or within its target operating temperature range; obtain operating mode information for a plurality of operating modes of the thermal management system, the operating mode information comprising, for each operating mode, a respectve thermal criterion for each of the at least one thermal customer, each thermal criterion indicating whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range, select one or more compatible operating mode, among the plurality of operating modes, based on a comparison between the at least one thermal indicators and the operating mode information for each operating mode, and provide an output indicating the selected one or more compatible operating mode Aspects of the invention provide a control system for controlling a thermal management system of an electric vehicle, the control system comprising one or more processing means (e g. one one or more processors) collectively configured to carry out any of the methods described herein.

Aspects of the invention provide computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform any of the methods described herein.

Aspects of the invention provide a computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of any of the methods described herein.

The computer readable medium may be a non-transitory computer readable medium Aspects of the invention provide a vehicle comprising, any of the control systems described herein, and a thermal management system communicatively coupled to the control system.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, end in particular the individual features thereof, may be taken independently or in any combination_ That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which, in accordance with embodiments of the invention FIG 1 illustrates a thermal management system for an electric vehicle, FIG. 2 illustrates a vehicle including the system of FIG. 1; FIG 3 illustrates a schematic representation of a powertrain thermal management system; FIG 4A to FIG 4F illustrate example configurations of the thermal management system, FIG. 5 illustrates refrigerant circuit of a climate control system, FIG 6 illustrates a method for controlling a thermal management system of an electric vehicle, FIG 7 illustrates a method for controlling a thermal management system of an electric vehicle, FIG. 8 illustrates a method for controlling a thermal management system of an electric vehicle, and FIG 9 illustrates a control system suitable for performing the methods described herein.

DETAILED DESCRIPTION

A control system may select an operating mode of a thermal management system of an electric vehicle, such as a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV). Compatible operating mode may be selected based on a comparison between one or more thermal indicators and respective thermal criteria associated with the operating mode. Thermal indicators indicate whether an associated thermal customer is above, below, or within its target operating temperature range, and a thermal criterion indicates whether, in an associated operating mode, a respective thermal customer acts as a heat source, a heat sink, or nether a heat source no a heat sink. An output is provided indicating the selected (compatible) operating modes Accordingly, compatible operating modes may be determined efficiently In some examples, an operating mode may be selected based on an energy cost associated with the operating mode (e g, an operating mode having a lowest energy cost) Thus, an energy based calculation may be performed for at least some compatible operating modes of the thermal management system to determine the energy cost associated with that operating mode The energy cost may be determined using predictive thermal models of the thermal management system The determination of an energy cost associated with modes that are not compatible operating modes may be avoided, providing computational efficiency when selecting an operating mode The selected operating mode can be output as a signal to provide an indication of a selected, or recommended, operating mode of the system to meet the current demands being placed on the thermal management system, and the thermal management system may be controlled according to the output signal to place the thermal management system in the selected operating mode.

The compatible operating modes may also be referred to as candidate operating modes With reference to FIG 1, there is illustrated a thermal management system 100 for an electric vehicle 200 in accordance with an embodiment of the present invention. The thermal management system 100 includes a controller 106 that is communicatively coupled to a powertrain thermal management system (PTIvI) 102 and a climate control system 104. The climate control system 104 may comprise heating, ventilation and air conditioning (HVAC) system. The controller 106 is to receive state information and/or sensor readings from one or more components of the powertrain thermal management system 102 and the climate control system 104, e g, temperature and mass flow rate values (e.g. based on measurements, or models). The mass flow rate may indicate, for example, one or more of a mass flow of a coolant of a cooling circuit, a refrigerant of a refrigerant circuit, or air flow in an air conditioning unit In embodiments, the controller 106 may be communicatively coupled to one or more components of the electric vehicle 200, for example via a controller area network (CAN) bus or similar network present on the electric vehicle 200, and operable to obtain operating state information from the components, the operating state information defining a thermal energy transfer requirement for each of the components of the electric vehicle 200 (e g, thermal energy transfer request/demand by a thermal customer). The controller 106 is further arranged to provide indications of a selected operatirg mode to the powertrain thermal management system 102 and a climate control system 104 to influence the operation of those systems.

In the arrangement of FIG 1, the thermal management system 100 comprises one controller 106, although it will be appreciated that this is merely illustrative. The controller comprises processing means (e g processor 108) and memory means (e.g., memory device 110). The processing means may be one or more electronic processing device which operably executes computer-readable instructions 112. The memory means may be one or more memory device 110. The memory means is electrically coupled to the processing means. The memory means is configured to store instructions 112 and the processing means is configured to access the memory means and execute the instructions 112 stored thereon.

FIG. 2 illustrates an electric vehicle 200 such as an automobile, provided with a controller 106 powertrain thermal management system 102, and climate control system 104, as shown in FIG 1 A powertrain of the electric vehicle 200 comprises at least one electric drive unit 202 (e g, front electric drive unit 202a and rear electric drive unit 202b) and a traction battery 204 The electric drive units 202 comprise one or more electric traction motors for propelling the electric vehicle 200 The traction battery 204 is a high voltage (HV) battery and is configured to supply electrical current to the at least one electric drive unit 202 In the present embodiment, the electric vehicle 200 comprises a front electric drive unit 202a for driving the front wheels of the electric vehicle 200 and a rear electric drive unit 202b for driving the rear wheels of the electric vehicle 200. In use, the front electric drive unit 202e and rear electric drive unit 202b are both powered by the traction battery 204 Each electric drive unit 202 may include power electronics, such as an inverter, to convert DC current sourced from the traction battery 204 to AC current to be supplied to the electric traction moors. As illustrated in FIG. 1, the powertrain thermal management system 102 is coupled to the climate control system 104 of the cabin of the electric vehicle 200 which is able to control a temperature of the vehicle cabin for occupant comfort.

While the traction battery 204 electric drive units 202 and climate control system 104 may be the most significant generators and/or users of thermal energy supplied by the powertrain thermal management system 102 it will be recognized that other vehicle components may be coupled to the powertrain thermal management system 102 and may have thermal requirements to be met by the thermal management system 100 For example, in embodiments, the electric vehicle 200 may further include separate power electronics, such as an on-board AC charger, that may be significant generators of thermal energy while requiring cooling to maintain an operating temperature. Similarly, the electric vehicle 200 may be provided with computer processing hardware that requires active cooling.

The components of the electric vehicle 200 may have target operating temperature ranges, and operating a component outside of an associated target operating temperature range may lead to increased power consumption by the component or by the electric vehicle 200 For example, when the temperature of the traction battery 204 increases, internal resistive losses within the traction battery 204 may also be expected to increase, while chemical reactions in the traction battery 204 may be inhibited when cold, similarly leading to increased losses n the battery 204. Such losses may result in recuced range for the electric vehicle when the powertrain components are not maintained within the desired operating temperature range.

The thermal management system 100 is operable as a source (supply) or sink of thermal energy to components of the vehicle 200. The powertrain thermal management system 102 is thermally coupled to the traction battery 204 and electric drive units 202 and is able to extract or supply thermal energy to satisfy thermal energy transfer requirements of these components Similarly, thermal energy may be transferred between the cabin and the climate control system 104 For example, energy may be supplied to the traction battery 204 and electric drive units 202 when beginning operation of the electric vehicle 200 from cold to more quickly bring the components to the desired operating temperature range. During operation of the electric vehicle 200, heat may be generated in the traction battery 204 and electric drive units 202, for example due to internal resistance of the cells of the traction battery 204. To maintain the temperature of the powertrain components within the desired temperature range, heat generated in the powertrain components of the electric vehicle 200 may be extracted by the thermal management system 100 The extracted thermal energy may be transferred between components of the electric vehicle 200 or may be transferred off the electric vehicle 200 for example via a low temperature radiator, to transfer the thermal energy to the outside environment The thermal management system 100 may be operable in a large number of different modes of operation to meet the various thermal transfer requirements of the components. Identifying a most efficient operating mode for the thermal management system 100, based on the current thermal requirements of the vehicle's components, may be difficult and may depend on a range of factors. Some of those factors may be external to the vehicle, such as an ambient temperature.

A schematic representafion of an example powertrain thermal management system 102 is shown in FIG 3 A control valve apparatus 302 is configured to control the circulation of thermal transfer fluid, or coolant, to manage a thermal load of the front electric drive unit 202a the rear electric drive unit 202b, the battery 204 and the climate control system 104 of the vehicle cabin for occupant comfort. The powertrain thermal management system 102 comprises a coolant heater 304 a first heat exchanger 306, and a second heat exchanger 308 The coolant heater 304 is configured to heat the coolant, for example to provide fast warm-up of traction battery 204 when inifially operafing the electric vehicle 200 The coolant heater 304 may be a high voltage (HV) heater that draws electrical power directly from traction battery 204. In some examples the cooling system comprises, or is in thermal communication with, at least one of a traction battery; an electric drive unit, a radiator (second heat exchanger 308) and a coolant heater.

The first heat exchanger 306 can be configured selectively to cool the coolant of the powertrain thermal management system 102 A refrigerant circuit of the climate control system 104 is coupled to a refrigerant side of the first heat exchanger 306 to cause the first heat exchanger 306 to operate as a chiller Thus, the first heat exchanger 306 enables the transfer of heat energy extracted from the coolant to the refrigerant of the climate control system 104 In this way, excess thermal energy may be transferred from powertrain components for use in heating the cabin of the vehicle In some embodiments, the first heat exchanger 306 may be bi-directional can be configured to transfer thermal energy from the refrigerant of the climate control system 104 to the coolant of the powertrain thermal management system 102, for example to allow for the supply heat from the outside environment via an outside heat exchanger of the climate control system 104 to heat the coolant The refrigerant circuit may be coupled to an outside heat exchanger operable to transfer heat between the refrigerant and the outside environment. The supply of refrigerant can be halted to reduced or prevent heat exchange in the first heat exchanger 306 The second heat exchanger 308 is a low temperature heat exchanger (or a low temperature radiator) and is operative to reject heat from the coolant to the outside environment The control valve apparatus 302 comprises a first pump 310 and a second pump 312. The powertrain thermal management system 102 comprises a first coolant circulation loop 314 and a second coolant circulation loop 316 A liquid coolant, or thermal transfer fluid, is circulated through the first coolant circulation loop 314 and second coolant circulafion loop 316 to perform supply or sink of thermal energy to the front electric drive unit 202a and rear electric drive unit 202b and the battery 204. At least one coolant temperature sensor 318 may be provided for measuring the temperature of the coolant. In the illustrated example, the coolant temperature sensor 318 is provided at an inlet to the second pump 312. The coolant temperature sensor 318 measures the temperature of the coolant supplied to the second pump 312 An electric fan (not shown) may optionally be provided to circulate air over the second heat exchanger 308 to promote cooling of the coolant.

The first coolant circulation loop 314 is configured to supply coolant to the traction battery 204 The coolant heater 304 and the first heat exchanger 306 are provided in the first coolant circulation loop 314 The coolant heater 304 is provided downstream of the traction battery 204 and, in use, is operative to heat the coolant The first heat exchanger 306 is disposed upstream of the traction battery 204 and, in use, can be configured to cool the coolant prior to introduction into the traction battery 204. As described herein, the first coolant circulation loop 314 and second coolant circulation loop 316 may be selectively connected to each other to enable the supply of coolant from the first heat exchanger 306 to the front electric drive unit 202a and rear electric drive unit 2026 Bypass conduits may be provided for one or more components of the first 314 or second 316 coolant loops. A bypass conduit may controllably opened or closed by a valve to control the supply of coolant to the respective component For example, the first coolant circulation loop 314 comprises a battery supply conduit 320, and a battery bypass conduit 322. The battery supply conduit 320 is configured to supply coolant to the battery 204. The battery bypass conduit 322 can be selectively opened and closed to control the supply of coolant to perform cooling of the battery 204.

