变电站直流故障检测准确率提升方法研究  

Methods for Improving Substation DC Fault Detection Accuracy

作　　者：盛炜[1] 雷兴[1] 徐楠[1] 孙婕韵[1] 董志赟[1] 刘高原[1] 

机构地区：[1]国网上海市电力公司检修公司,上海201204

出　　处：《电力与能源》2016年第3期287-290,共4页Power & Energy

摘　　要：直流接地故障检测不准确的原因主要包括漏电电力互感器(TA)零漂、调用切换时间长、存在分布电容。针对TA零漂,采用不平衡电桥的差流算法进行辨识,对接地电阻及零漂电流进行趋势分析,并制定相应的检修计划。针对调用切换时间长,根据故障前后电流电压的状态量、接地电阻的计算量及三者的电气联系进行故障特征辨识,提出基于逻辑事件驱动的自动巡检模式。针对系统分布电容,设计微小交直流测量元件和基于恒电阻电子电路的负载电路,并实现母线电压的自适应平衡控制。The inaccurate causes of DC grounding fault detection are analyzed,mainly including zero drift of the leakage TA,long switching time of dynamic invocation,and distributed capacitance.In view of the TA zero drift,the differential current algorithm is used to identify zero drift based on the unbalanced bridge,the grounding resistance and zero drift current are analyzed,and the corresponding maintenance plan is made.For long switching time of dynamic invocation,the fault characteristics are identified according to the logical relationship between state variables such as voltage,current and calculated value such as grounding resistance before and after the fault.Automatic inspection mode based on logic event driven is proposed.In view of the distributed capacitance of the system,the design of the micro AC and DC measuring element and the load circuit based on the constant resistance electronic circuit are designed,and the adaptive control of the bus voltage is realized.

关 键 词：接地故障 零漂电流 分布电容 动态调用 

分 类 号：TM63[电气工程—电力系统及自动化]