HK1228349A1 - Electric vehicle thermal management system with series and parallel structure - Google Patents

Abstract

Electric vehicle thermal management systems and electric vehicles using the thermal management system, are disclosed. A passenger cabin is heated by the heat dissipated from a battery and /or a motor. A cooling circuit in the management system fluidly connects the battery, the motor and a first radiator in series. The first radiator provides a heat source to the passenger cabin by means of the heat dissipated from the battery and/or the electric motor. Under certain conditions, the electric motor is selectively separated from the cooling circuit, so that when the passenger cabin needs to be heated, the thermal management system can provide heat to the passenger cabin without affecting the heat dissipation of the battery.

Description

Electric vehicle thermal management system with series and parallel structures

Cross Reference to Related Applications

This application claims priority from us provisional patent application No. 62/133,991 filed on day 16, 3/2015 and us provisional patent application No. 62/150,848 filed on day 22, 4/2015, the entire disclosure of which is incorporated by reference herein for all purposes and requirements of the present application.

Technical Field

The invention relates to an electric vehicle thermal management system with series and parallel structures.

Background

Exemplary embodiments of the present disclosure relate to thermal management systems for vehicles, and more particularly to the field of electric vehicles.

The battery can be used as a power source for an electric vehicle, and the range of the electric vehicle is a very important aspect of the vehicle. The temperature in the passenger compartment of existing electric vehicles is typically regulated by an air conditioning system to maintain the temperature in the passenger compartment within a comfortable range. The battery can also be used as an energy source of an air conditioning system, which often consumes a large amount of battery energy, thereby affecting the driving range of the electric vehicle.

Disclosure of Invention

In view of the above problems, aspects of the present disclosure are directed to providing an electric vehicle thermal management system that can be used to effectively save electric power of an electric vehicle and an electric vehicle using the same.

According to a first aspect of the present disclosure, there is provided an electric vehicle thermal management system for heating a passenger compartment of an electric vehicle by means of heat absorbed from a battery and/or an electric motor of the electric vehicle. The thermal management system may include one or more cooling circuits for circulating a coolant, wherein the battery, the electric motor, and the first heat sink are fluidly connected in series in the cooling circuit such that the coolant in the cooling circuit can cool the battery and/or the electric motor to absorb heat. In an embodiment, the first heat sink may provide a heat source for the passenger compartment by dissipating heat absorbed by the cooling liquid. In an embodiment, the electric motor may be selectively decoupled from the cooling circuit.

In an embodiment, the cooling circuit may comprise a first partial path fluidly connecting the battery and the first heat sink, wherein the first partial path is provided with a first partial path inlet for inflow of the cooling liquid and a first partial path outlet for outflow of the cooling liquid. In an embodiment, the cooling circuit may comprise a second path portion fluidly connecting the electric motor, wherein the second path portion is provided with a second partial path inlet for inflow of the cooling liquid and a second partial path outlet for outflow of the cooling liquid. The system may further comprise a switching device configured to connect the first part-path outlet with the second part-path inlet and to connect the second part-path outlet with the first part-path inlet in the first state, so as to fluidly connect the battery, the electric motor and the first heat sink in series. The switching device may be further configured to connect the first partial path outlet with the first partial path inlet in the second state in order to disconnect the electric motor from the cooling circuit.

In some examples, the switching device may connect the second partial path outlet with the second partial path inlet in the second state such that the electric motor is connected to another cooling circuit independent of the cooling circuit.

In some examples, after the electric motor is separated from the cooling circuit, the electric motor may be connected to another cooling circuit independent of the cooling circuit.

In some examples, the first radiator may be separated from the cooling circuit when heating of the cabin is not required.

Embodiments may further include a controller configured to control the switching device to switch between the first state and the second state according to an operating condition of the battery.

Embodiments may further comprise a second radiator, wherein the second radiator is arranged to radiate heat to the outside of the vehicle, and the second radiator is selectively connected in the second partial path.