The second coolant circulation loop 316 is configured to supply coolant to the front electric drive unit 202a and rear electric drive unit 202b The second heat exchanger 308 is provided in the second coolant circulation loop 316 downstream of the front electric drive unit 202a and rear electric drive unit 202b. In some examples, the front 202a and rear 2026 electric drive units may each be provided with a respective bypass conduit (not shown) to selectively bypass the respective electric drive unit 202a, 202b, accordingly, transfer of thermal energy to or from the front 202a and rear 202b electric drive units may be permitted when the respective electric drive unit 202 is not bypassed and may be avoided when the respective electric drive unit 202 is bypassed.

In use, the second heat exchanger 308 rejects thermal energy from the coolant to the external environment. The second coolant circulation loop 316 comprises a heat exchanger coolant conduit 324 for supplying coolant to the second heat exchanger 308, and a heat exchanger bypass conduit 326 for selectively bypassing the second heat exchanger 308 The control valve apparatus 302 may provide proportional control of the coolant flow rate through the heat exchanger bypass conduit 326 thereby controllably increasing or decreasing the flow through the second heat exchanger 308.

Control valve apparatus 302 includes crossflow valves 328 that are arranced to couple or decouple the first coolant circulation loop 314 (battery coolant circulation loop) and second coolant circulation loop 316 (electric drive unit coolant circulation loop). In addition, the crossflow valves 328 determine whether the first heat exchanger 306 is coupled in a coolant circulation loop with the battery 204 or the electric drive units 202. In other words, the crossflow valves 328 determine whether the first heat exchanger 306 is coupled in the first coolant circulation loop 314 or the second coolant circulation loop 316, or both when the first 314 and second 316 coolant circulation loops are coupled The coupling and decoupling of the first coolant circulation loop 314, second coolant circulation loop 316 and first heat exchanger 306, as well as a state (on or off) of the first heat exchanger 306 defines the configuration of the thermal management system 100.

The first heat exchanger 306, when activated, couples the coolant circulation loop that it is in with the refrigerant circuit As such, the first heat exchanger 306 is an example of a thermal link component of the powertrain thermal management system 102 A thermal link component is a component that is switchable between a first state, in which the thermal link component provides thermal communication between the cooling system and the refrigerant system, and a second state, in which the thermal link component does not provide thermal communication between the cooling system and the refrigerant system. For example, the thermal link component may be placed in the first state by including the thermal link component in both the coolant circulation loop and the refrigerant circuit (e g, by not bypassing the thermal link component in the cooling system and not bypassing the thermal link component in the refrigerant system). Similarly, the thermal link component may be placed in the second state by bypassing the thermal link component in one or both of the cooling system and the refrigerant system.

Herein coupling between the first coolant circulation loop 314 second coolant circulation loop 316 and/or the refrigerant circuit indicates that the first coolant circulation loop 314, second coolant circulation loop 316 and/or refrigerant circuit are H thermal communication, such that thermal energy may be transferred between them. Similarly, when they are decoupled, they are not in thermal communication, and no thermal energy (or a negligible amount of thermal energy) is transferred between them.

The control valve apparatus 302 allows the thermal management system 100 to be controlled to selectively bypass certain components of the powertrain thermal management system 102 such as the second heat exchanger 308, as well as to selectively couple the first coolant circulafion loop 314 and second coolant circulation loop 316 together to allow transfer of thermal energy between the components served by the different coolant circulation loops This means that there may exist a large number of possible arrangements of the thermal management system 100. For each arrangement, one or more components may be controlled to different states, for example the first heat exchanger 306 may be on or off depending on whether refrigerant is provided to the first heat exchanger 306 the second heat exchanger 308 may be selectively bypassed, etc. As such, there may be multiple operating modes of the thermal management system 100 for each of the configurations of the thermal management system 100, resulfing in a large total number of possible operating modes for the thermal management system 100 from which an operafing mode is to be selected controller 106 In embodiments, climate control system 104 includes the refrigerant circuit, the refrigerant circuit including a compressor, at least one internal evaporator operable to extract thermal energy from air in the cabin, at least one internal condenser operable to supply thermal energy to the air in the cabin and an outside heat exchanger for exchanging thermal energy with an outside environment. As discussed above, refrigerant of the climate control system 104 may be selectively provided to first heat exchanger 306 to allow heat energy to be transferred between the coolant of the powertrain thermal management system 102 and the refrigerant of the climate control system 104 Thus, climate control system 104 may be operable in multiple modes. In some embodiments, selection of an operating mode for the climate control system 104 may be coordinated with a selected operating mode for powertrain thermal management system 102 to further improve overall efficiency of the vehicle thermal management system 100. In some examples, the refrigerant system may have a plurality of refrigerant configurations, and each refrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system In examples, the thermal management system 100 may include a cooling system and a refrigerant system. The cooling system may be operable in a plurality of coolant configurations, each coolant configuration defining a direcfion of flow of thermal transfer fluid to at least one component of the cooling system, and each operating mode may be associated with a respective coolant configuration In some examples, the refrigerant system may be operable in a plurality of refrigerant configurations, each refrigerant configuration defining a direction of flow of thermal transfer fluid to at least one component of the refrigerant system, where each operating mode is associated with a respective refrigerant configuration. In some examples, each operating mode may be associated with a respective coolant configuration and a respective refrigerant configuration In some examples, each operating mode may further be associated with a respective state of a thermal link component of the thermal management system 100, such that the operating mode depends on whether or not a coolant circulafion loop is in thermal communication with a refrigerant circuit via the thermal link component.

The components of the vehicle may include one or more thermal customers Each thermal customer may have a respective target operating temperature range, or a target operating temperature (for example where the upper and lower limits of the target operating temperature range may be considered to be the same) The thermal management system 100 may be arranged to control temperatures of the thermal customers, e.g. to cause the hermal customers have respective temperatures that are in respective target operafing temperature ranges. The traction battery 204, electric drive units 202, and vehicle cabin are examples of thermal customers.

When a thermal customer is above its target operating temperature range the thermal customer is to act as a source of thermal energy, when the thermal customer is below its target operating temperature range the thermal customer is to act as a sink of thermal energy, and when the thermal customer is within its target operating temperature range the thermal customer is either availab e to ad as a source or a sink of thermal energy, or to act as neither a source nor a sink of thermal energy.

FIG 4A to FIG 4F show examples of configurations of a thermal management system that includes the powertrain thermal management system of FIG 3 Here, the first coolant circulation loop 314 includes the battery 204 and the coolant heater 304, the second coolant circula-ion loop 316 includes the electric drive units 202 and the second heat exchanger 308. For illustration purposes, the refrigerant circuit 408 is shown as having an internal evaporator 404 and an outside heat exchanger 406, but the refrigerant circuit 408 may include other additional or alternative components.

The first coolant circulation loop 314 and second coolant circulation loop 316 may be selectively coupled or decoupled by the crossbow valves 328 Further the first heat exchanger 306 may be coupled with either of the first coolant circulation loop 314 or the second coolant circu ation loop 316 (or both when the first coolant circulation loop 314 and the second coolant circulation loop 316 are coupled with each other) by the crossflow valves 328. As shown in FIG 3 the valves 328 in the first and second coolant circulation loops 314, 316 may be arranged in multiple operational positions interconnecting their respective ports 1-4 and 5-8 In FIGS 4A-4F they have the following arrangements, as will become evident from the description below of the circulation loops resulting when the valves are so arranged FIGS. 4A and 48. as shown in FIG. 3, with ports 1 and 3, 2 and 4 5 and 7 and 6 and 8 being interconnected; FIGS 4C and 4D. different from FIG 3 and 4A having ports 5 and 8 interconnected and ports 6 and 7 interconnected; and FIG. 4E and 4F as for FIGS. 4C and 4D, except ports 1 and 4 are interconnected, as are ports 2 and 3.

In FIG 4A the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled, and the first heat exchanger 306 is in the first coolant circulation loop 314 The first heat exchanger 306 is not active, such that the first coolant circulation loop 314 is decoupled from the refrigerant circuit 408 This leads to three thermal circuits being formed. The first thermal circuit 402a corresponds with the first coolant circulation loop 314 and includes the battery 204 and coolant heater 304 The second thermal circuit 402b corresponds with the second coolant circulation loop 316 and includes the electric drive units 202 and the second heat exchanger 308 The third thermal circuit 402c corresponds with the refrigerant circuit 408 and includes the internal evaporator 404 and the outside heat exchanger 406.

FIG 4B shows the same configuration as FIG 4A, with the first coolant cirnlation loop 314 and second coolant circulation cop 316 being decoupled and the first heat exchanger 306 being in the first coolant circulation loop 314 However, in FIG 4B the first heat exchanger 306 is active, and so the first coolant circulation loop 314 is coupled with the refrigerant circuit 408. This leads to two thermal circuits. A first thermal circuit 402a includes battery 204, coolant heater 304, first heat exchanger 306 internal evaporator 404 and outside heat exchanger 406 The second thermal circuit 4026 includes the electric drive units 202 and the second heat exchanger 308 In FIG. 4C the first coolant circulation loop 314 and second coolant circulation loop 316 are coupled. The first heat exchanger 306 is also coupled in the first coolant circulation loop 314 and the second coolant circulation loop 316. The first heat exchanger 306 is not active, such that the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled from the refrigerant circuit 408 This leads to two thermal circuits being formed. The first thermal circuit 402a corresponds with the combined first coolant circulation loop 314 and second coolant circulation loop 316, and includes the battery 204 coolant heater 304 electric drive units 202, and second heat exchanger 308. The second thermal circuit 402b corresponds with refrigerant circuit 408.

FIG 4D shows the same configuration as FIG. 40, with the first coolant cirahation loop 314 and second coolant circulation loop 316 being coupled. However, in FIG 4D the first heat exchanger 306 is active, and so the first coolant circulation loop 314 and second coolant circulation loop 316 are coupled with the refrigerant circuit 408. This leads to an arrangement with one thermal circuit 402a that includes all of the illustrated components.

In FIG 4E the first coolant circulation loop 314 and second coolant circulation loop 316 are decoupled, as in FIG 4A, but now the first heat exchanger 306 is in the second coolant circulation loop 316. The first heat exchanger 306 is not active, such that the second coolant circulation loop 316 is decoupled from the refrigerant circuit 408. This leads to three thermal circuits being formed. These thermal circuits are the same as in FIG. 4A, except that the first heat exchanger 306 is in the second coolant circulation loop 315 As such, the thermal transfer in this arrangement is the same or similar to the arrangement of FIG 4A However, these modes of operation are not necessarily equivalent. For example, an energy cost to transition to the mode of FIG 4A may be less than the energy cost to transition to the mode of FIG 4E and so the mode of FIG 4A may be a better selection than the mode of FIG 4E in that case The energy cost of transitioning may be associated with driving actuators to control the crossflow valves 328 for example Other energy costs may be considered in selecting an operating mode, as described in more detail below.

FIG 4F shows the same configuration as FIG 4E, with the first coolant circulation loop 314 and second coolant circulation loop 316 being decoupled and the first heat exchanger 306 being in the second coolant circulation loop 316 However, in FIG 4F the first heat exchanger 306 is active, and so the second coolant circulation loop 316 is coupled with the refrigerant circuit 408. This leads to two thermal circuits. A first thermal circuit 402e includes battery 204 and coolant heater 304. The second thermal circuit 402b includes the electric drive units 202 the second heat exchanger 308, the first heat exchanger 306, the internal evaporator 404, and outside heat exchanger 406 Arrangements, such as those shown in FIG. 3 and FIG. 4A to FIG. 4F, lead to a significant number of possible operating modes for the thermal management system 100 In each of the configurations, components such as the second heat exchanger 308 coolant heater 304 and outside heat exchanger 406 may each be active or inactive. Similarly, one or more components may be bypassed in the thermal transfer fluid loop, such that bypassed components do not exchange thermal energy via that thermal management system 100 In some examples the number of modes may exceed one hundred. In some examples, the number of modes may exceed two hundred.

