GB2623490A

GB2623490A - An electric vehicle charger control system

Info

Publication number: GB2623490A
Application number: GB2214747.4A
Authority: GB
Inventors: hearn David; Duffin James
Original assignee: Esmart Networks Ltd
Current assignee: Esmart Networks Ltd
Priority date: 2022-10-07
Filing date: 2022-10-07
Publication date: 2024-04-24
Also published as: GB202214747D0

Abstract

Methods and systems for adjusting a charging rate of an EV charger 230a-d. The method comprises: receiving temperature data measured by a temperature sensor 250, the temperature data being indicative of a temperature of an EV charger feeder cable 210; receiving load current data indicative of a load current through the EV charger feeder cable 210; determining a cyclic load rating for the EV charger feeder cable 210 based on the received temperature data and load current data; and adjusting the charging rate of the EV charger 230a-d based on a comparison between a load current through the EV charger feeder cable 210 of the EV charger 230a-d and the determined cyclic load rating. Also disclosed is a system and method for adjusting a cooling rate of an EV charger feeder cable.

Description

AN ELECTRIC VEHICLE CHARGER CONTROL SYSTEM FIELD OF INVENTION

The present invention relates to electric vehicle (EV) charger control systems and, in particular, devices and methods for adjusting charging and cooling rates associated with EV chargers.

BACKGROUND

EV charging equipment is rapidly developing in order to enable EVs to recharge within shorter timescales to facilitate widespread EV adoption and minimize the inconvenience to drivers of EVs who are making long distance journeys. Due to current EV charging stations and customer adoption of EVs still being within their infancy, there is uncertainty around forecasting future usage patterns and utilisation percentages for rapid EV charging hubs and the charging profiles of EVs themselves.

Electric power cables connecting EV chargers to the grid can be specified to achieve either a continuous electrical load rating, or a cyclic load rating where the electrical load will not be continuous. The cyclic load rating allows for some concepts of thermodynamics to be utilised to allow a higher peak electrical load to be placed on the cable on an intermittent or cyclic basis without exceeding the maximum permissible operating temperature of the cable.

Some existing EV chargers implement load current control to prevent the EV charger itself from overheating. However, the temperature measured at the EV charger, or between the EV charger and the charging vehicle often does not reflect the temperature at the EV charger feeder cable, which could be significantly higher based on its thermal environment. Additionally, high-power EV chargers are typically equipped with their own liquid cooling system causing the EV charger to have a vastly different temperature to that of the feeder cable. Furthermore, such EV charger load current control systems are particularly ineffective at preventing overheating of feeder cables supplying an EV charger hub feeding a plurality of EV chargers, since each EV charger is only aware of its own load current.

Due to the aforementioned uncertainty of how EV charging patterns and EV battery technology will develop in the future, it is difficult to define a cyclic loading profile to enable a cyclic cable rating to be utilised for cables which supply an EV charger. As a result of this uncertainty, larger, higher-rated (usually overrated) EV charger feeder cables are typically selected on the assumption that the EV charger will operate at maximum power continuously to ensure that the cables operate within their thermal limits. Consequently, this results in the under utilisation of EV charger feeder cables. Furthermore, in many cases, there is limited space in the available cable trenches and/or ducts such that it is not always possible to accommodate multiple larger, higher-rated power cables in the same location while allowing the necessary physical separation between the cables.

It would be desirable to improve the efficiency of known EV charging networks. SUMMARY OF INVENTION The invention in its various aspects is defined in the independent claims below to which reference should now be made. Optional features are set forth in the dependent claims.

Hereafter, the term EV charger feeder cable refers to the supply cable(s) located upstream from the EV charger for connecting the EV charger to the local power network. Likewise, the term EV charger hub feeder cable refers to the supply cable(s) located upstream from the EV charger hub for connecting the EV charger hub to the local power network.

The term EV charger hub refers to a connector supplying power to a plurality of EV chargers.

In some embodiments, the EV charger hub may comprise a feeder pillar or a low voltage (LV) switchboard.

In a first aspect, the disclosure provides a processor for adjusting a charging rate of an EV charger. The processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder cable; determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the charging rate of the EV charger based on a comparison between a load current through the feeder cable and the determined cyclic load rating.

The processor of the present disclosure therefore utilises the combination of EV charger feeder cable temperature and load current data to determine a cyclic load rating of the EV charger feeder cable. The processor is configured to adjust the charging rate of the EV charger based on a difference between the determined cyclic load rating of the EV charger feeder cable and the charging rate of the EV charger. Advantageously, the processor of the present disclosure enables EV chargers to maximise their charging performance without exceeding the thermal operating limits of the EV charger feeder cable. Furthermore, EV charging systems implementing the disclosed EV charger control no longer need to rely on the use of oversized feeder cables and, may instead, safely use smaller, lower-rated feeder cables which are utilised to a greater extent.

