GB2577048A

GB2577048A - Charging electric vehicles

Info

Publication number: GB2577048A
Application number: GB1814725.6A
Authority: GB
Inventors: Lawrence Powell Damian
Original assignee: Zapinamo Ltd
Current assignee: Zapinamo Ltd
Priority date: 2018-09-11
Filing date: 2018-09-11
Publication date: 2020-03-18
Also published as: GB201814725D0

Abstract

The charging of electric vehicles (EVs) is managed by identifying a maximum level of power available at a charging station. Requests are received for charging power from vehicles connected to respective supply equipment at a notional charging power that represents the highest power level that the vehicle can receive. Power is selectively supplied to supply equipment (e.g. electric vehicle supply equipment, EVSE) and data of actual charging power supplied by a supply device is received by an energy management system. A record of the notional charging power is then modified to a value closer to the actual charging power. Each supply device may include: a recording device for recording a notional charging power; a power measuring device for measuring actual charging power; and an output device for supplying the data of actual charging power to the energy management system. The actual charging power values may be summed to determine a total power output. By comparing the sum of the actual charging power values, rather than the sum of the notional charging power values, against the maximum level of power available, additional vehicles may receive charge without exceeding the maximum power available.

Description

(71) Applicant(s):

Zapinamo Limited

6-7 Pollen Street, London, W1S 1NJ, United Kingdom (72) Inventor(s):

Damian Lawrence Powell (56) Documents Cited:

EP 3119638 A1

WO 2013/009178 A2

WO 2013/100764 A1 (58) Field of Search:

INT CL B60L, H02J

Other: EPODOC, WPI, Patent Fulltext (74) Agent and/or Address for Service:

Atkinson & Company Intellectual Property Limited 7 Moorgate Road, ROTHERHAM, S60 2BF, United Kingdom (54) Title of the Invention: Charging electric vehicles Abstract Title: Managing charging of electric vehicles (57) The charging of electric vehicles (EVs) is managed by identifying a maximum level of power available at a charging station. Requests are received for charging power from vehicles connected to respective supply equipment at a notional charging power that represents the highest power level that the vehicle can receive. Power is selectively supplied to supply equipment (e.g. electric vehicle supply equipment, EVSE) and data of actual charging power supplied by a supply device is received by an energy management system. A record of the notional charging power is then modified to a value closer to the actual charging power. Each supply device may include: a recording device for recording a notional charging power; a power measuring device for measuring actual charging power; and an output device for supplying the data of actual charging power to the energy management system. The actual charging power values may be summed to determine a total power output. By comparing the sum of the actual charging power values, rather than the sum of the notional charging power values, against the maximum level of power available, additional vehicles may receive charge without exceeding the maximum power available.

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Charging Electric Vehicles

CROSS REFERENCE TO RELATED APPLICATIONS

This application represents the first application for a patent directed towards the invention and the subject matter.

BACKGROUND OF THE INVENTION

The present invention relates to a method of charging electric vehicles and an apparatus for charging electric vehicles.

It is known to charge electric vehicles from a mains supply, from locally generated electricity or from batteries that may be permanently resident or may themselves have been transported to a recharging location. Increasingly, charging stations are provided that include many individual supply devices, each sometimes referred to as “electric vehicle supply equipment”, working with a charging station management system and an energy management system. The charging station management system is responsible for authorising users and overseeing financial arrangements for using the charging station. The energy management system managers local loads in terms of consumption of the available power, based on local and contractual constraints and contractual incentives. Thus, at any point during the operation of the charging station, there is a total maximum amount of power that is available for charging individual vehicles.

Requests are made by vehicles for receiving power which identify the total level of power that the vehicle is capable of receiving. Thus, it is known to allow newly connected vehicles to receive charge, based on the sum of all of the previous allocations deducted from the total level of charge available. However, a problem may arise in terms of making use of the total power available, given that the actual power taken tends to diminish during a charging cycle.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a method of managing the charging of electric vehicles, comprising the steps of: identifying a maximum level of power available at a station for charging electric vehicles; receiving requests for charging power from vehicles connected to respective supply equipment at a notional charging power; recording data of said notional charging powers representing a total power receivable by a vehicle; selectively supplying power to said supply equipment; receiving data of actual charging power supplied by a supply device; and modifying a record of said notional charging power to a value closer to said actual charging power.

