雷电波对低压电源系统干扰的仿真分析

微机保护系统是电力系统的重要组成部分,但其耐压水平低,雷电波侵入电源系统时易导致设备的损坏,严重影响电力系统的正常运行。依据雷电波侵入变电站微机电源的途径,建立模型,对雷电波侵入低压电源系统引起的冲击电压干扰进行ATP仿真分析,讨论变压器低压侧有无压敏电阻、雷电波侵入位置、压敏电阻装设位置等情况对冲击电压的影响。结果表明:在变压器低压侧加装压敏电阻,能有效抑制侵入的雷电波;压敏电阻安装位置离变压器低压侧越近,保护效果越好;线路带负载后冲击电压进一步降低;根据需求,在低压电缆不同位置装设不同等级的保护器配合使用,可以有效降低雷电侵入波对低压电源系统的干扰。

Simulation Analysis on Interference to Low Voltage Power System Caused by Lightning Wave

The computer protection system constitutes a major component of power system,but the invasion of lightning surge may lead to its failure due to its low voltage withstand level which may af-fect the normal service of power system.Model was established according to the path of lightning inva-sion to power supply of microcomputer at substation.Simulation analysis was done on impulse voltage caused by lightning invasion into low-voltage power supply system.Influence on impulse voltage was discussed under conditions whether there is varistor on low-voltage side of transformer,location from lightning invasion,and disposition of varistor.Simulation results demonstrate that,installation of varistor on low-voltage side of transformer can effectively inhibit invasion lightning;the smaller the distance of varistor to low-voltage side of transformer,the better it turns out;impulse voltage is droped when line is on load;install protector with different level to combined with according to need,can effectively re-duce interference of lightning invasion to low-voltage power supply.