Grounding faulted feeder detection with fault resistance measurement in mining power systems

Many mining power systems have been operated with floating neutral or high resistance grounded. The earth fault current is no more than a few tens of amperes. Traditional earth fault detection methods based on zero sequence current have poor sensitivity in this case. For improvement, a fault detection scheme with fault current and fault resistance measurement is presented in the paper. It can detect high impedance grounding faults (HIGF). The scheme has been verified by EMTP simulation, and fault detection prototype has been developed and tested. Results show that the scheme has with high sensitivity and robustness.