POWER QUALITY CONTROL

• US 20140133185A1
• Filed: 11/15/2012
• Published: 05/15/2014
• Est. Priority Date: 11/15/2012
• Status: Active Grant

• Current Assignee: GE Infrastructure Technology, LLC (GE Vernova, Inc.)
• Original Assignee: General Electric Company
• Inventors: Panosyan, Ara, Shah, Manoj Ramprasad, Wijekoon, Pinwan Thiwanka Bandara
• Granted Patent: US 9,042,129 B2
• Time in Patent Office: Days
• US Class Current: 363/16
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/1878 using tap changing or phase shifting transformers
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

An integrated power quality control system includes a transformer with a primary winding, a secondary winding and a compensation winding wound on a magnetic core. A power electronic converter in the system provides a reference voltage to the compensation winding for injecting a series voltage in the secondary winding of the transformer. A controller is utilized to generate the reference voltage for the power electronic converter based on a power quality control requirement.

Claims

1. An integrated power quality control system, comprising:

a transformer including a primary winding, at least one secondary winding and at least one compensation winding wound on a magnetic core;

a power electronic converter providing a reference voltage to the compensation winding for injecting a series voltage in the secondary winding; and

a controller to generate the reference voltage for the power electronic converter based on a power quality control requirement.

2. The integrated power quality control system of claim 1, wherein the compensation winding is connected in series with the primary winding or the secondary winding or is wound separately on the magnetic core.

3. The integrated power quality control system of claim 1, wherein the compensation winding is configured to control a magnetic flux in the magnetic core for injecting the series voltage in the secondary winding.

4. The integrated power quality control system of claim 1, wherein the power electronic converter comprises a plurality of bidirectional converters utilizing a common DC link or a three phase converter.

5. The integrated power quality control system of claim 4, wherein at least one of the plurality of the bidirectional converters is connected across the primary winding or the secondary winding.

6. The integrated power quality control system of claim 1, wherein the transformer comprises a three phase transformer or a single phase transformer or a split phase secondary transformer.

7. The integrated power quality control system of claim 4, wherein the plurality of the bidirectional converters include a DC to AC converter to control the reference voltage across the compensation winding and a AC to DC converter for charging the common DC link by exchanging active power with the transformer.

8. The integrated power quality control system of claim 7, wherein the controller includes a first controller to control the DC to AC converter and a second controller to control the AC to DC converter.

9. The integrated power quality control system of claim 8, wherein the controller is configured to generate an amplitude modulation ratio for generating PWM pulses for the AC to DC converter based on an error between a reference DC voltage and an actual DC voltage.

10. The integrated power quality control system of claim 8, wherein the first controller is configured to generate the reference voltage based on a relationship between a turns ratio of the compensation winding and the secondary winding and a reference secondary winding voltage determined based on the power quality requirement.

11. The integrated power quality control system of claim 10, wherein the first controller includes a voltage magnitude and phase calculation module to determine a magnitude and a phase of a secondary winding voltage.

12. The integrated power quality control system of claim 11, wherein the first controller includes an error detection module to generate an error signal based on comparison of the magnitude and the phase of the secondary winding voltage with a magnitude and a phase of the reference secondary winding voltage.

13. The integrated power quality control system of claim 12, wherein the first controller includes proportional-integral (PI) controllers configured to reduce the error signal to zero.

14. The integrated power quality control system of claim 1, wherein the power quality control requirement includes one of a voltage regulation, power factor correction, harmonic distortion compensation, and reactive power compensation.

15. A method of controlling power to a load, comprising:

providing a transformer including a primary winding, at least one secondary winding and at least one compensation winding wound on a magnetic core;

generating a reference voltage for a power electronic converter based on a power quality control requirement; and

utilizing the power electronic converter to provide the reference voltage across the compensation winding for injecting a series voltage in the secondary winding.

16. The method of controlling power to the load of claim 15, wherein providing a transformer comprises connecting the compensation winding in series with the primary winding or the secondary winding or is wound separately on the magnetic core.

17. The method of controlling power to the load of claim 15, wherein injecting the series voltage in the secondary winding comprises controlling a magnetic flux in the magnetic core.

18. The method of controlling power to the load of claim 15, wherein the power quality control requirement includes at least one of a voltage regulation, power factor correction, harmonic distortion compensation, and reactive power compensation.

19. The method of controlling power to the load of claim 15, wherein utilizing the power electronic converter comprises utilizing at least one bidirectional converter with a common DC link.

20. The method of controlling power to the load of claim 19, wherein utilizing the bidirectional converter includes utilizing a DC to AC converter to control the reference voltage across the compensation winding and a AC to DC converter for charging the common DC link by exchanging active power with the transformer.