Embodiments may also include a refrigerator for exchanging heat with the first portion path. In some embodiments, the refrigerator may be selectively separated from the first portion path based on, for example, the temperature of the battery.

According to a further aspect of the present disclosure, there is provided an electric vehicle comprising a thermal management system as described herein.

Embodiments of the present disclosure may provide advantages over other approaches, at least in part, such as efficient transfer of heat generated by components that generate heat to a passenger compartment while ensuring efficient heat dissipation by the components, in order to heat the passenger compartment when desired. Therefore, the electric power of the electric vehicle can be effectively saved, and the endurance mileage of the electric vehicle is increased.

Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. However, the detailed description and specific examples merely indicate preferred embodiments of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. No attempt is made to show structural details in more detail than is necessary for a fundamental understanding of the invention, the various ways in which the invention may be practiced. In the drawings:

FIG. 1 illustrates a block diagram of a first mode of operation of an electric vehicle thermal management system according to an embodiment of the present disclosure;

FIG. 2 is a more detailed schematic diagram of the first mode of operation of FIG. 1;

FIG. 3 illustrates a block diagram of a second mode of operation of an electric vehicle thermal management system according to an embodiment of the present disclosure;

FIG. 4 is a more detailed schematic diagram of the second mode of operation of FIG. 3;

FIG. 5 illustrates a control block diagram of an electric vehicle thermal management system according to an embodiment of the present disclosure;

FIG. 6 is a block diagram illustrating a third mode of operation of an electric vehicle thermal management system according to an embodiment of the present disclosure; and

fig. 7 shows a block diagram of a fourth mode of operation of the electric vehicle thermal management system according to an embodiment of the present disclosure.

Detailed Description

Various example embodiments of the disclosure will now be described with reference to the accompanying drawings, which form a part hereof. It should be understood that although directional terms, such as "front," "rear," "upper," "lower," "left," "right," etc., are used in this disclosure to describe various example structural portions and elements of the disclosure, these terms are used herein for convenience of description only and are determined based on the example orientations shown in the drawings. Since the disclosed embodiments of the present disclosure can be arranged according to different directions, these directional terms are used for illustration only and should not be construed as limiting. Wherever possible, the same or similar reference numbers used throughout this disclosure refer to the same or like parts.

Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Embodiments of the present invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale and features of one embodiment may be employed with other embodiments, as the skilled artisan will recognize, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it should be noted that like reference numerals refer to similar parts throughout the several views of the drawings.

An exemplary electric vehicle thermal management system according to aspects of the present disclosure may be capable of supplying heat to a passenger compartment by means of heat dissipation from a battery and an electric motor of an electric vehicle. For example, these thermal management systems may be configured to connect the coolant flow path of the battery and/or the electric motor to a heat sink capable of dissipating heat into the passenger compartment, and the heat sink supplies heat to the passenger compartment by heat absorbed by the coolant from the battery and/or the electric motor. The thermal management system may have multiple modes of operation depending on whether the passenger cabin needs to supply heat and/or whether the temperature of the battery is outside of a normal operating range.

Various modes of operation of the thermal management system according to the present disclosure will be described in detail below with reference to the accompanying drawings.

Fig. 1-4 illustrate various modes of operation of an exemplary thermal management system according to aspects of the present disclosure when the passenger cabin requires a supply of heat.

Referring now to FIG. 1, FIG. 1 illustrates a block diagram of a first mode of operation of an exemplary thermal management system, according to aspects of the present disclosure. According to fig. 1, a first radiator 104 is disposed near a passenger compartment 1, heat emitted from the first radiator heats the passenger compartment 1, and a heat source of the first radiator 104 is derived from heat emitted from a battery 101 and an electric motor 102 of an electric vehicle. The electric vehicle thermal management system includes a cooling circuit for circulating a coolant, wherein the battery 101, the electric motor 102, and the first radiator 104 are fluidly connected in series in the cooling circuit such that the coolant in the cooling circuit can cool the battery 101 and the electric motor 102, and the coolant transfers heat emitted from the battery 101 and the electric motor 102 to the first radiator 104, thereby supplying heat to the passenger compartment 1 through the first radiator 104.

