基于零序电压幅值差的配电网断线识别与隔离

摘要

由于配电网断线故障没有及时处理而造成的过电压、人畜伤亡、旋转电机损坏等事故时有发生.针对这一问题,首先分析了配电网发生断线后零序电压的分布特征,指出由于纵向断线造成系统的不平衡且电压不连续,断口两侧零序电压幅值差别较大.基于此特征,提出了基于零序电压幅值差的断线故障识别方法,并给出了基于配电网自动化系统的智能分布式和集中式两种故障处理模式.PSCAD仿真表明,所述方法在各种断线形态下都可以可靠定位,具有不受中性点接地方式、过渡电阻、负荷大小影响的特点,但依赖于通信.%The over-voltage,personnel and animal casualties,rotating motor damage and other accidents often occur in distribution network,which are caused by line breakage fault.In order to solve this problem,distribution characteristics of the zero sequence voltage are analyzed when a line breakage fault in distribution network occurs.There exists a large zero sequence voltage amplitude difference on both sides of the fault point because the system is unbalanced and the voltage is not continuous due to the longitudinal disconnection.Based on this characteristic,a fault identification method based on zero sequence voltage amplitude differential principle is proposed,and two fault processing modes of distributed mode and centralized mode based on distribution automation are given.PSCAD simulation shows that the proposed method can locate all kinds of line breakage fault and is immune to neutral point grounding mode,grounding transition resistance and load size,but it depends on communication.