Power system detection of sustained oscillations based on synchrophasor frequency measurements

Patent metadata

Field	Value
Publication number	US-10948527-B2
Application number	US-201916418377-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	May 21, 2019
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A method includes performing by a processor: receiving a plurality of power system phase angle measurements over a time interval from a plurality of phasor measurement units (PMUs) in a power system, generating a phase angle curve over the time interval based on the plurality of power system phase angle measurements, and detecting a sustained oscillation event in a power signal generated by the power system based on an envelope of the phase angle curve.

First claim

What is claimed is:

1. A method comprising:
performing by a processor:
receiving a plurality of power system phase angle measurements over a time interval from a plurality of phasor measurement units (PMUs) in a power system;
generating a phase angle curve over the time interval based on the plurality of power system phase angle measurements; and
detecting a sustained oscillation event in a power signal generated by the power system based on an envelope of the phase angle curve.

2. The method of claim 1 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve.

3. The method of claim 2 , wherein detecting the sustained oscillation event based on the magnitude of the envelope of the phase angle curve comprises:
determining a maximum peak-to-peak magnitude of the envelope of the phase angle curve;
comparing the maximum peak-to-peak magnitude of the envelope of the phase angle curve to a threshold; and
detecting the sustained oscillation event based on the maximum peak-to-peak magnitude of the envelope of the phase angle curve exceeding the threshold.

4. The method of claim 1 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a damping of the envelope of the phase angle curve.

5. The method of claim 4 , wherein detecting the sustained oscillation event based on the damping of the envelope of the phase angle curve comprises:
determining a first peak-to-peak magnitude of the envelope of the phase angle curve for a first cycle of the phase angle curve;
determining a second peak-to-peak magnitude of the envelope of the phase angle curve for a second cycle of the phase angle curve occurring later in time than the first cycle of the phase angle curve;
determining a ratio of the second peak-to-peak magnitude to the first peak-to-peak magnitude;
comparing the ratio to a threshold; and
detecting the sustained oscillation event based on the ratio exceeding the threshold.

6. The method of claim 1 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve exceeding a magnitude threshold for a time duration that exceeds a time duration threshold.

7. The method of claim 6 , wherein the method further comprises:
determining a probability density function of the magnitude of the envelope of the phase angle curve;
wherein the magnitude threshold corresponds to a magnitude value of the envelope of the phase angle curve that is greater than other magnitude values of the envelope of the phase angle curve with a probability of about 99.5%.

8. The method of claim 1 , further comprising:
adjusting an assignment of a power generator to a load in the power system based on the sustained oscillation event.

9. A system, comprising:
a processor; and
a memory coupled to the processor and comprising computer readable program code embodied in the memory that is executable by the processor to perform operations comprising:
receiving a plurality of power system phase angle measurements over a time interval from a plurality of phasor measurement units (PMUs) in a power system;
generating a phase angle curve over the time interval based on the plurality of power system phase angle measurements; and
detecting a sustained oscillation event in a power signal generated by the power system based on an envelope of the phase angle curve.

10. The system of claim 9 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve.

11. The system of claim 10 , wherein detecting the sustained oscillation event based on the magnitude of the envelope of the phase angle curve comprises:
determining a maximum peak-to-peak magnitude of the envelope of the phase angle curve;
comparing the maximum peak-to-peak magnitude of the envelope of the phase angle curve to a threshold; and
detecting the sustained oscillation event based on the maximum peak-to-peak magnitude of the envelope of the phase angle curve exceeding the threshold.

12. The system of claim 9 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a damping of the envelope of the phase angle curve.

13. The system of claim 12 , wherein detecting the sustained oscillation event based on the damping of the envelope of the phase angle curve comprises:
determining a first peak-to-peak magnitude of the envelope of the phase angle curve for a first cycle of the phase angle curve;
determining a second peak-to-peak magnitude of the envelope of the phase angle curve for a second cycle of the phase angle curve occurring later in time than the first cycle of the phase angle curve;
determining a ratio of the second peak-to-peak magnitude to the first peak-to-peak magnitude;
comparing the ratio to a threshold; and
detecting the sustained oscillation event based on the ratio exceeding the threshold.

14. The system of claim 9 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve exceeding a magnitude threshold for a time duration that exceeds a time duration threshold.

15. The system of claim 9 , wherein the operations further comprise:
adjusting an assignment of a power generator to a load in the power system based on the sustained oscillation event.

16. A computer program product, comprising:
a tangible computer readable storage medium comprising computer readable program code embodied in the medium that is executable by a processor to perform operations comprising:
receiving a plurality of power system phase angle measurements over a time interval from a plurality of phasor measurement units (PMUs) in a power system;
generating a phase angle curve over the time interval based on the plurality of power system phase angle measurements; and
detecting a sustained oscillation event in a power signal generated by the power system based on an envelope of the phase angle curve.

17. The computer program product of claim 16 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve.

18. The computer program product of claim 16 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a damping of the envelope of the phase angle curve.

19. The computer program product of claim 16 , wherein detecting the sustained oscillation event comprises:
detecting the sustained oscillation event based on a magnitude of the envelope of the phase angle curve exceeding a magnitude threshold for a time duration that exceeds a time duration threshold.

20. The computer program product of claim 16 , wherein the operations further comprise:
adjusting an assignment of a power generator to a load in the power system based on the sustained oscillation event.

Assignees

• Univ Tennessee Res Found

Inventors

• Liu Yilu
• Wu Ling
• Yu Wenpeng

Classifications

• H02J3/00142

  Oscillations concerning frequency · CPC title

• H02J13/12 Primary

  Monitoring network conditions, e.g. electrical magnitudes or operational status · CPC title

• G01R25/00 Primary

  Arrangements for measuring phase angle between a voltage and a current or between voltages or currents · CPC title

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title

• Y02E60/00

  Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation · CPC title