Research and application of finite-element time-domain method for transient response of buried cable excited by an electromagnetic wave

To analyze electromagnetic (EM) transient responses of a buried cable, an accurate and reliable time-domain method is proposed in this paper. The approach is based on the transmission line (TL) second-order telegrapher's current equation, and the expressions of ground impedance and admittance at higher frequencies are used to obtain the discrete finite-element time-domain (FETD) equations for the cable. Finally, transient responses at termination loads of the buried cable are obtained based on the global FETD equation, which is assembled using discrete FETD equations on all intervals. The accuracy and effectiveness of the proposed FETD method are demonstrated by comparing numerical results to those of the finite-difference time-domain (FDTD) method. The proposed method is also employed to investigate the effects of numerous parameters on transient currents of the buried cable, including the soil conductivity, buried cable depth, and incident and polarization angles of the external EM wave.