The battery 101 and the electric motor 102 are connected in series in the cooling circuit to efficiently transfer heat of the two heat-generating components to the first radiator 104, thereby rapidly heating the passenger compartment, so that the heating efficiency is high. This is particularly useful when the ambient temperature is low.

FIG. 3 illustrates a block diagram of a second mode of operation of an exemplary thermal management system, in accordance with aspects of the present disclosure. In this embodiment, the electric motor 102 is separated from the cooling circuit to which the first radiator is connected as shown in fig. 1. At this time, in the cooling circuit to which the first radiator is connected, only the first radiator 104 and the battery 101 are connected in series, and the first radiator 104 heats the passenger compartment 1 by the heat radiated from the battery 101.

This mode of operation may be selected, for example, based on the temperature of the battery. Since the battery 101 may be very sensitive to temperature, it may be necessary to preferentially ensure heat dissipation from the battery 101. In a general case, the passenger compartment 1 may be heated by heat emitted from both the battery 101 and the electric motor 102, but when the battery temperature is relatively high, in order to ensure effective heat dissipation from the battery 101, separating the electric motor 102 from the cooling circuit may effectively shorten the heat dissipation circuit of the battery 101 and prevent the heat of the electric motor 102 from affecting the heat dissipation from the battery 101, while, at the same time, the heat supply of the passenger compartment 1 is still well ensured because the battery 101 continues to provide heat to the first heat sink 104. In this operating mode, the heat of the heat-generating component (i.e., the battery) is efficiently transferred to the passenger compartment 1 without affecting the heat dissipation of the component.

After the electric motor 102 is separated from the cooling circuit to which the first radiator is connected, the electric motor 102 can dissipate heat through another cooling circuit 108 that is independent of the cooling circuit to which the first radiator is connected. This ensures that the electric motor can also dissipate heat after the electric motor 102 is separated from the cooling circuit, and that the heat dissipation of the battery is not affected by the heat of the electric motor 102.

Reference is now made to fig. 6 and 7. Fig. 6 and 7 illustrate a third mode of operation and a fourth mode of operation, respectively, of an exemplary thermal management system, according to aspects of the present disclosure. In both operating modes, the first radiator 104 is decoupled from the cooling circuit, since the passenger cabin does not require a heat supply due to the high ambient temperature. In a third operating mode as shown in fig. 6, the first radiator 104 is separated from the cooling circuit, and the battery 101 and the electric motor 102 are connected in series in the cooling circuit. In a fourth operation mode as shown in fig. 7, the first radiator 104 is separated from the cooling circuit, and the battery 101 and the electric motor 102 are connected in two independent cooling circuits, respectively. When the temperature of the battery 101 is normal, the thermal management system may operate in the third operation mode, and when the temperature of the battery 101 is excessively high, the thermal management system may be switched to the fourth operation mode.

Some of the components in an exemplary cooling circuit that may be used in a thermal management system are described below to illustrate how the various operating modes described above may be switched.

Referring first to fig. 1 and 2, fig. 2 shows a more detailed schematic diagram of the first mode of operation of fig. 1. As shown in fig. 1, the cooling circuit includes a first partial path (a), and the first partial path (a) fluidly connects the battery 101 and the first heat sink 104. As shown in fig. 2, the first partial path (a) is provided with a first partial path inlet 1052 for inflow of the cooling liquid and a first partial path outlet 1051 for outflow of the cooling liquid. The cooling circuit further comprises a second partial path (B), wherein the second partial path (B) is fluidly connected to the electric motor 102 and is provided with a second partial path inlet 1054 for inflow of the cooling liquid and a second partial path outlet 1053 for outflow of the cooling liquid. The first partial path (a) and the second partial path (B) are connected and separated by a switching device 105.

