Frequency-Dependent Coupled Field-Circuit Modeling of Armored Power Cables Using Finite Elements

This paper proposes a frequency-dependent electromagnetic model for armored power cables using Coupled circuit-field method. The model parameters were obtained by conducting a series of coupled field-circuit studies at different frequencies. The cable capacitance matrix is calculated using an electrostatic FE analysis. The frequency response of the cable was obtained by coupling the cable FE domain model and external electric circuits. This technique allows the physical representation of the nonlinear magnetization behavior of the cable shell as well as the frequency dependence of the cable parameters. This frequency response was then fitted with rational function approximation. The resulting vector fitting (VF) rational function was then represented by an equivalent electrical network. This model represents the cable´s high-frequency dynamic behavior to account for overvoltages or spikes in the current waveforms.