埋地电缆耦合雷电电磁波的过程及特性分析

Analysis on Procedure and Characteristics of Lightning Electromagnetic Wave the Coupling Process between and Buried Cables

针对埋地电缆耦合雷电电磁波形成过电压对精密设备造成干扰及损坏的问题。根据脉冲场作用下地下电缆内感应电压的理论分析，建立了架空电缆、大地、埋地电缆一体化模型，利用模拟8／20μs波形雷电流进行冲击试验，得出以下结论：在埋地电缆终端无负载的情况下，架空电缆与埋地电缆位置相互平行相比于垂直时，埋地电缆耦合到的雷电电压幅值及能量要小：在架空电缆与埋地电缆相互位置一样的情况下。埋地电缆终端无负载时．相比于终端接与其特性阻抗相匹配的负载．埋地电缆耦合到的雷电电压幅值大3～6倍．耦合到的雷电能量大3个数量级左右．研究结果对埋地电缆在实际雷电防护应用中具有一定的参考价值。

In order to solve the damage and interference problems to the precision devices induced by overvohage excited by the coupling process.According to the pulse field under the action of underground cable induced voltage in the theoretical analysis, establish the integration model of aerial cables , the earth, buried cables,using 8/20 txs waveform of lightning current to perform impulse test, the following conclusions are got：In the case of a buried cable terminal with no load, aerial cable compared with buried cable position parallel to each other in the vertical, buried cable coupled to lightning voltage amplitude and energy is smaller; In the aerial cables and buried cable mutual position, under the condition of buried cable terminal with no load, compared to the terminal and its characteristic impedance matching load, buried cable coupling to the lightning around 3-6 times larger voltage amplitude, coupled to the electrical energy is big about 3 orders of magnitude , which has a certain reference value to the protection on buried cables.