Method and system for locating single-phase grounding fault of distribution network

A technology of single-phase ground fault and positioning method, applied in the field of electric power, can solve the problems of increasing the difficulty of positioning, and the line is no longer symmetrical.

Inactive Publication Date: 2018-05-18
NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in order to save costs, many distribution networks adopt single-phase power distribution at the distribution end, and the lines are no longer symmetrical, which increases the difficulty of positioning

Method used

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  • Method and system for locating single-phase grounding fault of distribution network
  • Method and system for locating single-phase grounding fault of distribution network
  • Method and system for locating single-phase grounding fault of distribution network

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Experimental program
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Effect test

Embodiment 1

[0058] figure 1 It is a flowchart of a method for locating a single-phase-to-ground fault in a distribution network provided by Embodiment 1 of the present invention.

[0059] refer to figure 1 , the method includes the following steps:

[0060] Step S101, obtaining a voltage traveling wave, and performing a Karen Bell transformation on the voltage traveling wave to obtain a line-mode component and a zero-mode component;

[0061] Step S102, performing Hilbert-Huang HHT transformation on the linear mode component and the zero mode component to obtain the arrival time of the initial wave head;

[0062] Step S103, determining the area where the fault occurs according to the voltage traveling wave;

[0063] Step S104, if the fault occurs in a single-phase power distribution branch, obtain a first time difference according to the arrival time of the initial wave head;

[0064] Step S105, if the fault occurs on a three-phase line, then obtain a second time difference according t...

Embodiment 2

[0087] figure 2 It is a schematic diagram of a hybrid distribution network model provided by Embodiment 2 of the present invention.

[0088] refer to figure 2 , the hybrid distribution network model includes single-phase distribution branches, in which the end of the distribution network is a two-phase line connected to a distribution transformer. The power supply phases of the single-phase distribution branch circuit are A phase and B phase, and the non-power supply phase is C phase. FTU refers to the fault acquisition device on the feeder. In addition, A node, B node and C node are also included.

Embodiment 3

[0090] image 3 It is a schematic diagram of the actual distribution network topology provided by Embodiment 3 of the present invention.

[0091] refer to image 3 , the actual distribution network includes single-phase distribution branches, and the actual distribution network is simulated by EMTP (Electro-Magnetic Transient Program, Electromagnetic Transient Program). Among them, the dotted line at point C represents the single-phase power distribution branch. The fault occurs in the single-phase power distribution branch circuit, the distance from point C is 2100m, the fault type is A-phase ground fault, the ground resistance is 10Ω, and the sampling frequency is 2MHz. The wire model in the model is LGJ-120, and the positive sequence and zero sequence parameters of the three-phase line and single-phase power distribution branch can be obtained, as shown in Table 1:

[0092] Table 1

[0093]

L 1 (10 -3 mH / km)

L 0 (10 -3 mH / km)

C 1 (10 -6 ...

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Abstract

The invention provides a method and a system for locating a single-phase grounding fault of a distribution network. The method includes the following steps: obtaining a voltage traveling wave, and carrying out Karenbauer transformation on the voltage traveling wave to obtain an aerial mode component and a zero mode component; carrying out Hilbert-Huang transformation on the aerial mode component and the zero mode component to obtain the time of arrival of the initial wave front; determining the fault area according to the voltage traveling wave; if the fault occurs in a single-phase distribution branch, obtaining a first time difference according to the time of arrival of the initial wave front; if the fault occurs in a three-phase line, obtaining a second time difference according to thetime of arrival of the initial wave front; and obtaining a first fault distance and a second fault distance according to the first time difference and the second time difference respectively. A faultof a single-phase distribution branch can be located quickly.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a single-phase ground fault location method and system for a power distribution network. Background technique [0002] With the development of our country's national economy, the higher people's requirements for the reliability of power supply, the higher the reliability of the distribution network that is closely related to the residents' electricity consumption. This requires that the faults of the distribution network can be accurately identified and quickly eliminated. . However, in order to save costs, many distribution networks adopt single-phase power distribution at the distribution end, and the lines are no longer symmetrical, which increases the difficulty of positioning. Contents of the invention [0003] In view of this, the object of the present invention is to provide a single-phase ground fault location method and system for a distribution network, which...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/08G01R31/02
CPCG01R31/086G01R31/50
Inventor 齐郑郑宇航薛融杭天琦
Owner NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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