高压开关操作引起瞬态电磁干扰的实测分析

Actual Measurement Analysis of Transient Electromagnetic Interference Caused by High-Voltage Switch Operation

为研究高压开关重击穿过程的发生规律,分析隔离开关和断路器操作产生电磁骚扰的特性,对500 k V变电站开关操作过程中导致二次回路的电磁干扰进行现场测量,并对开关操作产生的骚扰电压进行时域和频域特性分析,确定骚扰等级及主频范围。测量结果表明,就地汇控柜内二次设备端口骚扰电压幅值达到320 V,频率分布集中在45.83 MHz之内。断路器操作时端口骚扰电压有较大的幅值水平,尤其是断路器分闸-合闸-分闸操作时端口骚扰电压在幅值、微脉冲持续时间和上升沿上,相对于隔离开关操作有更为严重的情况出现。

In order to research the outbreak regularity of the repeated break down process, analysis was made to the characteristics of the electromagnetic disturbance caused by the isolation switch and circuit breaker operation. The electromagnetic disturbance of secondary circuits caused by the switching operation was measured in the fi eld, when 500 k V substation just put into operation. This paper analyzed the time and frequency characteristics of disturbance voltage in the transient process and determined the disturbance level and the range of dominant frequency. Measurement results show that the maximum disturbance voltage on the ports of secondary equipment in control cabinets is 320 V, and the disturbance frequency is focus on the range of 45.83 MHz. There is considerable disturbance voltage amplitude during circuit breaker closing operations. Especially, there is more serious situation on the amplitude, micro-pulse duration and rising time of the disturbance voltage during circuit breaker under opening-closing-opening operations.