Three-dimensional fault line selection method based on random resonance and transient current signal

Abstract

The invention relates to a three-dimensional fault line selection method based on random resonance and a transient current signal. The method comprises the following steps of: (1) after a power distribution network is faulted, recording the zero-sequence current iZn(t) and the fault phase current iXn(t) of each branch line fault, and computing transient zero-sequence current izn(t) and transient fault phase current ixn(t); (2) performing variable-scale bistable treatment on the transient zero-sequence current izn(t) and transient fault phase current ixn(t); (3) computing a cross correlation coefficient matrix M and an integrated correlation coefficient Mn among the transient characteristic zero-sequence current iczn(t) of the branch lines and selecting the line ln with the minimum Mn; (4) performing seven-layer db10 wavelet packet decomposition on the transient characteristic phase current icxn(t) of each branch line and computing simplified energy E*sn and simplified gravity center frequency f*gn; and (5) forming a three-dimensional coordinate system by using the simplified gravity center frequency f*gn as a horizontal ordinate, the simplified energy E*sn as a vertical coordinate, and a polarity parameter value as a longitudinal coordinate. Compared with a method in the prior art, the method is high in reliability and is not liable to suffer from external interference.

Description

technical field [0001] The invention relates to a fault line selection method of a distribution network, in particular to a three-dimensional fault line selection method based on stochastic resonance and transient current signals. Background technique [0002] With the development of my country's power system, the huge power grid will inevitably cause power interruption. A power outage will cause huge losses to the national economy. Reliable and continuous power supply is the goal of my country's power system development. [0003] As an important part of the power system, the distribution network has the closest connection with users and the most direct impact on users. The 3-60kV distribution network in my country widely adopts the non-effective neutral point grounding method, also known as the small current grounding system, and most of the faults in the small current grounding system are single-phase grounding faults. When a single-phase ground fault occurs, the ground...

AI Technical Summary

Problems solved by technology

The so-called stochastic resonance is a new technology with practical application value that uses the principle of stochastic resonance to enhance detection of weak signals. Its research and application have involved many disciplines such as physics, signal processing, mechanical fault diagnosis, biology, and chemistry. Relatively little research has been done in power systems

Images