Where a system is capable of fewer configurafions, a smaller number of potential operating modes exist and there are fewer options for heat transfer among the components of a vehicle. In such systems, the selection of an operating mode may be straightforward, e.g., using a lookup table that indicates a mode based on temperatures of components of the vehicle (e g, taking into account the temperatures of three or fewer components). However, the reduced options of transferring heat between components may limit the achievable energy efficiency.

In some systems that provide a range of configurations of the thermal management system 100 that are comparable to the examples in FIG. 3 and FIG. 4A to FIG. 4F, the full benefit of these configurations may not be achieved whe-e the system significantly limits selectable combinations of configurations with operation states of components (such as a heater on/off or radiator used/bypassed) In such systems, only a small subset of the potential modes is selectable Similarly to the case where few configurations are available, in such systems, a mode of the thermal system may be selected based on relative temperatures of the components according to a table of selectable modes. In such systems, the number of selectable modes may be fewer than 20 or fewer than 15 for example. Accordingly, these systems provide limited flexibility in controlling heat transfer between components, potentially losing opportunities for energy efficiency.

As noted above, in systems having a relatively small number of selectable operating modes (e g, 20 or fewer), an operating mode may be selected in a relatively straightforward way, e.g. from a table based on temperatures of the components. The table (or other mode selection method) may be defined in advance based on engineer intuition.

Where the number of selectable operating modes significantly increases, a selection of a mode based on engineer intuition becomes impractical. and reliably selecting an appropriate operating mode becomes increasingly difficult using a simple table-based rules-based or similar, approach.

Where a large number of operating modes are to be considered, detailed consideration of each operating mode (e g, by obtaining energy costs for every operating mode) may be computationally prohibitive. This may be ameliorated by removing non-compliant operating modes from consideration without obtaining associated energy costs Computational efficiency may be important where computational resources are limited, such as in some on-board controllers in vehicles. In addition, in some implementations, interfaces with other elements of the vehicle control system may place strict time constraints on the selection of the operating mode, and for this reason also, computational efficiency may be important when implementing the selection of the operating mode According to examples herein, compatible, that is to say, candidate, operating modes are determined. Compatible operating modes are operating modes in which thermal energy is removed from components that have excess thermal energy, and thermal energy is provided to components that have a thermal energy deficit. A recommended operating mode is then selected based on the determination of compatible operating modes. Accordingly, the compatible operating modes may form a shortlist of operating modes from which a recommended operating mode may be selected.

This may be more computationally efficient than directly selecting a single operating mode from among the full set of operating modes This approach may be particularly beneficial, albeit not necessarily essential, where there are a large number of operating modes, e g, by reducirg the number of operating modes that are to be assessed in detail when selecting a recommended operating mode.

In some examples, energy costs associated with different operating modes are determined and used in the selection of an operating mode to be implemented This may allow for more reliable selection of an energy efficient operating mode. Moreover, the selection of the operating mode may better take into account the current state of the components of the vehicle compared with temperature-based, table-based or rules-based approaches.

A schematic representation of an example refrigerant circuit 408 of climate control system 104 is shown in FIG. 5. The refrigerant circuit of FIG. 5 includes an outside heat exchanger 406, chiller (first heat exchanger 306), in-vehicle evaporator (internal evaporator 404), in-vehicle condenser 502, and compressor 504 arranged in a circuit Internal evaporator 404 may comprise more than one evaporator operable to provide multi-zone climate control within the vehicle. As would be appreciated by the skilled person, other components, such as one or more expansion valves, bypass conduits, etc may be provided in the refrigerant circuit, but are not shown in Fig. 5 for clarity and brevity In operation, the compressor 504 operates to raise the pressure of the refrigerant which is then supplied to an input of condenser 502 where heat may be released for use in heating the cabin, if required An output of condenser 502 is coupled to an input of the outside heat exchanger 406 which may be bidirectional and capable of recovering or rejecting heat energy from/to an ambient environment An output of the outside heat exchanger 406 is coupled to an input of the first heat exchanger 306. The first heat exchanger 306 is configured to selectively cool a thermal transfer fluid, or coolant, of the powertrain thermal management system 102 to allow heat energy to be transferred from the powertrain thermal management system 102 to the refrigerant of the climate control system 104 An output of the first heat exchanger 306 is coupled to an input of the internal evaporator 404 where the refrigerant may absorb heat energy from the cabin (i e provide cooling) An output of the internal evaporator 404 is coupled to the compressor 504 to complete the refrigerant circuit 408.

One or more electric blowers, or fans, may be provided, associated with internal evaporator 404 and/or in-vehicle condenser 502 to provide airflow over the evaporator/condenser and distribute thermal energy through the cabin. Similarly, airflow may be provided to outside heat exchanger 406 through the use of an electric fan, or by one or more controllable ducts, arranged to direct air from the outside environment over the outside heat exchanger 406 Also provided in the refrigerant circuit 408 are a number of bypass valves to allow components of the refrigerant circuit 408 to oe selectively bypassed according to a desired operating configuration of the climate control system 104 A first bypass valve 506 is arranged to selectively bypass refrigerant around the outside heat exchanger 406. A second bypass valve 508 is arranged to selectively bypass refrigerant around the first heat exchanger 306 A third bypass valve 510 is arranged to selectively bypass refrigerant around internal evaporator 404. Bypassing a component effectively removes that component from the refrigerant circuit 408 so that no heat transfer occurs in that component. For example, by selectively bypassing first heat exchanger 306 using second bypass valve 508, heat exchange between the climate control system 104 and powertrain thermal management system 102 is disabled.

Example climate control modes, of the climate control system 104 may include * Cabin cooling with thermal energy rejected to ambient via the outside heat exchanger 406 In this climate control mode, second bypass valve 508 is selectively controlled to bypass first heat exchanger 306, while first 506 and third 510 bypass valves are selectively controlled to cause the refrigerant to pass through the outside heat exchanger 406 and internal evaporator 404, * Cabin cooling and assisted powertrain cooling with thermal energy rejected to ambient via the outside heat exchanger 406 H this climate control mode, first 506 second 508 and third 510 bypass valves are selectively cortrolled to cause the refrigerant to pass through the outside heat exchanger 406, first heat exchanger 306 and internal evaporator 404 Thermal energy is transferred from powertrain thermal management system 102 via the first heat exchanger 306 providing increased cooling to the powertrain components coupled to the powertrain thermal management system 102; * No cabin thermal demand with assisted powertrain cooling. In this climate control mode, first 506 and second 508 bypass valves are selectively controlled to cause the refrigerant to pass through the outside heat exchanger 406 and first heat exchanger 306 Third bypass valve 510 is selectively controlled to bypass internal evaporator 404 as there is no heat/cooling demanded by the cabin, * Cabin heating supplied by ambient heat recovery. In this climate control mode, the second bypass valve 508 is selectively controlled to bypass first heat exchanger 306 and the third bypass valve 510 is selectively controlled to bypass internal evaporator 404 while first bypass valve 506 is selectively controlled to cause the refrigerant to pass through the outside heat exchanger 406 Heat energy is recovered from ambient via the outside heat exchanger 406 and provided to the cabin via condenser 502 * Cabin heating supplied by powertrain heat recovery. In this climate control mode, the first bypass valve 506 is selectively controlled to bypass the outside heat exchanger 406 and the third bypass valve 510 is selectively controlled to bypass internal evaporator 404 while second bypass valve 508 is selectively controlled to cause the refrigerant to pass through the first heat exchanger 306. Heat energy is transferred from powertrain thermal management system 102 to the refrigerant via first heat exchanger 306 and is provided to the cabin via condenser 502 * Cabin heating supplied by ambient heat recovery and powertrain heat recovery. In this climate control mode, first 506 and second 508 bypass valves are selectively controlled to cause the refrigerant to pass through the outside heat exchanger 406 and first heat exchanger 306 Third bypass valve 510 is selectively controlled to bypass internal evaporator 404. Heat energy recovered from both ambient and the powe-train to provide a thermal energy requirement of the cabin For the climate control system 104 illustrated in FIG 5 (circuit 408), there may be more than one climate control mode that is able to meet a thermal demand associated with the cabin of the vehicle 200 For example, to supply heat to the cabin, different operating modes may be available to source thermal energy either from the powertrain via powertrain thermal management system 102 and first heat exchanger 306 and/or from ambient via outside heat exchanger 406 Furthermore, the relative efficiency of each available operating mode of the climate control system 104 may depend on a configuration or arrangement of powertrain thermal management system 102 which is itself reconfigurable to allow thermal energy transfer requirements of powertrain components to be met Therefore, a whole system approach may be taken to identify a low energy cost operating mode for the vehicle thermal energy management system 100 FIG. 6 illustrates a method 600 for controlling a thermal management system 100 of an electric vehicle 200. As described above, the electric vehicle comprises one or more thermal customers, each thermal customer having a respective target operating temperature range. At block 602 a respective thermal indicator is obtained for each of at least one thermal customer. The thermal indicator is indicative of whether the respective thermal customer is above, below, or within its target operating temperature range. At block 604 operating mode information is obtained for a plurality of operating modes of the thermal management system 100 The operating mode information includes, for each operating mode, a respective thermal criterion for each of the at least one thermal customers, each thermal criterion indicating whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range At block 606 one or more compatible operating mode are selected from among the plurality of operating modes The selection of the one or more compatible operating mode is based on a comparison between the at least one thermal indicator and the operating mode information for each operating mode. At block 608 an output is provided indicating the selected one or more compatible operating mode.

According to the method 600 of FIG 6, operating modes compatible with the operating state of the vehicle may be efficiently determined. For example, by identifying thermal energy transfer requirements in terms of the requested direction of heat flow via the thermal indicators, and identifying thermal energy transfer requirements that each operating mode is suitable for providing, it is possible to efficiently reduce the number of modes to be considered. It is also possible to distinguish between operating modes compatible with states in which a thermal customer requires heat transfer (i e_, is too hot or too cold) and operating modes compatible with the thermal customer being available for heat transfer (e g. acting acting as a thermal storage component) when heat transfer is not required to/from the thermal customer.

In examples, selecting one or more compatible operating mode comprises determining, for each operating mode, whether the operating mode is a compatible operating mode based on the comparison between the at least one thermal indicator and the operating mode information For example, compatibility may be based on determining modes that provide thermal energy to thermal customers that are below their target operating temperature range and extracting thermal energy from thermal customers that are above their target operating temperature range In some examples, the one or more compatible operating mode are selected in dependence on each thermal criterion in a compatible operating mode being determined to satisfy the respective thermal indicator for each of the one or more thermal customers of the thermal management system. In some examples, the one or more compatible operating mode are selected in dependence on each thermal criterion in a compatible operating mode being determined to satisfy the respective thermal indicator for each of the at least one thermal custome-of the thermal management system.

The comparison may be efficiently carried out for all operating modes (of the plurality of operating modes) As such, can of the operating modes may be assessed for compatibility with the thermal indicators This reduces the likelihood of suitable operating modes, e.g., which a-e potentially more efficient, being overlooked Each operating mode may indicate a configuration of the thermal management system, each configuration defining thermal connections between the one or more thermal customers. Each operating mode may indicate an arrangement of the thermal management system, wherein the arrangement indicates an operating state of each element of the thermal management system. For example, selection of an operating mode may defire valve positions for the valves of the coolant circulation loops 314, 316 valve positions of valves of the refrigerant circuit 408 whether the first heat exchanger 306 is on or off, whether the coolant heater 304 is on or off, whether components are bypassed (such as the second heat exchanger 308), whether the outside heat exchanger is on or off, etc "on or off here including whether a respective fan or duct is activated_ The method 600 may include obtaining operating state information indicative of an operating state of the thermal management system The operating state information may comprise the at least one thermal indicators.