In an embodiment, the actual charging power values are summed to determine a total power output. Furthermore, a power availability value may be calculated by subtracting the value of the total power output from the maximum power level. In this way, power may be supplied in response to a new request if the notional charging power of said request is below said power availability.

According to a second aspect of the present invention, there is provided an apparatus for charging electric vehicles, comprising: an electrical-power source having a maximum power output; a plurality of supply devices, in which each said supply device is configured to receive a request from a connected vehicle, record a notional charging power and charge said vehicle for a predetermined charge period at or below said notional charging power; and an energy management system for selectively supplying electricity to said supply devices from said electrical-power source, wherein said energy management system is configured to: receive data of actual charging power being supplied by a supply device; and modify a record of said notional charging power to a value closer to said actual charging power.

In an embodiment, each supply device includes a recording device for recording a notional charging power. Furthermore, each supply device may include power measuring devices for measuring actual charging power; and an output device for supplying said data of actual charging power to said energy management system.

Embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings. The detailed embodiments show the best mode known to the inventor and provide support for the invention as claimed. However, they are only exemplary and should not be used to interpret or limit the scope of the claims. Their purpose is to provide a teaching to those skilled in the art. Components and processes distinguished by ordinal phrases such as “first” and “second” do not necessarily define an order or ranking of any sort.

BREIF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Figure 1 show a charging station for charging electric vehicles;

Figure 2 shows an electric vehicle connected to a supply device;

Figure 3 shows operations performed by an energy management system;

Figure 4 shows a protocol diagram illustrating communications that take place between a vehicle and a supply device;

Figure 5 illustrates notional power requirements;

Figure 6 illustrates an accumulation of notional power requirements;

Figure 7 shows examples of actual charging characteristics;

Figure 8 shows an accumulation of actual power requirements;

Figure 9 shows an example of a charging device; and

Figure 10 details procedures for updating power usage, identified in Figure 3.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Figure 1

A charging station for charging electric vehicles is illustrated in Figure 1. The charging station includes an electrical power source 101 which, in this embodiment, is configured to receive power from a national grid supply 102. In addition, power may also be received from a local power source 103; that may include rechargeable batteries and local renewable sources.

The station includes a plurality of supply devices and in the example shown in Figure 1, ten supply devices are provided; consisting of a first supply device 111, a second supply device 112, a third supply device 113, a fourth supply device 114, a fifth supply device 115, a sixth supply device 116, a seventh supply device 117, an eighth supply device 118, a ninth supply device

119 and a tenth supply device 120. Each supply device (111 to 120) is configured to receive a request from a connected vehicle, record a notional charging power and charge the vehicle for a predetermined charge period at or below the notional charging power.

The station also includes an energy management system 121 for selectively supplying electricity to the supply devices from the electrical power source 101. The energy management system is configured, in accordance with an aspect of the present invention, to receive data of actual charging power being supplied by each supply devices and to modify a record of the respective notional charging power to a value closure to the actual charging power.

The energy management system 121 communicates with a communication management system 222 and the communication management system 222 also communicates with each of the supply devices 111 to 120, possibly using a wireless protocol.

The communication management system 222 is responsible for authenticating the availability of power to particular users and for concluding financial arrangements when transactions take place. The communication management systems 222 issues instructions to the energy management system 121 to the effect that a particular connection may be made, thereby allowing a particular supply device to receive power, as indicated by the presence of individual respective switches 131 to 140.

Figure 2

An electric vehicle 201 is connected to the second supply device 112 and, upon connection, the vehicle 201 issu.es a request for power to be supplied. This request identifies a notional charging power, which represents the maximum power level that the vehicle 201 is capable of receiving from the second supply device 112. In some environments, device 112 may not be capable of providing power to this level and power is therefore supplied at a lower level. Management systems within the vehicle 201 then accommodate the reception of this lower power to optimise charging characteristics within the vehicle itself.

