时域有限元法求解传输线瞬态波过程

Transients Analysis of Transmission Line by Time Domain Finite Element Method

讨论了求解多导体传输线(multi-conductor transmission line,MTL)的时域有限元法(time domain finite element method,TDFE),并给出了计算动态集中元件的时域处理方法。通过与传统的数值计算方法时域有限差分法(finite difference time domain,FDTD)和国际上通用的电磁暂态计算程序EMTP的计算结果进行比较,验证了TDFE法的正确性。该方法克服了FDTD不能直接计算带有集中参数网络的传输线这一不足,而且在相同条件下,可以有效地抑制由于在FDTD方法中使用中心差分所造成的吉布斯效应。相对于EMTP只能求解所设定传输线两端的响应这一缺憾,该方法的优势在于能够得到沿线所有离散点的电压电流分布。最后,将TDFE应用于500kV变电站开关操作时,由于电容式电压互感器的影响而在二次电缆上产生的电磁干扰的数值预测。

A time domain finite element method （TDFE） applied to the analysis of electrical transients on multiconductor transmission line （MTL） was presented. Together with finite elements that represent electrical elements with lumped parameters, an effective method for transient simulation in electrical networks was put forward. This method overcomes the disadvantages of finite difference time domain （FDTD）, which is difficult to solve MTL with lumped parameter networks, and EMTP, which is not effective for calculation of entire wave processes of voltage and current distributed along the MTL. TDFE can effectively depress the Gibbs phenomena resulted from FDTD method. This method was applied to numerical prediction of the electromagnetic interference （EMI） in substation secondary cable caused by switching transient current through capacitance voltage transformer （CVT）.