Fault detection and protection during steady state using traveling waves

• US 10,236,675 B2
• Filed: 07/07/2017
• Issued: 03/19/2019
• Est. Priority Date: 07/26/2016
• Status: Active Grant

• Current Assignee: Schweitzer Engineering Laboratories, Incorporated
• Original Assignee: Schweitzer Engineering Laboratories, Incorporated
• Inventors: Schweitzer, III, Edmund O., Kasztenny, Bogdan Z., Whitehead, David E.
• Primary Examiner(s): Kitov, Zeev V
• Application Number:
  US15/644,355
• Publication Number:
  US 20180034258A1
• Time in Patent Office: 620 Days
• CPC Class Codes: H02H 1/0007 concerning the detecting means in general G01R or other subclasses of G01; reed switches H01H71/2445
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02H 3/083 for three-phase systems
• CPC Class Codes: H02H 3/20 responsive to excess voltage
• CPC Class Codes: H02H 3/38 responsive to both voltage and current; responsive to phase angle between voltage and current
• CPC Class Codes: H02H 7/222 for switches
• CPC Class Codes: H02H 7/265 making use of travelling wave theory

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.

Claims

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;

determine whether a distribution circuit breaker is capable of opening before a voltage condition resulting from the fault exceeds a rated voltage of the distribution circuit breaker; and

,

signal the distribution circuit breaker to open before the voltage condition resulting from the fault exceeds the rated voltage condition of the distribution circuit breaker.

2. 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;

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 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;

determine whether the second circuit breaker is capable of opening before a voltage condition resulting from the fault will exceed a rated voltage of the second circuit breaker; and

,

signal the second circuit breaker to open before the voltage condition resulting from the fault exceeds the rated voltage condition of the distribution circuit breaker.

3. The system of claim 2, wherein the protection module is further configured to signal the first circuit breaker to open when it determines that the second 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 3, wherein the protection module is further configured to signal the second circuit breaker to open after the first circuit breaker has opened.

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

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

7. The system of claim 2, wherein the second circuit breaker is a microelectromechanical system (“

MEMS”

) device.

8. 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;

determining whether a circuit breaker is capable of opening before an overvoltage condition resulting from the in-zone fault will exceed a rated voltage of the circuit breaker; and

signaling the circuit breaker to open the portion of the electric power delivery system before the overvoltage condition from the fault arrives at the circuit breaker.

9. 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;

determining whether a circuit breaker is capable of opening before an overcurrent condition resulting from the in-zone fault will exceed a rated current of the circuit breaker; and

signaling the circuit breaker to open the portion of the electric power delivery system before the overcurrent condition from the fault arrives at the circuit breaker.

10. 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;

determining whether a circuit breaker is capable of opening before a state of the electric power system at the circuit breaker due to the in-zone fault exceeds a rated condition of the circuit breaker; and

signaling a circuit breaker to open the portion of the electric power delivery system before the state of the electric power system at the circuit breaker exceeds the rated opening condition of the circuit breaker.

11. The method of claim 10, wherein the state comprises current.

12. 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 a first portion of the electric power delivery system;

determining whether a first circuit breaker selectively connecting the first portion of the electric power delivery system is capable of opening before a state of the electric power delivery system at the first circuit breaker exceeds rated opening conditions of the circuit breaker;

when the first circuit breaker is capable of opening before the state of the electric power delivery system at the first circuit breaker exceeds the rated opening conditions, signal the first circuit breaker to open.

13. The method of claim 12, further comprising:

when the first circuit breaker is not capable of opening before the state of the electric power delivery system at the first circuit breaker exceeds the rated opening conditions, signal a second circuit breaker to open.

14. The method of claim 13, further comprising:

opening the first circuit breaker after the second circuit breaker has opened; and

,

closing the second circuit breaker after the first circuit breaker has opened.

15. The method of claim 14, wherein the second circuit breaker connects both the first portion of the electric power delivery system and a second portion of the electric power delivery system.

16. The method of claim 15, wherein first portion of the electric power delivery system is a distribution feeder, and the second portion of the electric power delivery system is another distribution feeder.

17. The method of claim 15, wherein the second portion of the electric power delivery system includes the first portion of the electric power delivery system.

18. The method of claim 12, wherein the first circuit breaker is a solid-state circuit breaker.

19. 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 in-zone fault; and

,

a protection module in communication with the traveling wave fault detection module configured to;

signal a fault current limiter to engage and a distribution circuit breaker to open upon receipt of the traveling wave fault signal;

determine wither the circuit breaker opened; and

when it is determined that the circuit breaker has opened, disengage the fault current limiter.

20. 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,

determine whether the second circuit breaker has opened; and

,

when the second circuit breaker has not opened, signal the first circuit breaker to open.

21. The system of claim 20, wherein the protection module is further configured to signal the fault current limiter to engage upon detection of the traveling wave.

22. The system of claim 21, 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.