High resistance ground fault detection method of distribution network based on wavelet transform and neural network

Abstract

The invention relates to a high-resistance-ground fault detection method based on wavelet transform and neural network for power distribution network. When the high resistance grounding fault occurs on the power distribution network, failure current is small, arcs are often accompanied, and ordinary zero sequence current protection is difficult to be detected; according to the high-resistance-ground fault detection method based on the wavelet transform and the neural network for the power distribution network, evolutionary neural network is used for improving a traditional detection method; and the evolutionary neural network is an intelligent system based on a dynamic connection structure, and topology structure can be adjusted to incorporate new information through incremental learning.According to the high-resistance-ground fault detection method based on the wavelet transform and the neural network for the power distribution network, trouble signals are processed by discrete wavelet transform and inputted into the evolutionary neural network to detect the high-resistance-ground fault of the power distribution network.

Description

technical field [0001] The invention relates to detection of grounding faults in distribution networks, in particular to a detection method for high-resistance grounding faults in distribution networks based on wavelet transform and neural network. Background technique [0002] High-impedance ground fault (HIF) refers to the ground fault that occurs when power lines pass through conductive media such as roads, soil, branches or cement buildings. It may occur at various voltage levels and affect the normal operation of the distribution network. Due to the high-impedance characteristics of non-metallic conductive media, when a high-resistance ground fault occurs in the distribution network, the fault current is very small and often accompanied by arcing, which is difficult to detect with ordinary zero-sequence current protection. Among the high-resistance ground faults in low-current grounding systems, especially resonant grounding systems, arcing ground faults account for a l...

AI Technical Summary

Problems solved by technology

Due to the free air, the grounding impedance of arc grounding changes greatly, causing the existing protection to start and recover repeatedly, which may cause the protection of adjacent lines and equipment to trip over the level, and also cause the overvoltage of the whole system, and then damage the electrical equipment. Expand the accident and reduce the power supply reliability of the power grid

Long-term operation of the line with a fault may cause the temperature of the fault point to be too high, causing a fire and causing permanent damage to electrical equipment, and the step voltage around the grounding point can reach several thousand volts, seriously threatening the stable operation of the power system and personal safety

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