Specifically, the switching device 105 has two states, fig. 2 shows a first state of the switching device 105, and fig. 4 shows a second state of the switching device 105. In the first state shown in fig. 2, the switching device 105 connects the first partial path outlet 1051 with the second partial path inlet 1054 and the second partial path outlet 1053 with the first partial path inlet 1052, thereby connecting the first partial path (a) and the second partial path (B), i.e., connecting the battery 101, the electric motor 102 and the first radiator 104 in series in the cooling circuit. In the second state shown in fig. 4, the switching device 105 connects the first partial path outlet 1051 with the first partial path inlet 1052, thereby separating the first partial path (a) from the second partial path (B), i.e. separating the electric motor 102 from the cooling circuit of the battery. In the second state, the switching device 105 further connects the second partial path outlet 1053 with the second partial path inlet 1054, thereby forming another cooling circuit for independently cooling the electric motor 102. Accordingly, the thermal management system may be switched to a second mode of operation as shown in FIG. 3.

The switching device 105 may be selected from, for example, a four-way valve or a combination of three-way valves.

As shown in fig. 2 and 4, pumps 103, 103' are connected in the first partial path (a) and the second partial path (B), respectively, for supplying the cooling liquid to the component to be cooled in each path and determining the flow rate of the cooling liquid in each path. A coolant source 109 may be connected to the cooling circuit and used to replenish the cooling circuit with coolant as it is lost.

The first radiator 104 is connected to the cooling circuit via a switch 113. In both modes of operation, as shown in fig. 2 and 4, switch 113 is turned on to connect the first radiator 104 into the cooling circuit to supply heat to the passenger compartment. When the passenger cabin does not require a heat supply, the switch 113 may be opened, thereby separating the first radiator 104 from the cooling circuit. At this point, the thermal management system may be in an operating mode as shown in fig. 6 and 7.

As shown in fig. 2 and 4, a second heat sink 108 may also be provided in the thermal management system. The second radiator 108 is arranged to be selectively connected in the cooling circuit to radiate heat absorbed from the cooling circuit to the outside of the vehicle. When the second heat sink 108 is connected in the cooling circuit, the thermal management system may be in an operating mode as shown in fig. 6 and 7.

Referring again to fig. 2 and 4, the second heat sink 108 is connected to the second partial path (B) via the switch 112. When the switch is turned on, the second heat sink 108 may be connected to the second partial path (B), at which time the thermal management system may be in an operating mode as shown in fig. 6 and 7. When the switch is open, the second heat sink 108 may be disconnected from the second partial path (B), at which time the thermal management system may be in an operating mode as shown in fig. 1 and 3.

For the operation mode as shown in fig. 6, the battery 101, the electric motor 102, and the second radiator 108 are connected in series, and heat of the battery 101 and the electric motor 102 is radiated to the outside of the vehicle through the second radiator 108; for the operation mode as shown in fig. 7, the electric motor 102 and the second radiator 108 are connected in series in the second partial path, and the heat of the battery 101 is not radiated to the outside of the vehicle through the second radiator 108 any more, and only the heat of the electric motor 102 is radiated to the outside of the vehicle through the second radiator 108.

Still referring to fig. 2 and 4, an example of a refrigerator 106 that may also be provided in the thermal management system is shown, for example, for selectively connecting in the cooling circuit depending on the temperature of the battery. The refrigerator 106 may cool the cooling liquid in the cooling circuit so that the cooling liquid can better cool the components having a high temperature. Since the battery 101 has a higher requirement for the operating temperature than the other components (e.g., the electric motor 102), the refrigerator 106 is preferably arranged to be selectively connected with the first partial path (a) to rapidly cool the battery 101 when the temperature of the battery 101 is excessively high. For example, the refrigerator 106 may be connected to the first partial path (a) through the switch 111, and when the temperature of the battery 101 is too high and cooling of the cooling liquid is required, the switch 111 may be turned on to connect the refrigerator 106 in the first partial path (a); when cooling of the cooling liquid is not required, the switch 111 can be opened to separate the refrigerator 106 from the first partial path (a). In other embodiments, the chiller 106 may be connected to other locations of the cooling circuit.

