Thyristor-switched capacitor circuit with a thyristor-saving architecture

Patent metadata

Field	Value
Publication number	US-9853475-B2
Application number	US-201514876030-A
Country	US
Kind code	B2
Filing date	Oct 6, 2015
Priority date	Sep 25, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

There are provided methods, devices, and systems relating to discharging thyristor-switched capacitors. For example, there is provided a method for discharging a first capacitor, a second capacitor, and a third capacitor. Each of the capacitors is coupled to respective phases of a transmission line. The first capacitor and the third capacitor are each coupled to their respective phase of the transmission line via a pair of anti-parallel thyristors, and the second capacitor is coupled directly to another phase of the transmission line with no thyristors therebetween. The method can include determining whether an angle of a voltage on the transmission line is within a threshold angle. Further, the method can include discharging the first, second, and third capacitors when the angle is within a threshold angle and the threshold angle is any value from a predetermined set of threshold angles.

First claim

What is claimed is:

1. A controller, comprising:
a processor communicatively coupled to a first capacitor, a second capacitor, and a third capacitor, each coupled to phases of a transmission line, the first capacitor and the third capacitor each being coupled to a respective phase of the transmission line via a pair of anti-parallel thyristors, and the second capacitor being coupled directly to another phase of the transmission line with no thyristors therebetween;
a memory having instructions stored thereon, which when executed by the processor, cause the processor to perform operations comprising:
determining whether an angle of a voltage on the transmission line is within a threshold angle; and
discharging the first, second, and third capacitors when the angle is within a threshold angle and the threshold angle is any value from a predetermined set of threshold angles.

2. The controller of claim 1 , wherein the angle is obtained by summing a measured value with a predetermined correction angle value.

3. The controller of claim 1 , wherein the pair of thyristors and the capacitors are connected to the transmission line in a Wye-type TSC configuration having a thyristor-saving architecture.

4. The controller of claim 1 , wherein the operations further comprise determining whether a turn-off command has been issued prior to discharging the first, second, and third capacitors.

5. The controller of claim 1 , wherein the predetermined set of threshold angles is the set of threshold angle values consisting of 270 degrees and 90 degrees.

6. The controller of claim 1 , wherein the predetermined set of threshold angles is the set of threshold angle values consisting of 150 degrees and 330 degrees.

7. The system of claim 6 , wherein the processor is configured to discharge the first, second, and third capacitors in response to receiving a turn-off command.

8. The controller of claim 1 , wherein the pair of anti-parallel thyristors are activated or deactivated simultaneously and for the same duration.

9. A system, comprising:
a first capacitor, a second capacitor, and a third capacitor, each coupled to respective phases of a transmission line, the first capacitor and the third capacitor each being coupled to a respective phase of the transmission line via a pair of anti-parallel thyristors, and the second capacitor being coupled directly to another phase of the transmission line with no thyristors therebetween; and
a processor configured to discharge the capacitors based on an angle of a voltage on the transmission line.

10. The system of claim 9 , wherein the angle is obtained by summing a measured value with a predetermined correction value.

11. The system of claim 9 , wherein the processor is configured to discharge the capacitors based on the angle being in a predetermined set of threshold angles.

12. The system of claim 11 , wherein the predetermined set of threshold angles is the set of threshold angle values consisting of 270 degrees and 90 degrees.

13. The system of claim 11 , wherein the predetermined set of threshold angles is the set of threshold angle values consisting of 150 degrees and 330 degrees.

14. The system of claim 9 , wherein the first, second, and third capacitors and the pairs of anti-parallel thyristors form a Wye-type thyristor-switched capacitor circuit having a thyristor-saving architecture.

15. The system of claim 9 , wherein the pair of anti-parallel thyristors are activated or deactivated simultaneously and for the same duration.

Assignees

• Gen Electric

Inventors

• Ren Wei
• Larsen Einar

Classifications

• Y02E40/34

  Cross-Sectional Technologies · mapped topic

• H02J3/16 Primary

  by adjustment of reactive power · CPC title

• H02J7/007 Primary

  Electricity · mapped topic

• H02J7/0063

  Electricity · mapped topic

• Y02E40/12

  Cross-Sectional Technologies · mapped topic