基于热电耦合模型的500kV氧化锌避雷器温度分析

Analysis of Temperaturefor 500 kV ZnO Surge Arrester Based on Thermal-Electric Coupling

建立500 kV变电站用氧化锌避雷器模型,运用ANSYS Workbench对其进行热电耦合仿真计算,分析工况及内部阀片损坏时,其电位及温度分布;模拟避雷器各节阀片损坏试验,红外成像观测避雷器温升情况。仿真结果表明,避雷器内部阀片发生损坏时,损坏节分得较小一部分的电压,主要由其他两节承担;正常工况下避雷器外表面温度分布较为均匀,由于两端的铝合金散热效果较好,内部阀片柱表面温度呈现中间高两端低的现象。试验结果显示,受损节温度较低,其他两节温升较为显著,加压3小时外部温升4℃,内部温升高达45.7℃。由于避雷器电阻片损坏时,其电位分布及内外温升较为明显,故可通过监测避雷器电位情况及温度大小来判别其运行状态。

The model of was built for 500 kV zinc oxide arrester in substation,Adapting a methodology based on ANSYS Workbench thermal-electric coupling FEM to analyze the voltage distribution and temperature distributionin the condition of normal operationand inner varistors occurring failure;Simulating the damage of each section of varistorsin the experiment and detectingthe temperature rise of the external arrester by using infrared imager. Simulation results show thatthe voltage of the damaged part is smaller, mainly by the other two sections When the internal valve of the arrester is damaged;Under normal operating conditions, the temperature distribution of the outer surface of the arrester is more uniform,As the heat dissipation effect of the aluminum alloy at both ends is better, the surface temperature of the inner valve column shows the phenomenon that the middle high both ends low. Experiment results demonstrate that the damaged section of the lower temperature, the other two temperature rise is more significant;Applying voltage for 3 hours, the external temperature rise 4℃, the internal temperature rise up to 45.7℃. Due to the arrester varistors damaged, the potential distribution versus internal and external temperature rise is more obvious, it can monitor the potential and temperature of arrester to determine its operating status.