用于线路绝缘测试的工频滤波器仿真分析

Simulation Analysis of Frequency Filter Applied to Insulation Test of Transmission Line

采用兆欧表对架空线路进行绝缘测试或定相试验时,由于线路上的感应电压有时会超出兆欧表的耐压水平导致兆欧表损坏。对此采用将工频滤波器串接到兆欧表和被测线路之间的方法,能够有效降低兆欧表承受的工频感应电压。用Matlab/Simulink对加装工频滤波器的兆欧表和高感应电压输电线路进行单体和系统建模,仿真结果证明,工频滤波器能够在不影响测量结果的情况下有效保护兆欧表。

When the induced voltage of the line which is measured in a megger insulation test is higher than the voltage withstand level of the megger, the test tool may be damaged. In order to lower the induced voltage applied on the megger, a series circuit was formed with the megger, the frequency filter and the line under test. The basic principle and usage of the frequency filter were described in detail. Then the megger in series with a frequency filter and multi-circuit overhead transmission lines with highly induced voltage were modeled. The imitation results proved that the frequency filter could provide effective protection for the megger and would not affect the test results.