Optionally, the EV charger feeder cable may be an EV charger hub feeder cable supplying a plurality of EV chargers. The processor may be further configured to: receive load current data indicative of a load current through each of the plurality of EV chargers; and adjust a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the EV charger feeder cable. The disclosed processor may therefore adjust the charging rate of multiple EV chargers based on the cyclic load rating of the EV charger feeder cable in order to ensure that the EV charger feeder cable operates within its thermal operating limits.

Optionally, the load current data may be received from the EV charger. This avoids the need to use additional current measurement devices.

Optionally, the received load current data may comprise historical load currents through the EV charger feeder cable. The historical load current data may be used to improve the accuracy of the determined cyclic load rating.

Optionally, the charging rate may be reduced where the load current through the EV charger feeder cable exceeds the cyclic load rating and/or the charging rate may be increased where the load current through the EV charger feeder cable is less than the cyclic load rating. This ensures that when the EV charger feeder cable is found to be operating above its cyclic rating, the charging rate is reduced to prevent overheating. Additionally, where the EV charger feeder cable is found to be operating below its cyclic rating, the charging rate is increased to improve EV charger feeder cable utilisation and charging performance.

Optionally, the received temperature data may comprise historical temperature data of the EV charger feeder cable. The historical temperature data may be used to improve the accuracy of the cyclic load rating.

Optionally, the received temperature data may be indicative of the temperature at a single position on the EV charger feeder cable. Advantageously, since the length of EV charger feeder cables is relatively short, a single temperature measurement point is sufficient to provide an accurate indication of the temperature along the entire cable.

Optionally, the temperature data may comprise temperature measurement data of an exterior surface of the EV charger feeder cable, and wherein the processor is configured to: determine a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determine the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Optionally, the processor may be further configured to adjust the cooling rate of an EV charger feeder cable cooling system based on a comparison between the charging rate of the EV charger and the determined cyclic load rating. Advantageously, the disclosed processor may improve the cooling efficiency of an EV charger feeder cable cooling system by modifying the cooling rate of the cooling system based on the where the EV charger feeder cable is operating relative to its cyclic load rating. For instance, where the charging rate of the EV charger is below the cyclic load rating of the EV charger feeder cable, a lesser degree of cooling is required to keep the EV charger feeder cable within its thermal operating limits, and so the cooling rate of the cooling system may be reduced. Correspondingly, where the charging rate of the EV charger is above the cyclic load rating of the EV charger feeder cable, a greater degree of cooling is required to keep the EV charger feeder cable within its thermal operating limits, and so the cooling rate of the cooling system may be increased.

Optionally, the processor may be further configured to adjust the charging rate of the EV charger based on the cooling capacity of the cooling system. Advantageously, where it is determined that the EV charger feeder cable is operating above its cyclic load rating and the cooling rate of the cooling system is operating below its maximum capacity, the charging rate of the EV charger may be reduced by a lesser extent (or not at all). Accordingly, where it is determined that the EV charger feeder cable is operating above its cyclic load rating and the cooling rate of the cooling system is operating at its maximum capacity, the charging rate of the EV charger may be reduced by a greater extent. Therefore, the disclosed processor is configured to account for the operating capacity of the EV charger feeder cable cooling system when adjusting the charging rate of the EV charger in order to maximise the charging performance of the EV charger while ensuring that the feeder cable is kept within its thermal operating limits.

In a second aspect, the disclosure provides a device for adjusting a charging rate of an EV charger, the device comprising a processor as described in relation to the first aspect.

Optionally, the device may further comprise a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable. The temperature sensor may include one or more of a thermistor, a resistance temperature detector (RID), a thermocouple, a thermometer, an infrared (IR) temperature sensor, Fibre Optic Sensor or a semiconductor-based sensor.

Optionally, the device may further comprise a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable. The current measurement device may include one or more of a current transformer, fibre optic sensor, Rogowski coil or magnetic field sensor (such as a Hall-effect sensor). Current data may be obtained directly from an integral current measurement device associated with the EV charger.

According to a third aspect, the disclosure provides a system for charging electric vehicles (EVs). The system may comprise: an EV charger; an EV charger feeder cable coupling the EV charger to a power network; and a device as described in relation to the second aspect.

Optionally, the system may further comprise an EV charging hub connecting a plurality of EV charger feeder cables supplying a respective plurality of EV chargers to the power network via an EV charger hub feeder cable.

Optionally, the system may further comprise an EV feeder cable cooling system operably coupled to the EV charger feeder cable. The cooling system may comprise one of a liquid or gas cooled system in the vicinity of the EV charger feeder cable.

According to a fourth aspect, the disclosure provides a method for adjusting a charging rate of an EV charger. The method comprises: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the charging rate of the EV charger based on a comparison between a load current through the feeder cable of the EV charger and the determined cyclic load rating.

The advantages of the disclosed method correspond with those in relation to the first aspect described above.

Optionally, the EV charger feeder cable may be a feeder cable of an EV charger hub supplying a plurality of EV chargers. The method may further comprise: receiving load current data indicative of a load current through each of the plurality of EV chargers; and

S

adjusting a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the EV charger feeder cable.

