Grounding Faulted Feeder Detection Methods Applied in Chinese Ineffectively Earthed Distribution Systems

Medium voltage (MV) power systems have been operated with floating neutral or Petersen-coil grounded. Grounding fault current is no more than ten amperes. Traditional grounding faulted feeder detection methods based on zero sequence current have poor sensitivity in this case. In the last ten years, many novel faulted feeder detection methods have been developed in China. Some of them have widely and successfully applied in Chinese distribution systems. Four best of them (Harmonic currents comparison based fault detection, signal injection based detection, traveling wave based detection, and phase current difference based detection) are presented in the paper. The advantage and disadvantage of each method are analyzed, and problems that need further study are also brought forward.