标题：Detection method of high impedance grounding fault based on differential current of zero-sequence current projection and neutral point current in low-resistance grounding system [基于中性点电流与零序电流投影量差动的小电阻接地系统高阻接地故障判断方法]
作者：Sheng, Yaru ;Cong, Wei ;Bu, Xianghai ;Li, Xiaoming
作者机构：[Sheng, Yaru ;Cong, Wei ;Li, Xiaoming ] Key Laboratory of Power System Intelligent Dispatch and Control, Ministry of Education, Shandong University, J 更多
通讯作者地址：[Sheng, Y] Key Laboratory of Power System Intelligent Dispatch and Control, Ministry of Education, Shandong UniversityChina;
来源：Dianli Zidonghua Shebei/Electric Power Automation Equipment
页码：17-22 and 29
关键词：Current difference; Current projection; High impedance grounding fault; Low-resistance grounding distribution network
摘要：Based on the analysis of the vector relation between the neutral point current and zero-sequence current of faulty and normal lines, a detection method of high impedance grounding fault based on the differential current of zero-sequence current projection and neutral point current is proposed. As grounding fault occurs, the fault line passes through grounding point and neutral point of the system to form a basic zero-sequence circuit. Because the neutral point current is resistive, the difference between the projection of zero-sequence current of fault line on neutral point current and the neutral point current is small. However, the zero-sequence current of non-fault line is capacitive, so the difference between the projection of zero-sequence current of non-fault line on neutral point current and the neutral point current is large. Therefore, the ratio method is introduced to detect high impedance grounding fault effectively. Then a further investigation is made about the effects of asymmetric line parameters, asymmetric load and asymmetric voltage of the system on the presented method. Simulative results by PSACD proves that the presented method can reliably detect high resistance grounding fault, which is less affected by various asymmetric conditions, and has high sensitivity and reliability. © 2019, Electric Power Automation Equipment Press. All right reserved.