Method for locating distribution network circuit fault based on full waveform information

Patent metadata

Field	Value
Publication number	US-9851390-B2
Application number	US-201414530627-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Aug 29, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A method for detecting and locating faulty line on the distribution network circuit based on full waveform information, which uses the current data on the fault occurrence and whole-process operation of the compensation device to effectively solve such common problems as low fault current, poor reliability and low sensitivity in case of single-phase grounding fault to the low-current system through precise GPS synchronization. It improves the sensitivity and reliability of the grounding fault detection, which does not interfere with the system and is applicable to high-resistance grounding.

First claim

We claim:

1. A method for locating a faulty section on a line in an electrical power distribution network having multiple measurement points along each line and protected by protection devices, comprising:
measuring a three-phase current and a zero-sequence voltage on a busbar in an electrical power distribution network where a fault has occurred at a section on a line,
determining a type, phase, and time of the fault based on the three-phase current and zero-sequence voltage being measured,
measuring the three-phase current or a zero-sequence current and a zero-sequence voltage at initial ends of each line in the electrical power distribution network during a time period from occurrence of the fault to action by the protection device,
determining a faulty line that has the faulty section thereon based on the type of the fault and the three-phase current or the zero-sequence current and the zero-sequence voltage at initial ends of each line being measured,
measuring a current at each of measurement points along the faulty line, and
locating the faulty section on the faulty line by the current at each of the measurement points along the faulty line,
wherein the protection device is a relay protection device or an arc suppression coil;
when the type of the fault is determined to be an inter-phase fault, the three-phase current at the initial ends of each line during the time period from the occurrence of the fault to the action of the relay protection device are measured to determine the faulty line, and a fault-phase current at each measurement points along the faulty line are measured to locate the faulty section; and
when the type of the fault is determined to be a grounding fault, the zero-sequence current and the zero-sequence voltage at the initial ends of each line during the time period from the occurrence of the fault to action of the arc suppression coil are measured to determine the faulty lire, and zero-sequence current at each measurement points along the faulty line are measured to locate the faulty section.

2. The method as claimed in claim 1 , further comprising
detecting an over-current on the three-phase current on the busbar and determining the type of the fault to be an inter-phase fault;
obtaining the phase of the fault; and
determining the time of the fault to be a time period that the three-phase current is detected to the action of the relay protection device.

3. The method as claimed in claim 2 , further comprising
detecting the over-current on the three-phase current on a line on the busbar, and
determining that the line having the over-current is the faulty line.

4. The method as claimed in claim 3 , further comprising
collecting a fault-phase current of each of the measurement points along the faulty line as characteristic current,
calculating a standard deviation d p.u. of formula (7) based on the characteristic current of each of the measurement points along the faulty line:

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Assignees

• Univ Shanghai Jiaotong

Inventors

• Liu Yadong
• Sheng Gehao
• Dai Jiejie
• Liu Jiamei
• Hu Yun
• Xie Xiaolei
• Qian Yong
• Hu Yue
• Jiang Xiuchen

Classifications

• H02H7/261 Primary

  involving signal transmission between at least two stations (transmission of signals in general H02H1/0061) · CPC title

• H02H7/28

  for meshed systems · CPC title

• G01R31/086

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

• G01R31/088

  Aspects of digital computing · CPC title

• G01R31/025 Primary

  Physics · mapped topic