抑制变压器雷击过电压关键因素分析

Analysis on the Key Factors of Restraining Transformer Lightning Overvoltage

随着电网装备技术的飞速发展,电网抗击恶劣天气的能力不断提高,然而雷击对电网设备的危害始终无法完全避免。对雷击引起变电所变压器过电压进行分析,分别考虑变压器的入口电容、装设避雷器及避雷器的安装距离等因素对冲击电压的影响。仿真计算结果表明:变压器入口电容值越大,电容对雷电侵入波幅值的抑制作用越明显;在变电所母线上装设避雷器可以限制雷电侵入波幅值,避免引起变压器冲击过电压,且避雷器距变压器的电气距离越短,防雷效果越好。

With the rapid development of power grid equipment technology,the power grid's ability to resist severe weather is constantly improving,but the damage of lightning to power grid equipment can not be completely avoided.This paper analyzes the overvoltage of substation transformer caused by lightning strike,and analyzes the effects of the entrance capacitance of transformer,the installation of surge arrester and the installation distance on the impulse voltage.The simulation results show that the larger the capacitance value at the transformer entrance is,the more obvious the inhibition effect of the capacitance on the lightning wave amplitude value is;the lightning arrester installed on the bus bar of the substation can limit the lightning wave amplitude value and avoid the transformer surge overvoltage,and the shorter the electrical distance between the lightning arrester and the transformer,the better the lightning protection effect.