In other installations, it is possible for the supply device 112 to provide power at higher levels than that requested by a vehicle. Under these circumstances, the availability of power is “throttled back”, to ensure that damage does not occur to the vehicle and, in particular, to the vehicle’s battery. Thus, under transactions of this type, the management system of the vehicle is in charge, to ensure that the battery resident within the vehicle does not sustain any permanent damage. Furthermore, it is also possible that the management system within the vehicle may take account of previous charging histories, and, for example, may reduce charging levels if a second or third fast charge is requested during a short interval of, possibly twenty-four hours.

In any event, the vehicle 201 identifies a notional charging power to the supply device 112. The supply device will then make this power available to the vehicle if possible but will not exceed this power level. Consequently, the notional charging power is recorded by the supply device with relevant data being returned back to the management systems 121/122. The energy management system 121 must therefore make sufficient power available to the supply device 112, thereby allowing the supply device 112 to supply the requested notional charge to the requesting vehicle 201. The energy management system 121 is also aware of the total level of power that may be received from the electrical power source 101.

Figure 3

Operations performed by the energy management system 121 are illustrated in Figure 3; providing a method of managing the charging of electric vehicles. In particular, a maximum level of power available at the station is identified for charging electric vehicles. Requests are then received for charging power from vehicles connected to respective supply equipment at the notional charging power. Data for the notional charging powers are recorded, representing a total power receivable by a vehicle. Supply power is selectively supplied to the supply equipment. However, in addition, data is received of actual charging power being supplied to a supply device and a record of the notional charging power is modified to a value closer to the actual charging power.

As illustrated in Figure 3, a new request is made at step 301, requiring an update to the total power that is being supplied by the station at the present time; represented as the power that is being drawn now. Thereafter, at step 302, a value for the power that is being drawn now is updated.

At step 303, a question is asked as to whether the sum of the new power required plus the existing power being supplied is greater than the maximum power that may be supplied. The procedure to update the present power (now) is required at step 302 because since the last iteration, power transfers may have completed and therefore the total power drawn may have been reduced. Such a requirement exists under existing systems when notional powers are being considered. However, the present invention provides a greater level of sophistication in that the update step 302 is not made with respect to notional power levels, as described with reference to Figure 6, but is made with reference to actual power levels as described with reference to Figure 8.

Thus, if the question asked at step 303 is answered in the affirmative, to the effect that the power level has been exceeded, the request is declined at step 304. Thereafter, a wait period exists before new requests are considered again at step 301.

If the question asked at step 303 is answered in the negative, to the effect that the new total power level does not exceed the maximum power level, the request is accepted at step 306 and the present power level is updated for record keeping purposes. Thus, the new present power level is derived from the sum of the previous power level plus the new addition.

At step 308 a question is asked as to whether the procedure is to end and if answered in the negative, the next request is considered at step 301.

The present invention provides for more occasions for the question asked at step 303 to be answered in the negative. In this way, more requests are accepted at step 306, resulting in more vehicles being charged over a particular period of time. Analysis suggests that the number of vehicles receiving charge may be increased by as much as twenty-five percent or, viewed in an alternative way, the system allows five vehicles to be charged instead of four; without increasing the total level of power available from the power supply at any instant.

Figure 4

A protocol diagram is illustrated in Figure 4, illustrating communications that take place between the vehicle 201, the supply device 112 and the energy management system 121. At 401 the vehicle 201 makes a request for charging power and identifies a maximum power level that it is capable of receiving. The supply device 112 retains a record of this notional power such that, during a charging process, it is not possible for the power level to exceed this notional power level. Thereafter, at 402 the request is relayed from the supply device 112 to the energy management system 121.

For the purposes of this illustration, it is assumed that too much power is presently being taken by other supply devices, therefore at 403 the request is declined.

In this example, the vehicle remains connected and the system will automatically wait until power becomes available. Thus, after a period of waiting, an acceptance is issued at 404 from the energy management system 121 back to the supply device 112.

