Treatment of frequency-dependent underground cable using the FDTD method

Based on the finite difference time-domain (FDTD) method, a new model is presented for the transient simulation of underground cable in this paper. For the convenience of the time-domain convolution, the vector fitting method (rational approximation in the frequency domain) is adopted to synthesize the skin effects of conductors and ground in the frequency domain. Thus, the problems associated with frequency-dependent transformation matrices are avoided. Additionally, the voltage and current wave processes on the underground cable can be obtained. Compared with other cable models, the new model proposed is demonstrated to be effective.