Optionally, the load current data may be received from the EV charger.

Optionally, the received load current data may comprise historical load currents through the EV charger feeder cable.

Optionally, adjusting the charging rate may comprise: reducing the charging rate where the load current through the EV charger feeder cable exceeds the cyclic load rating; and/or increasing the charging rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Optionally, the received temperature data may comprise historical temperature data of the EV charger feeder cable.

Optionally, the received temperature data may be indicative of the temperature at a single position on the EV charger feeder cable.

Optionally, the temperature data may comprise temperature measurement data of an exterior surface of the EV charger feeder cable. The method may further comprise: determining a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determining the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Optionally, the method may further comprise adjusting the cooling rate of an EV charger feeder cable cooling system based on a comparison between the charging rate of the EV charger and the determined cyclic load rating.

Optionally, the method may further comprise adjusting the charging rate of the EV charger based on a cooling capacity of an EV charger feeder cable cooling system.

According to a fifth aspect, the disclosure provides a computer program for causing a processor to perform a method described in relation to the fourth aspect.

The disclosure also provides a computer-readable storage medium comprising program code for causing a processor to carry out the method described in relation to the fourth aspect.

The disclosure additionally provides a non-transitory computer-readable storage medium comprising instructions which when executed by a processor, cause the processor to carry out the method described in relation to the fourth aspect.

According to a sixth aspect, the disclosure provides a processor for adjusting a cooling rate of an EV charger feeder cable cooling system. The processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder cable: determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the feeder cable and the determined cyclic load rating.

The processor of the present disclosure utilises the combination of EV charger feeder cable temperature and load current data to determine a cyclic load rating of the EV charger feeder cable. The processor is configured to adjust the cooling rate of the EV charger cooling system based on a difference between the determined cyclic load rating of the EV charger feeder cable and the charging rate of the EV charger. Advantageously, the processor of the present disclosure enables EV chargers to efficiently maximise their charging performance without exceeding the thermal operating limits of the EV charger feeder cable by actively managing the output of a EV charger feeder cable cooling system. Furthermore, EV charging systems implementing the disclosed cooling system control no longer need to rely on the use of oversized feeder cables and, may instead, safely use smaller, lower-rated feeder cables which are utilised to a greater extent using the disclosed active cooling management.

Optionally, the cooling rate may be increased where the load current through the EV charger feeder cable exceeds the cyclic load rating. Alternatively or additionally, the cooling rate may be reduced where the load current through the EV charger feeder cable is less than the cyclic load rating. Such active cooling management results in efficient use of the EV charger feeder cable cooling systems and reduces the need to adjust the charger rate of the EV charger by maximising utilisation of the EV charger feeder cable within its thermal operating parameters.

S

Optionally, load current data may be received from the EV charger. This avoids the need to use additional current measurement devices.

Optionally, the temperature data may be indicative of the temperature at a single position on the EV charger feeder cable. Advantageously, since the length of EV charger feeder cables is relatively short, a single temperature measurement point is sufficient to provide an accurate indication of the temperature along the entire cable.

Optionally, the temperature data may comprise temperature measurement data of an exterior surface of the EV charger feeder cable. The processor may be further configured to: determine a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determine the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

According to a seventh aspect, the disclosure provides a device for adjusting a cooling rate of an EV charger feeder cable cooling system. The device may comprise a processor according to that described in relation to the sixth aspect.

Optionally, the device may further comprise a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable. The temperature sensor may include one or more of a thermistor, a resistance temperature detector (RTD), a thermocouple, a thermometer, an infrared (IR) temperature sensor, fibre optic sensor or a semiconductor-based sensor.

Optionally, the device may further comprise a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable. The current measurement device may include one or more of a current transformer or magnetic field sensor. Load current data may be obtained directly from an integral current measurement device associated with the EV charger.

Optionally, the device may further comprise an EV charger feeder cable cooling system. The EV charger feeder cable cooling system may comprise one or more of a liquid cooling system or an air cooling system.

According to an eighth aspect, the disclosure provides a system for cooling an EV charger feeder cable. The system may comprise: an EV charger; a feeder cable coupling the EV charger to a power network; and a device according to that described in relation to the seventh aspect.

According to a nineth aspect, the disclosure provides a method for adjusting a cooling rate of an EV charger feeder cable cooling system. The method comprises: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.

The advantages of the disclosed method correspond with those in relation to the sixth aspect described above.

Optionally, adjusting the cooling rate of the cooling system may comprise increasing the cooling rate where the load current through the EV charger feeder cable exceeds the cyclic load rating. Alternatively or additionally, adjusting the cooling rate of the cooling system may comprise reducing the cooling rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Optionally, load current data may be received from the EV charger.

Optionally, the temperature data may be indicative of the temperature at a single position on the EV charger feeder cable.

According to a tenth aspect, the disclosure provides a computer program for causing a processor to perform a method described in relation to the nineth aspect.