At 405 a charging procedure takes place, which may be terminated by a time-out driven by the supply device 112 or by a disconnection taking place. Thus, for the purposes of this illustration, a disconnection takes place at step 406 and the status of the disconnection is then relayed from the supply device 112 back to the management system 121 at 407.

Figure 5

When a notional power requirement is recorded by a supply device, it will identify an acceptable power level for charging a vehicle and will assume that charging at this power level will continue for a predetermined period of time, unless a physical disconnection occurs before this period has expired.

Thus, as illustrated in Figure 5, a power request level 501 is plotted against time 502. The actual request 401 may, in this example, identify a first level of charge 511, a second level of charge 512, a third level of charge 513 or a fourth level of charge 514. It is possible that different vehicles could be charged for differing periods of time, depending on the capacity of their battery. However, on this occasion, it is assumed that a charge cycle will take place for the same amount of time irrespective of the level of charge. Thus, charging starts at time 520 and stops at time 521.

Figure 6

An accumulation of charging activities, based on individual charging possibilities as illustrated in Figure 5, is shown in Figure 6. Again, power 601 is plotted against time 602 but, on this occasion, power represents the total amount of power being supplied by the power supply 101.

The first request for power is issued at time 611, followed by a second request by a second vehicle at time 612, a third request by a third vehicle at time 613, a fourth request by a fourth vehicle at time 614 and a fifth request from a fifth vehicle at time 615.

A maximum power level 616 is available. The first request is for a power level of 621 which, as the first, is well below the maximum level 616. When the second request is made at time 612, the total level of power required becomes 622. At time 613, the third request is added, giving a total power requirement of 623 which, again, is below the maximum level 616. The fourth request made at time 614 results in a total power level of 624, which is still below the maximum level 616. Thus, the first four requests for power will be accepted and the total power level will be 624.

At time 615, the fifth request is made which, if accepted, would result in the total power draw being taken to a level of 625. As illustrated in Figure 6, this level is higher than the maximum level of 616. Consequently, the request will be declined and this request cannot be accepted until one of the existing charging sessions has completed.

Figure 7

As described with reference to Figure 5, it is assumed that once a charging level has been accepted and the charging session initiated, this notional power level will be required throughout the charging duration. The requested details of the requested power level are retained by the supply device and are known to the management system. It is not possible for a supply device to provide power that exceeds this level but, in existing systems, this level of charge is guaranteed and is reserved for the particular charging session under consideration. Thus, as described with reference to Figure 6., some charging requests, such as that made at 615, will be rejected.

In practice, experiments show that batteries within electric vehicles do not receive power in the way described with respect to Figure 5. A first example is shown at 701 and a second example is shown at 702. In each example, charging level 703 is plotted against time 704. Charging starts at time 710 and completes at time 711. For the first battery, the notional charging level is indicated by a first maximum level 705. Similarly, for the second example, the notional maximum charging level is indicated at 706.

In the first example, charging is performed at the maximum notional level until time 707. Thereafter, the charging level declines, as indicated at 708; such that at the end of the charging period the power transfer level has reduced by approximately 50%. This decline starts after approximately 60% of the charging session has been completed. Furthermore, this may be identified as a high-quality charging session with a relatively new battery. Even then, a first region 721 exists in which charging power has been allocated but is not actually being used.

In the second example, a second region 722 exists which, again, has been allocated for the charging session but has not actually been used. In this example, the vehicle identifies a maximum notional charging level 706 but in practice, the charging session fails to reach this level. Thereafter, further decline occurs at time 723 and by time 724 the actual level of charge has reduced quite significantly.

Figure 8

The present invention aims to take advantage of the actual charging characteristics described with reference to Figure 7, compared to the notional charging characteristics described with reference to Figures 5 and 6. In the example shown in Figure 8, for the purposes of illustration, it is assumed that the same requests are made as those described with reference to Figure 6. Thus, a first request occurs at time 611, a second request occurs at time 612, a third request occurs at time 613, a fourth request occurs at time 614 and a fifth request occurs at time 615. Under the regime described with reference to Figure 6, charging was permitted for the first four requests but rejected for the fifth. This is because the total power demand was based on the notional charging levels, representing the maximum amount of power that may be transferred; usually at the start of a charging process.

