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 micro-grid

作　　者：田新和 陈皓[1] 郑思琦 闫重熙 高传薪 Tian Xinhe;Chen Hao;Zheng Siqi;Yan Chongxi;Gao Chuanxin(College of Electrical Engineering and Information Technology, Sichuan University, Chengdu 610065, China)

机构地区：[1]四川大学电气信息学院

出　　处：《电测与仪表》2019年第15期8-13,20,共7页Electrical Measurement & Instrumentation

摘　　要：当直流微网线路发生故障时,为快速切除故障并恢复供电,减少停电时间,需要快速准确的故障定位。以低压双极环形直流微网为研究对象,针对单极接地故障和极间短路故障,提出了一种差分法与伪逆法相结合的新型故障定位方法,可在线确定出不同故障条件下的故障位置,且定位准确性高。根据暂态期间故障回路的KVL矩阵方程,利用差分法和伪逆法,计算故障线路的等效电感,进而计算出故障距离,从而实现故障定位。通过PSCAD/EMTDC仿真验证了该方法的有效性,对两种故障类型及不同故障距离和故障电阻,故障距离估计误差均小于1.43%,故障电阻相对误差小于0.04%。该方法可针对两种不同的故障类型,不受故障距离和故障电阻的影响,能准确地确定出故障点位置并计算出故障电阻,具有较好的实用性。When a fault occurs on DC micro-grid 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. Aiming at 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 micro-grid. 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 proposed 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%. The proposed scheme is suitable for two different fault types, and it is not affected by fault distance and fault resistance, which can accurately locate fault point and calculate fault resistance, as well as has good practicability.

关 键 词：低压双极环形直流微网 单极接地故障 极间短路故障 故障定位 差分法 伪逆法 

分 类 号：TM933[电气工程—电力电子与电力传动]