Method and apparatus for detection of power system disturbance within a digital substation

Patent metadata

Field	Value
Publication number	US-2018024183-A1
Application number	US-201715701221-A
Country	US
Kind code	A1
Filing date	Mar 11, 2015
Priority date	Mar 11, 2015
Publication date	Jan 25, 2018
Grant date	—

Abstract

An objective of the application is to provide a method for detecting a disturbance in a power system within a digital substation and an apparatus using the same. The method includes: sensing electrical parameters at an end of a transmission line; sampling the sensed electrical parameters; extracting traveling-wave information from high frequency component of the samples using a signal processing method; and if the extracted traveling-wave information indicating occurrence of the disturbance, transmitting the extracted traveling-wave information to an intelligent electronic device of the digital substation from a merging unit or non-conventional instrument transformer of the digital substation. As compared with the amount of the sample data of the sensed electrical parameters, the amount of the data representing the extracted traveling-wave information is reduced. Thus the extracted traveling-wave information can be transmitted via a data link with a relatively narrow bandwidth, such as the process bus under standard IEC 61850.

First claim

1 . A method for detecting a disturbance in a power system within a digital substation, including:
sensing electrical parameters at an end of a transmission line; sampling the sensed electrical parameters; extracting travelling-wave information from a high frequency component of the samples using a signal processing method; and if the extracted travelling-wave information indicates occurrence of the disturbance, transmitting the extracted travelling-wave information to an intelligent electronic device of the digital substation from a merging unit or non-conventional instrument transformer of the digital substation.

2 . The method according to claim 1 , wherein:
the electrical parameters are voltage, current at the end of the transmission line.

3 . The method according to claim 1 , wherein:
the travelling-wave information represents polarity, direction, amplitude, rate of change and/or timing of the travelling wave.

4 . The method according to claim 1 , wherein:
the signal processing, method is one of wavelet transformation or filter-based signal processing method.

5 . The method according to claim 1 , further including:
if the extracted travelling-wave information indicates existence of the disturbance, transmitting it to a disturbance recorder of the digital substation from a merging unit or non-conventional instrument transformer of the digital substation,

6 . The method according to claim 1 , wherein:
the intelligent electronic device includes a protection relay and/or a fault locator.

7 . A disturbance detection apparatus for a power system within a digital substation, including:
an electrical parameter sensor for sensing an electrical parameter at an end of a transmission line; a sampling device, for sampling the sensed electrical parameter; a processor, for extracting travelling-wave information from high frequency component of the samples using a signal processing method and judging if it indicates occurrence of the disturbance; and a transmitter arranged in a merging unit of the digital substation or a non-conventional instrument transformer of the digital substation, for transmitting the extracted travelling-wave information to an intelligent electronic device of the digital substation from the merging unit or the non-conventional instrument transformer if it indicates the occurrence of the disturbance.

8 . The disturbance detection apparatus according to claim 7 , wherein:
the sampling device is arranged in the merging unit of the digital substation or the non-conventional instrument transformer of the digital substation.

9 . The disturbance detection apparatus according to claim 7 , wherein:
the processor is arranged in the merging unit of the digital substation or the non-conventional instrument transformer of the digital substation.

10 . The disturbance detection apparatus according to claim 7 , wherein:
the electrical parameter sensor is of a current transformer or as a part of the non-conventional instrument transformer.

11 . The disturbance detection apparatus according to claim 7 , wherein:
the electrical parameter sensor is of a voltage transformer or as a part of the non-conventional instrument transformer.

12 . The disturbance detection apparatus according to claim 7 , wherein:
the transmitter is further adapted for transmitting the extracted travelling-wave information to a disturbance recorder of the digital substation if it indicates existence of the disturbance.

13 . The disturbance detection apparatus according to claim 7 , wherein:
the intelligent electronic device includes a protection relay and/or fault locator.

14 . A digital substation, including:
the disturbance detection apparatus according to claim 7 ; the merging unit or the non-conventional instrument transformer; and the intelligent electronic device.

15 . The method according to claim 2 , wherein:
the travelling-wave information represents polarity, direction, amplitude, rate of change and/or timing of the travelling-wave.

16 . The method according to claim 2 , wherein:
the signal processing method is one of wavelet transformation or filter-based signal processing method.

17 . The method according to claim 2 , further including:
if the extracted travelling-wave information indicates existence of the disturbance, transmitting it to a disturbance recorder of the digital substation from a merging unit or non-conventional instrument transformer of the digital substation.

18 . The disturbance detection apparatus according to claim 8 , wherein:
the processor is arranged in the merging unit of the digital substation or the non-conventional instrument transformer of the digital substation.

19 . The disturbance detection apparatus according to claim 8 , wherein:
the electrical parameter sensor is of a current transformer or as a part of the non-conventional instrument transformer.

20 . The disturbance detection apparatus according to claim 11 , wherein:
the transmitter is further adapted for transmitting the extracted travelling-wave information to a disturbance recorder of the digital substation if it indicates existence of the disturbance.

Assignees

• Abb Schweiz Ag

Inventors

• Liu Kai
• Li Youyi
• Wang Jianping

Classifications

• G01R31/086

  in power transmission or distribution networks, i.e. with interconnected conductors · CPC title

• H02J13/00

  Circuit arrangements for providing remote monitoring or remote control of equipment in a power distribution network · CPC title

• G01R31/088

  Aspects of digital computing · CPC title

• G01R31/085 Primary

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

• H02H7/265

  making use of travelling wave theory · CPC title