考虑分布电容的IT系统绝缘故障相判别方法研究

摘要

分析了考虑分布电容影响的IT系统发生首次单相接地故障前后系统对地电压的变化情况:研究了故障相的特征,找出了4个特征量用以判别故障相.提出了一种基于特征量的故障相判别方法,并给出判定阈值的整定方法以及故障相判别流程.最后利用原型系统对故障相判别方法进行了验证,结果表明该方法有效.%This paper analyzed the system voltage variation vs grounding resistance before and after grounding fault was conducted,considering the influence of distributed capacitance.Four characteristics quantities which indicate the fault phase were found.Furthermore,a fault phase locating method based on these characteristics was proposed.And also,judging threshold turning method and fault phase locating flowchart were provided.Finally,experiments were conducted in a prototype system,and the results show that the locating method is effective.