SYSTEMS AND METHODS FOR SYNCHRONIZED CONTROL OF ELECTRICAL POWER SYSTEM VOLTAGE PROFILES

• US 20110084672A1
• Filed: 10/12/2010
• Published: 04/14/2011
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Moxley, Roy E., Pope, Jeffrey G., Labuschagne, Casper A.
• Granted Patent: US 8,476,874 B2
• Time in Patent Office: Days
• US Class Current: 323/255
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: H02J 3/1878 using tap changing or phase shifting transformers
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

Disclosed herein are various embodiments of systems and methods for controlling a voltage profile delivered to a load in an electric power system. According to various embodiments, an electric power system may include an electric power line, a variable tap transformer, and a capacitor bank. The variable tap transformer may include a plurality of tap positions. A tap change controller may be coupled with the variable tap transformer and may control the tap positions of the variable tap transformer. A capacitor bank controller may be coupled with the capacitor bank and may selectively couple the capacitor bank to the electric power line. The tap change controller and the capacitor bank controller may share system information related to the voltage profile along the electric power line and to change the voltage profile along the line using the variable tap transformer and the capacitor bank depending on the system information.

Claims

1. A system, comprising:

an electric power line;

a variable tap transformer including a plurality of tap positions selectively coupleable with the line;

a tap change controller communicatively coupled with the variable tap transformer and configured to control the tap positions of the variable tap transformer;

a capacitor bank selectively coupleable with the line; and

a capacitor bank controller communicatively coupled with the capacitor bank and configured to selectively couple the capacitor bank to the line,

wherein the tap change controller and the capacitor bank controller are configured to share system information related to the voltage profile along the electric power line and to change the voltage profile along the line using the variable tap transformer and the capacitor bank depending on the system information.

2. The system of claim 1, wherein the system information comprises synchronized phasor information.

3. The system of claim 1, wherein the system information comprises line current information.

4. The system of claim 1, wherein the system information comprises line voltage information.

5. The system of claim 1, wherein the system further comprises a time reference common to the tap change controller and the capacitor bank controller used to coordinate operations of the tap change controller and the capacitor bank controller.

6. The system of claim 1, wherein the system further comprises a breaker communicatively coupled to the capacitor bank and the capacitor bank controller is configured to selectively couple the capacitor bank to the power line based on a control signal received from the capacitor bank controller.

7. The system of claim 1, wherein the capacitor bank comprises a plurality of capacitors.

8. The system of claim 1, wherein the tap change controller and the capacitor bank controller are configured to optimize the voltage profile delivered to a load communicatively coupled with the line by controlling the variable tap transformer and the capacitor bank based on the shared system information.

9. The system of claim 1, wherein the voltage profile along the line is changed by the tap change controller by changing a tap position of the variable tap transformer.

10. The system of claim 6, wherein the voltage profile along the line is changed by the capacitor bank controller by issuing the control signal to the breaker.

11. A method for controlling a voltage profile delivered to a load in an electric power system, the system comprising:

receiving, by a tap change controller communicatively coupled with a variable tap transformer coupled to an electric power line, first system information relating to the voltage profile along the line;

receiving, by a capacitor bank controller communicatively coupled with a capacitor bank including at least one capacitor coupled to the line, second system information relating to the voltage profile along the line;

receiving, by the tap change controller from the capacitor bank controller, the second system information;

receiving, by the capacitor bank controller from the tap change controller, the first system information; and

controlling, by the tap change controller or the capacitor bank controller, the voltage profile of the line based on the first and second system information using the variable tap transformer or capacitor bank.

12. The method of claim 11, wherein the first and second system information comprise synchronized phasor information.

13. The method of claim 11, wherein the first and second system information comprise line current information.

14. The method of claim 11, wherein the first and second system information comprise line voltage information.

15. The method of claim 11, wherein the method further comprises receiving, by the tap change controller and the capacitor bank controller, a reference time signal used to coordinate operations of the tap change controller and the capacitor bank controller.

16. The method of claim 11, wherein the method further comprises generating, by the capacitor bank controller, a control signal provided to a breaker communicatively coupled to the capacitor bank and the line configured to cause the breaker to selectively couple the capacitor bank to the power line.

17. The method of claim 11, wherein the capacitor bank comprises a plurality of capacitors.

18. The method of claim 11, wherein the voltage profile is controlled by the tap change controller through changing a tap position of the variable tap transformer.

19. The method of claim 16, wherein the voltage profile delivered to the load is controlled by the capacitor bank controller through issuing the control signal to the breaker.

20. An intelligent electronic device comprising:

an interface configured to receive first system information related to a voltage profile of an electric power delivery system that includes a variable tap transformer communicatively coupled with the interface;

a processor communicatively coupled to the interface;

a computer-readable storage medium communicatively coupled to the processor, the computer-readable storage medium storing instructions that when executed by the processor cause the processor to change the voltage profile by controlling a tap position of the variable tap transformer based on the first system information and second system information received from an intelligent electronic device associated with a shunt capacitor bank system.

21. The intelligent electronic device of claim 20, wherein the first and second system information comprises synchronized phasor information.

22. The intelligent electronic device of claim 20, wherein the first and second system information comprises current information.

23. The intelligent electronic device of claim 20, wherein the first and second system information comprises voltage information.

24. An intelligent electronic device comprising:

an interface configured to receive first system information related to a voltage profile along an electric power line coupled with a shunt capacitor bank system communicatively coupled with the interface;

a processor communicatively coupled to the interface;

a computer-readable storage medium communicatively coupled to the processor, the computer-readable storage medium storing instructions that when executed by the processor cause the processor to change the voltage profile of the line by selectively connecting the capacitor bank system to the line based on the first system information and second system information received from an intelligent electronic device associated with a variable tap transformer.

25. The intelligent electronic device of claim 24, wherein the first and second system information comprises synchronized phasor information.

26. The intelligent electronic device of claim 24, wherein the first and second system information comprises line current information.

27. The intelligent electronic device of claim 24, wherein the first and second system information comprises line voltage information.