Generator control system to accommodate a decrease in a power grid voltage

• US 6,498,462 B2
• Filed: 02/05/2001
• Issued: 12/24/2002
• Est. Priority Date: 02/05/2001
• Status: Expired due to Term

• Current Assignee: Plug Power Inc.
• Original Assignee: Plug Power Inc.
• Inventors: Torpey, Mark R., Ballantine, Arne W.
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US09/777,156
• Publication Number:
  US 20020105306A1
• Time in Patent Office: 687 Days
• Field of Search: 322/20, 322/7, 322/8, 322/29, 290/1.R, 290/40.B, 307/85, 307/86, 307/87
• US Class Current: 322/8
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network

Abstract

A system includes a generator and a circuit. The generator is coupled to provide power to a power grid. The circuit is coupled to the generator and is adapted to use a scheme to detect a shut down of the power grid and prevent the generator from providing power to the power grid in response to the detection of the shut down of the power grid. The circuit is also adapted to receive an indication to modify the scheme and modify the scheme based on the indication.

Claims

1. A method comprising:

coupling a generator to a power grid to provide power to the power grid;

using a scheme to detect a shut down of the power grid;

preventing the generator from providing power to the power grid in response to the detection of the shut down of the power grid;

receiving an indication to modify the scheme; and

modifying the scheme based on the indication.

2. The method of claim 1, wherein the using the scheme comprises:

comparing a voltage of the power grid to a predefined threshold; and

indicating detection of the shut down of the power grid based on the determination.

3. The method of claim 2, wherein the indicating the detection comprises:

indicating the detection of the shut down if the voltage is below the predefined threshold.

4. The method of claim 2, wherein the modifying the scheme comprises:

changing the threshold based on the indication.

5. The method of claim 4, wherein the changing comprises:

lowering the threshold based on the indication.

6. The method of claim 4, wherein the changing comprises:

raising the threshold based on the indication.

7. The method of claim 1, further comprising:

communicating the request to the power grid in response to an impending decrease in a voltage of the power grid.

8. The method of claim 1, wherein the generator comprises a fuel cell system.

9. The method of claim 8, wherein the preventing comprises:

isolating a fuel cell stack from the power grid.

10. The method of claim 8, wherein the preventing comprises:

shutting off a fuel flow to a fuel cell stack.

11. The method of claim 1, wherein the indication is received from the power grid.

12. The method of claim 1, wherein the indication is received from one of a telephone line and a wireless link.

13. A system comprising:

a generator coupled to provide power to a power grid; and

a circuit coupled to the generator and adapted to;

use a scheme to detect a shut down of the power grid,

prevent the generator from providing power to the power grid in response to the detection of the shut down of the power grid,

receive an indication to modify the scheme, and

modify the scheme based on the indication.

14. The system of claim 13, wherein the circuit is adapted to:

compare a voltage of the power grid to a predefined threshold; and

indicate detection of the shut down of the power grid based on the determination.

15. The system of claim 14, wherein the circuit is adapted to:

indicate detection of the shut down if the voltage is below the predefined threshold.

16. The system of claim 14, wherein the circuit is adapted to change the threshold based on the indication.

17. The system of claim 16, wherein the circuit is adapted to lower the threshold based on the indication.

18. The system of claim 16, wherein the circuit is adapted to raise the threshold based on the indication.

19. The system of claim 13, wherein the request is communicated to the power grid in response to an impending decrease in a voltage of the power grid.

20. The system of claim 13, wherein the generator comprises a fuel cell stack to produce the power provided to the power grid.

21. The system of claim 20, further comprising:

a switch to isolate the fuel cell stack from the power grid in response to the shut down of the power grid.

22. The system of claim 20, further comprising:

a fuel processor to provide a fuel flow to the fuel cell stack.

23. The system of claim 13, wherein the circuit shuts off the fuel flow in response to the shut down of the power grid.

24. The system of claim 13, wherein the indication is received from the power grid.

25. The system of claim 13, wherein the indication is received from one of a telephone line and a wireless link.