Transient Electromagnetic-Thermal Simulation of Dispersive Media Using DGTD Method

In this paper, the transient electromagnetic-thermal simulation is performed for dispersive media using the discontinuous Galerkin time-domain (DGTD) method. Both the frequency-dependent and temperature-dependent properties of dispersive media are considered in the modeling. Instead of executing the complex convolution in the time domain, an auxiliary differential equation (ADE) method is employed to manipulate dispersive media, where the polarization current density is introduced as an auxiliary variable. While dealing with the thermal issue by the DGTD, the heat flux is utilized to construct the ADE for solving the thermal conduction equation. As the heat source in electromagnetic-thermal simulation, the transient power loss density for three typical dispersive media (Debye, Lorentz, and Drude) is derived by the electrodynamic approach and also explained with equivalent circuit models. The validity and accuracy of the proposed electromagnetic-thermal co-simulation method are demonstrated by the numerical examples.