Cable Early Fault Detection Method Based on Complex Wavelet Singularity Detection

Abstract

The invention discloses a detection method of an early fault of a cable based on complex wavelet singularity detection. The method mainly comprises the following steps of: acquiring a current signal of a cable to be detected in a power distribution network, and performing N-layer discrete wavelet transform on the current signal by using complex wavelets to obtain a wavelet transform coefficient on each decomposition level; and extracting amplitude information of a wavelet coefficient on each decomposition level, tracking the modulus maximum of the wavelet coefficient on each decomposition level, and recording a point on which the modulus maximum occurs in each decomposition level, wherein the corresponding occurrence moment of a first recorded modulus maximum point is the occurrence moment of an early fault, and the corresponding occurrence moment of a last recorded modulus maximum point is the ending moment of the early fault. According to the method disclosed by the invention, the early fault of the cable can be detected effectively, so that a defective cable can be pre-warned; and measures are adopted before the occurrence of the fault, and therefore losses caused by a permanent fault are reduced greatly, the running safety of a power grid is enhanced, and the running service life of the cable is prolonged.

Description

technical field [0001] The invention relates to a method for cable early fault detection based on complex wavelet singularity detection in a power system. Background technique [0002] With the development of modern urban construction, cables are becoming more and more important in urban power supply, and have gradually replaced bare wires for overhead power supply, and are widely used in distribution networks. [0003] In the actual operation process, many electrical equipment have strict requirements on the reliability of power supply, and failure of the power supply system will lead to very serious consequences; this requires early warning and rapid recovery of power supply system failure. The cable is easy to cause its own permanent failure due to partial discharge, flashover, etc., which will lead to the failure of the power supply system. When the permanent failure of the cable is about to occur, the power supply system is already in a dangerous state. Normal state, e...

AI Technical Summary

Problems solved by technology

The cable is easy to cause its own permanent failure due to partial discharge, flashover, etc., which will lead to the failure of the power supply system. When the permanent failure of the cable is about to occur, the power supply system is already in a dangerous state. Normal state, even if the working condition can be restored to normal state, it will seriously affect the operation of the power supply system

Images