Fault arc detection method based on wavelet coefficient average difference value

Abstract

The invention discloses a fault arc detection method based on a wavelet coefficient average difference value. The method comprises steps of based on features of randomness and intermittency of fault arcs, by using the characteristic that fault arcs can be precisely detected through wavelet transformation, analyzing and calculating current data which is continuously acquired in multiple periods; using the Mallat algorithm to decompose and reconstruct a wavelet high frequency coefficient so as to solve the average difference values; and finally carrying out difference value operation, wherein all the average difference values are used for detecting the fault arcs. According to the invention, the defect that in the wavelet transformation, the fault arcs cannot be effectively differentiated from similar arcs generated by special load can be overcome; the fault arcs can be effectively detected; the fault arcs can be effectively differentiated from similar arcs generated by special load; and interference for detection of the fault arcs imposed by the similar arcs generated by the special load can be avoided.

Description

technical field [0001] The invention relates to an arc detection method, in particular to a fault arc detection method based on the mean difference of wavelet coefficients. Background technique [0002] With the development of society, people have higher and higher requirements for the safety of living, office and public environment, and frequent electrical fire accidents have brought great safety hazards to people's life and property safety. Electrical fire accidents caused by arc faults caused by short circuits, aging lines, poor contact, and electrical product failures account for a large proportion of electrical fire accidents. In the low-voltage power distribution system of buildings, on the one hand, due to the limitation of impedance, when a fault arc occurs, the fault current generated is too small to make the overcurrent protection device operate, the fault arc continues to occur, and frequent ignition and arcing , can directly ignite electrical lines or combustibl...

AI Technical Summary

Problems solved by technology

In the low-voltage power distribution system of buildings, on the one hand, due to the limitation of impedance, when a fault arc occurs, the fault current generated is too small to make the overcurrent protection device operate, the fault arc continues to occur, and frequent ignition and arcing , can directly ignite electrical lines or combustibles adjacent to equipment, which is a particularly dangerous ignition source, and its fire risk is much greater than that of metal short circuits; on the other hand, there are loads with similar fault arc waveform characteristics in the circuit, which makes the fault Arc detection misjudgment rate is high

[0003] The method of detecting arc faults by wavelet transform can detect arc fault signals, but because the current signals of special loads such as computers can also detect the characteristics of arc faults during normal operation, the traditional wavelet transform detection method cannot effectively area Sub-fault arc and similar arc generated by special load

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