Systems and methods for synchronized control of electrical power system voltage profiles

• US 8,816,652 B2
• Filed: 06/14/2013
• Issued: 08/26/2014
• Est. Priority Date: 10/13/2009
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Labuschagne, Casper A., Pope, Jeffrey G.
• Primary Examiner(s): STERRETT, JEFFREY L
• Application Number:
  US13/918,640
• Publication Number:
  US 20130282197A1
• Time in Patent Office: 438 Days
• Field of Search: 323/208, 323/209, 323/210, 323/211, 323/255, 323/256, 323/257, 323/258
• US Class Current: 323/211
• 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. An intelligent electronic device (IED), comprising:

a communication system configured to share system information related to a voltage profile on an electric power line with a variable tap transformer and a shunt capacitor bank, the variable tap transformer including a plurality of tap positions selectively coupleable with the electric power line, and the shunt capacitor bank being selectively coupleable with the electric power line;

a processor communicatively coupled to the communication system; and

a non-transitory computer-readable storage medium communicatively coupled to the processor, the computer-readable storage medium storing a plurality of instructions that when executed by the processor cause the processor to change the voltage profile by controlling one of a tap position of the variable tap transformer and a connection status of the shunt capacitor bank.

2. The IED of claim 1, wherein the IED comprises a tap change controller.

3. The IED of claim 2, wherein the communication system comprises a monitored equipment interface in communication with the variable tap transformer;

and

wherein controlling the tap position comprises issuing an instruction to the variable tap transformer via the monitored equipment interface to selectively couple one of the plurality of tap positions with the electric power line.

4. The IED of claim 1, wherein the IED comprises a shunt capacitor bank controller.

5. The IED of claim 4, further comprising:

wherein controlling the connection status of the shunt capacitor bank comprises issuing an instruction to selectively couple the shunt capacitor bank to the electric power line.

6. The IED of claim 5, wherein the instruction is configured to cause a breaker communicatively coupled to the shunt capacitor bank to close to selectively couple the shunt capacitor bank to the electric power line.

7. The IED of claim 1, wherein the IED comprises an automation controller.

8. The IED of claim 1, wherein the first and second system information comprise synchronized phasor information.

9. The IED of claim 1, wherein the first and second system information each comprise one of electric power line voltage information and line current information.

10. The IED of claim 1, further comprising a reference time signal input, and wherein the reference time signal input is used to coordinate a plurality of control instructions to change the voltage profile by operation of one of the variable tap transformer and the shunt capacitor bank.

11. The IED of claim 1, wherein the change to the voltage profile maintains a voltage on the electric power line within a predetermined voltage range.

12. The IED of claim 1, wherein the change to the voltage profile optimizes the voltage profile delivered to a load communicatively couple with the electric power line.

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

receiving, by an IED, a first system information from a tap change controller communicatively coupled with a variable tap transformer coupled to an electric power line;

receiving, by the IED, a second system information from a shunt capacitor bank controller communicatively coupled with a shunt capacitor bank including at least one capacitor coupled to the electric power line;

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

14. The method of claim 13, further comprising:

receiving a reference time signal; and

coordinating an operation of one of the shunt capacitor bank and the variable tap transformer based on the reference time signal.

15. The method of claim 13, wherein each of the first system information and the second system information relates to a voltage profile along the electric power line.

16. The method of claim 15, further comprising controlling one of the tap change controller and the shunt capacitor bank controller to maintain the voltage profile along the electric power line within a predetermined voltage range.

17. The method of claim 13, wherein each of the first system information and the second system information comprise synchronized phasor information.

18. The method of claim 13, wherein the each of the first system information and the second system information comprise one of a voltage of the electric power line and a current of the electric power line.

19. The method of claim 13, wherein controlling the voltage profile using the variable tap transformer comprises adjusting a tap position coupled to the electric power line.

20. The method of claim 13, wherein controlling the voltage profile using the shunt capacitor bank comprises selectively coupling the shunt capacitor bank to the electric power line.