Obtaining a thermal indicator for each of at least one thermal customer may include obtaining operating state information that indicates an operating state of the thermal management system 100 the operating state information may comprise the at least one thermal indicators, or information from which the at least one thermal indicator may be derived. For example, the operating state information may describe temperatures of components (including thermal customers) of the electric vehicle 200. The thermal indicators are examples of thermal energy transfer requirements of the respective components/customers.

Thermal customers above their target operating temperature range may be described as too hot or as having excess thermal energy. Thermal customers that are below their target operating temperature range may be described as too sold as having a deficit of thermal energy, or as requesting thermal energy.

Thermal customers may include, for example, one or more of a traction battery, an electric drive unit, and a cabin air conditioning unit, for example A traction battery or an electric drive unit may have sufficient heat capacity and a sufficiently broad target operating temperature range to allow thermal energy to be stored until requested by other components of the system.

Some (e g. one one or more) thermal customers may be indicated as usable either to receive or supply thermal energy (e g act as a source or a sink) when the thermal customer is within its target operating temperature range For example, when the thermal customer is within its target operating temperature range and has capacity to either provide thermal energy to other components, or to store excess thermal energy. Such thermal customers may be designated as thermal storage components.

A component designated as a thermal storage component has an associated operating temperature range, and is usable to store excess thermal energy when the thermal storage component is within its target operating temperature range. This may reduce the transfer of thermal energy off of the electric vehicle 200, instead retaining the thermal energy on the electric vehicle 200 for possible future use. Accordingly, if a component has a subsequent deficit in thermal energy, the previously stored excess thermal energy may be extracted from the thermal storage component and provided to the component having the deficit. This may, for example, avoid or reduce usage of the coolant heater 304 to address the thermal energy deficit. leading to a corresponding reduction in electrical energy drawn from the traction battery 204 to power the coolant heater 304. Thus, when a component designated as a thermal storage component is within its target operating temperature range, the component is able to act as a source or a sink of thermal energy In some examples, one or both of a traction battery or an electric drive unit may be designated as a thermal storage comporent Some thermal customers may be indicated as not to receive or supply thermal energy when the thermal customer is in its target operating temperature range That is, in some examples one or more thermal customers are not designated as thermal storage components (or are designated as not thermal storage components) When a component designated as not a thermal storage component is within its target operating temperature range, the component is to act as neither a source nor a sink of thermal energy (i.e., is to act as neither a heat source nor a heat sink when it is in its target operating temperature range).

Accordingly, where the thermal customer is designated as not to be used as a thermal storage component, an indication that the thermal customer is below its target operating temperature range may correspond with a state in which thermal energy is to be supplied to the thermal customer (i e is to act as a heat sink), an indication that the thermal customer is above its target operating temperature range may correspond with a state in which thermal energy is to be extracted from the thermal customer (i e, it is to act as a heat source) and an indication that the thermal customer is within its target operating temperature range may correspond with a state in which no thermal energy is to be transferred from or to the thermal customer (i e. it is to act as neither a heat source nor a heat sink) In some examples a cabin of the electric vehicle 200 may be designated as not usable as a thermal storage component This may avoid unwanted temperature changes in the cabin, for example.

Thus, in some examples, when a thermal customer is above its target operating temperature range the thermal customer is to act as a source of thermal energy, when the thermal customer is below its target operating temperature range the thermal customer is to act as a sink of thermal energy, and when the thermal customer is within its target operating temperature range the thermal customer is either available to act as a source or a sink of thermal energy (if it is designated as a thermal storage component) or to act as neither a source nor a sink of thermal energy (if it is designated as not a thermal storage component). The operating mode may be determined to be a compatible operating mode if the thermal criteria indicate that the operating mode is consistent with these transfers Accordingly, a temperature of the thermal customer may be brought closer to target operating temperature range if its temperature is outside of that range Further, some thermal customers may be used to store thermal energy while within their respective target operating temperature range. Thus, in a compatible operating mode, thermal customers that are too hot may be cooled and thermal customers that are too cold may be heated. Further, thermal customers that have capacity to be warmed or cooled may be used as either a heat source or a heat sink e if they are designated as thermal storage components) When a component designated as a thermal storage component is within its target operating temperature range, the component is available to act (i e optionally useable as) as a source or a sink of thermal energy, at least while it remains within its target operating temperature range In some examples, the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range if the thermal customer does not act as a source or sink m the operating mode; and/or the thermal customer is determined to be useable as an optional heat source or optional heat sink in the operating mode.

Accordingly, when the thermal customer does not act as a source or sink in an operating mode, the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range, and when the thermal customer is determined to be useable as an optional heat source or optional heat sink in the operating mode the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range.

A thermal customer is usable as an optional heat source or optional heat sink in an operating mode if transfer of thermal energy to or from the thermal customer is indicated as allowable in that operating mode when the thermal customer is within its target operating temperature range (e.g. when the thermal customer is not requesting a transfer of thermal energy in order to meet a thermal target associated with the thermal customer) For example, when the thermal customer is within its target operating temperature range and is designated as a thermal storage component In some embodiments, whether a thermal customer is able to act as a source or sink may depend on a temperature difference between the thermal customer and the corresponding dermal transfer fluid This may be determined separately from the determination that the thermal customer is in its target operating temperature range and is available to act as a source or sink. That is, in some examples, an operating mode may be determined to be a compatible operating mode, and a subsequent determination may be made as to whether the thermal transfers that are achievable in the operating mode (e g, including whether the thermal customer is capable of acting as a particular one of a source or a sink) are consistent with the desired thermal transfers In contrast. a thermal customer that is above or below its target operating temperature may be considered as an obligatory (or required) heat sink or heat source, respecfively. This is because a transfer of thermal energy is required in order to bring the thermal customer within its target operating temperature range, and the thermal management system should ideally provide the thermal customer's requested thermal energy transfer, if possible.

Operating state information may be obtained. The thermal indicators may be included in, or derivable from, the operating state information. In addition to the thermal indicators operating state information may describe the status of other components of the electric vehicle 200 For example, the operating state information may indicate thermal energy transfers requested by the components. The thermal energy transfers requested by components may indicate target rates of thermal energy transfer to or from respective components requesting thermal energy transfers. The thermal energy transfers requested by components may indicate amounts of thermal energy to be transferred to or from respective components requesting thermal energy transfers The operating state information may include one or more of temperatures of one or more of the components, an amount of thermal energy to be supplied to or extracted from one or more of the components, or a rate at which thermal energy is to be supplied to or extracted from one or more of the components. The components described by the operating state information may include the thermal customers In some examples the operating state information may indicate temperatures of thermal customers, and the thermal indicators may be derived from the indicated temperatures and other information about the system, such as a lookup table storing target operating temperature ranges associated with the thermal customers, and/or information indicating whether a component is usable to store excess thermal energy In this way, the thermal indicators may be indicated by the operating state information without being explicitly included in the operating slate information In other examples, the thermal energy transfer requirements may be explicitly included in the operating state information.

Operating mode information includes, for each operating mode, a thermal criterion for each respective thermal customer Each thermal criterion indicates whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range Accordingly, each thermal criterion has a first state if the operating mode is compatible with the respective thermal customer being above its target operating temperature range, a second state if the operating mode is compatible with the respective thermal customer being below its target operating temperature range, and a third state if the operating mode is compatible with the respective thermal customer being within its target operating temperature range.

The operating mode information may be obtained 604 in the form of a lookup table that includes the thermal criteria Obtaining the thermal criteria in this way allows for a straightforward, and computationally efficient, comparison of the directions of flow of thermal energy in the mode with the directions of flow of thermal energy requested by the thermal customers Selecting 606 one or more compatible operating modes may comprise determining, for each operating, mode whether the operating mode is a compatible operating mode based on the comparison between the at least one thermal indicator and the operating mode information Accordingly, an operating mode may be a compatible operating mode if, in that operating mode the thermal management system is arranged to remove thermal energy from components (thermal customers) that are indicated by the thermal indicators as being above their target operating temperature range, and is arranged to provide thermal energy to components that are indicated by the thermal indicators as being below their target operating temperature range Accordingly, compatible operating modes may be considered to be operating modes that have appropriate thermal energy transfer directions (i.e., cool, or remove thermal energy from, thermal customers that are indicated as too hol, and heat, or provide thermal energy to, thermal customers that are too cool) Compatible operating modes may be selected in dependence on each thermal criterion in a compatible operating mode being determined to satisfy the respective thermal indicator for each of the at least one thermal customers of the thermal management system. For example, an operating mode may be a compatible operating mode if each thermal criterion of the operating mode satisfies or matches the corresponding thermal indicator Accordingly, determining compatible operating modes may be based on determining whether the operating mode heats all thermal customers that are too cool (i e have a temperature below their target operating temperature range) and cools all thermal customers that are too hot (i e have a temperature above their target operating temperature range) A compatible operating mode may be an operafing mode that additionally does not transfer thermal energy to or from a thermal customer that is indicated as not to provide or receive thermal energy (e g, where the thermal customer is in its target operating tempe-ature range and is not designated as a thermal storage component).

An operating mode may be determined to be a compatible operating mode when, for each of the at least one thermal customer, the thermal indicator of the thermal customer is consistent with the operating mode's thermal criterion to-the thermal customer. An operating mode is consistent with a thermal criterion if any of (a) the thermal indicator indicates that the thermal customer is above its target operating temperature range and the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being above its target operafing temperature range, (b) the thermal indicator indicates that the thermal customer is below its target operating temperature range and the thermal criterion indicates that the operafing mode is compatible with the respective thermal customer being below its target operating temperature range, and (c) the thermal indicator indicates that the thermal customer is within its target operating temperature range and the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range.

An output is provided 608 indicating the compatible operating modes. In some examples, the output may be provided as a signal to a module of the controller 106, for example, in order to select a recommended operating mode, to be implemented in the thermal management system 100, from among the compatible operating modes. The module of the controller 106 may be a hardware module, a software module, a routine, etc In some examples, a recommended operating mode may be selected from among the compatible operating modes. The recommended operating mode may be an operating mode to be implemented in the thermal management system 100 According to some examples, the output (of operation 608) indicating the compatible operating modes is obtained, and the recommended operating mode selected from among the compatible operating modes An output is then provided indicating the recommended operating mode FIG 7 illustrates a method 700 for controlling a thermal management system 100 of an electric vehicle 200, where the method includes selecting a recommended operating mode. According to the method 700 operating state information and operating mode information are obtained at operation 702, similar to operations 602 and 604 of FIG. 6. The operating state information includes thermal indicators associated with thermal customers of the electric vehicle 200.

Compatible operating modes are determined at operation 704 from among one or more of the operating modes, similar to operation 606 of FIG 6 At operation 706 a recommended operating mode may be selected from among the compatible operating modes. The selection may be based on an energy cost associated with the operating mode, for example The recommended operating mode may be based on an output of operation 704 (e g corresponding with the output at operation 608 of FIG 6) that is received at operation 606 At operation 708 an output is provided indicating a recommended operating mode (which may also be referred to herein as a selected operating mode). The output may be provided as a signal to provide an indication of a recommended operating mode of the system In some examples, the output causes the thermal management system 100 to transition to the selected operating mode.