The switch 113, the switch 111, and the switch 112 may use, for example, a three-way valve. The switch 113 and the switch 111 may be constituted by, for example, two three-way valves.

A heater 107 may also be provided in the thermal management system, and the heater 107 may be connected in the first partial path (a) to selectively heat the coolant flowing to the battery. Specifically, the heater 107 is disposed upstream of the battery 101, i.e., the coolant flows through the heater 107 first and then through the battery 101, and the control device 201 controls the heater 107 to be activated or deactivated so as to select whether or not to heat the coolant. Due to this arrangement, it is possible to quickly heat the battery 101 when the temperature of the battery 101 is low.

In addition to the electric motor 102, other components 110 (e.g., a charger, etc.) capable of generating heat in the electric vehicle may also be connected in the second partial path (B) so that the other components 110 capable of generating heat may be cooled through the second partial path. When the switching device 105 is in the first state, heat of the other components 110 capable of generating heat is also transferred to the first radiator 104, thereby providing heat to the passenger compartment 1.

The control flow of an exemplary electric vehicle thermal management system according to aspects of the present invention will be described below with reference to a control block diagram of the electric vehicle thermal management system as shown in fig. 5. As shown in fig. 5, a cabin temperature sensor 204, a battery temperature sensor 203, a motor temperature sensor 202, and a control device 201 may be provided in an electric vehicle thermal management system. The cabin temperature sensor 204, the battery temperature sensor 203, and the motor temperature sensor 202 detect the temperatures of the cabin, the battery, and the motor, respectively, and transmit the detected temperatures to the control device 201. The control device 201 controls the operations of the pump 103, the switching device 105, the switch 111, the switch 112, the switch 113, and the heater 107 so that the thermal management system switches between the respective operation modes, based on the comprehensive determination of the temperatures of these devices and the outside passenger commands.

When the vehicle is in a normal running state, the control device 201 first determines whether to connect the first radiator 104 or the second radiator 108 in the cooling circuit, based on an instruction issued by the passenger indicating whether the passenger compartment requires heat supply.

Typically, if no instruction has been received from the passenger indicating whether the passenger cabin requires heat supply, the second radiator 108 is connected in the cooling circuit to radiate heat absorbed by the cooling circuit to the outside of the vehicle, while the first radiator 104 is separated from the cooling circuit.

When the passenger gives an instruction indicating that heat needs to be supplied to the passenger compartment, the control device 201 controls the switch 112 of the second radiator 108 to be turned off to separate the second radiator 108 from the cooling circuit, and controls the switch 113 of the first radiator 104 to be turned on to connect the first radiator 104 in the cooling circuit. Then, the control device 201 determines whether the battery 101 and the electric motor 102 are within the normal operating temperature range, based on the temperatures detected by the battery temperature sensor 203 and the motor temperature sensor 202. If it is determined that both the battery 101 and the electric motor 102 are within the normal operating temperature range, the control device 201 controls the switching device 105 to be in the first state in which the battery 101, the electric motor 102 and the first radiator 104 are fluidly connected in series and the battery 101 and the electric motor 102 simultaneously heat the passenger compartment 1. When the temperature of the battery 101 is out of the normal operating temperature range, the control device 201 controls the switching device 105 to be in the second state and controls the switch 112 of the second radiator 108 to be turned on, at which time the battery 101 and the electric motor 102 are respectively connected in different cooling circuits, the first radiator 104 supplies heat to the passenger compartment by means of the temperature of the battery, and the heat of the motor 102 can be radiated to the outside of the vehicle through the second radiator. At this time, the control device 201 can also control the switch 111 of the refrigerator 106 to be turned on to connect the refrigerator 106 with the cooling circuit, so that the cooling liquid flowing through the battery is cooled by the refrigerator 106, thereby further accelerating the cooling of the battery. Furthermore, whether the switching device 105 is in the first state or the second state, the control device 201 can determine whether the pump 103, 103' needs to be controlled to accelerate according to the temperatures of the battery 101 and the electric motor 102, so as to increase the flow rate of the cooling liquid in the cooling circuit and thus the cooling speed.

