Random Restart Apparatus and Method for Electric Vehicle Service Equipment

• US 20140159658A1
• Filed: 05/24/2013
• Published: 06/12/2014
• Est. Priority Date: 11/24/2010
• Status: Abandoned Application

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Kiceniuk, Taras Jr., Flack, Albert Joseph, Bai, Ming
• Application Number:
  US13/902,557
• Publication Number:
  US 20140159658A1
• Time in Patent Office: Days
• US Class Current: 320/109
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• 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 90/14 Plug-in electric vehicles

Abstract

An electric vehicle (EV) charger restart method includes determining a respective restart delay time (T_del) for each of one or more electric vehicle chargers, each respective restart delay time (T_del) comprising a respective delay time increment based on a generated random number and a group time interval for reset (T_int) (block 212), and initiating a restart of at least one of the one or more electric vehicle chargers, if an existing time (T_now) is greater than an established time line start time (T_POK) plus T_del.

Claims

1. An electric vehicle (EV) charger restart method, comprising:

determining a respective restart delay time (T_del) for each of one or more electric vehicle chargers, each respective restart delay time (T_del) comprising a respective delay time increment based on a generated random number and a group time interval for reset (T_int); and

initiating a restart of at least one of the one or more electric vehicle chargers, if an existing time (T_now) is greater than an established time line start time (T_POK) plus T_del.

2. The method according to claim 1, further comprising:

determining a difference between a measured source voltage and a normal source voltage at at least one of the one or more electric vehicle chargers; and

if the determined difference between the measured source voltage and the normal source voltage is within a threshold, then setting the established time line start time (T_POK) for the at least one electric vehicle charger.

3. The method according to claim 2, wherein the respective restart delay time (T_del) further comprises a predetermined time grid stabilization delay (T_int2).

4. The method according to claim 2, wherein if the determined difference between the measured source voltage and the normal source voltage is not within a threshold, then performing the determining a difference between a measured source voltage and a normal source voltage step again after a predetermined delay (DT1).

5. The method according to claim 1, wherein the respective restart delay time (T_del) further comprises a predetermined time grid stabilization delay (T_int2).

6. The method according to claim 5, wherein T_int2 is between 20-60 seconds.

7. The method according to claim 6, wherein T_del is between 25-60 seconds.

8. The method according to claim 1, wherein the group time interval for reset (T_int) is between five and 20 seconds.

9. The method according to claim 1, wherein the generated random number is between zero and one.

10. The method according to claim 9, wherein the generated random number function further comprises an exponent (m) greater than 1.

11. The method according to claim 1, further comprising:

monitoring a difference between at least one PMU feedback signal indicative of a power grid phasor value and a reference phasor value; and

if the difference between the power grid phasor value and reference phasor value is within a threshold (f), then setting the established time line start time (T_POK) for the at least one electric vehicle charger.

12. The method according to claim 1, further comprising:

receiving a power grid health signal from a power grid control processing unit in the at least one electric vehicle charger;

setting the established time line start time (T_POK) for the at least one electric vehicle charger in response to receipt of the power grid health signal.

13. The method according to claim 12, wherein the respective restart delay time (T_del) further comprises a predetermined time grid stabilization delay (T_int2).

14. The method according to claim 13, wherein T_int2 is between 20-60 seconds.

15. The method according to claim 14, wherein T_del is between 25-60 seconds.

16. The method according to claim 15, wherein the generated random number is between zero and one.

17. The method according to claim 16, wherein the generated random number further employs a function with an exponent (m) greater than 1.

18. The method according to claim 12, wherein the power grid health signal represents a comparison of at least one phasor measurement unit (PMU) phasor measurement to a reference phasor measurement.

19. The method of claim 1, further comprising:

providing a pulse width modulated EVSE pilot signal to an electric vehicle, the pulse width modulated EVSE pilot signal over-riding an on-board charger current loading ramp function to extend the electric vehicle'"'"'s power ramp time.

20. A device comprising a processing module for restarting one or more electric vehicle chargers, wherein the processing module comprises a processor having addressable memory, and wherein the processor is configured to:

determine if grid power quality is acceptable;

set an established time line start time (T_POK) for the at least one electric vehicle charger in response to determining grid power quality is acceptable;

determine a respective restart delay time (T_del) for each of one or more electric vehicle chargers, the respective restart delay time (T_del) comprising a delay time increment based on a respective generated random number function and a group time interval for reset (T_int); and

initiate a restart of at least one of the one or more electric vehicle chargers, if a current time (T_now) is greater than T_del plus T_POK.

21. The device according to claim 20, wherein the respective restart delay time (T_del) further comprises a predetermined time grid stabilization delay (T_int2).

22. The device according to claim 20, wherein the generated random number function further comprises an exponent (m) greater than 1.

23. A method, comprising:

receiving in an electric vehicle (EV) charger a PMU power quality signal;

determining a difference between the PMU power quality signal and a reference PMU power quality signal;

if the determined difference between the PMU power quality signal and a reference PMU power quality signal is within a threshold, then setting an established time line start time (T_POK) for the at least one electric vehicle charger;

determining a respective restart delay time (T_del) for the EV charger, the restart delay time (T_del) comprising a respective delay time increment based on a generated random number and a group time interval for reset (T); and

initiating a restart of the EV charger if an existing time (T_now) is greater than T_POK plus T_del

24. The method of claim 23, wherein the PMU power quality signal is indicative of a measured power grid phasor.

25. The method of claim 24, wherein the restart delay time (T_del) further comprises a predetermined time grid stabilization delay (T_int2).

26. The method of claim 25, wherein T_int2 is between 20-60 seconds.

27. The method according to claim 26, wherein T_del is between 25-60 seconds.

28. The method according to claim 23, wherein the generated random number is produced by a function comprising an exponent (m) greater than 1.