Safety measurement of capacitive current for coal mine distribution network

Existing schemespsila characteristics to measure capacitive current are analyzed, in order to measure capacitive current of distribution network in formidable conditions of coal mine. The new measurement scheme of capacitive current is put forward, which is based on a resistant added single-Phase line. Using this new method, the capacitive current of single-phase ground fault is predicted through examining zero sequence voltage and current of grounding resistant in good running condition of distribution network. The capacitive current measurement device used this new method and DSP is designed. Veracity of this new system is testified by giving a simulation distribution network example and by Matlab analysis. The results show that capacitive current, insulation resistant current, single-phase grounding current, and etc, the key parameters of single phase grounding fault can all be measured exactly, using the discussed capacitive current measurement system, when distribution network is running normally. This new device can be operated easily and safely, measuring result is accurate, measurement is rapidly.