配电系统零线断线保护原理及现场应用配电系统零线断线保护原理及现场应用.pdf

Transmission and Distribution Engineering and Technology 输配电工程与技术, 2015, 4(4), 87-92 Published Online December 2015 in Hans. /journal/tdet /10.12677/tdet.2015.44009 Distribution System Zero Line Break Protection Principle and Application 1 2 2 1 2 1 Zhixiang He , Chunfang Liu , Zengsheng Chen , Hui Zhang , Tangjie Liang , Shuzhao Wu 1 Foshan Chancheng District Power Supply Bureau, Guangdong Power Grid Corporation, Foshan Guangdong 2 Foshan Electric Power Design Institute Co., Ltd., Foshan Guangdong th st th Received: Nov. 6 , 2015; accepted: Nov. 21 , 2015; published: Nov. 26 , 2015 Copyright © 2015 by authors and Hans Publishers Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). /licenses/by/4.0/ Abstract When zero line disconnection occurs in three-phase distribution system, a displacement voltage will appear at the neutral point of client, which may cause the equipment and personal safety ac- cident. The relation between neutral point voltage and load unbalance is studied when zero line disconnection occurs in three-phase distribution system. The theoretical analysis shows that: zero sequence voltage appears at the neutral point and there is no zero sequence current when the ze- ro line disconnection occurs. Based on this characteristic, a new method to detect zero line dis- connection is proposed based on zero sequence voltage with zero line current blocking, and the layout scheme is studied. Keywords Three-Phase Distribution System, Zero Line Disconnection, Load Unbalance, Displacement Voltage 配电系统零线断线保护原理及现场应用