Fault detection of a transmission line

Patent metadata

Field	Value
Publication number	US-10295586-B2
Application number	US-201616060680-A
Country	US
Kind code	B2
Filing date	Jan 20, 2016
Priority date	Jan 20, 2016
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

There is provided mechanisms for detecting a fault of a transmission line ( 20 ) in a power system ( 10 ) comprising at least one of an extreme weak system ( 10 a ) and an extreme strong system ( 10 b ). A method comprises obtaining travelling wave polarities from two terminals ( 21 a, 21 b ) of the transmission line during occurrence of the fault, the travelling wave polarities being defined by two current polarities and two voltage polarities. The method comprises determining the obtained travelling wave polarities to be detectable and the obtained travelling wave polarities to be non-detectable. The method comprises detecting the fault to be internal based on the detectable travelling wave polarities and the non-detectable travelling wave polarities. There is also provided an arrangement configured to perform such a method.

First claim

The invention claimed is:

1. A method for detecting a fault of a transmission line in a power system comprising at least one of an extreme weak system and an extreme strong system, the method comprising:
obtaining travelling wave polarities from two terminals of the transmission line during occurrence of the fault, the travelling wave polarities being defined by two current polarities (Δi 1 , Δi 2 ) and two voltage polarities (Δu 1 , Δu 2 );
determining some of the obtained travelling wave polarities to be detectable and some of the obtained travelling wave polarities to be non-detectable; and
detecting the fault to be internal based on the detectable travelling wave polarities and the non-detectable travelling wave polarities.

2. The method according to claim 1 , wherein said obtained travelling wave polarities are non-detectable if their values are zero or close to zero.

3. The method according to claim 1 , wherein said obtained travelling wave polarities are detectable if their values are reliably detectable.

4. The method according to claim 1 , wherein the fault is detected as internal if the two current polarities (Δi 1 , Δi 2 ) are equal or the two voltage polarities (Δu 1 , Δu 2 ) are equal, and the detectable polarities at first terminal of said two terminals are mutually opposite each other.

5. The method according to claim 1 , wherein the fault is detected as internal if

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6. The method according to claim 1 , wherein the fault is detected as internal if the voltage polarity (Δu 1 ) at a first terminal of said two terminals is zero, the current polarity (Δi 2 ) at a second terminal of said two terminals is zero, and the detectable voltage polarity (Δu 2 ) and one detectable current polarity (Δi 1 ) are mutually opposite each other.

7. The method according to claim 1 , wherein the fault is detected as internal if

Assignees

• Abb Schweiz Ag

Inventors

• Li Youyi
• Liu Kai
• Wang Jianping

Classifications

• G01R1/00

  Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00 (constructional details particular to {electromechanical} arrangements for measuring the electric consumption G01R11/02) · CPC title

• G01R31/085 Primary

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

• H02H7/22

  for distribution gear, e.g. bus-bar systems; for switching devices {(detecting mechanical or electrical defects in gas-insulated switchgears H02B13/065)} · CPC title

• H02H7/265

  making use of travelling wave theory · CPC title

• G01R31/08

  Locating faults in cables, transmission lines, or networks · CPC title