Modeling of Power Cables with Arbitrary Cross Section: From Parameter Calculation to Electromagnetic Transients Simulation

Abstract

A full computer-based methodology is proposed for electromagnetic transient simulations in power cables characterized by an arbitrary cross-section geometry. The frequency-dependent parameters of the cables are calculated using finite element method, and the three-phase cable modeling is carried out using modal decoupling and fitting techniques. The multiconductor representation of a sector-shaped cable is possible from the calculation of a constant and real modal transformation matrix, resulting four independent propagation modes (three phases and cable shield), which are modeled from the inclusion of frequency effect in the classic Bergeron method. The currents and voltages are expressed as a system of differential equations, which are presented as state equations and solved using numerical integration methods. The proposed modeling technique allows the inclusion of time-variable and nonlinear elements during electromagnetic transient simulations in the time domain, which is not possible from frequency-domain models that are solved using inverse transforms. The proposed model is validated from results simulated using numerical Laplace transform and exact modal transformation matrix for calculation of phase currents and voltages.