Research On Arc Fault Real-time Diagnosis Method

With the rapid development of national economy and the improvement of residents’living standards, the electricity consumption of residential and social production increasing,the electrical equipment’s type and quantity of life and production is increasing, thecomposition and working state of power system is more complicated. In this condition, thepower system accidents will get a higher probability. Among the many factors cause the powersystem accidents, arcing fault is an unneglectable factor. Since there is no ideal protectiondevice to detect the series arc fault, the device and combustibles surrounding may get ignitedeasily when the series arc fault generates, which will cause significant property damages andpersonal injury. Therefore, it is necessary to research on arc fault real-time diagnosis methodon line or equipment, which can detect arc fault fast and timely. Then appropriate protectivemeasures will be taken to avoid the property damages and personal injury, which hasimportant significance to peoples’ life and social production,With the several typical load experiments have been done based on the arc faultexperimental device, and a large number of experiment data on arc fault has been collected,this paper presents a method of arc fault diagnosis in series based on mathematicalmorphology. The noise interferences in the current signal can be filtrated effectively by usingthe combination of morphological opening and closing operation. Then the abrupt changefeatures of current waveform from the pre and post of the arc fault in series could be exactedthrough the multi-resolution morphological gradient (MMG) computing. Finally themorphological gradient values of current under the normal working or arc fault conditionscould be obtained. It can be judged accurately whether arc fault has been occurred or not bycomparing the size of current morphology gradient values pre and post of the arc fault.The proposed method of arc fault in series diagnosis has simple logic operation, smallcomputation amount, and it is especially suitable for arc fault in series rapid diagnosis devicebased on MCU or DSP.