中性点不接地配电系统馈线单相接地故障的暂态电流保护新原理  

A NEW PRINCIPLE OF TRANSIENT CURRENT GROUNDED RELAY FOR FEEDER IN UNGROUNDED DISTRIBUTION SYSTEMS

作　　者：苗友忠[1] 孙雅明[1] 杨华[2] 

机构地区：[1]天津大学电气与自动化工程学院,天津300072 [2]天津电力局,天津300010

出　　处：《中国电机工程学报》2004年第2期28-32,共5页Proceedings of the CSEE

摘　　要：当中性点不接地系统发生单相接地故障时,通过对馈线上各相电流暂态分量的形成与分布特征的分析可知:故障相暂态电流分量(Transient Current Component,TCC)是由故障馈线的非故障相提供的自供性TCC和其它非故障馈线提供的相似性TCC组成,该重要特征使基于正交小波分解提取 特征频带具有可行性、有效性和稳定性。文中所提出的构成单相接地保护继电器的判断准则是理论分析的定义,所以是固定不变的,即:不需整定计算,适合于中性点不接地模式的任何配电网。该保护方式容易融于分布式馈线保护间隔单元中,不需配置监控系统选线模块或专用选线装置。经过大量的ATP和MATLAB仿真验证表明:该原理能够准确地识别不同类型的单相接地故障,可靠性和灵敏度较高。A new principle of the transient current protective relay for feeder single-phase-to-ground-fault is proposed in distribution systems. The protective judge criterion is defined theoretically and is changeless. The judge criterion is formed by extracting ratio of feature band measure between phase transient current component (TCC) in faulty feeder (FF) based on algorithm of orthogonal wavelet, through analysis distributed characteristic of three-phase current transient components in feeders of distribution systems. Because the TCC of faulty phase in FF are supplied and composed of self-supply TCCs of healthy phases in FF and similar TCCs of all healthy feeders (HF), it is feasibility, validity and stability to detect grounding fault for any ungrounded-neural systems and without setting calculation. The protective mode is fused with the gap units of distributed feeder protection easily, and does without disposing appropriative devices for the selection grounded feeders and its software. ATP simulation and wavelet transform (WT) analysis of MATLAB verify that the proposed method can correctly distinguish all kinds of single-phase-to-groundfaults, and has high reliability and sensitiveness.

关 键 词：中性点不接地配电系统 馈线 单相接地 故障 暂态电流保护 

分 类 号：TM642[电气工程—电力系统及自动化]