When the vehicle is just started, the control device 201 also needs to determine whether the battery needs to be heated according to the temperature of the battery 101, so that the battery is rapidly warmed up to a degree sufficient for normal operation of the battery. If it is determined that the battery needs to be heated, the control device 201 controls the heater 107 to be activated, the heat of the heater 107 will help to heat the battery 101, and the switching device 105 is controlled and switched to the second state in which the battery 101 and the electric motor 102 are respectively connected to different cooling circuits, thereby preventing the heat of the heater 107 from affecting the temperature of the electric motor 102.

Furthermore, when the cabin temperature is low or when the passenger instructs to heat the cabin, the control device 201 may control the heater 107 to be activated and the heat provided by the heater 107 will also supply heat to the cabin 1.

In response to a passenger command indicating that no heat needs to be supplied to the passenger cabin, the control means 201 may also control the switch 113 of the first radiator 104 to be open to disconnect the first radiator 104 from the cooling circuit and control the switch 112 of the second radiator 108 to be closed to connect the second radiator 108 in the cooling circuit.

By employing the above-described heat exchange system, various embodiments of the present disclosure may supply heat to the passenger compartment by using heat absorbed by the coolant from the battery and/or the electric motor, so that the electric power of the electric vehicle can be effectively utilized, thereby increasing the endurance mileage of the electric vehicle.

The present disclosure also provides an electric vehicle using the vehicle thermal management system, and other parts of the electric vehicle may adopt the structure of the existing electric vehicle, wherein the vehicle thermal management system is as described herein and will not be described again.

Although the present disclosure has been described with reference to the particular embodiments illustrated in the accompanying drawings, it should be understood that the electric vehicle thermal management system provided by the present disclosure can have numerous variations without departing from the spirit, scope, and background of the present disclosure. The description set forth above is merely illustrative and is not intended to be an exclusive list of all possible embodiments, applications or modifications of the invention. Those of ordinary skill in the art will also appreciate that parameters in the disclosed embodiments of the disclosure may be varied in different ways and that such variations are within the spirit and scope of the disclosure and claims. Thus, various modifications and variations of the described methods and systems of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention.

Claims (21)

1. An electric vehicle thermal management system for heating a passenger compartment of an electric vehicle by means of heat absorbed from a battery and/or an electric motor of the electric vehicle, comprising:

a cooling circuit for circulating a cooling fluid, wherein a battery, an electric motor and a first radiator are fluidly connected in series in the cooling circuit such that the cooling fluid in the cooling circuit can cool the battery and/or the electric motor to absorb heat;

and wherein the first radiator provides a heat source for the passenger compartment by radiating the heat absorbed by the coolant;

the electric motor is selectively decoupled from the cooling circuit.

2. The system of claim 1, wherein:

after the electric motor is separated from the cooling circuit, the electric motor is connected to another cooling circuit independent of the cooling circuit.

3. The system of claim 1, wherein:

the first radiator can be separated from the cooling circuit when the passenger cabin does not require heating.

4. The system of claim 3, wherein:

when the first radiator is separated from the cooling circuit, the motor and the battery are connected in the cooling circuit or each connected in a different cooling circuit.

