Detection and correction of fault induced delayed voltage recovery

• US 9,798,342 B2
• Filed: 02/23/2015
• Issued: 10/24/2017
• Est. Priority Date: 02/23/2015
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Gubba Ravikumar, Krishnanjan, Manson, Scott M.
• Primary Examiner(s): Fennema, Robert
• Assistant Examiner(s): PATEL, JIGNESHKUMAR C
• Application Number:
  US14/629,292
• Publication Number:
  US 20160246666A1
• Time in Patent Office: 974 Days
• Field of Search: 700292
• CPC Class Codes: G05F 1/625 wherein it is irrelevant whether the variable actually regulated is ac or dc

Abstract

Disclosed herein are methods for detecting and correcting a fault induced delayed voltage recovery event in an electric power transmission and distribution system. In some embodiments, a fault detection subsystem may receive an indication of a fault in the electric power transmission and distribution system. The system may also include a load analysis subsystem to analyze a plurality of loads supplied by the electric power system and to generate an estimated response of the loads. A fault analysis subsystem may analyze a plurality of factors relating to the fault and to determine a probability of the fault generating a fault induced delayed voltage recovery event. A control system may then implement a control strategy within a control window following the fault based on the probability of the fault generating a fault induced delayed voltage recovery event and the estimated response of the at least one load.

Claims

1. A system configured to detect and correct a fault induced delayed voltage recovery event in an electric power transmission and distribution system, the system comprising:

a remote fault detection subsystem configured to receive an indication of a fault in the electric power transmission and distribution system;

a load analysis subsystem configured to analyze a plurality of loads supplied by the electric power transmission and distribution system to generate an estimated response of at least one load to a control action;

a remote fault analysis subsystem configured to analyze when the fault occurs with respect to a point on a voltage waveform of the faulted electrical phase at a time of the fault, a duration of the fault, and a drop in a voltage due to the fault and to determine a probability of the fault generating a fault induced delayed voltage recovery event based on the point on the voltage waveform of the faulted electrical phase at the time of the fault;

a temperature analysis subsystem configured to determine a temperature in the geographic area supplied by the electric power distribution and transmission system; and

a control system configured to implement a control strategy within a control window following the fault, the control strategy comprising at least one control action to respond to the fault induced delayed voltage recovery event based on the probability of the fault generating a fault induced delayed voltage recovery event, the estimated response of the at least one load, and the temperature in the geographic area supplied by the electric power distribution and transmission system.

2. A system configured to detect and correct a fault induced delayed voltage recovery event in an electric power transmission and distribution system, the system comprising:

a fault detection subsystem configured to receive an indication of a fault in the electric power transmission and distribution system and when the fault occurs with respect to a point on a waveform at a time of the fault;

a load analysis subsystem configured to analyze a plurality of loads supplied by the electric power transmission and distribution system, to determine a load type, and to generate an estimated response of at least one load based on the determined load type;

a fault analysis subsystem configured to analyze a plurality of factors relating to the fault and to determine a probability of the fault generating a fault induced delayed voltage recovery event based on the point on the waveform at the time of the fault; and

a control system configured to implement a control strategy within a control window following the fault, the control strategy comprising at least one control action to respond to the fault induced delayed voltage recovery event based on the probability of the fault generating a fault induced delayed voltage recovery event and the estimated response of the at least one load.

3. The system of claim 2, wherein the at least one control action comprises selectively connecting a capacitor bank to provide reactive power support.

4. The system of claim 2, further comprising a load priority subsystem configured to identify at least one high-priority load and to prevent shedding of the at least one high-priority load in the implementation of the control strategy.

5. The system of claim 2, wherein the load analysis subsystem is further configured to identify a feeder with low impact on the fault induced delayed voltage recovery event and to prevent disconnection of the identified feeder in the implementation of the control strategy.

6. The system of claim 2, further comprising identifying at least one feeder with a reactive component and wherein the at least one control action comprises selectively disconnecting the identified feeder.

7. The system of claim 2, wherein the control window comprises a time of 50 milliseconds to 100 milliseconds after the fault and excluding breaker operation time.

8. The system of claim 2, wherein implementing the control strategy to respond to the fault induced delayed voltage recovery event comprises communicating the control strategy to a plurality of intelligent electronic devices in a plurality of substations and coordinating a plurality of control actions at the plurality of substations.

9. The system of claim 2, wherein the plurality of factors relating to the fault comprises at least one of a duration of the fault, and a drop in a voltage due to the fault.

10. The system of claim 2, further comprising a temperature analysis subsystem configured to determine a temperature in the geographic area supplied by the electric power distribution and transmission system.

11. The system of claim 2, wherein analyzing the plurality of factors relating to the fault comprises estimating a power factor of a feeder.

12. The system of claim 11, wherein estimating the power factor further comprises estimating an inductive power ratio to a resistive power ratio.

13. A method for detecting and correcting a fault induced delayed voltage recovery event in an electric power transmission and distribution system comprising:

monitoring an electric power transmission and distribution system;

detecting a fault;

analyzing when the fault occurs with respect to a point on a waveform at a time of the fault;

analyzing a first load supplied by the electric power transmission and distribution system;

determining a probability of the fault generating a fault induced delayed voltage recovery event based on the point on the waveform; and

implementing a control strategy within a control window following the fault, the control strategy comprising at least one control action to respond to the fault induced delayed voltage recovery event based on the probability of the fault generating a fault induced delayed voltage recovery event and the estimated response of the at least one load.

14. The method of claim 13, wherein the at least one control action comprises selectively connecting a capacitor bank to provide reactive power support.

15. The method of claim 13, further comprising identifying at least one feeder supplying a critical load and wherein the control strategy avoids disconnection of the identified feeder.

16. The method of claim 13, further comprising identifying a feeder with low impact on the FIDVR event and wherein the control strategy avoids disconnection of the identified feeder.

17. The method of claim 13, further comprising identifying at least one feeder with a reactive component and wherein the at least one control action comprises selectively disconnecting the identified feeder.

18. The method of claim 13, wherein the control window comprises a time of 50 milliseconds to 100 milliseconds after the fault and excluding breaker operation time.

19. The method of claim 13, wherein implementing the control strategy to respond to the fault induced delayed voltage recovery event comprises communicating the control strategy to a plurality of intelligent electronic devices in a plurality of substations and coordinating a plurality of control actions at the plurality of substations.

20. The method of claim 13, further comprising determining when the fault occurs with respect to the phase of the waveform, determining a duration of the fault, and determining a drop in a voltage due to the fault.

21. The method of claim 13, further comprising assessing an ambient temperature in the geographic area supplied by the electric power distribution and transmission system.

22. The method of claim 13, further comprising estimating a power factor of a feeder.

23. The method of claim 22, wherein estimating the power factor further comprises estimating an inductive power ratio to a resistive power ratio.