小电阻接地系统单相断线故障分析及对策研究Analysis and Countermeasures of Single-phase Disconnection Fault in Low Resistance Grounding System
盛方正,陈福良,范秉翰,王文成
SHENG Fang-zheng,CHEN Fu-liang,FAN Bing-han,WANG Wen-cheng(Pudong Power Supply Company of SMEPC
摘要(Abstract)：
在城市中压配电网中小电阻接地系统是很常见的,这类系统一般不会配置专门用于反应断线故障的继电保护装置,发生断线故障后往往由用户首先发现,供电部门在处理这类故障时存在延时问题。为此,分析了变压器高压和低压侧单相断线对用户造成的影响,计算出故障后零序、负序分量,证明目前配电网通常配置的过流和零序过流保护难以反应此类故障,提出了利用零序和负序故障分量对单相断线故障进行判断的改进方法。
Low resistance grounding system is very common in urban medium voltage distribution networks,and there is usually no relay protection against disconnection fault in these systems.When such faults occur,these are always found by the users first.And there is delay for power supply companies to deal with this type of fault.Through the analysis of the impact of single-phase disconnection on high-voltage and low-voltage sides of transformers on the users,this paper calculates the zero sequence and negative sequence components after the fault and proves the relay protection of overcurrent and zero sequence current in the existing distribution networks is difficult to respond to this kind of fault.In addition,it proposes the ways of improvement in detecting faults by means of zero sequence and negative sequence components.
关键词(KeyWords)：
小电阻接地;单相;断线;继电保护
low resistance grounding;single-phase;disconnection;relay protection
基金项目(Foundation):
作者(Author):
盛方正,陈福良,范秉翰,王文成
SHENG Fang-zheng,CHEN Fu-liang,FAN Bing-han,WANG Wen-cheng(Pudong Power Supply Company of SMEPC
DOI: 10.19585/j.zjdl.2011.07.002
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