5. The system of claim 1, wherein:

the cooling circuit includes:

a first partial path that fluidly connects the battery and the first heat sink, wherein the first partial path is provided with a first partial path inlet for inflow of the cooling liquid and a first partial path outlet for outflow of the cooling liquid, and

a second path portion that is fluidly connected to the electric motor, wherein the second path portion is provided with a second partial path inlet for inflow of the cooling liquid and a second partial path outlet for outflow of the cooling liquid;

the system further includes a switching device configured to:

connecting the first partial path outlet with the second partial path inlet and the second partial path outlet with the first partial path inlet in a first state to fluidly connect the battery, the electric motor, and the first heat sink in series; and

connecting the first partial path outlet with the first partial path inlet in a second state in order to separate the electric motor from the cooling circuit.

6. The system of claim 5, wherein the switching device connects the second partial path outlet with the second partial path inlet in the second state, such that the electric motor is connected to another cooling circuit independent of the cooling circuit.

7. The system of claim 5, further comprising:

a controller, wherein the controller controls the switching device to switch between the first state and the second state according to an operating condition of the battery.

8. The system of claim 1, further comprising:

and the cooling liquid source is connected with the cooling loop and used for supplementing cooling liquid for the cooling loop.

9. The system of claim 5, further comprising:

a refrigerator for exchanging heat with the first partial path;

wherein the refrigerator is selectively separated from the first partial path according to the temperature of the battery.

10. The system of claim 5, further comprising:

a second radiator, wherein the second radiator is arranged to radiate heat to an outside of the vehicle, and the second radiator is selectively connected in the second partial path.

11. The system of claim 5, further comprising:

a heater, wherein the heater is connected in the first partial path;

wherein the control device controls the heater to start or stop.

12. The system of claim 6, further comprising:

a controller, wherein the controller controls the switching device to switch between the first state and the second state according to an operating condition of the battery.

13. The system of claim 6, further comprising:

a refrigerator for exchanging heat with the first partial path;

wherein the refrigerator is selectively separated from the first partial path according to the temperature of the battery.

14. The system of claim 6, further comprising:

a second radiator, wherein the second radiator is arranged to radiate heat to an outside of the vehicle, and the second radiator is selectively connected in the second partial path.

15. The system of claim 6, further comprising:

a heater, wherein the heater is connected in the first partial path;

the control device controls the heater to start or stop.

16. An electric vehicle comprising:

a passenger cabin;

a battery;

an electric motor configured to be powered by the battery; and

a thermal management system for heating the passenger compartment by means of heat absorbed from the battery and/or the electric motor, the thermal management system comprising a cooling circuit for circulating a coolant, wherein the battery, the electric motor and a first heat sink are fluidly connected in series in the cooling circuit such that the coolant in the cooling circuit can cool the battery and/or the electric motor to absorb heat;

wherein the first radiator provides a heat source for the passenger compartment by radiating the heat absorbed by the coolant, and

the electric motor is selectively decoupled from the cooling circuit.

17. The electric vehicle of claim 16, wherein:

the cooling circuit includes:

a first partial path that fluidly connects the battery and the first heat sink, wherein the first partial path is provided with a first partial path inlet for inflow of the cooling liquid and a first partial path outlet for outflow of the cooling liquid,

a second path portion that is fluidly connected to the electric motor, wherein the second path portion is provided with a second partial path inlet for inflow of the cooling liquid and a second partial path outlet for outflow of the cooling liquid;

the thermal management system further includes a switching device configured to:

connecting the first partial path outlet with the second partial path inlet and the second partial path outlet with the first partial path inlet in a first state so as to fluidly connect the battery, the electric motor, and the first heat sink in series; and

connecting the first partial path outlet with the first partial path inlet in a second state in order to separate the electric motor from the cooling circuit.

18. The electric vehicle as set forth in claim 17, wherein the switching device connects the second partial path outlet with the second partial path inlet in the second state, so that the electric motor is connected to another cooling circuit independent of the cooling circuit.

19. The electric vehicle of claim 17, further comprising:

a controller, wherein the controller controls the switching device to switch between the first state and the second state according to an operating condition of the battery.

20. An electric vehicle thermal management system comprising the features or any combination of the features of any one of claims 1 to 15.

21. An electric vehicle comprising the features or any combination of the features of any one of claims 16 to 19.