Systems and methods for providing arc fault and/or ground fault protection for distributed generation sources

• US 8,717,720 B2
• Filed: 07/19/2011
• Issued: 05/06/2014
• Est. Priority Date: 07/20/2010
• Status: Active Grant

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: DeBoer, John
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Comber, Kevin J
• Application Number:
  US13/185,549
• Publication Number:
  US 20120019966A1
• Time in Patent Office: 1,022 Days
• Field of Search: 361/42
• US Class Current: 361/42
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 3/162 for ac systems
• CPC Class Codes: H02H 7/20 for electronic equipment for converters H02H7/10; for electric measuring instruments G01R1/36; for dc voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08

Abstract

A system is provided including: (1) an arc fault circuit interrupter having a line side terminal and a load side terminal, wherein the line side terminal is coupled to a voltage source, and (2) a current source coupled to the load side terminal to backfeed the arc fault circuit interrupter. Numerous other aspects also are provided.

Claims

1. A system comprising:

an arc fault circuit interrupter (“

AFCI”

) comprising a line side terminal, a load side terminal, and an actuator coupled to the line side terminal and the load side terminal, wherein the line side terminal is coupled to a voltage source; and

a current source coupled to the load side terminal to backfeed the AFCI, the current source comprising circuitry for disconnecting the current source from the AFCI in response to a voltage source voltage dropping below a predetermined value, the current source having a disconnect time;

wherein;

the actuator is adapted to operate at full load during the disconnect time in response to the actuator causing the line side terminal to be disconnected from the load side terminal.

2. The system of claim 1, wherein the AFCI comprises:

a switch coupled between the line side terminal and the load side terminal and coupled to the actuator; and

an arc fault detector circuit coupled to the actuator,

wherein;

if the arc fault detector circuit detects an arc fault on the load side terminal, the arc fault detector circuit causes the actuator to open the switch to disconnect the line side terminal from the load side terminal.

3. The system of claim 1, wherein the AFCI comprises a single-pole AFCI.

4. The system of claim 1, wherein the AFCI comprises a two-pole AFCI.

5. The system of claim 1, wherein the voltage source comprises an electric utility voltage source.

6. The system of claim 1, wherein the actuator is adapted to operate at full load for 250 to 1500 milliseconds during the disconnect time.

7. The system of claim 1, wherein the line side terminal comprises a line terminal, a neutral terminal and a ground terminal.

8. The system of claim 1, wherein the line side terminal comprises a first line terminal, a second line terminal, a neutral terminal and a ground terminal.

9. The system of claim 1, wherein the current source comprises one or more of a photovoltaic system, a wind turbine system, a hydroelectric system, and a current source generator.

10. The system of claim 1, wherein the current source comprises a photovoltaic system that includes a string inverter.

11. The system of claim 1, wherein the current source comprises a photovoltaic system that includes a plurality of micro-inverters.

12. The system of claim 1, wherein the current source comprises circuitry for phase synchronizing the current source to the electric utility voltage source.

13. A method comprising:

providing an arc fault circuit interrupter (“

AFCI”

) comprising a line side terminal, a load side terminal, and an actuator coupled to the line side terminal and the load side terminal, wherein the line side terminal is coupled to a voltage source; and

coupling a current source to the load side terminal to backfeed the AFCI, the current source comprising circuitry for disconnecting the current source from the AFCI in response to a voltage source voltage dropping below a predetermined value, the current source having a disconnect time;

wherein;

the actuator is adapted to operate at full load during the disconnect time in response to the actuator causing the line side terminal to be disconnected from the load side terminal.

14. The method of claim 13, wherein the AFCI comprises:

a switch coupled between the line side terminal and the load side terminal and coupled to the actuator; and

an arc fault detector circuit coupled to the actuator,

wherein;

if the arc fault detector circuit detects an arc fault on the load side terminal, the arc fault detector circuit causes the actuator to open the switch to disconnect the line side terminal from the load side terminal.

15. The method of claim 13, wherein the AFCI comprises a single-pole AFCI.

16. The method of claim 13, wherein the AFCI comprises a two-pole AFCI.

17. The method of claim 13, wherein the voltage source comprises an electric utility voltage source.

18. The method of claim 13, wherein the actuator is adapted to operate at full load for 250 to 1500 milliseconds during the disconnect time.

19. The method of claim 13, wherein the line side terminal comprises a line terminal, a neutral terminal and a ground terminal.

20. The method of claim 13, wherein the line side terminal comprises a first line terminal, a second line terminal, a neutral terminal and a ground terminal.

21. The method of claim 13, wherein the current source comprises one or more of a photovoltaic system, a wind turbine system, a hydroelectric system, and a current source generator.

22. The method of claim 13, wherein the current source comprises a photovoltaic system that includes a string inverter.

23. The method of claim 13, wherein the current source comprises a photovoltaic system that includes a plurality of micro-inverters.

24. The method of claim 13, wherein the current source comprises circuitry for phase synchronizing the current source to the electric utility voltage source.

25. A photovoltaic system comprising:

an arc fault circuit interrupter (“

AFCI”

) comprising a line side terminal, a load side terminal, and an actuator coupled to the line side terminal and the load side terminal, wherein the line side terminal is coupled to a voltage source; and

an inverter coupled to the load side terminal to backfeed the AFCI, the inverter comprising circuitry for disconnecting the inverter from the AFCI in response to a voltage source voltage dropping below a predetermined value, the inverter having a disconnect time;

wherein;

the actuator is adapted to operate at full load during the disconnect time in response to the actuator causing the line side terminal to be disconnected from the load side terminal.

26. The system of claim 25, wherein the AFCI comprises:

a switch coupled between the line side terminal and the load side terminal and coupled to the actuator; and

an arc fault detector circuit coupled to the actuator,

wherein;

if the arc fault detector circuit detects an arc fault on the load side terminal, the arc fault detector circuit causes the actuator to open the switch to disconnect the line side terminal from the load side terminal.

27. The system of claim 25, wherein the AFCI comprises a single-pole AFCI.

28. The system of claim 25, wherein the AFCI comprises a two-pole AFCI.

29. The system of claim 25, wherein the voltage source comprises an electric utility voltage source.

30. The system of claim 25, wherein the actuator is adapted to operate at full load for 250 to 1500 milliseconds during the disconnect time.

31. The system of claim 25, wherein the line side terminal comprises a line terminal, a neutral terminal and a ground terminal.

32. The system of claim 25, wherein the line side terminal comprises a first line terminal, a second line terminal, a neutral terminal and a ground terminal.

33. The system of claim 25, wherein the inverter comprises a string inverter.

34. The system of claim 25, wherein the inverter comprises a plurality of micro-inverters.

35. The system of claim 25, wherein the inverter comprises circuitry for phase synchronizing an output of the inverter to the electric utility voltage source.