架空线路雷电感应电压的改进时域有限元法研究

Research on the Improved Finite Element Time Domain Method of the Lighting Induced Overvoltage of the Overhead Transmission Line

为了提高配电线路的安全可靠性并对线路防雷设计提供有价值的参考依据,基于Agrawal场线耦合模型,推导出了仅以传输线沿线电压作为求解变量的数值方法,实现了一种用于求解场线耦合模型改进电报方程的单变量时域有限元法(FETD)。针对三相架空配电线路,分别计算了垂直排列、水平排列和架设地线三种典型线路结构的感应雷过电压,通过与双变量的FETD法计算结果对比,验证了该方法的正确性。此外,通过计算复杂度分析,说明了本方法相对于双变量FETD法在效率上的优势。

In order to improve the safety and reliability of distribution lines and provide valuable reference for lightning protection design,this paper derived a numerical method which only takes the voltage along the transmission line as the solution variable and proposed a single variable finite-element time-domain method（ FETD） for solving improved telegraph equation of the field-to-line coupling model on the basis of Agrawal field-to-line coupling model. For the typical three-phase overhead distribution lines,the authors calculated the lightning induced voltages of three kinds of line structure including vertical arrangement,horizontal arrangement and the one with ground line. The method was verified by comparing it with the calculation results of the bivariate FETD method. Furthermore,the proposed method has simpler computation than the bivariate FETD method.