Finite-Element Time-Domain Method for Multiconductor Transmission Lines Based on the Second-Order Wave Equation

Based on the second-order wave equation of voltage, discrete equations for multiconductor transmission lines (MTLs) are derived by using finite-element time-domain (FETD) method and Newmark-Beta formulation. And then, the time-domain method to process lumped elements is also given based on the node admittance method of circuit analysis. Combining all the discrete equations and lumped elements, the global FETD equation is obtained based on the single iteration variable voltage. Finally, by means of the coupled equations between current and voltage, the iteration formulas of current along MTLs are derived. Compared with EMTP program by numerical examples, the proposed method in this paper is proved to be correct and effective. Furthermore, the simulation result demonstrates that the proposed method is better than the existing FETD methods in computation efficiency and convenience for the treatment of complex lumped networks.