基于EMTP仿真和实测的接地电缆雷电过电压特性分析

Research on Lightning Overvoltage Characteristics of Grounding System Cable Based on EMTP Simulation and Experimental Test

针对目前缺少有效设备仪器和方法保护接地系统雷击浪涌的问题,文中系统化地研究了地下配电电缆中使用的接地系统的暂态特性。通过现场实验测试与EMTP仿真分析,对传统多点接地电缆系统和非捆绑式公共接地电缆系统中性线感应的雷电过电压进行了评估计算与详细比较。首先通过EMTP软件建立配电缆雷击感应电压计算仿真模型;然后通过比较实际测量结果与EMTP仿真所得到的数值结果,验证本研究所建立的仿真模型的有效性和准确性。最终,通过验证后的模型的EMTP仿真结果对雷电绝缘水平进行预测。

Aiming at the problem that there are no effective equipment, instruments and methods to protect the grounding system from lightning surges, the author systematically studies the transient characteristics of the grounding system applied in underground distribution cables. Through field test and EMTP simulation analysis, the lightning overvoltage induced by the neutral line of the traditional multi-point grounding cable system and the unbundled public grounding cable system is calculated and compared in detail. Firstly, based on EMTP, a simulation model for calculating the lightning induced voltage of the distribution cable is established;then, the validity and accuracy of the established simulation model are verified by comparing the actual measurement results with the numerical results obtained by EMTP simulation. Finally, the EMTP simulation results of the verified model are used to predict the lightning insulation level.