雷电流建模方法及其对架空线路耐雷性能分析影响的研究

Study on the Modeling Approach of Lightning Current and Its Influence on Overhead Line Lightning Withstand Performance Analysis

摘要：雷电流参数是输电线路雷电过电压分析和雷电防护分析的基础。总结了雷电流波形实测参数和雷电流模型．分别从波形和频谱两个方面对典型的雷电流模型进行了对比研究。利用PSCAD建~＋800kV特高压直流线路模型．采用不同的雷电流模型计算了线路的反击和绕击耐雷水平，结果表明：Heidler波和Concave波波头呈凹形，Concave波波头较Heidler波、双指数波和斜角波与实测雷电流波头最为接近。各雷电流模型的频谱都主要集中在0～100kHz以内，能量主要集中在0～50kHz以内．各雷电流模型频谱的区别主要在0～10kHz。雷电流波形对反击耐雷水平影响较大．对绕击耐雷水平影响较，J、。雷电流建模方法相同时，反击耐雷水平与雷电流波头斜率成反比。雷电流波形参数的实测结果分布范围较大．在输电线路防雷分析时，需要根据线路实际情况．测量和选取雷电流波形参数．

The lightning current parameters is essential for the calculation of transmission line lightning overvoltage and lightning protection analysis. The measured parameters of lightning waveform and the models of lightning current were summarized. The waveform and spectrum of typical lightning current models are analyzed. A simulation model about ＋800 kV UHVDC transmission line is established by PSCAD. The lightning strike back and shielding withstand levels were calculated using different lightning current model. The result show that the wavefront of Heidler wave and Concave wave were concave. The wavefront of Concave wave is most similar to that of actual lightning current than Heidler wave, double exponential wave and oblique wave. Spectrums of all lightning current models are focused within 0-100 kHz. Energy of all lightning current models is focused within 0-50 kHz. The difference between lightning current models is focused within 0-10 kHz. The influence of lightning waveform on back-flashover lightning withstand level is great. However, the influence of lightning waveform on shielding failure lightning withstand level is small. Back-flashover lightning withstand level is inversely proportion to slope of lightning waveform when modeling approaches of lightning current are same. The range of measured parameters of lightning waveform is quite diverse. It is necessary to measure and select waveform parameters according to the actual condition of transmission line in lightning protection analysis.