Selecting the recommended operating mode may include evaluating each operating mode from among the compatible operating modes and selecting the recommended operating mode based on the evaluation. Evaluating an operating mode may include one or more of evaluating whether the operating mode is consistent with indicated thermal energy transfer requirements (e g, with target rates or magnitudes of thermal energy transfers indicated by the thermal energy transfer requirements), evaluating a degree to which the operating mode is consistent with the thermal energy transfer requirements, and evaluating an energy cost associated with the operating mode The energy cost may be based on one or more of an energy usage associated with the operating mode, and thermal energy transferred to the environment according to the operating mode, for example.

In some examples, the evaluation may include assessing an energy cost associated with the one or more compatible operating modes, assessing whether thermal energy transfers requested by thermal customers are achievable in The one or more compatible operating modes. In some examples, thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, rates at which thermal energy is transferable to respective components correspond with respective indicated target rates of thermal energy transfer (requested thermal energy transfers may be indicated in the operating state information, for example) In some examples, thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operafing mode, amounts of energy transferable to respective components correspond with the respective indicated amounts of thermal energy.

In some examples, the components requesting thermal energy transfers have respective target operating temperature ranges, and thermal energy transfers requested by components are achievable in a candidate operating mode if, in the candidate operating mode, the amounts of energy transferable to respective components result in the respective components having a temperature in their respective target operating temperature ranges In some examples, the operating state information indicates target thermal energy transfers of components, and assessing whether thermal energy transfers requested by components are achievable in a candidate operating mode includes obtaining a thermal energy balance value based on aggregating the target thermal energy transfers of components in thermal communication in the candidate operating mode (via the thermal management system 100), and determining, based on the thermal energy balance value, whether the target thermal energy transfers are satisfied in the candidate operating mode.

Where it is determined whether an operating mode is a compatible operating mode before performing an evaluation of the operating mode, the evaluation may be avoided for operating modes that are not compatible operating modes. Put another way, in some examples the evaluating may be carried out only for operating modes that are determined to be compatible operating modes In some examples, evaluating a compatible operating mode may use more computing resource (e.g., memory, processor cycles, etc.) than determining whether the operating mode is a compatible operating mode (e g, evaluating an operating mode uses more computing resource than comparing the at least one thermal indicator and the operating mode information for the operating mode) Accordingly, the (relatively) computationally demanding evaluation of an operating mode may be avoided for operating modes that do not provide heat to thermal customers that are below their target operating temperature range, and remove heat from thermal customers that are above their target operating temperature range.

In some examples, selecting the recommended operating mode comprises evaluating each operating mode from among the compatible operating modes and selecting the recommended operating mode based on the evaluation. For one or more of the compatible operating modes the evaluation may comprise obtaining an energy cost associated with a respective operating mode of the one or more of the compatible operating modes.

The method 700, shown in FIG 7, is suitable for rapidly considering a large number of operafing modes in order to select an operating mode to be implemented This may be particularly beneficial for real-time use in a vehicle with limited on-board computing resources, but other possibilities are also contemplated. In some examples, the method 700 may be repeated during operation of the electric vehicle 200 (e g while the electric vehicle 200 is driving) in order to reassess whether the current operating mode is still a desired operating mode. For example, method 700 may be repeated at regular intervals (e g, intervals corresponding with a time step of the vehicle control system) to select an operating mode. In some examples, the method 700 may be performed in response to other triggers instead of, or in addifion to, periodically For example, the method 700 may be performed in response to a change in situation of the electric vehicle 200 such as a change in driving mode, or based on a change in average driving speed, etc. Similarly, the selecting may be performed, for example, if it is determined that the battery 204 is to be preconditioned, that is, heated in preparation for charging Each thermal indicator may comprise a high indicator if the respective thermal customer is above its target operating temperature range, a low indicator if the respective thermal customer is below its target operating temperature range, or an in-range indicator if the respective thermal customer is within its target operating temperature range The thermal indicator may comprise a field to store one of the high indicator, the low indicator and the in-range indicator In some examples the high indicator, low indicator and in-range indicator may be mutually exclusive, such that at any particular time, a thermal customer is associated with no more than one of the high indicator, low indicator and in-range indicator In examples, each of at least one thermal customer is associated with exactly one of the high indicator, low indicator and in-range indicator at any particular time In some examples, one of the high indicator, the low indicator and the in-range indicator may be stored in a field of the thermal indicator, where the field stores a value or symbol that indicates one of the high indicator, the low indicator and the in-range indicator, for example by storing one of a first symbol, a second symbol or a third symbol (or a first value, a second value or a third value) The first value or symbol indicates that the respective thermal customer is below its target operating temperature range, the second value or symbol indicates that the respective thermal customer is above its target operating temperature range, the third value or symbol indicates that the respective thermal customer is within its target operating temperature range.

For example, the first value or symbol may be -1 the second value or symbol may be +1, and the third value or symbol may be 0 Accordingly, the high indicator may be the low indicator may be -1, and the in-range indicator may be 0 However, other values or symbols may be used Further, in some examples, the first value may be a negative number, the second value may be a positive number, and the third value may be 0 (here 0 is considered to be unsigned, and neither positive nor negative, such that neither of the first nor second values are zero) Accordingly, the high indicator may be positive, the low indicator may be negative, and the in-range indicator may be 0 In some examples, the negative or positive number representing the first and second values may correspond with an amount of thermal energy to be transferred to or from the thermal customer, or a rate at which thermal energy is to be transferred to or from the thermal customer In some examples, the number may indicate a temperature difference between the current temperature of the thermal customer and a target operating temperature (or target operating temperature range) of the thermal customer.

Absolute values of the high indicator and low indicator may indicate a target rate of thermal energy transfer, respectively from or to the thermal customer Similarly, in some examples absolute values of the high indicator and low indicator may indicate an amount of thermal energy to be transferred from or to the thermal customer. For example, the high and low indicator may be indicatve, respectively, of a thermal energy excess or a thermal energy deficit in the associated thermal customer. In some examples, the high and low indicator may be derived from, or based on, a difference between a current temperature of the thermal customer and a target operating temperature of the thermal customer In terms of energy transfer requested by a thermal customer, the meaning of the in-range indicator depends on whether the thermal customer is usable to store excess thermal energy (i e whether the thermal customer is designated as a thermal storage component) Whether the thermal customer is designated as a thermal storage component may be a predetermined state that is fixed for the thermal customer, or may be included 'm the operating state information.

Accordingly, when the respective thermal customer is designated as a thermal storage component, the thermal indicator for the respective thermal customer may correspond with an indication that thermal energy is requested by the respective thermal customer (e g., required or obligatory transfer of thermal energy to the thermal customer when the thermal customer is below its target operating temperature range), an indication that the respective thermal customer has excess thermal energy (e g, required or obligatory transfer of thermal energy from the thermal customer when the thermal customer is above its target operating temperature range) or an indication that the respective thermal customer is able to either receive or supply thermal energy (e g optional transfer of thermal energy is possible when the thermal customer is within its target operating temperature range) Each of these indications may be associated with a respective value of the field (e.g., -1 +t. or 0, respectively).

When the respective thermal customer is designated as not a thermal storage component, the thermal indicator for the respective thermal customer may correspond with as above, an indication that thermal energy is requested by the respective thermal customer and an indication that the respective thermal customer has excess thermal energy, or an indication that no thermal energy is to be transferred to or from the thermal customer (e g the thermal customer is within its target operating temperature range and is to be maintained at its current temperature) Each of these indications may be associated with a respective value of the field (e g, -1 +1 or 0, respectively)_ Accordingly, it is possible to efficiently and intuitively indicate whether a component is (i) to act as a sink, (ii) to act as a source, (m) available to act as either a sink or a source, or (iv) is available to act as neither a sink nor a source of thermal energy.

As described above, mode information for the operating modes is obtained. The mode information comprises, for each operating mode, a thermal criterion for each thermal customer (of at least a subset of thermal customers) The thermal criterion indicates whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range.

As described above, each thermal criterion may have, a first state if the operating mode is compatible with the respective thermal customer being above its target operating temperature range, a second state if the operating mode is compatible with the respective thermal customer being below its target operating temperature range, or a third state if the operating mode is compatible with the respective thermal customer being within its target operating temperature range. The first state may correspond with a high criterion, the second state may correspond with a low criterion, and third state may correspond with an in-range thermal criterion. In some examples, each of the high criterion, low criterion, and in-range criterion may by indicated by a respective symbol. For example, the thermal criterion may be represented by a field of the mode information that stores one of the first, second, or third states (e g the high criterion, low criterion, or in-range criterion) The first, second and third states may be mutually exclusive, such that for a given operating mode, a thermal criterion is associated with no more than one of the first, second and third states In examples, each thermal criterion is associated with exactly one of the first, second and third states for a particular operating mode The high and low criteria may be numbers having opposite signs, and the in-range criterion may be zero. For example, the high and low criteria may be positive and negative, respectively. In some examples, the high and low criteria are '41' and '-1 respectively.

Determining whether the operating mode is a compatible operating mode may comprise comparing the thermal criterion with the thermal indicator.

In some examples a thermal criterion is compatible with a thermal indicator if the thermal criterion is a high criterion and the thermal indicator is a high indicator, or if the thermal criterion is a low criterion and the thermal indicator is a low irdicator, or if the thermal criterion is an in-range criterion and the thermal indicator is an in-range indicator.

In some examples, the thermal indicator has values of +1 -1 or 0 to indicate that the thermal customer is, respectively, above, below, or within its target operating temperature range, and the thermal criterion has values of +1, -1 or 0 to indicate that the operafing mode is, respectively, compatible with the respective thermal customer being above, below, or within its target operating temperature range In this case, there is a match between the thermal criterion and the thermal indicator if they have the same value An operating mode may be a compatible operating mode if for each thermal customer, the thermal criterion associated with that thermal customer in that mode matches the thermal indicator associated with that thermal customer The assessment may be made for all thermal custome-s such that an operating mode is a compatible operating mode if there is a match between the respective thermal indicator of every thermal customer and the respective thermal criterion of that operating mode. In some examples, each thermal criterion of each compatible operating mode is determined to match each corresponding thermal indicator In some examples, the thermal indicator has a positive value, a negative value, or is zero to indicate that the thermal custoner Is, respectively, above, below, or within its target operating temperature range, and the thermal criterion has values of +1, -1 or 0 to indicate that the operating mode is, respectively, compatible with the respective thermal customer being above, below, or within its target operating temperature range. In this case, there is a match between the thermal criterion and the thermal indicator if they are (i) both positive, Op both negative, or (iii) both zero.

Other representations are possible for the thermal indicator and thermal criterion, and embodiments are not restricted to the particular examples herein The thermal management system 100 may include various controllable components. Herein, a description of the state of each controllable element of the thermal management system 100 is referred to as an arrangement of the thermal management system 100 As such, identifying an arrangement of the thermal management system may identify a respective operating state of each component (or each controllable component) of the thermal management system.

The configurations described herein define the thermal communication between the coolant first coolant circulation loop 314, second coolant circulation loop 316, and refrigerant circuit 408 However, for a particular configuration there may be various possible settings for other elements of the thermal management system 100 such as a coolant heater 304, for example As such, each configuration may correspond with multiple arrangements.

The arrangement may, for example, identify a valve position of each valve of the thermal management system, whether a heater of the thermal management system is on or off, whether a chiller of the thermal management system is on or off, etc In some examples, two or more operating modes may be corresponded with the same arrangement of the thermal management system 100 For example, an operating mode may be suitable for providing thermal energy to battery 204, and so may satisfy a thermal indicator indicating that the battery 204 is cold. However, the same mode may be appropriate for a situation where the battery 204 is in its target operating temperature range and so is available to receive excess thermal energy from other components. However, not all such modes are efficient or appropriate in both circumstances.

