【摘要】 电力系统杆塔接地模型是研究架空输电线路耐雷性能的重要方法,杆塔接地模型影响着绝缘子串的过电压值以及地电位升(GPR)。本文的主要工作是研究不同土壤模型对雷电过电压值的影响以及土壤参数是否随频率改变。本文将基于EMTP-ATP软件建立接地系统模型,使用RLC合成网络模型代替集中参数电阻,其中RLC网络参数取自对频域麦克斯韦方程进行严格求解后得到的接地系统。本文通过计算实例验证了过电压数值对频变土壤参数较为敏感,并且在土壤电阻率较高的情况下该现象更为明显。更多还原

【Abstract】 A key method in the evaluation of the lightning performance of an overhead line is the tower grounding modeling approach. It affects the insulator string overvoltage and the ground potential rise( GPR). This work aims to assess the impact of the soil model i. e. using frequency independent and frequency dependent parameters. The developed grounding system model was implemented in the EMTP-ATP program. A RLC synthetized network is used instead of a constant lumped resistance. The RLC elements are derived from the rational approximation of the grounding system response obtained using a rigorous model based on the direct solution of Maxwell’s equations in the frequency domain. An application example is presented,showing that the computed overvoltage is sensitive to the frequency dependence of the soil parameters. This effect is more pronounced for high resistivity soil.更多还原