Research On Arc Fault Detection Device

With the rapid development of industry and economy in China,the scale of power grid is expanding,and the consumption of electricity and daily life is increasing.Electrical fire can not be ignored as a huge hidden danger in life safety and property loss.The arc fault on the distribution line is one of the most important causes of the electric fire.Arc faults are caused by the loosening of the contacts of the plug,the aging of the insulation layer of the line or the contact of contact with the contact.Traditional low voltage protective devices are all protected by overcurrent and leakage current.These products do not meet the future development request for low-voltage distribution system,and can't detect series arcing faults on single-phase distribution lines.Therefore,it is very important for the research of arc fault protection electrical apparatus(AFDD).This subject takes low voltage series arc fault as the research object,and simulate the fault arc by configuring the circuit according to the requirement of the related standard.The current signal is obtained under normal work and arc failure.The signal is compared and analyzed,and the characteristic value of the arc wave is extracted.Based on the latest AFDD national standards,this paper designs four configuration circuits with 7 shielded loads.The arc fault detection algorithm is studied on the basis of obtaining detailed time domain and frequency domain data.The effects of time domain and frequency domain(FFT)detection methods on fault arc recognition are compared.It is found that it is difficult to identify the 7 kinds of load arc faults in the standard by single method.Therefore,a discriminative method combining time domain and frequency domain is proposed to realize the arcing fault recognition of the 7 loads.With the STM32 controller as the core,the low voltage series arc fault detection device is designed and made by using the method of time domain and frequency domain quantization.