In Figure 8, results are shown when the total power level is considered with reference to the actual power that is being taken when a new request arrives.

Thus, the first charging process starts with a power level of 621 but when the second request is made at time 612, the actual power requirement has dropped to 801. Thus, when the new request is added to the existing power requirement, the total power requirement becomes 802, instead of 622.

Similarly, the power taken for the second charging process also declines such that, when a third request is made at time 613, the total power requirement becomes 803 instead of 623. Furthermore, when the fourth request is made at time 614, the total power requirement becomes 804 instead of 624. Again, when the fifth request is made at time 615, the total power requirement becomes 805 instead of 625.

As described with reference to Figure 6, the total power requirement 625 is above the maximum power level 616. However, total power requirement 805 is below this maximum level. Consequently, following the procedure established by the present embodiment, it is possible for the fifth vehicle to receive charge without exceeding the total power available.

Figure 9

An example of a charging device, such as charging device 112, is illustrated in Figure 9. The charging device includes a recording device 901 for recording a notional charging power. Initially, data is supplied to the recording device from a vehicle, as indicated by a first data line 902. This information is also relayed to the energy management system over a second data line 903. In conventional systems, when the recording device 901 has received an indication of a notional power from a vehicle, this value is retained throughout the charging period. Similarly, from total power assessment perspectives, the energy management system reserves this notional power level.

In an embodiment of the present invention, the energy management system makes an assessment as to the actual power that is being taken and from this, it is capable of making more accurate calculations in relation to the availability of total power within the station itself. However, in an embodiment, in order to achieve this, it is not necessary to make any major modifications to the supply devices themselves. In an embodiment, the energy management system makes use of the second data line 903 in order to overwrite the notional value stored in the recording device 901 to a lower value that is equal to or at least closer to the actual power that is being delivered to the vehicle. Furthermore, once this throttling back operation has been performed, it is no longer possible for the degree of power being delivered to exceed the value that has now been recorded by the recording device 901. From the perspective of systems operating within the charging device itself, it is as if this modified value had been received initially from the vehicle during initial communication procedures as described with reference to Figure 4.

In an embodiment, each supply device includes power measuring devices for measuring actual charging power and are provided with an output device for supplying data of actual charging power to the energy managing system. In some embodiments, a visual display may also be provided at the charging device itself in order to provide users with a visible indication as to the actual power that is being delivered. Thus, when equipment of this type is available, it is possible for an embodiment of the present invention to make full use of this and thereby further reduce the amount of additional equipment required in order to obtain the desired benefits of the present invention.

Thus, in this embodiment, power is delivered to the vehicle as direct current, by connecting the charging system resident within the vehicle to a positive line 904 and a negative line 905. An ammeter 906 measures current through the positive line 904 and a volt meter 907 measures voltage across the positive line 904 and the negative line 905. A multiplication process 908 forms the product of outputs from the ammeter and the volt meter to provide an indication of the level of power being delivered to a second recording device 909.

In an alternative embodiment, the power measuring device may be located between the energy management system and the supply device if the supply device does not include equipment of this type.

In some situations, power measuring devices may not be available. However, in such situations, advantages of the invention may still be derived by calculating the charging power independently at the energy management system, based on duration of charge. Such an approach may be refined when the actual charging power is derived from an indication of the battery type being charged. Thus, when the type of vehicle has been identified, the charging characteristic may be modelled in order to provide a more accurate estimate of the actual total power requirement. Furthermore, in an alternative embodiment, data for the actual charging power is derived from historical data relating to previous charging operations performed on a specific identified battery. Thus, data may be available that uniquely identifies the battery. A charging characteristic for the battery may be obtained during a charging process using equipment where power management devices are available. The charging characteristic data may be then stored centrally and deployed, in order to provide model data, at stations where direct measurement of charging power is not available.

It has also been appreciated that, given sufficient resolution, each individual battery will display a unique charging characteristic. Thus, when charging characteristic data can be determined ata charging station, it would be possible, from the charging characteristic, to identify the particular battery being charged and hence the actual vehicle being charged.

