Power limiter system

• US 8,509,958 B2
• Filed: 09/22/2011
• Issued: 08/13/2013
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (General Electric Company)
• Original Assignee: General Electric Company
• Inventors: Larsen, Einar Vaughn, Klodowski, Anthony Michael, Barker, Sidney Allen
• Primary Examiner(s): Padmanabhan, Kavita
• Assistant Examiner(s): GARLAND, STEVEN R
• Application Number:
  US13/239,647
• Publication Number:
  US 20120010759A1
• Time in Patent Office: 691 Days
• Field of Search: 700/287, 700292-294, 361/20, 290/44
• US Class Current: 700/294
• CPC Class Codes: F03D 7/0284 in relation to the state of the electric grid
• CPC Class Codes: F05B 2270/10711 applying a low voltage ride through method
• CPC Class Codes: F05B 2270/335 Output power or torque
• CPC Class Codes: F05B 2270/337 Electrical grid status parameters, e.g. voltage, frequency or power demand
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/44 with means for ensuring correct phase sequence
• CPC Class Codes: H02J 3/48 Controlling the sharing of the in-phase component
• CPC Class Codes: H02J 3/50 Controlling the sharing of the out-of-phase component
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A power limiter system is described. The power limiter system is configured to receive a phase locked loop (PLL) error signal; analyze the PLL error signal to identify an occurrence of a grid contingency event; generate a first power command signal corresponding to an occurrence of the grid contingency event; and, transmit the first command signal to a converter interface controller. The system further includes a memory configured to store at least one variable that corresponds to the PLL error signal upon identification of an occurrence of the grid contingency event.

Claims

1. A grid-dependent power limiter system comprising:

a power limiter configured to;

receive a phase locked loop (PLL) error signal;

analyze the PLL error signal to identify an occurrence of a grid contingency event;

generate a first power command signal corresponding to an occurrence of the grid contingency event; and

,

transmit the first command signal to a converter interface controller;

a voltage regulator configured to;

receive a terminal grid voltage feedback signal;

generate a second power command signal based at least partially on the terminal grid voltage feedback signal; and

,

transmit the second power command signal to the converter interface controller; and

,

a memory configured to store at least one variable that corresponds to the PLL error signal upon identification of an occurrence of the grid contingency event.

2. A system in accordance with claim 1, wherein the power limiter is further configured to:

receive the terminal grid voltage feedback signal; and

,

analyze the terminal grid voltage feedback signal to identify the occurrence of the grid contingency event.

3. A system in accordance with claim 2, wherein the power limiter is configured to generate the first power command signal that corresponds to the grid contingency event when the terminal grid voltage feedback signal indicates that a terminal grid voltage is below a predefined level.

4. A system in accordance with claim 1, wherein the power limiter is configured to generate the first power command signal that corresponds to the grid contingency event when the PLL error signal is above a predefined level.

5. A system in accordance with claim 1, further comprising a power regulator coupled to the power limiter, the power regulator configured to:

receive the first power command signal and the terminal grid voltage feedback signal;

generate a third power command signal based at least partially on the first power command signal and the terminal grid voltage feedback signal; and

,

transmit the third power command signal to the converter interface controller.

6. A system in accordance with claim 5, wherein the third power command signal directs the converter interface controller to rapidly reduce a real current output by a corresponding power converter after identification of the grid contingency event.

7. A system in accordance with claim 6, wherein the third power command signal directs the converter interface controller to slowly increase the real current output by the corresponding power converter after a recovery from the grid contingency event.

8. A system in accordance with claim 1, wherein the second power command signal comprises a reactive current command signal.

9. A system in accordance with claim 8, wherein the reactive current command signal directs the converter interface controller to increase a reactive component of current output by a corresponding power converter after identification of the grid contingency event.

10. A system in accordance with claim 1, wherein the power limiter is further configured to receive a reference power control signal and to identify an occurrence of the grid contingency event by comparing at least one of the PLL error signal and the terminal grid voltage feedback signal to the reference power control signal.

11. A system in accordance with claim 1, wherein the power limiter system is included within a wind farm, the wind farm comprising a plurality of wind turbines.

12. A system in accordance with claim 11, further comprising a higher-level control coupled to the power limiter and configured to:

receive a wind farm input signal corresponding to a voltage measurement at a point of common coupling for the plurality of wind turbines;

generate a curtailment signal based at least partially on the wind farm input signal; and

,

transmit the curtailment signal to the power limiter.

13. A system in accordance with claim 12, wherein the power limiter is further configured to generate the first power command signal that curtails an output power of a wind turbine associated with the power limiter in response to receipt of the curtailment signal.

14. A system in accordance with claim 12, wherein the higher-level control is configured to monitor the voltage at the point of common coupling for the plurality of wind turbines and to generate the curtailment signal when the voltage has remained below a predefined level for more than a predefined period of time.

15. A power limiter system for reducing pole-slipping within an electric generator coupled to a power grid, said system comprising:

a power limiter configured to;

receive a phase locked loop (PLL) error signal;

analyze the PLL error signal to identify an occurrence of a grid contingency event; and

,

generate a first power command signal corresponding to the occurrence of the grid contingency event;

a power regulator coupled to said power limiter, said power regulator configured to;

receive the first power command signal;

generate a second power command signal based at least partially on the first power command signal; and

,

transmit the second power command signal to a converter interface controller; and

,

a memory configured to store at least one variable that corresponds to identification of the occurrence of the grid contingency event.

16. A system in accordance with claim 15, wherein said power limiter is configured to generate the first power command signal that corresponds to the grid contingency event when the PLL error signal is above a predefined level.

17. A system in accordance with claim 15, wherein said power limiter is further configured to receive a reference power control signal and to identify the occurrence of the grid contingency event by comparing the PLL error signal to the reference power control signal.

18. A system in accordance with claim 15, wherein the second power command signal directs the converter interface controller to rapidly reduce a real current output by a corresponding power converter after identification of the grid contingency event.

19. A system in accordance with claim 15, wherein the third power command signal directs the converter interface controller to slowly increase the real current output by the corresponding power converter after a recovery from the grid contingency event.