Numerical modelling of 3-D coupled electromagnetic and heating diffusion problems

In this paper a hybrid integral-finite difference approach for the analysis of the transient electromagnetic heating effects in three-dimensional conductor bodies, is presented. The electromagnetic analysis is carried out by the discretization of the conductive regions in suitable slabs, that allows the transformation of the Maxwell´s equations to the equilibrium equation of an equivalent three-dimensional network. The thermal diffusion equation is solved by means of a finite difference approach in the time domain, using the same grid of the equivalent network above mentioned. The numerical solutions of the electrical and thermal equilibrium equations are performed separately and alternatively, and the values of the temperature dependent physical parameters are updated in time at each step. The method described in the paper has been tested with experimental data with regard to steady and transient state conditions of a bus-bars compartment of a low-voltage power center