田新和,陈皓,郑思琦,闫重熙,高传薪.低压双极环形直流微网的新型故障定位法[J].电测与仪表,2019,56(15):8-13，20. tianxinhe,chenhao,Zheng Siqi,Yan Chongxi,Gao Chuanxin.A Novel Fault Location Method for Low Voltage Bipolar Ring DC Microgrid[J].Electrical Measurement & Instrumentation,2019,56(15):8-13，20.
低压双极环形直流微网的新型故障定位法
A Novel Fault Location Method for Low Voltage Bipolar Ring DC Microgrid
When a fault occurs on DC microgrid cable, in order to achieve quick fault clearance, fast restoration, and reduction of power outage duration, it is necessary to quickly and accurately locate fault point. For pole-to-ground fault and pole-to-pole fault, a novel fault location method combining difference method and pseudo inverse method is proposed for low voltage bipolar ring DC microgrid. The proposed scheme can online locate fault point under different fault conditions, which has high location accuracy. According to the KVL matrix equation of fault circuit during transient state, the equivalent inductance of fault cable is calculated by using difference method and pseudo inverse method, and then fault distance is calculated to locate fault point. The effectiveness of the method is verified by PSCAD/EMTDC simulation. For two fault types as well as different fault distance and fault resistance, the estimated error of fault distance is less than 1.43% and the relative error of fault resistance is less than 0.04%. Not affected by fault distance and fault resistance, the proposed scheme, which is suitable for two different fault types, can accurately locate fault point and calculate fault resistance, so it has good practicability.
