摘要
通过理论分析和大量6 kV模拟实验验证,得到了电弧接地故障时暂态零序电压和电流的特征:1)零序电压和各馈线零序电流暂态分量的频率主要与变压器漏抗、电网对地电容和相间电容有关,与中性点接地方式无关;2)故障线路与非故障线路的零序暂态电流的频率、衰减速度等特性是相同的.非故障线路零序暂态电流的大小与本线路对地电容的大小呈正比,而故障线路零序暂态电流等于所有非故障线路零序暂态电流之和,方向相反;3)单相接地故障发生在相电压最大值附近时,暂态零序电流最大.在此基础上,提出一种新的、能在单片机上实现并满足在线实时选线计算需要的单相接地故障暂态电流方向选线算法.经挂网运行证明,所提算法对电弧接地故障是有效的.
Based on theory analyses and simulating experimental verifications in a 6 kV power network, the characteristics of transient zero-sequence voltage and current during arc-earth fault were obtained as follows： 1） The frequency of transient component in the zero-sequence voltage and current was mainly relevant to the leakage impedance of transformer, to-earth capacitances and capacitances between phases and not relevant to the neutral earthed 2） The zero-sequence transient currents of non-fault feeders and fault feeder have identical frequency, attenuation speed and so on. The intensity of non-fault feeders was directly proportional to the to-earth capacitance, and the intensity of the fault feeder is equal to sum of that of all non-fault feeders with opposite direction 3） As the single-phase earth fault occurs nearby the maximum value of phase voltage, the zero-sequence transient current was the largest. A new method, which can detect single-phase-to-ground fault feeder using a transient zero-sequence current direction, was proposed. The method can be operated in the single-chip micro-processor and locate the fault feeder on-time. The operation results indicate that this method can effectively raised the accuracy of the detecting fault feeder for arc-earth fault.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2008年第2期201-206,共6页
Journal of China University of Mining & Technology
基金
中国矿业大学科学基金项目(E200427)
关键词
配电网
暂态零序电流
小电流接地选线
单相接地故障
distribution network transient zero-sequence current earthed fault feeder detection in the indirectly power system
one-phase-to-ground fault