For example, a first arrangement that includes active battery cooling (e g, via an outside heat exchanger) may be useable when the battery is indicated as being above its target operating temperature range by the corresponding thermal indicator However, the same arrangement may be inefficient when the battery is indicated as being within its target operating temperature range by the corresponding thermal indicator. Accordingly, the operating modes may include a mode corresponding to the first arrangement that is indicated as compatible with the battery being above its target operating temperature. However, the operating modes may omit a mode having the first arrangement indicated as compatible with the battery being within its target operating temperature range.

In contrast. a second arrangement that moves heat from the battery to the front electric drive unit may be practical when the battery is indicated as being above its target operating temperature range and the front electric drive unit is indicated as being below its target operating temperature range. The second arrangement may also be practical when the battery is indicated as within its target operating temperature range and the front electric drive unit is indicated as being below its target operating temperature range, as thermal energy stored on the battery may be transferred to the front electric drive unit Accordingly, the operating mode information may include an operating mode corresponding with the second arrangement indicated as compatible with the battery being above its target operating temperature range and the front electric drive unit being below its target operating temperature range, and the operating mode information may also include an operating mode corresponding with the second arrangement indicated as compatible with the battery being within its target operating temperature range and the front electric drive unit being below its target operating temperature range.

As such, by including multiple operating modes corresponding with the same arrangement, arrangements suitable for particular operating conditions may be reliably determined, while excluding impractical or inefficient arrangements.

Physical settings of the thermal management system may be the same H each mode having the same arrangement of the thermal management system.

Table 1 shows an example of a portion of operating mode information for a subset of modes. In some examples, the number of modes in the operating mode information may exceed 200. The ordering of operating modes in the Table is arbitrary. Moreover, embodiments are not limited to systems having the indicated components, or arrangements of components.

Configuration Thermal customers Cabin elements Mode Cooling Mode Chiller Battery Front EDU Rear EDU Cabin Condenser Evap 2 0 -1 0 66 2 1 1 0 -1 0 67 2 1 0 1 -1 -1 0 68 2 0 -1 0 69 2 -1 0

Table 1

Each row corresponds with an operating mode of the thermal management system 100 The mode column enumerates the operating modes This numbering may be arbitrary The cooling mode column indicates the coupling between the first coolant circulation loop 314 and second coolant circulation loop 316, as well as the coolant circulation loop that includes the first heat exchanger 306 (chiller) For example, cooling mode 2 may correspond with the first coolant circulation loop 314 and second coolant circulation loop 316 in thermal communication with each other (such that the battery, front electric drive unit 202a, rear electric drive unit 202b and first heal exchanger 306 are all in the same thermal circuit The chiller column indicates the state of the chiller. For example, a value of "-V' may indicate that the chiller is active and transfers thermal energy from the coolant system to the refrigerant system. A value of '0" may indicate that the first heat exchanger 306 is off and does not transfer thermal energy between the coolant system and the refrigerant system As such, the cooling mode and chiller columns combined indicate the configuration of the thermal management system 100 In this example the chiller column may be viewed as indicating a thermal energy transfer between the coolant system and the refrigerant system from the point of view of the coolant system (e g, in Table 1, thermal energy is transferred from the coolant system to the refrigerant system, cooling the coolant system and heating the refrigerant system). Alternatively or additionally, a column may be provided that indicates the thermal energy transfer between the coolant system and the refrigerant system from the point of view of the refrigerant system This column would indicate the opposite of the chiller column (e g, be "-EV if the chiller column is and "0 if the chiller column is '01 The battery, front EDU, rear EDU and cabin columns indicate the thermal criteria associated with those thermal customers, as described above In some examples, the value of the cabin column may be derived from states of components of the climate control system 104 For example Table 1 gives the example of a condenser (condenser column) that is cold (value ''-1" in Table 1) and an internal evaporator 404 (evap column) that does not require a thermal energy transfer (value 0" in Table 1). This corresponds with a cabin state in which the cabin is cold and is requesting a transfer of thermal energy to the cabin (e g, from the outside heat exchanger 406 or from the powertrain thermal management system 102) In some examples, if the condenser 502 is cold and the internal evaporator 404 (or internal evaporators 404) are not requesting a transfer of thermal energy (i.e., is within its target operating temperature range), the cabin may be considered to be cold. Where the condenser 502 coes not request a thermal energy transfer (i.e is within its target operating temperature range) and the internal evaporator 404 (or at least one internal evaporator 404) is hot, the cabin may be considered to be hot Where neither the condenser 502 nor the internal evaporator 404 (none of the internal evaporators 404) requests a thermal energy transfer (both in their respective target operating temperature ranges), the cabin may be considered to be within its target operating temperature range.

In some examples, the value in the cabin column may be considered to be a thermal criterion The values in the condenser and evaporator columns may be considered to be thermal indicators. In that case the condenser 502 and internal evaporator 404 may be considered to be thermal customers, in place of the cabin.

The thermal indicator and/or thermal criterion of the cabin may be derived from the operating state information in some examples Furthermore, in some examples a thermal indicator for the cabin is not explicitly calculated.

Table 2 shows an example of thermal indicators that may be obtained in relation to the system of Table 1. Of the operating modes shown in Table 1, operating modes 65 and 66 are compatible with the thermal indicators in Table 2 Operating modes 65 and 66 have identical values in the columns shown in Table 1 but the difference between operating modes 65 and 66 will be explained below Battery Front EDU Rear EDU Cabin Condenser Evap 0 0

Table 2

Note that, according to the thermal indicators of Table 2, the rear electric drive unit 202b is available for optional thermal energy transfer. However, this is not consistent with operating mode 69, for example, which is indicated as suitable for obligatory (or required) cooling of the rear electric drive unit 202b Table 3 shows an extended version of Table 1, according to some embodiments. The column headings of Table 1 have been abbreviated and the condenser and evap columns have been omitted The columns are in the same order in Table 3 Configuration Thermal customers State indications Mode CM Chiller Battery F-EDU R-EDU Cabin EDU mode OHX Heater R-Mode 2 0 0 0 7 66 2 0 3 0 0 7 67 2 0 2 0 0 7 68 2 0 3 0 0 7 69 2 3 0 0 7

Table 3

The additional columns of Table 3 may include state indications, to identify the arrangement of the thermal management system 100 These columns are merely examples, and additional columns may be included, and some columns shown in Table 3 may be omitted For example, state indications may indicate respective functional states of components of the thermal management system in the operating mode, such as whether the components are on or off in the operating mode, or whether components are bypassed For example, a state indication may indicate whether a coolant heater 304 is on or off, or may indicate whether the first heat exchanger 306 (e g a radiator) is bypassed in a coolant circuit In some examples, the state indication may indicate a setting of a component, such as a duty cycle or other parameter For example, a power level of a coolant heater 304 may be indicated. In some cases, the state indications may indicate whether, in the operating mode, the component acts as a source of thermal energy, a sink of thermal energy, or as neither a source nor a sink of thermal energy. In some examples this may be indicated in a manner similar to the representation of the thermal criteria, e.g., a component that transfers thermal energy to the thermal transfer fluid may be represented with a positive value, a component that removes thermal energy from the thermal transfer fluid may be represented with a negative value, and a component that does not transfer thermal energy to or from the thermal transfer fluid may have a zero value In some examples the state indications are not used in the determination of whether a mode is a compatible operating mode, but may be used in subsequent evaluation of the compatible operating modes. For example, to identify components of the system that are active, such that their associated energy cost should be considered, or to identify actuator costs to transition to the operating mode.

For example Table 3 includes an EDU mode column indicating which, if any, electric drive units 202 are bypassed in the mode. For example, EDU mode 0 may correspond with both electric drive units 202 being bypassed EDU mode 1 may correspond with the rear electric drive unit 202b being bypassed and the front electric drive unit 202a not being bypassed EDU mode 2 may correspond with the front electric drive unit 202a being bypassed and the rear electric drive unit 202b not being bypassed, EDU mode 3 may correspond with neither of the electric drive units 202 being bypassed. OHX may indicate the state of the outside heat exchanger 406 For example, a value of '0" may indicate that the outs de heat exchanger 406 is off and does not transfer thermal energy between the refrigerant circuit 408 and the ambient air. Similarly, a value of may indicate that the heat exchanger is operating in a heat pump mode to heat the cabin, and a value of -1' may indicate an air condifioning mode to cool the refrigerant (e _g. to cool the cabin or battery) Heater may have a value of when the coolant heater (304) is off, and a value of when the heater is on The R-Mode column may indicate the climate control mode, and so identity valve positions in the refrigerant circuit 408. For example, mode '7' in the example of Table 3 may indicate a powertram heat recovery mode.

As noted above, operating modes 65 and 66 have the same thermal criteria as each other. That is, both operating modes are suitable for a battery and front electric drive unit 202a that are above their respective target operating temperatures, a rear electric drive unit 202b that is within its target operating temperature range, and a cabin that is below its target operating temperature range. These modes are the same except for the EDU mode column. In operating mode 65, the rear electric drive unit 2026 is bypassed, and so operating mode 65 corresponds with an arrangement in which no thermal energy is transferred between the rear electric drive unit 2026 and the coolant. In contrast, operating mode 66 corresponds with a mode that is the same as operating mode 65, except for the rear electric drive unit 202b not being bypassed. Accordingly, in operating mode 65 the rear electric drive unit 2026 is able to act as (at least one of) a source or sink of thermal energy.

In Table 3, operating modes 66, 68 and 69 have identical arrangements (i e, the same values in the Clvi, chiller, EDU mode, 041X heater, and R-mode columns). Operating mode 69 corresponds with both the front electric drive unit 202a and rear electric drive unit 202b acting as obligatory sources of thermal energy That is, operating mode 69 is suitable for situations when both the front electric drive unit 202a and rear electric drive unit 2026 are above their target operating temperature ranges. Operating mode 66 differs from operating mode 69 in that the rear electric drive unit 2026 is indicated as being an optional source or sink of thermal energy (i e the rear electric drive unit 2026 is wi-hin its target operating temperature range) Similarly, operating mode 68 differs from operating mode 69 in that the front electric drive unit 202a is indicated as being an opfional source or sink of thermal energy (i e the front electric drive unit 202a is within its target operating temperature range) Accordingly, in some examples, the operating mode information may include, for each operating mode, an indication cf an arrangement of the thermal management system in the respective operating mode.

In some examples, the operating modes include a first operating mode and a second operating mode, the second operating mode having the same arrangement of the thermal operating system as the first operating mode, a first thermal criteria of the first mode indicates that the first operating mode is one of compatible with the respective thermal customer being above its target operating temperature range, or compatible with the respective thermal customer being below its target operating temperature range, and the first thermal criteria of the second mode indicates that the second operating mode is compatible with the respective thermal customer being within its target operating temperature range This allows separate consideration of an arrangement in which a thermal customer has an optional thermal energy transfer and the same arrangement when the thermal customer has an obligatory thermal energy transfer. This allows inefficient potential operating modes to be omitted from the list of operating modes.

The thermal transfers to and from components of the thermal management system may be identical in the first and second operating modes. The first and second operating modes may differ in their indicated compatibility. As such, potential operating modes that are inefficient (e g, corresponding with an arrangement that is inefficient when a thermal energy transfer is optional but efficient when a thermal energy transfer is obligatory) may be omitted from the plurality of operating modes of the operating mode information That is, the operating mode information may include multiple operating modes that correspond with the same arrangement of the thermal management system. Operating modes corresponding with the same arrangement may differ in the indicated compatibility This may allow impractical or inefficient potential operating modes to be omitted from the operating mode information In some examples, the selection of an operating mode as a recommended operating mode is based on comparing thermal energy transfer requirements with an achievable thermal energy transfer in the thermal management system according to the operating mode The achievable thermal energy transfer may be determined based on aggregating potential sources or sinks of thermal energy. Determining achievable thermal energy transfers may be based on state indications to determine the potential sources and sinks of thermal energy.

