POWER SYSTEM STABILIZER AND METHOD

• US 20090001940A1
• Filed: 06/29/2007
• Published: 01/01/2009
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Sihler, Christof Martin, Schramm, Simon Herbert, Achilles, Alfredo Sebastian
• Granted Patent: US 8,004,252 B2
• Time in Patent Office: Days
• US Class Current: 322/58
• CPC Class Codes: H02J 3/24 Arrangements for preventing or reducing oscillations of power in networks by control effected upon a single generator H02P9/00

Abstract

A power system stabilizer includes: a sensor configured for sensing a signal representative of electromechanical oscillations of the power system; a controller configured for using the sensed signal for generating control signals for damping the electromechanical oscillations; and a damper including a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electromechanical oscillations.

Claims

1. A power system stabilizer, the stabilizer comprising:

a sensor configured for sensing a signal representative of electro-mechanical oscillations of the power system;

a controller configured for using the sensed signal for generating control signals for damping the electromechanical oscillations; and

a damper comprising a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electromechanical oscillations.

2. The stabilizer of claim 1 wherein the controller is configured for, during normal operation, generating control signals for damping the electromechanical oscillations, and, during transient operation, generating control signals for providing electromechanical braking through the damper.

3. The stabilizer of claim 2 wherein, during normal operation, the damper is configured to provide a level of modulation of less than or equal to 10 Hz.

4. The stabilizer of claim 2 wherein the resistor includes an inductance.

5. The stabilizer of claim 1 wherein the damping converter comprises a diode rectifier coupled in parallel to a capacitor which in turn is coupled to an IGBT module.

6. The stabilizer of claim 5 wherein the IGBT module comprises three pairs of IGBTs with each pair of IGBTs being coupled in parallel to the other pairs.

7. The stabilizer of claim 6 wherein the resistor comprises three resistors, and wherein each resistor is coupled across one IGBT of a respective pair of IGBTs.

8. The stabilizer of claim 5 wherein the damping converter comprises at least two IGBT modules.

9. The stabilizer of claim 8 wherein the stabilizer is further configured for providing voltage ride-through capability.

10. The stabilizer of claim 9 wherein the controller is configured for selectively switching IGBTs of the at least two IGBT modules simultaneously or sequentially.

11. The stabilizer of claim 10 wherein at least some of the at least two IGBT modules are coupled in parallel.

12. The stabilizer of claim 8 wherein each module has a power rating of no more than two MVA.

13. The stabilizer of claim 1 wherein the damping converter comprises an alternating current to direct current thyristor rectifier.

14. The stabilizer of claim 13 wherein the damper comprises at least two damping converters with each damping converter being coupled to a respective resistor.

15. The stabilizer of claim 13 further comprising a transformer configured for coupling the damping converters the power bus, wherein at least one of the damping converters is coupled to the transformer in a wye configuration and wherein at least one other of the damping converters is coupled to the transformers in a delta configuration.

16. The stabilizer of claim 1, wherein the damper is embodied within an island or island-like power system.

17. A power system comprising

a power system stabilizer, the stabilizer comprising:

a sensor configured for sensing a signal representative of electro-mechanical oscillations of the power system;

a controller configured for using the sensed signal for generating control signals for damping the electromechanical oscillations; and

a damper comprising a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electromechanical oscillations.

18. The power system of claim 17, wherein the power system comprises a power system configured for providing power to an assembly for obtaining oil, gas, or combinations thereof.

19. The power system of claim 17, wherein the power system comprises a wind turbine.

20. The power system of claim 17 wherein the damper comprises a plurality of dampers at different locations within the power system.

21. The power system of claim 17 wherein,

the sensor comprises a plurality of sensors configured for sensing signals at different locations within the power system,

the controller comprises one or more controllers configured for using the sensed signals for generating control signals for damping the electromechanical oscillations, and

the damper comprises a plurality of dampers at the different locations.

22. A method of stabilizing an island or island-like power system comprising:

sensing a signal representative of electromechanical oscillations of the power system;

using the sensed signal for generating control signals for damping the electromechanical oscillations; and

providing the control signals to a damper comprising a damping converter and a resistor coupled to the damping converter, wherein the damping converter is coupled to the power system through a power bus.

23. The method of claim 22 further comprising, during transient operation, generating control signals for providing electromechanical braking.

24. The method of claim 22 wherein the damping converter comprises a diode rectifier coupled in parallel to a capacitor which in turn is coupled to at least two IGBT modules, and where using the sensed signal for generating control signals comprises generating control signals for selectively switching IGBTs of the at least two IGBT modules simultaneously or sequentially.