Fault detection and protection during steady state using traveling waves

Patent metadata

Field	Value
Publication number	US-11056874-B2
Application number	US-201916260473-A
Country	US
Kind code	B2
Filing date	Jan 29, 2019
Priority date	Jul 26, 2016
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

An electric power delivery system may be protected upon occurrence of a fault condition by the systems and methods disclosed herein by detecting the fault condition and signaling a protective action before the overcurrent condition reaches the protective equipment. The protective action may be an opening of a circuit breaker or engagement of a fault current limiter. The overcurrent condition may be a non-steady-state condition. The fault may be detected using traveling wave or incremental quantity techniques.

First claim

What is claimed is:

1. A device for detecting a fault in an electric power delivery system, comprising:
an acquisition circuit in communication with a distribution branch of the electric power delivery system for obtaining current signals therefrom and producing current quantities;
a traveling wave fault detection module in communication with the acquisition circuit configured to detect an in-zone fault using the current quantities, determine a fault condition, and provide a traveling wave fault signal upon detection of the traveling wave; and,
a protection module in communication with the traveling wave module configured to signal a second circuit breaker to open before a voltage condition resulting from the fault exceeds a rated voltage condition of a distribution circuit breaker, and signal the distribution circuit breaker to open after the second circuit breaker has opened.

2. The device of claim 1 , wherein the second circuit breaker is configured for selectively connecting a distribution bus with the distribution branch.

3. The device of claim 2 , wherein the protection module is further configured to signal the second circuit breaker to open when it determines that the distribution circuit breaker is not capable of opening before the voltage condition resulting from the fault will exceed the rated voltage.

4. The system of claim 1 , wherein the protection module is further configured to signal the distribution circuit breaker to close after the second circuit breaker is open.

5. The system of claim 2 , wherein the second circuit breaker is a solid-state circuit breaker.

6. The system of claim 2 , wherein the second circuit breaker is a microelectromechanical system (“MEMS”) device.

7. A method of protecting an electric power delivery system, comprising:
an intelligent electronic device (“IED”) in communication with the electric power delivery system obtaining current signals from the electric power delivery system;
detecting an in-zone fault using the current signals from a portion of the electric power delivery system;
signaling a first circuit breaker to open the portion of the electric power delivery system before a non-steady-state condition from the fault arrives at a second circuit breaker; and
signaling the second circuit breaker to open after the first circuit breaker has opened.

8. The method of claim 7 , wherein the non-steady state condition comprises overcurrent.

9. The method of claim 7 , wherein the non-steady state condition comprises overvoltage.

10. A system for protecting an electric power delivery system, comprising:
a first circuit breaker for selectively connecting a transformer with a distribution bus;
a second circuit breaker for selectively connecting the distribution bus with a distribution branch;
a fault current limiter for selectively limiting current through a portion of the electric power delivery system;
an intelligent electronic device (“IED”) in communication with the first circuit breaker and the second circuit breaker, and including:
an acquisition circuit in communication with the distribution branch for obtaining current signals therefrom and producing current quantities;
a traveling wave fault detection module in communication with the acquisition circuit configured to detect an in-zone fault condition using the current quantities, and provide a traveling wave fault signal upon detection of the in-zone fault; and,
a protection module in communication with the traveling wave module configured to signal the second circuit breaker to open upon detection of the in-zone fault after engagement of the fault current limiter;
wherein the protection module is further configured to signal the fault signal limiter to disengage after the second circuit breaker has opened.

11. The system of claim 10 , wherein the protection module is further configured to signal the fault current limiter to engage upon detection of the traveling wave.

12. The system of claim 11 , wherein the protection module is further configured to:
determine whether the second circuit breaker has opened and;
when the second circuit breaker has opened, signal the fault current limiter to disengage.

Assignees

• Schweitzer Engineering Lab Inc

Inventors

• Schweitzer Iii Edmund O
• Kasztenny Bogdan Z
• Whitehead David E

Classifications

• H02H7/222

  for switches · CPC title

• H02H3/05 Primary

  with means for increasing reliability, e.g. redundancy arrangements {(for logic circuits H03K19/003)} · CPC title

• H02H1/0007 Primary

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H02H3/083

  for three-phase systems · CPC title

• H02H7/265

  making use of travelling wave theory · CPC title