In some examples, assessing whether thermal energy transfers requested by components are achievable in the one or more compatible operating modes may include assessing thermal energy transfer requirements and achievable thermal energy transfers separately for each thermel circuit of the operating mode.

As described in relation to FIG. 4A to FIG 4F, each operating mode may be associated with a respective set of thermal circuits, each thermal circuit comprising a group of the components that are in mutual thermal communication via the thermal management system in the operating mode. Comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode may include determining, for each thermal circuit in the set of thermal circuits associated with the operating mode, whether an achievable thermal energy transfer in the thermal circuit is consistent with thermal energy transfer requirements of components in the thermal circuit For example, in the mode illustrated in FIG 4A the achievable thermal energy transfer in the first thermal circuit 402a is compared with the thermal energy transfer requirements associated with the first thermal circuit 402a, the achievable thermal energy transfer in the second thermal circuit 402b is compared with the thermal energy transfer requirements associated with the second thermal circuit 402b, and the achievable thermal energy transfer in the third thermal circuit 402c is compared with the thermal energy transfer requirements associated with the third thermal circuit 402c In some examples, the operating mode may be determined to comply with the thermal energy transfer requirement if it is determined that the achievable thermal energy transfer in each thermal circuit of the operating mode is consistent with the thermal energy transfer requirements in each respective thermal circuit. On the other hand, the operating mode may be determined not to comply with the thermal energy transfer requirement if it is determined that, for any thermal circuit of the operating mode the achievable thermal energy transfer in that thermal circuit of the operating mode is not consistent with the thermal energy transfer requirements in that thermal circuit The thermal energy transfer requirements may indicate one or more of respective amounts of thermal energy transfer requested by respective components requesting thermal energy transfers, and respective rates of transfer of thermal energy requested by respective components requesting thermal energy transfers. Accordingly, the thermal energy transfer requirement for a component may include at least one of an indication of a rate of thermal energy to be supplied to the component, a rate of thermal energy to be extracted from the component, an indication of an amount of thermal energy to be supplied to the component, or an indication of an amount of thermal energy to be extracted from the component.

In some examples, thermal energy transfers requested by components are achievable in an operating mode if, in the operating mode, amounts of energy transferable to respective components correspond with the respective indicated amounts of thermal energy. In some examples, thermal energy transfers requested by components are achievable in an operating mode if, in the operating mode, energy is transferable to respective components at rates that correspond with the respective indicated rates of thermal energy transfer.

Where the thermal energy transfer requirements indicate target rates for thermal energy transfers, a thermal energy transfer requirement may indicate a target rate of heating or cooling of a thermal customer in order for the operating mode to be considered satisfactory Accordingly, comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operat ng mode may comprise, for each thermal circuit in the operating mode obtaining an indication of achievable thermal energy transfer rate in the thermal circuit, obtaining an indication of target thermal energy transfer rate in the thermal circuit, and comparing the indicated achievable thermal energy transfer rate with the target thermal energy transfer rate In some examples the target thermal energy transfer rate of a thermal customer may be determined based on a temperature of the thermal customer and a target operating temperature range of the thermal customer. In some examples the target thermal energy transfer rate may be based on a model of the thermal customer. In some examples, the target thermal energy transfer rate may be obtained from a lookup table. In some examples the thermal energy transfer requirement for a thermal customer may be based on a difference between a current temperature of the thermal customer and a target operating temperature or target operating temperature range associated with the thermal customer In some examples, the target thermal energy transfer rate may be fixed values for respective thermal customers Where a component has a target operating temperature range, the target operating temperature of the component may be a high temperature point or a low temperature point of a target operating temperature range of the component The target operating temperature may be whichever of the high temperature point or the low temperature point of a target operating temperature range is closest to a current temperature of the component. For example, if the component is above its target operating temperature range, the target operating temperature may be the high temperature point of the target operating temperature range, and if the component is below its target operating temperature range, the target operating temperature may be the low tempe'atu re point of the target operating temperature range.

Where the thermal energy transfer requirements indicate amounts of thermal energy to be transferred, a thermal energy transfer requirement may indicate an amount of thermal energy to be provided to or removed from a thermal customer to bring the thermal customer within its target operating temperature range Accordingly, comparing the thermal energy transfer requirement with an achievable thermal energy transfer in an operating mode may comprise, for each thermal circuit in the operating mode obtaining an indication of thermal energy availability in the thermal circuit, obtaining an indication of thermal energy demand in the thermal circuit and comparing the indicated thermal energy availability with the indicated thermal energy demand.

Where there is more than one thermal energy transfer requirement an operating mode may be considered to comply with the thermal energy transfer requirements if the operating mode complies with all of the thermal energy transfer requirements.

Comparing the thermal energy transfer requirement with an achievable thermal energy transfer may be performed before the energy costs are obtained, and operating modes may be indicated as accepted or rejected based on the comparing the thermal energy transfer requirement with an achievable thermal energy transfer. H this case, the accepted operating modes include the one or more operating modes for which energy costs are to be determined. Accordingly, the rejection of operating modes on the basis of their achievable thermal energy transfer may be determined before obtaining the associated energy cost, and so the determination of the energy cost associated with rejected operating modes may be avoided. This may improve computat onal efficiency, particularly where obtaining an energy cost associated with an operating mode uses more computing resource than determining whether an operating mode is accepted or rejected. In some examples, the energy cost is not obtained for rejected operating modes.

In some examples, selecting a recommended operating mode may include determining whether or not the thermal energy transfer requirement is satisfied in the operating mode. In some examples, when the operating mode does not satisfy the thermal energy transfer requirement, a degree to which the operating mode does not satisfy the thermal energy transfer requirement may be determined. The information regarding the degree to which the operating mode does not satisfy the thermal energy transfer requirement may be used in selecting a recommended operating mode For example, if it is determined that none of the operating modes satisfy the thermal energy transfer requirement, an operating mode that comes closest to satisfying the thermal energy transfer requirement may be selected.

In some examples, selecting a recommended operafing mode may include, where the operafing mode does not satisfy the thermal energy transfer requirements, determining a difference between a target thermal energy transfer rate and an achievable thermal energy transfer rate in the operating mode In some examples, selecting a recommended operating mode may include, where the operating mode does not satisfy the thermal energy transfer requirements, determining a difference between an amount of energy to be transferred according to the thermal energy transfer requirement and an amount of energy transferred (or transferrable) in the operating mode.

The energy cost may indicate one or more of: an energy requirement to transition to the respective operating mode, and an energy requirement to operate the thermal management system in the respective operating mode. In some examples, heat energy transferred off the vehicle in that operating mode may also be taken into account. For example, the energy cost associated with an operating mode may comprise one or more of a thermal energy cost value representing an amount of thermal energy transferred off the vehicle in that operating mode and an actuator energy cost value representing an energy cost associated with operating the thermal management system in that operating mode.

The energy costs associated with a component may take into account operating parameters, or predicted operafing parameters, of the component in the operating mode. For example, where the operafing mode would lead to a temperature increase of the battery, a change in internal resistance and associated losses may be taken into account when obtaining an energy cost associated with operating the battery in the operating mode. Similarly, torque losses in the electric drive unit may be taken into account when obtaining an energy cost associated with the electric drive unit The actuator energy cost value associated with an operating mode may be representative of at least one of an energy cost of operating a compressor according to that operating mode, a valve actuation energy cost associated with that operating mode, a vehicle drag cost associated with operation of a heat exchanger according to that operating mode, an energy cost of operating a pump according to that operating mode; and an energy cost of operating a fan according to that operating mode.

The energy cost may, for example, be obtained from a lookup table, or by using a model of the thermal management system 100.

In some examples, the actuator energy cost may include any energy associated with operating the thermal management system 100 for example an energy cost required to operate the compressor of the refrigerant circuit 408 to provide refrigerant to the first heat exchanger 306 or a drag cost associated with providing airflow to the outside heat exchanger. Examples of actuator energy costs associated with an operating mode may include an energy cost of operating a compressor according to that operating mode, a valve actuation energy cost associated with that operating mode, a vehicle drag cost associated with operation of a heat exchanger according to that operating mode (e g. vehicle vehicle drag associated with active vane management), an energy cost of operating a pump according to that operating mode, and an energy cost of operating a fan according to that operating mode. Certain actuators in the thermal management system 100, for example pumps, compressors, fans, etc, may have an associated duty cycle or activation level setting to satisfy the thermal energy transfer requirements of the components when the thermal management system 100 is operating in a particular operating mode. Energy costs for actuators may be further calculated based on the duty cycle to provide a more accurate determination of the energy associated with operating the actuator.

The energy cost for each operating mode may be determined using a predictive model of the thermal management system 100. In embodiments, the predictive model of the thermal management system 100 may comprise a plurality of predictive models each associated with a respective sub-component of the thermal management system 100 Thus, each actuator energy cost may be calculated using a model of the respective actuator that cefines a relationship between one or more operating parameters of the thermal management system 100 and an energy cost associated with the actuator For example, a predictive model for the compressor of the refrigerant circuit 408 may allow an energy cost of operating the compressor to be determined basec on certain operating parameters, such as the duty cycle. Each model may be determined empirically or through simulation of the thermal management system 100 and climate control system 104 In some embodiments, a model for each actuator may be stored as a look up table (LUT) associating one or more operating parameters of the actuator with an associated actuator energy cost Similarly predictive models may be provided for the first and second heat exchangers and for an outer heat exchanger of the refrigerant circuit 408 to allow the thermal energy to be transferred off the vehicle to the outside environment to be determined based on one or more measured parameters. For example, heat rejected to the outside environment by the second heat exchanger 308 may be predicted based on one or more of an ambient temperature of the outside environment, a flow rate and/or temperature of coolant through the second heat exchanger 308 a functional state of a far associated with the second heat exchanger 308 etc. In embodiments, the actuator energy cost for an operating mode may be determined by summing all of the actuator energy costs associated with operating the thermal management system 100 in that operating mode to meet the thermal transfer requirements of the components. In some examples, the energy cost associated with the operating mode maybe calculated by summing the actuator energy cost with other energy costs, such as thermal costs associated with the components, such as the battery and electric drive units For example, where the operating mode would lead to a temperature increase of the battery, a change in internal resistance and associated losses may be determined. Similarly, torque losses in the EDUs may be calculated. In some examples, the total amount of thermal energy transferred off the vehicle via the second heat exchanger 308 and the outside heat exchanger of the refrigerant circuit 408 may be taken into account in the assessment of the energy cost.

By assessing energy costs associated with respective operating modes, the selection of an operating mode can improve energy efficiency compared to temperature based approaches, for example by avoiding operating modes that have a high energy cost. This may reduce the amount of energy that would otherwise be drawn from the traction battery, resulting in increased range and a corresponding improved user experience.

Further, by determining an energy cost associated with transitioning to and/or maintaining an operating mode, such as energy to be supplied to actuators, heating elements, compressors, etc. it is possible to select an operating mode that helps to avoid unnecessary energy use.

In some examples, the energy cost may be based, in part on state indications in the operating mode information. The state indications may be used to determine which components are active in the operating mode, and so may contribute to the energy cost. For example, heaters, compressors, etc., that may be active and have an associated energy cost when active and may be indicated as active or inactive in the state information.

By taking a whole system energy based approach for multiple components of the vehicle while taking into account thermal requirements of those components, the amount of thermal energy retained on the vehicle for use by other systems and components may be maximised, or at least substantially increased compared to temperature based approaches, for example by avoiding rejecting (to an external environment) heat generated in a traction battery during operation that could usefully be transferred to another system such as a climate control system 104 This increase in retained thermal energy may reduce the amount of electrical energy that would otherwise be drawn from the traction battery to provide heat energy for those other systems (e g via coolant heater 304), increasing efficiency with which energy is used on the electric vehicle, resulting in increased range and a corresponding improved user experience.