The disclosure also provides a computer-readable storage medium comprising program code for causing a processor to carry out the method described in relation to the nineth aspect.

The disclosure additionally provides a computer-readable storage medium comprising instructions which when executed by a processor, cause the processor to carry out a method according to that described in relation to the nineth aspect.

Further implementations of the disclosure are described in the below examples.

Ex1. A processor for adjusting a charging rate of an Electric Vehicle (EV) charger, wherein the processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder 20 cable; determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the charging rate of the EV charger based on a comparison between a load current through the feeder cable and the determined cyclic load rating.

Ex2. A processor according to Ex 1, wherein the EV charger feeder cable is an EV charger hub feeder cable supplying a plurality of EV chargers, wherein the processor is further configured to: receive load current data indicative of a load current through each of the plurality of EV chargers; and adjust a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the feeder cable.

Ex3. A processor according to any preceding Ex, wherein load current data is received from the EV charger.

Ex4. A processor according to any preceding Ex, wherein the received load current data comprises historical load currents through the EV charger feeder cable. 10 Ex5. A processor according to any preceding Ex, wherein the processor is configured to: reduce the charging rate where the load current through the EV charger feeder cable exceeds the cyclic load rating; and/or increase the charging rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Ex6. A processor according to any preceding Ex, wherein the received temperature data comprises historical temperature data of the EV charger feeder cable.

Ex7. A processor according to any preceding Ex, wherein the temperature data is indicative of the temperature at a single position on the EV charger feeder cable.

Ex8. A processor according to any preceding Ex, wherein the temperature data comprises temperature measurement data of an exterior surface of the EV charger feeder cable, and wherein the processor is configured to: determine a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determine the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Ex9. A processor according to any preceding Ex, wherein the processor is further configured to adjust the cooling rate of an EV charger feeder cable cooling system based on a comparison between the charging rate of the EV charger and the determined cyclic load rating.

Ex10. A processor according to any preceding Ex, wherein the processor is further configured to adjust the charging rate of the EV charger based on a cooling capacity of the EV charger feeder cable cooling system.

Ex11. A device for adjusting a charging rate of an EV charger, the device comprising a processor according to any preceding Ex.

Ex12. A device according to Ex 11, further comprising: a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable.

Ex13. A device according to any of Ex 11 to 12, further comprising: a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable.

Ex14. A system for charging electric vehicles (EVs), the system comprising: an EV charger; an EV charger feeder cable coupling the EV charger to a power network; and a device according to any of Ex 11 to 13.

Ex15. A system according to Ex 14, further comprising an EV charger hub supplying a plurality of EV chargers via a respective plurality of EV charger feeder cables, wherein the EV charger hub is coupled to the power network via an EV charger hub feeder cable.

Ex16. A system according to any of Ex 14 to 15, further comprising an EV charger feeder cable cooling system operably coupled to the EV charger feeder cable.

Ex17. A method for adjusting a charging rate of an Electric Vehicle (EV) charger, the method comprising: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the charging rate of the EV charger based on a comparison between a load current through the feeder cable of the EV charger and the determined cyclic load rating.

Ex18. A method according to Ex 17, wherein the EV charger feeder cable is an EV charger hub feeder cable supplying a plurality of EV chargers, the method further comprising: receiving load current data indicative of a load current through each of the plurality of EV chargers; and adjusting a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the EV charger feeder cable.

Ex19. A method according to any of Ex 17 to 18, wherein load current data is received from the EV charger.

Ex20. A method according to any of Ex 17 to 19, wherein the received load current data comprises historical load currents through the EV charger feeder cable.

Ex21. A method according to any of Ex 17 to 20, wherein adjusting the charging rate comprises: reducing the charging rate where the load current through the EV charger feeder cable exceeds the cyclic load rating; and/or increasing the charging rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Ex22. A method according to any of Ex 17 to 21, wherein the received temperature data comprises historical temperature data of the EV charger feeder cable.

Ex23. A method according to any of Ex 17 to 22, wherein the temperature data is indicative of the temperature at a single position on the EV charger feeder cable. 30 Ex24. A method according to any of Ex 17 to 23, wherein the temperature data comprises temperature measurement data of an exterior surface of the EV charger feeder cable, wherein the method further comprises: determining a conductor temperature of the feeder cable based on deconvolution of the temperature data; and determining the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Ex25. A method according any of Ex 17 to 24, wherein the method further comprises: adjusting the cooling rate of an EV charger feeder cable cooling system based on a comparison between the charging rate of the EV charger and the determined cyclic load rating.

Ex26. A method according to any of Ex 17 to 25, wherein adjusting the charging rate of the EV charger is based on a cooling capacity of an EV charger feeder cable cooling system.

Ex27. A computer program for causing a processor to carry out the method according to any of Ex 17 to 26.

Ex28. A processor for adjusting a cooling rate of an Electric Vehicle (EV) charger feeder cable cooling system, wherein the processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder cable; determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the feeder cable and the determined cyclic load rating.

