A New Method of Using Pulse Broadening to Realize Selective Leakage Protection in Coal Mine

In order to improve the reliability of selective leakage protection of power network in mine, a hardware circuit using pulse broadening to realize selective leakage protection of zero-sequence current direction was proposed. Its test on 660 V test device and waveform on TEK DPO2014 oscilloscope proved that the proposed circuit is correct and reliable. Leakage protection devices with the proposed circuit have been successfully applied in coal mines.