Design of fault arc detection device based on STM32

Abstract

The detection of the load current signal is one of the effective methods for judging whether an arc fault occurs in the low-voltage distribution line; according to the national standard GB/T 31143-2014 General Requirements for Arc Fault Protection Devices (AFDD), the analog series fault arc is built. The experimental platform studies the characteristics of the current waveform when the fault arc occurs. The db4 wavelet function is used as the wavelet basis function to decompose and reconstruct the current waveform after noise reduction, and extract the wavelet high-frequency component, calculate the periodic variance value of the wavelet high-frequency component, and detect the arc fault according to this value; The feasibility and effectiveness of the detection algorithm are verified. The arc fault detection algorithm is transplanted to the STM32 platform, and the fault arc detection device based on STM32 is designed. The device can realize the functions of current signal acquisition, data processing and series arc fault detection and recognition. Experiments with resistive loads, LED light, vacuum cleaners and microwave ovens have shown that the device can detect series arc faults with high reliability and will not cause false positives without generating fault arcs.