Method for detecting and positioning section faults of power distribution network containing DGs (distributed generators)

Abstract

The invention relates to a method for detecting and positioning section faults of a power distribution network containing DGs (distributed generators). The method is characterized in that three-phase current information acquired by protection device installation points at two end nodes of a section is utilized, Clark transformation is adopted, three-phase current is transformed into Clark alpha-mode current and Clark beta-mode current, the Clark alpha-mode current and the Clark beta-mode current are subjected to Fourier transformation to acquire a phase angle of the Clark alpha-mode current and a phase angle of the Clark beta-mode current, data of the phase angles is uploaded to a relay protection control center, the relay protection control center can detect a fault and find out the section in which a fault point is located when the fault occurs in an electric power system through calculating the phase angle difference of the Clark alpha-mode current and the Clark beta-mode current of each section and through comparing a relation between an absolute value of the phase angle difference of the Clark alpha-mode current and the Clark beta-mode current of each section and a threshold value, and remove the fault section timely so as to complete a protection action. The method provided by the invention can be applied to detecting and positioning the section faults of the power distribution network containing the DGs under high permeability.

Description

technical field

[0001] The invention relates to a fault detection and location method of a distribution network containing DG. Background technique

[0002] The fault detection and location of the distribution network is an important part of the relay protection of the distribution network power system, which is of great significance to the safe operation of the distribution network and an important guarantee for the self-healing of the distribution network. After the fault, the fault area is removed in time, so that the entire system is affected by the fault to a minimum. With the development of distributed power generation technology, more and more distributed generators (Distributed Generators, DG) are connected to the distribution network, resulting in changes in the network structure of the distribution network and changes in the magnitude and direction of fault currents. The relay protection of the distribution network has brought many problems, such as the detection ...

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