Ex29. A processor according to Ex 28, wherein the processor is configured to: increase the cooling rate where the load current through the EV charger feeder cable exceeds the cyclic load rating and/or reduce the cooling rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Ex30. A processor according to any of Ex 28 to 29, wherein load current data is received from the EV charger.

Ex31. A processor according to any of Ex 28 to 30, wherein the received load current data comprises historical load currents through the EV charger feeder cable.

Ex32. A processor according to any of Ex 28 to 31, wherein the received temperature data comprises historical temperature data of the EV charger feeder cable.

Ex33. A processor according to any of Ex 28 to 32, wherein the temperature data is indicative of the temperature at a single position on the EV charger feeder cable.

Ex34. A processor according to any of Ex 28 to 33, wherein the temperature data comprises temperature measurement data of an exterior surface of the EV charger feeder cable, and wherein the processor is configured to: determine a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determine the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Ex35. A device for adjusting a cooling rate of an EV charger feeder cable cooling system, the device comprising a processor according to any of Ex 28 to 34. 20 Ex36. A device according to Ex 35, further comprising: a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable; and/or a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable.

Ex37. A device according to any of Ex 35 to 36, further comprising an EV feeder cable cooling system.

Ex38. A system for cooling an EV charger feeder cable, the system comprising: an EV charger; a feeder cable coupling the EV charger to a power network; and a device according to any of Ex 35 to 37.

Ex39. A method for adjusting a cooling rate of an Electric Vehicle (EV) charger feeder cable cooling system, the method comprising: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.

Ex40. A method according to Ex 39, wherein adjusting the cooling rate comprises: increasing the cooling rate where the load current through the EV charger feeder cable exceeds the cyclic load rating; and/or reducing the cooling rate where the load current through the EV charger feeder cable is less than the cyclic load rating.

Ex41. A method according to any of Ex 39 to 40, wherein load current data is received from the EV charger.

Ex42. A method according to any of Ex 39 to 41, wherein the received load current data comprises historical load currents through the EV charger feeder cable.

Ex43. A method according to any of Ex 39 to 42, wherein the received temperature data comprises historical temperature data of the EV charger feeder cable.

Ex44. A method according to any of Ex 39 to 43, wherein the temperature data is indicative of the temperature at a single position on the EV charger feeder cable.

Ex45. A method according to any of Ex 39 to 44, wherein the temperature data comprises temperature measurement data of an exterior surface of the feeder cable, and wherein the method further comprises: determining a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determining the cyclic load rating for the EV charger feeder cable based on the conductor temperature.

Ex46. A computer program for causing a processor to carry out a method according to any of Ex 39 to 45.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic of an EV charger control system according to a first embodiment of the present invention; Figure 2 is a schematic of an EV charger control system according to a second embodiment of the present invention; Figure 3 shows a flow diagram of a method for adjusting the charging rate of an EV charger according to an embodiment of the disclosure; and Figure 4 shows a flow diagram of a method for adjusting the cooling rate of an EV charger feeder cable cooling system according to an embodiment of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 illustrates an EV charger control system 100 according to a first embodiment of the present invention. System 100 comprises an EV charger feeder cable 110 for supplying power from a power network 120 to an EV charger 130.

Operably coupled to feeder cable 110 is a cooling system 140 for applying cooling to feeder cable 110. Cooling system 140 may comprise one or more of a liquid or gas cooling system configured to transfer heat away from an exterior surface of feeder cable 110. Operably positioned in the vicinity of feeder cable 110 is a temperature sensor 150 configured to collect temperature data indicative of the temperature of feeder cable 110. Temperature sensor 150 may comprise one or more of a thermistor, a resistance temperature detector (RTD), a thermocouple, a thermometer, an infrared (IR) temperature sensor, fibre optic sensor or a semiconductor-based sensor. Temperature sensor 150 may be positioned on or near the exterior surface of feeder cable 110. Temperature sensor 150 may be positioned at an expected "hot spot" along feeder cable 110.

Operably coupled to EV charger 130 is a controller 160 for adjusting a charging rate of EV charger 130. In some embodiments, controller 160 may be physically connected to, or integral with EV charger 130, as shown in Figure 1. In other embodiments, a communicative coupling may exist between controller 160 and EV charger 130. In some embodiments, controller 160 receives load current data from EV charger 130 indicative of a load current through EV charger feeder cable 110. In other embodiments, controller 160 may be communicatively coupled with a current measurement device (not shown) configured to collect load current data indicative of a load current through EV charger feeder cable 110. The current measurement device may be located either at feeder cable 110 or at EV charger 130. The load current data collected by the current measurement device is received by controller 160. In some embodiments, the current measurement device may relay measured load current data to the cloud or a central data collection point which is either accessed by or relayed to controller 160.

Controller 160 is also communicatively coupled with temperature sensor 150 to received collected temperature data associated with feeder cable 130. In some embodiments, controller 160 may be indirectly coupled with temperature sensor 150. For instance, temperature sensor 150 may relay measured temperature data to the cloud or a central data collection point which is either accessed by or relayed to controller 160.

