赵淼

摘 要：地电位浮动会对电压瞬变系统中的控制测量回路造成干扰甚至不可逆的损伤，为研究开关位置对地电位的影响规律，分析了典型电压瞬变电路中2种典型开关位置对地电位的影响，估算电路中的各元件参数并仿真得到了2种开关位置情况下电压瞬变电路中公共接地点的电压波形，搭建试验电路测得了2种开关位置情况下电压瞬变电路中公共接地点的电压波形。研究结果表明，电压瞬变过程中分布电容的充电电流流过接地阻抗形成电压降落是导致地电位浮动的根本原因;开关位置不同，电压瞬变过程中充电的电容不同，因此地电位的浮动不同;合理布置高压开关可以减小电压瞬变电路中地电位的浮动幅值。

关键词：高压开关;电压瞬变;地电位浮动;控制测量回路;干扰

DOI：10.15938/j.jhust.2021.04.008

中图分类号：TM835

文献标志码：A

文章编号：1007-2683（2021）04-0056-07

Abstract：Ground potential fluctuation caused interferences or even irreversible damage to the control and measurement circuit in the voltage transient system. To study the influence law of wiring on ground potential， two typical wirings were analyzed in the simplest voltage transient circuit. The parameters of each component in the circuit were estimated and simulated to obtain the voltage waveforms of the common ground point in the voltage transient circuit with two wirings. The test circuit was built to measure the voltage waveforms of the common ground point in the voltage transient circuit. The results showed that the voltage drop which was formed by the charging current of the distributed capacitance flowing through the ground impedance during a voltage transient was the basic reason for the ground potential floating; the switch positions were different and the capacitances charged during the voltage transient was different， therefore the floating of the ground potential was different; the floating amplitude of ground potential in voltage transient circuits could be reduced by arranging high voltage switches rationally.

Keywords：high voltage switch; voltage transient; ground potential fluctuation; control and measurement circuit; interference

0 引 言

许多情况下，只有负载上被施加瞬变电压时才能得到预期的试验效果，如脉冲杀菌、静电除尘、电力设备的脉冲振荡电压试验等[1-4]。当负载上的电压发生快速变化时，试验回路的公共接地点存在地电位升高[5-7]。地电位升高会对整个系统的二次回路，包括测量、控制及显示等弱电部分，产生干扰，严重时会造成不可逆的损伤[8-10]。文献调查表明，对变电站内地电位升高原因及其对二次回路影响的研究成果较多[11-15]。也有少量成果研究了电压瞬变试验回路中的地电位升高及其对二次回路的干扰等问题。文[16]针对试验大厅现场设备接线情况，通过测量回路电流研究了地电位升高原因，并研制了一套可有效避免空间辐射干扰和线路传导干扰的智能组件端口电压测量系统。……