Fault location using traveling waves

Patent metadata

Field	Value
Publication number	US-10228409-B2
Application number	US-201715413004-A
Country	US
Kind code	B2
Filing date	Jan 23, 2017
Priority date	Sep 16, 2013
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

The present disclosure relates to calculating a fault location in an electric power transmission system based on traveling waves. In one embodiment, a system consistent with the present disclosure may be configured to detect a fault in an electric power transmission system. The system may include a traveling wave detection subsystem configured to detect and measure traveling waves on a transmission line and a fault location estimation subsystem. The fault location estimation subsystem may receive from the traveling wave detection subsystem a first plurality of traveling waves on the transmission line generated during a reference event. The fault location estimation subsystem may receive from the traveling wave detection subsystem a second plurality of traveling waves generated during an unplanned event. An unmatched traveling wave in the second plurality of waves may be detected and a location of the unplanned event based on the unmatched traveling wave.

First claim

What is claimed is:

1. A system configured to detect an unplanned event in an electric power transmission system, the system comprising:
a traveling wave detection subsystem configured to receive electric power transmission system measurements during a reference event and during an unplanned event, and calculate traveling waves using the electric power transmission system measurements;
an event location estimation subsystem configured to:
receive from the traveling wave detection subsystem a first plurality of detected traveling waves on the transmission line generated during a reference event;
generate a reference train from the first plurality of detected traveling waves during the reference event the reference train defining timing of traveling wave reflections detected during the reference event;
store the reference train;
upon occurrence of an unplanned event, receive from the traveling wave detection subsystem a second plurality of detected traveling waves calculated from electric power transmission system measurements during the unplanned event, the traveling waves generated by the unplanned event;
identify a plurality of matched traveling waves common in the reference train and the second plurality of traveling waves;
align the reference train and the second plurality of traveling waves based on the plurality of matched traveling waves;
generate a final stream of unplanned event traveling waves by identifying and including at least one unmatched traveling wave and a time of the unmatched traveling wave in the second plurality of waves as a traveling wave present in the second plurality of waves and not present in the reference train; and
apply the final stream of unplanned event traveling waves to an event location estimation subsystem to calculate a distance to the unplanned event based on the time of the unmatched traveling wave and a predetermined traveling wave propagation velocity on the electric power transmission line; and,

an interface to effect operational control of the electric power transmission system based on the calculated distance to the unplanned event.

2. The system of claim 1 , wherein the unplanned event comprises an electric fault.

3. The system of claim 1 , wherein the reference event comprises one of a planned event and an unplanned event.

4. The system of claim 1 , wherein the first plurality of traveling waves and the second plurality of traveling waves are detected from a local terminal.

5. The system of claim 1 , further comprising a communications interface configured to receive a second measurement indicative of the location of the unplanned event based on a traveling wave detected at a remote terminal.

6. The system of claim 5 , further comprising a time interface configured to associate a time stamp with each of a plurality of measurements associated with the first plurality of traveling waves, the second plurality of traveling waves, and the second measurement.

7. The system of claim 1 , wherein the reference event comprises one of a line energization event and an automatic reclosing event.

8. The system of claim 1 , wherein the first plurality of traveling waves comprises at least one reflection from a tap on the transmission line.

9. The system of claim 1 , wherein the first plurality of waves comprises a reflection from a discontinuity on the transmission line.

10. The system of claim 9 , wherein the discontinuity comprises a transition from an overhead section of the transmission line to an underground section of the transmission line.

11. The system of claim 1 , wherein the traveling wave detection subsystem further comprises a current sensor and the event location estimation subsystem is configured to determine the location of the unplanned event without reference to a voltage of the transmission line.

12. A system configured to detect an unplanned event in an electric power transmission system, the system comprising:
a traveling wave detection subsystem configured to receive electric power transmission system measurements during a reference event and during an unplanned event, and calculate traveling waves using the electric power transmission system measurements;
an event location estimation subsystem configured to:
generate a first record of a plurality of static reflection points on the transmission line from detected traveling waves on the transmission line and corresponding traveling wave arrival times of the detected traveling waves during the reference event
store the generated first record of the plurality of static reflection points;
upon occurrence of an unplanned event, receive from the traveling wave detection subsystem a first plurality of detected traveling waves generated during the first unplanned event, the first plurality of traveling waves generated by the unplanned event;
identify a subset of the first plurality of traveling waves based on the first record;
match the subset of the first plurality of traveling waves with the plurality of static reflection points on the transmission line based on the first record;
identify at least one unmatched traveling wave in the first plurality of traveling waves that is unmatched to any of the plurality of static reflection points and a time of the unmatched traveling wave;
apply the at least one unmatched traveling wave generated by the unplanned event to an event location estimation subsystem to calculate a distance to the unplanned event based on the unmatched traveling wave, the time of the unmatched traveling wave, and the propagation velocity of the transmission line; and,
effect operational control of the electric power transmission system based on the calculated distance to the unplanned event.

13. The system of claim 12 , wherein the event location estimation subsystem is further configured to generate the first record of a plurality of static reflection points on the transmission line based on user input identifying the plurality of static reflection points.

14. The system of claim 12 , wherein the first record comprises a representation indicating a plurality of differential times at which a traveling wave associated with each of the plurality of static reflection points arrives.

15. The system of claim 14 , wherein the event location estimation subsystem is further configured to selectively discard a predetermined time period before and after each of the plurality of differential times.

16. The system of claim 12 , wherein the plurality of static reflection points comprises at least one tap on the transmission line.

17. A method of detecting an unplanned event in an electric power transmission system using traveling waves, the method comprising:
obtaining a first plurality of electric power transmission system measurements during a reference event at a first location on the electric power transmission system;
calculating a first plurality of traveling waves on a transmission line of the electric power transmission system generated during a reference event at a first location using the first plurality of electric power transmission system measurements;
storing a representation of the first plurality of traveling waves;
obtaining a second plurality of electric power transmission system measurements during an unplanned event;
calculating, from the second plurality of electric power transmission system measurements, a second plurality of traveling waves generated during the unplanned event, the second plurality of traveling waves generated by the unplanned event;
identifying a plurality of matched traveling waves in the first plurality of t

Assignees

• Schweitzer Engineering Lab Inc

Inventors

• Schweitzer Iii Edmund O
• Mynam Mangapathirao Venkata
• Guzman-Casillas Armando

Classifications

• G01R31/11

  using pulse reflection methods · CPC title

• H02H1/0092

  concerning the data processing means, e.g. expert systems, neural networks · CPC title

• H02H7/265

  making use of travelling wave theory · CPC title

• G01R31/085

  in power transmission or distribution lines, e.g. overhead · CPC title

• Y04S10/522

  Cross-Sectional Technologies · mapped topic