Controller 160 may comprise a memory and a processor. The memory may comprise instructions, which when executed by the processor, cause the processor to carry out any of the methods described in this disclosure. Specifically, the processor of controller 160 may be configured to adjust a charging rate of EV charger 130 and/or adjust a cooling rate of cooling system 140 based on received temperature and load current data associated with feeder cable 110. Accordingly, a communicative coupling exists between controller 160 and the EV charger and/or cooling system 130.

Controller 160 may be located anywhere within system 100, providing that the required communicative coupling exists between the controller 160 each of the described components of the system 100. In some embodiments, controller 160 may be physically coupled with the current measurement device and/or temperature sensor 150.

Figure 2 illustrates an EV charger control system 200 according to a second embodiment of the present invention. System 200 comprises an EV charger hub feeder cable 210 for supplying power from a power network 220 to a plurality of EV chargers 230a-d via an EV charger hub 270. EV charger hub 270 is coupled to each of the plurality of EV chargers 230a-d via secondary feeder cables 215a-d.

As in system 100, system 200 comprises a cooling system 240 and a temperature sensor 250 operably coupled to EV charger hub feeder cable 210. Cooling system 240 and temperature sensor 250 may be identical to that described in relation to cooling system 140 and temperature sensor 150 respectively.

System 200 comprises a controller 260 communicatively coupled with a temperature sensor 250. As in system 100, controller 260 is configured to receive temperature data associated with EV charger hub feeder cable 210 measured by temperature sensor 250.

Controller 260 is also configured to receive load current data indicative of a load current through EV charger hub feeder cable 210. The load current data may be received from a current measurement device located on either EV charger hub feeder cable 210 or EV charger hub 270. Alternatively, the load current data may be received from a current measurement device located on each of the plurality of EV chargers 230a-d or secondary feeder cables 215a-d. In some embodiments, the current measurement device(s) may relay measured load current data to the cloud or a central data collection point which is either accessed by or relayed to controller 260.

As described in relation to controller 160, controller 260 may comprise a memory and a processor. The memory may comprise instructions, which when executed by the processor, cause the processor to carry out any of the methods described in this disclosure. Specifically, the processor of controller 260 may be configured to adjust a charging rate of EV charger 230 and/or adjust a cooling rate of cooling system 240 based on received temperature and load current data associated with feeder cable 210. Accordingly, a communicative coupling exists between controller 260 and the EV charger and/or cooling system 230. In some embodiments, controller 260 may adjust charging rates of each of the plurality of EV chargers 230a-d via control instructions to EV charger controllers 265a-d.

Controller 260 may be located anywhere within system 200, providing that the required communicative coupling exists between the controller 260 each of the described components of the system 200. In some embodiments, controller 260 may be located within EV charger hub 270, as shown in Figure 2. In some embodiments, controller 260 may be physically coupled with the current measurement device(s) and/or temperature sensor 250.

In some embodiments, the charging rate of each EV charger 230a-d may additionally be adjusted by an associated EV charger control system 100, as described in relation to figure 1.

Figure 3 shows a flow diagram of a method 300 for adjusting the charging rate of an EV charger according to an embodiment of the disclosure. At Step 310, temperature data indicative of a temperature of an exterior surface of an EV charger feeder cable is received. The received temperature data may comprise historical temperature data associated with the EV charger feeder cable. For instance, in some embodiments, the received temperature data may comprises temperature data for the EV charger feeder cable over a predetermined time duration (e.g., over the previous hour). In some embodiments, the temperature data is received directly from one or more temperature sensors positioned in proximity with the EV charger feeder cable. In other embodiments, the temperature data is received via an intermediary, such as the cloud or a central data storage point. At step 320, the conductor temperature of the EV charger feeder cable is determined based on the received temperature data. In some embodiments, the conductor temperature of the EV charger feeder cable is determined based on deconvolution of the measured EV charger feeder cable exterior surface temperature.

At step 330, load current data indicative of a load current through the EV charger feeder cable is received. The received load current data may comprise historical load current data associated with the EV charger feeder cable. For instance, in some embodiments, the received load current data may comprises load current data for the EV charger feeder cable over a predetermined time duration (e.g., over the previous hour). In some embodiments, the load current data is received directly from one or more current sensors positioned on the EV charger feeder cable or the EV charger itself. In other embodiments, the load current data is received via an intermediary, such as the cloud or a central data storage point. For embodiments comprising an EV charger hub feeding a plurality of EV chargers, such as that illustrated in Figure 2, load current data associated with each of the plurality of EV chargers may be received in order to determine the total load current through the EV charger hub feeder cable.

At step 340, the received load current data and the determined EV charger feeder cable conductor temperature are used to determine a cyclic load rating for the EV charger feeder cable. The cyclic load rating may be determined based on an International Electrotechnical Commission (IEC) standard based on the EV charger feeder cable's environment (e.g., IEC 60287 or IEC 60853).

