Devices and methods for testing the energy measurement accuracy, billing accuracy, functional performance and safety of electric vehicle charging stations

• US 9,020,771 B1
• Filed: 09/18/2014
• Issued: 04/28/2015
• Est. Priority Date: 05/27/2014
• Status: Active Grant

• Current Assignee: Power Measurements, LLC (Power Measurements, Inc.)
• Original Assignee: Power Measurements, LLC (Power Measurements, Inc.)
• Inventors: Hardy, William H.
• Primary Examiner(s): Huynh, Phuong
• Application Number:
  US14/489,724
• Time in Patent Office: 222 Days
• Field of Search: 702 61- 65
• US Class Current: 702/61
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2240/70 Interactions with external data bases, e.g. traffic centres
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 53/16 Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/18 Cables specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/63 in response to network capacity
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: G01R 21/1331 Measuring real or reactive component, measuring apparent energy
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

Testing of electric vehicle charging stations (EVCS) is performed using a device operable in either or both an active mode and a passive mode. In an active mode, the device provides or is connected with a programmable load capable of emulating the load of an electrical vehicle (EV). In passive mode, the load is an EV with the device being arranged in series between the EVCS and EV. In either case, energy delivery from the EVCS to the load is monitored by the device to determine energy measurement and billing accuracy of the EVCS. This enables a comparison to be made between a measured value of energy delivered and a metered value of energy delivered as given by the EVCS. Other measurements and safety tests may also be performed by the device.

Claims

1. An instrument for accurately verifying the active energy delivered by an electric vehicle charging station (EVCS), comprising:

a primary port for receiving a charging cable normally connecting the EVCS to an electric vehicle;

one or more measuring devices which simultaneously make sampling measurements of voltage and current from one or more supply lines delivering power from the EVCS to a load after the charging cable has been received at the primary port;

digital processing means configured to calculate a first value of active energy delivered by the EVCS to the load from the sampling measurements obtained from the one or more measuring devices; and

at least one output device for displaying or transmitting the first value of active energy delivered or one or more values determined from the first value of active energy delivered for comparison with a metered value of active energy delivered as given by the EVCS.

2. The instrument of claim 1, wherein the one or more measuring devices make a first sampling measurement at or before a start of power transfer through the primary port and a final sampling measurement at or after an end of power transfer through the primary port, the first value of active energy delivered being calculated from a continuous stream of sampling measurements made over an entire time period from the first sampling measurement to the final sampling measurement.

3. The instrument of claim 1, wherein the digital processing means is further configured to make the comparison of the first value of active energy delivered and the metered value of active energy delivered.

4. The instrument of claim 3, wherein the at least one output device displays or transmits a result of the comparison as one of the one or more values determined from the first value of active energy delivered.

5. The instrument of claim 3, wherein the result of the comparison is an indication of whether or not a difference between the first value of active energy delivered and the metered value of active energy delivered exceeds a predetermined threshold.

6. The instrument of claim 3, wherein the result of the comparison indicates a magnitude by which the first value of active energy delivered and the metered value of active energy differ from one another.

7. The instrument of claim 1, further comprising an energy pulse pickup connectable to the EVCS to receive pulses indicating delivery of one or more fixed quantities of active energy as given by the EVCS.

8. The instrument of claim 7, wherein the digital processing means is further configured to calculate a second value of active energy delivered over a predetermined number of pulses, the second value of active energy delivered being usable to verify EVCS metering accuracy.

9. The instrument of claim 8, wherein the digital processing means is capable of calculating both the first value of active energy delivered and the second value of active energy delivered during a single operational test sequence.

10. The instrument of claim 8, wherein the second value of active energy delivered is usable to verify EVCS metering accuracy independent of the first value of active energy delivered.

11. The instrument of claim 1, wherein the instrument comprises the load to which power from the EVCS is delivered.

12. The instrument of claim 1, further comprising a secondary port for connecting to an electric vehicle or a standalone programmable load capable of emulating an electric vehicle load, the electric vehicle or standalone programmable load serving as the load to which power from the EVCS is delivered.

13. The instrument of claim 1, further comprising a facility for testing operation of a ground fault protection of the EVCS.

14. The instrument of claim 1, wherein the one or more output devices includes one or more interfaces for communicating any or all of its test results and setup information to a laptop, tablet computer, smart phone, external memory device, or other device.

15. The instrument of claim 1, further comprising communication means which allow the instrument to communicate with the EVCS to determine the performance capability of the EVCS and synchronize operation of the EVCS if the EVCS is capable of providing performance information.

16. The instrument of claim 1, wherein the primary port allows a plurality of different types of EVCS connectors with different protocols to be accommodated through interchangeable connector modules.

17. The instrument of claim 1, wherein the one or more measuring devices are configured to measure both energy delivered by the EVCS to the load and energy delivered to the EVCS from an external source.

18. The instrument of claim 1, wherein the digital processing means is further configured to calculate a value of apparent energy.

19. The instrument of claim 1, wherein the digital processing means is further configured to calculate a value of reactive energy.

20. The instrument of claim 1, wherein the data processing means contains a memory in which the instrument stores site and test information for later upload.

21. The instrument of claim 1, further comprising a GPS subsystem usable to identify a test site and access site specific information stored in memory.

22. A method for accurately verifying the active energy delivered by an electric vehicle charging station (EVCS), comprising steps of:

receiving at a primary port a charging cable normally connecting the EVCS to an electric vehicle;

making sampling measurements of voltage and current simultaneously from one or more supply lines delivering power from the EVCS to a load after the charging cable has been received at the primary port;

calculating a first value of active energy delivered by the EVCS to the load from the sampling measurements with a digital processing means; and

displaying or transmitting the first value of active energy delivered or one or more values determined from the first value of active energy delivered with at least one output device for comparison with a metered value of active energy delivered as given by the EVCS.

23. The method of claim 22, wherein the step of making sampling measurements includes making a first sampling measurement at or before a start of power transfer through the primary port and a final sampling measurement at or after an end of power transfer through the primary port, the first value of active energy delivered being calculated in the calculating step from a continuous stream of sampling measurements made over an entire time period from the first sampling measurement to the final sampling measurement.

24. The method of claim 22, further comprising a step of comparing the first value of active energy delivered with the metered value of active energy delivered.

25. The method of claim 24, wherein said step of displaying or transmitting includes displaying or transmitting a result of the comparison as one of the one or more values determined from the first value of active energy delivered.

26. The method of claim 24, wherein the result of the comparison is an indication of whether or not a difference between the first value of active energy delivered and the metered value of active energy delivered exceeds a predetermined threshold.

27. The method of claim 24, wherein the result of the comparison indicates a magnitude by which the first value of active energy delivered and the metered value of active energy differ from one another.

28. The method of claim 22, further comprising a step of calculating a second value of active energy delivered over a predetermined number of pulses received from the ECVS with an energy pulse pickup, the second value of active energy delivered being usable to verify EVCS metering accuracy.

29. The method of claim 28, wherein the second value of active energy delivered is usable to verify EVCS metering accuracy independent of the first value of active energy delivered.