Figure 10

Procedures 302 for updating power are illustrated in Figure 10. Following reception of a new request at step 301, the supply devices are 5 considered sequentially. Thus, at step 1001 the first supply device 111 is selected and at step 1002 the actual power being delivered by this device is read. The value read at step 1002 is then added to a power now variable at step 1003, whereafter a question is asked at step 1004 as to whether another device is to be considered.

Ona first iteration, the question asked at step 1004 will be answered in the affirmative and the next supply device (supply device 112) will be selected, its actual power delivery value will be read at step 1002 and this value will be added to the power now variable at step 1003. Thus, this process continues until the final charging device 120 has been selected, read and its power value 15 added; which will then result in the question asked at step 1004 being answered in the negative. Thus, thereafter, a new request may be considered at step 303.

Claims

CLAIMS The invention claimed is:

1. A method of managing the charging electric vehicles, comprising the steps of:

identifying a maximum level of power available at a station for charging electric vehicles;

receive requests for charging power from vehicles connected to respective supply equipment at a notional charging power;

record data of said notional charging powers representing a total power receivable by a vehicle;

selectively supply power to said supply equipment;

receive data of actual charging power supplied by a supply device; and modify a record of said notional charging power to a value closer to said actual charging power.

2. The method of claim 1, further comprising the step of summing said actual charging power values to determine a total power output.

3. The method of claim 2, further comprising the step of calculating a power availability value by subtracting the value of said total power output from said maximum level.

4. The method of claim 3, further comprising the step of supplying power in response to a new request if the notional charging power of said request is below said power availability.

5. The method of any of claims 1 to 4, wherein each said supply device includes a recording device for recording a notional charging power.

6. The method of any of claims 1 to 5, wherein each said supply device includes:

power measuring devices for measuring actual charging power; and an output device for supplying said data of actual charging power to said energy management system.

7. The method of any of claims 1 to 5, wherein a power measuring device is located between the energy management system and each supply device.

8. The method of any of claims 1 to 5, wherein said data of actual charging power is derived independently at said energy management system, based on duration of charge.

9. The method of claim 8, wherein said data of actual charging power is derived from a charging model selected for the type of battery being charged.

10. The method of claim 8, wherein said data of actual charging power is derived from historical data relating to previous charging operations performed for a specific identified battery.

11. An apparatus for charging electric vehicles, comprising:

an electrical-power source having a maximum power output;

a plurality of supply devices, in which each said supply device is configured to receive a request from a connected vehicle, record a notional charging power and charge said vehicle for a predetermined charge period at or below said notional charging power; and an energy management system for selectively supplying electricity to said supply devices from said electrical-power source, wherein said energy management system is configured to:

receive data of actual charging power being supplied by a supply device; and modify a record of said notional charging power to a value closer to said actual charging power.

12. The apparatus of claim 11, wherein said energy management system is configured to sum actual charging power values to determine a total power output.

13. The apparatus of claim 12, wherein said energy management system is configured to calculate a power availability value by subtracting the value of said total power output from said maximum level.

14. The apparatus of claim 13, wherein said energy management system is configured to supply power in response to a new request if the notional charging power of said request is below said power availability.

15. The apparatus of any of claims 11 to 14, wherein each said supply device includes a recording device for recording a notional charging power.

16. The apparatus of any of claims 11 to 15, wherein each said supply device includes:

17. The apparatus of any of claims 11 to 15, further comprising power measuring devices, wherein a said power measuring device is located between the energy management system and each said supply device.

18. The apparatus of any of claims 11 to 15, wherein said data of actual charging power is derived independently at said energy management system, based on duration of charge.

19. The apparatus of claim 18, wherein said data of actual charging 5 power is derived from a charging model selected for the battery type being charged.

20. The apparatus of claim 18, wherein said data of actual charging power is derived from historical data relating to previous charging operations

10 performed for a specific identified battery.

Intellectual

Property

Office

Application No: GB1814725.6 Examiner: Mr Gareth John