The cyclic load rating may be determined for a predefined duration of time from receipt of the load current data and temperature data. In some embodiments, the cyclic load rating may be determined for a period of any of 10s, 30s, lm, 5m, 10m, 30m or 1h from receipt of the load current data and temperature data.

In some embodiments, the period of the determined cyclic load rating may be variable based on the EV charger. In some embodiments, the period of the determined cyclic load rating may be selected based on the received load current data. For instance, a shorter cyclic load rating period may be selected for an EV charger supplying power at a higher charging rate. The cyclic load rating period may be selected automatically by the controller based on the received load current data associated with the EV charger. Load current data and temperature data obtained during the previous cyclic load rating period may be used to recalculate the cyclic load rating for a subsequent cyclic load rating period. The load current data and temperature data obtained during the previous cyclic load rating period may be received all at once at the end of the previous cyclic load rating period, or alternatively, may be received continuously, or at multiple regular intervals during the previous cyclic load rating period.

In some embodiments, the cyclic load rating may be recalculated continuously or at regular intervals based on a continuous stream of load current data and temperature data.

Having determined the cyclic load rating of the EV charger feeder cable, step 350 involves adjusting the charging rate of the EV charger based on a comparison between an initial load current through the EV charger feeder cable and the determined cyclic load rating of the EV charger feeder cable. The initial load current through the EV charger feeder cable may be determined based on the received load current data. For instance, the initial load current through the EV charger feeder cable may be determined to be the most recent load current measurement in the received load current data. In some embodiments, the initial load current through the EV charger feeder cable may be determined based on an average of the most recent load current measurements in the received load current data. Where the initial load current is greater than the cyclic load rating, the charging rate of the EV charger may be reduced (e.g., down to the cyclic load rating). Where the initial load current is less than the cyclic load rating, the charging rate of the EV charger may be increased (e.g., up to the cyclic load rating). Therefore, based on the determined cyclic load rating of the EV charger feeder cable, the charging rate of the EV charger is optimised while maintaining operation of the EV charger feeder cable within its thermal limits.

For embodiments comprising an EV charger hub feeding a plurality of EV chargers, such as that illustrated in Figure 2, the charging rate of each of the plurality of EV chargers may be adjusted based on the comparison between an initial load current through the EV charger hub feeder cable and the determined cyclic load rating of the EV charger hub feeder cable.

In some embodiments, imbalances between the initial load current and the cyclic load rating may cause a charging rate adjustment which is spread across each of the plurality of EV chargers so as to reduce the impact on the charging rate of any individual EV charger. In some embodiments, the charging rate adjustment may be spread evenly across each of the plurality of EV chargers. In some embodiments, the charging rate adjustment to each of the plurality of EV chargers may be determined based on a charging session duration of each of the plurality of EV chargers. For instance, the EV chargers which have been charging over a greater duration may receive a greater charging rate adjustment than the EV chargers which have been charging for a lesser duration.

In some embodiments, the charging rate of each of the plurality of EV chargers may be adjusted based on the comparison between the initial load current through the EV charger hub feeder cable and the determined cyclic load rating of the EV charger hub feeder cable, and additional based on the comparison between an initial load current through the EV charger feeder cable associated with the respective EV charger and the determined cyclic load rating of the EV charger feeder cable associated with the respective EV charger. Such embodiments utilise charging rate control on both the EV charger level and the EV charger hub level to maximise utilization of both the individual EV charger feeder cables and the EV charger hub feeder cable, without exceeding their thermal operating limits.

Figure 4 shows a flow diagram of a method 400 for adjusting the cooling rate of an EV charger feeder cable cooling system according to an embodiment of the disclosure. Steps 410 to 440 correspond with steps 310 to 340 described in relation to method 300. At step 450, the cooling rate of an EV charger feeder cable cooling system is adjusted based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating. In some embodiments, where the initial load current is greater than the cyclic load rating, the cooling rate of the cooling system may be increased. Accordingly, where the initial load current is less than the cyclic load rating, the cooling rate of the cooling system may be reduced. Therefore, based on the determined cyclic load rating of the EV charger feeder cable, the cooling rate of the EV charger feeder cable cooling system is optimised while maintaining operation of the feeder cable within its thermal limits.

In some embodiments, method 400 may further comprise a step 460, wherein the charging rate of the EV charger is adjusted based on the cooling capacity of the EV charger feeder cable cooling system and a comparison between an initial load current through the feeder cable of the EV charger and the determined cyclic load rating. For example, where the initial load current is greater than the cyclic load rating but the cooling capacity of the cooling system is already at its maximum (e.g., cooling fans operating at full power), the charging rate of the EV charger may be reduced by a greater degree. Whereas if the initial load current is greater than the cyclic load rating but the cooling capacity of the cooling system is only at 50% (e.g., cooling fans at half power), the charging rate of the EV charging may be reduced by a less degree (if at all). Therefore, by adjusting an EV charger charging rate based on the cooling capacity of the cooling system in addition to the determined cyclic load rating, imbalances between the initial load current and the cyclic load rating may be managed using the cooling system as a buffer to mitigate the need for, or extent of charging rate reductions in an EV charging system during high load periods.

