AC fault arc detection method based on wavelet transform and time-domain hybrid features

Abstract

The invention relates to a method for detecting alternating-current fault arcs on the basis of wavelet transformation and time-domain hybrid features. The method includes steps of 1), initializing a system; 2), enabling a microprocessor to acquire output current signals of a signal acquisition circuit in real time at set sampling intervals; 3), enabling the microprocessor to judge whether an acquisition number reaches a set threshold value or not, executing a step 4) if the acquisition number reaches the set threshold value, or returning to the step 2) if the acquisition number does not reach the set threshold value; 4), enabling the microprocessor to normalize the sampled current signals in a period, respectively computing time-domain feature values and wavelet transformation feature values of the current signals and inputting the time-domain feature values and the wavelet transformation feature values into a converged BP (back propagation) neural network; 5), judging whether the fault arcs exist or not by the aid of output values of the BP neural network. Compared with the prior art, the method has the advantages of wide application range, high control precision and safety, good expansibility and the like.

Description

technical field [0001] The invention relates to an AC fault arc detection method, in particular to an AC fault arc detection method based on wavelet transform and time domain mixed features. Background technique [0002] With the continuous development of social economy, the number of fire accidents is also increasing year-on-year, among which electrical fires account for 30.1% of all fire accidents. The lines inside the house, such as electrical wiring, socket lines, internal lines of household appliances, and power lines, etc., will cause the insulation layer of the wires to age or be damaged when they are under load for a long time, overloaded or affected by external forces, which is easy Cause series and parallel arc faults between lines or line-to-ground short circuit faults. Compared with the short-circuit fault, the current amplitude in the line is small when the low-voltage fault arc occurs, and the traditional detection device cannot detect the fault arc, so the pr...

AI Technical Summary

Problems solved by technology

However, the current when fault arc is generated under different loads is very different, and the current characteristics of some loads (such as dimming lamp load) in normal operation are similar to the current characteristics of resistive load fault arc, which brings great difficulties to the detection of fault arc. difficulty

Therefore, the existing products on the market can only be used under certain specific load conditions, and do not have good versatility

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