In some examples, selection of an operating mode may take into account the thermal requirements of the vehicle as well as the energy cost associated with the operating mode. For example, an operating mode may be selected that has a lowest energy cost among operating modes that comply with the thermal energy transfer requirements. In another example, e.g., where it is determined that no operating mode complies with the thermal energy transfer requirements, an operating mode that is closest to meeting the thermal energy transfer requirements may be selected By assessing the energy costs associated with various operating modes, it is possible to avoid selection of modes that are associated with unnecessarily high energy costs, providing improved efficiency. Moreover, by determining compliance of various operating modes with thermal energy transfer requirements, the effectiveness of the thermal management system may be maintained FIG 8 illustrates a method 800 according to some examples Operating state information and operating mode information is received at operation 802, and at operation 804 a first operating mode is selected as the current operating mode. At operation 806 it is determined whether the current operating mode is a compatible operating mode If the operating mode is a compatible operating mode the method proceeds to operation 808, where it is determined whether the current operating mode satisfies one or more thermal energy transfer requirements. If the current operating mode is determined to satisfy the one or more thermal energy transfer requirements, the method proceeds to operation 810, where an energy cost for the current operating mode is determined. The method then proceeds to operation 812. The method also proceeds to operation 812 if it is determined at operation 806 that the current operating mode is not a compatible operating mode. Similarly, the method proceeds to operation 812 if is determined at operation 808 that the current operating mode does not satisfy the one or more thermal energy transfer requirements. At operation 812 it is determined whether there are any further operating modes If there are further operating modes to consider the method proceeds to operation 814, where the next operating mode is selected as the current operating mode, and the method returns to operation 806 If, at operation 812, it is determined that all operating modes that are to be considered have been considered, the method proceeds to operation 816 where a recommended operating mode is selected. The recommended operating mode may be selected frcm among the operating modes for which an energy cost was determined. In some examples, the operating mode having the lowest cost may be selected as the recommended operating mode. In some examples, the recommended operating mode may be selected based on a cost function, where the cost function is based on the energy cost of the operating mode, and possibly other factors In some examples, where no energy costs are determined, for example where none of the operating modes are determined at operation 808 to satisfy the one or more thermal energy transfer requirements, an operating mode may be selected at operation 816 based on the performance of the operating modes with respect to the one or more thermal energy transfer requirements. For example, an operating mode that best meets (e _g. comes closest to satisfying) the one or more thermal energy transfer requirements may be selected as the recommended operating mode. According to the example of FIG 8, determining whether the operating mode satisfies the one or more thermal energy transfer requirements may be avoided for operating modes that are not compatible operating modes. Similarly, the energy cost determination may be avoided for operating modes that do not satisfy the one or more thermal energy transfer requirements. This leads to an efficient selection of a recommended operating mode based on various considerations, such as a suitability of the operating mode and an energy cost associated with the operating mode. In some examples, the determination of an energy cost associated with an operating mode may require more computing resource (on average) than determining whether the operating mode satisfies the one or more thermal energy transfer requirements. Similarly, determining whether the operating mode satisfies the one or more thermal energy transfer requirements may require more computing resource (on average) than determining whether an operating mode is a compatible operating mode In such a case, the method 800 of FIG 8 may be particularly efficient.

In alternative arrangements, an assessment of energy transfer rates/amounts may be carried out before determining compatible operating modes, such that rejected modes are determined before compatible operating modes, and the compatible operating modes are selected from modes that are not rejected The selection of a recommended operating mode may then be performed, for example, on the basis of energy costs associa-ed with the compatible operating modes In other examples, a set of operating modes may be selected on the basis of energy costs of the operating modes and compatible operating modes selected from the set of operating modes. A recommended operating mode may then be selected from the compatible operating modes, e.g based on energy transfer rates/amounts. In some examples, each stage may happen m turn. For example, in the method 800 of FIG 8, a list of compatible operating modes may be determined, followed by acceptance or rejection of operating modes based on an amount/rate of thermal energy trarsfer, followed by a selection of an operating mode based on energy costs. Each stage may complete before the next begins, such that the complete list of compatible operating modes is determined before carrying out the assessment based on amount/rate of thermal energy transfer. This assessment may be completed before the energy costs associated with the operating modes are determined. Alternatively, the stages may be performed in parallel. For example, when a mode is determined to be a compatible operating mode, the assessment based on amount/rate of thermal energy transfer may be performed immediate y (or may be immediately queued for performance), while other operating modes continue to be assessed with regard whether or not they are compatible operating modes. Similarly, when an operating mode is determined to comply with the amount/rate of thermal energy transfer, the energy cost associated with that operating mode may be determined immediately (or may be immediately queued for determination) while the assessment of other operating modes with regard to amount/rate of thermal energy transfer continues to be assessed. In some examples the method may include determining one or more unavailable operating modes and excluding these from consideration. For example, the outside heat exchanger may not function below a certain temperature In such a case, when it is determined that the outside heat exchanger does not function, e.g., due to very a low temperature, operating modes that use the outside heat exchanger may be omitted from consideration. More generally, if a condition is met that is determined to render an operating mode unavailable, the operating mode may be removed from consideration. In some examples, the determination of unavailable operating modes may be performed before determining compatible operating modes. However, other possibilities are also envisaged Certain methods and systems as described herein may be implemented by one or more processors that process program code that is retrieved from a storage medium, such as non-transitory storage medium.

FIG. 9 shows an example of a device 900 comprising a computer-readable storage medium (e.g. memory device 110) coupled to at least one processor 108. The computer-readable medium 110 can be any media that can contain, store, or maintain programs and data for use by or in connection with an instruction execution system Computer-readable medium 110 can comprise any one of many physical media such as, for example, electronic, magnetic, optical, electromagnetic, or semiconductor media. More specific examples of suitable machine-readable media include, but are not limited to a hard drive, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory, or a portable disc. In FIG 9 the computer-readable storage medium 110 comprises program code 112 to perform a method 600 corresponding to the embodiment shown in FIG 6, that ist obtaining (602), for each of at least one thermal customer, a respective thermal indicator indicative of whether the respective thermal customer is above, below, or within its target operating temperature range, obtaining (604) operating mode information for a plurality of operating modes of the thermal management system, the operating mode information comprising, for each operating mode, a respective thermal criterion for each of the at least one thermal customers, each thermal criterion indicating whether the operating mode is compatible with the respective thermal customer being above, below, or within its target operating temperature range; selecting (606) one or more compatible operating mode, among the plurality of operating modes, based on a comparison between the at least one thermal indicators and the operating mode information for each operating mode, and providing (608) an output indicating the selected one or more compafible operating mode.

The device 900 may be included in controller 106 of an electric vehicle 200, as illustrated H FIG 2, for example It will be appreciated that various changes and modifications can be made to the embodiments of the present invention without departing from the scope of the present application.

Claims

CLAIMS1. A method for controlling a thermal management system of an electric vehicle, the electric vehicle comprising one or more thermal customers, each thermal customer having a respective target operating temperature range, the method comprising obtaining, for each of at least one thermal custorner, a respective thermal indicator ndicative of whether the respective thermal customer is above, below, or within its target operating temperature range; obtaining operating mode information for a plurality of operatirg modes of the thermal management system, the operating mode information comprising, for each operating mode, a respective thermal criterion for each of the at least one thermal customers, each thermal criterion indicating whether the operating mode is compatible with the respective thermal customer beinc above, below, or within its target operating temperature range; selecting one or more compatible operating mode, among the plurality of operating modes, based on a comparison between the at least one thermal indicator and the operating mode information for each operating mode, and providing an output indicating the selected one or more compatible operating mode 2 The method of claim 1, wherein the one or more compatible operating moce are selected in dependence on each thermal criterion in a compatible operating mode being determined to satisfy the respective thermal indicator for each of the at least one thermal customer of the thermal management system.3. The method of claim 1 or 2, wherein each thermal criterion has a first state if the operating mode is compatible with the respective thermal customer being above its target operating temperature range, a second state if the operating mode is compatible with the respective thermal customer being below its target operating temperature range, and a third state if the operating mode is compatible with the respective thermal customer being within its target operating temperature range 4. The method of any one of claims 1 to 3, wherein the thermal criterion indicates that the operating mode is compatible with the respective thermal customer being within its target operating temperature range if.the thermal customer does not act as a heat source or heat sink in the operating mode, and/or the thermal customer is determined to be useable as an optional heat source or optional heat sink in the operating mode.The method of any one of claims 1 to 4, wherein the operating mode information includes, for each operating mode, an indication of an arrangement of the thermal management system in the respective operating mode, wherein identifying an arrangement of the thermal management system identifies a respective functional state of each component of the thermal management system in the operating mode, and wherein the operating modes include a first operating mode and a second operating mode, the second operating mode having the same arrangement of the thermal management system as the first operating mode, a first thermal criterion of the first mode indicates that the first operating mode is one of compatible with the respective thermal customer being above its target operating temperature range, or compatible with the respective thermal customer being below its target operating temperature range, and the first thermal criterion of the second mode indicates that the second operating mode is compatible with the respective thermal customer being within its target operating temperature range.6. The method of any one of claims 1 to 5, the method comprising obtaining the output indicating the selected one or more compatible operating mode, selecting a recommended operating mode from among the compatible operating modes, the recommended opEating mode to be implemented in the thermal management system, and providing an output indicating the recommended operating mode 7 The method of claim 6, wherein selecting the recommended operating mode comprises evaluating each operating mode from among the compatible operating modes and selecting the recommended operating mode based on the evaluation, wherein for one or more of the compatible operating modes the evaluation comprises at least one of assessing an energy cost associated with the one or more compatible operating mode, or assessing whether thermal energy transfers requested by components are achievable in the one or more compatible operating mode.8 The method of claim 7 comprising obtaining operating state informafion that indicates the thermal energy transfers requested by components, the thermal energy transfers requested by components indicating target rates of thermal energy transfer to or from respective components requesting thermal energy transfers wherein thermal energy transfers requested by components are achievable in a compatible operating mode if, in the compatible operating mode, rates at which thermal energy is transferable to respective components correspond with the respective indicated target rates of thermal energy transfer 9 The method of claim 7 or 8, wherein operating mode information includes, for each operating mode of the plurality of operating modes, state indications that indicate respective functional states of components of the thermal management system in the operating mode, and the evaluation of each operating mode from among the selected one or more operating modes is based on the state indications for that operating mode The method of any one of claims 1 to 9, wherein each operating mode is associated with a respective coolant configuration of a cooling system of the thermal management system, wherein each coolant configuration defines a direction of flow of thermal transfer fluid to at least one component of the cooling system; and a respective refrigerant configuration of a refrigerant system of the thermal management system, wherein each 'efrigerant configuration defines a direction of flow of thermal transfer fluid to at least one component of the refrigerant system 11. The method of claim 10, wherein each operating mode is further associated with a respective functional state of a thermal link component of the thermal management system, the thermal link component being switchable between a first functional state, in which the thermal link component provides thermal communication between the cooling system and the refrigerant system, and a second functional state, in which the thermal link component does not provide thermal communication between the cooling system and the refrigerant system 12 A control system for controlling a thermal management system of an electric vehicle, the control system comprising ore or more processors collectively configured to carry out the method of any one of claims 1 to 11.13. Computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1 to 11 14. A computer readable medium comprising computer readable instructions that. when executed by a processor, cause performance of the method of any one of claims 1 to 11 15. A vehicle comprising the control system, of claim 12, and a thermal management system communicatively coupled to the control system