Instructions for a processor to perform any of the above described methods may be stored on a non-transitory computer-readable storage medium. The non-transitory computer-readable medium may be, for example, a CD-ROM, a DVD-ROM, a hard disk drive or solid state memory, such as a USB memory stick.

Embodiments of the present invention have been described. It will be appreciated that variations and modifications may be made to the described embodiments within the scope of the present invention.

Claims

24 CLAIMS 1. A processor for adjusting a charging rate of an Electric Vehicle (EV) charger, wherein the processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder cable; determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the charging rate of the EV charger based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.
2. A processor according to claim 1, wherein the EV charger feeder cable is an EV charger hub feeder cable supplying a plurality of EV chargers, wherein the processor is further configured to: receive load current data indicative of a load current through each of the plurality of EV chargers; and adjust a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the feeder cable.
3. A processor according to any preceding claim, wherein load current data is received from the EV charger.
4. A processor according to any preceding claim, wherein the received load current data comprises historical load currents through the EV charger feeder cable.
5. A processor according to any preceding claim, wherein the processor is configured to: reduce the charging rate where the load current through the EV charger feeder cable exceeds the cyclic load rating; and/or increase the charging rate where the load current through the EV charger feeder cable is less than the cyclic load rating.
6. A processor according to any preceding claim, wherein the temperature data is indicative of the temperature at a single position on the EV charger feeder cable.
7. A processor according to any preceding claim, wherein the temperature data comprises temperature measurement data of an exterior surface of the EV charger feeder cable, and wherein the processor is configured to: determine a conductor temperature of the EV charger feeder cable based on deconvolution of the temperature data; and determine the cyclic load rating for the EV charger feeder cable based on the conductor temperature.
8. A processor according to any preceding claim, wherein the processor is further configured to adjust the cooling rate of an EV charger feeder cable cooling system based on a comparison between the charging rate of the EV charger and the determined cyclic load rating.
9. A processor according to any preceding claim, wherein the processor is further configured to adjust the charging rate of the EV charger based on a cooling capacity of the EV charger feeder cable cooling system.
10. A device for adjusting a charging rate of an EV charger, the device comprising a processor according to any preceding claim.
11. A device according to claim 10, further comprising: a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable.
12. A device according to any of claims 10 to 11, further comprising: a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable.
13. A system for charging electric vehicles (EVs), the system comprising: an EV charger; an EV charger feeder cable coupling the EV charger to a power network; and a device according to any of claims 10 to 12.
14. A system according to claim 13, further comprising an EV charger hub supplying a plurality of EV chargers via a respective plurality of EV charger feeder cables, wherein the EV charger hub is coupled to the power network via an EV charger hub feeder cable.
15. A system according to any of claims 13 to 14, further comprising an EV charger feeder cable cooling system operably coupled to the EV charger feeder cable.
16. A method for adjusting a charging rate of an Electric Vehicle (EV) charger, the method comprising: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the charging rate of the EV charger based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.
17. A method according to claim 16, wherein the EV charger feeder cable is an EV charger hub feeder cable supplying a plurality of EV chargers, the method further comprising: receiving load current data indicative of a load current through each of the plurality of EV chargers; and adjusting a charging rate of each the plurality of EV chargers based on a comparison between a total charging rate of the plurality of EV chargers and the determined cyclic load rating of the EV charger feeder cable.
18. A computer program for causing a processor to carry out the method according to claim 17.
19. A processor for adjusting a cooling rate of an Electric Vehicle (EV) charger feeder cable cooling system, wherein the processor is configured to: receive temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receive load current data indicative of a load current through the EV charger feeder cable; determine a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjust the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.
20. A device for adjusting a cooling rate of an EV charger feeder cable cooling system, the device comprising a processor according to claim 19.
21. A device according to claim 20, further comprising: a temperature sensor communicatively coupled to the processor for measuring temperature data indicative of a temperature of an EV charger feeder cable; and/or a current measurement device communicatively coupled to the processor for collecting data indicative of a load current through an EV charger feeder cable.
22. A device according to any of claims 20 to 21, further comprising an EV feeder cable cooling system.
23. A system for cooling an EV charger feeder cable, the system comprising: an EV charger; a feeder cable coupling the EV charger to a power network; and a device according to any of claims 20 to 22.
24. A method for adjusting a cooling rate of an Electric Vehicle (EV) charger feeder cable cooling system, the method comprising: receiving temperature data measured by a temperature sensor, the temperature data being indicative of a temperature of an EV charger feeder cable; receiving load current data indicative of a load current through the EV charger feeder cable; determining a cyclic load rating for the EV charger feeder cable based on the received temperature data and load current data; and adjusting the cooling rate of the EV charger feeder cable cooling system based on a comparison between a load current through the EV charger feeder cable and the determined cyclic load rating.
25. A computer program for causing a processor to carry out a method according to claim 24.