中文摘要：

自然云地闪电的波形参数波动范围极大,使得雷电波波形参数对输电线路绝缘子串雷电冲击闪络特性的影响不可忽视。为此,利用电压积分法（disruptive effect method,简称DE法）对输电线路绝缘子串在不同雷电波下的伏秒特性曲线变化规律及其在输电线路绕击跳闸率（SFFOR）分析中的应用进行了研究。首先对传统DE法的参数设定进行分析,分析结果表明,模型参数k越小时,DE法的伏秒特性重构曲线越陡峭。在此基础上,提出了1种新的DE参数选取方法使重构曲线能更好地反映实际绝缘子串的伏秒特性曲线变化规律,并与试验数据进行对比来验证该方法的准确度。对500kV输电线路绝缘子串在多种雷电波下的伏秒特性曲线变化规律的研究表明,施加雷电波的波前时间越小,伏秒特性曲线就越陡峭,绝缘子串的绝缘性能也就越差。此外,输电线路绕击跳闸率还必须考虑雷击线路的分散性。因此,将输电线路雷电先导分形发展理论与DE法相结合,提出了1种同时考虑雷击线路分散性和雷电波参数波动性的输电线路绕击跳闸率（SFFOR）的评估方法,计算结果表明500kV输电线路绕击跳闸率为0.337次/（100km.a）,与运行统计数据相近。

英文摘要：

The wide variation of waveform parameters of natural lightning will remarkably affect the flashover characteristics of insulator strings of transmission lines.Therefore,we used the disruptive effect（DE） method to study the voltage-time characteristics variation pattern of the insulator strings under different lightning overvoltages,and to study its application to the analysis of the shielding failure flashover rate（SFFOR） of transmission lines.Firstly,the parameter setting of traditional DE method was analyzed,indicating that when the DE model parameter k was lower,the voltage-time characteristics reproduction curve of DE method was steeper.Consequently,a new parameter setting method was proposed to improve the reproduce curve to better reflect the actual distribution pattern of the insulator strings voltage-time characteristics.The effectiveness of this proposed method is verified by comparing with the experimental data.Based on the proposed method,the voltage-time characteristics curve variation pattern of a 500 kV transmission line insulator string under multiple lightning waves was further studied.The results indicate that,the smaller the applied lightning wave front time is,the steeper voltage-time characteristics curve is,the worse the insulation performance of the insulator strings will be.In addition,the statistical features of lightning strikes should be involved in the consideration of the lightning shielding performance of transmission lines.Therefore,combined the lightning fractal leader progression theory with the DE method,a method to assess the SFFOR of transmission line considering both the dispersion of the lightning shielding failure and the fluctuation of the lightning wave parameter is proposed.Calculation results of the method show that the SFFOR of 500 kV transmission line is 0.037 times /（100 km·a）,which is close to the operation data.