TV二次误并列问题分析

Detailed Explaination of TV Secondary Parallel by Mistake

介绍了电压互感器二次电压并列的工作原理、并列方法及误并列产生的影响,在理论分析的基础上,结合简单二次回路及序分量计算方法,分别对系统发生单相接地短路、两相短路等常见故障进行回路计算分析,得出不同故障情况下误并列的二次电压值,从模拟实际故障的角度总结了误并列使保护拒动及TV二次铅丝熔断的原因,分析了由于隔离开关接点造成电压自动切换回路不正常工作使TV二次误并列的原因,并给出解决办法。

This paper introduces the working principle of voltage transformer secondary voltage parallel, parallel method and the im- pact of parallel by mistake. On the basis of theoretical analysis combining with the simple secondary circuit and sequence component calculation methods, it respectively calculates and analyzes one-phase ground fault and two-phase fault occured to the system, reac- hing the second voltage value of different fault cases, from the perspective of the simulated actual fault, it summarizes the cause of TV secondary parallel by mistake making protection rejecting act and TV secondary lead wire fusing; Meanwhile it also analyzes the cause of the isolating switch contact making voltage automiatic switching circuit abnormal work and making the TV secondary parallel by mis- take.