Efficient frequency-transient co-simulation of coupled heat-electromagnetic problems

Abstract

Background: With the recent advent of inductive charging systems all major automotive manufacturers develop concepts to wirelessly charge electric vehicles. E¿cient designs require virtual prototyping that accounts for electromagnetic and thermal ¿elds. The coupled simulations can be computationally very costly. This is because of the high frequencies in the electromagnetic part. This paper derives a mixed frequency-transient model as approximation to the original problem. We propose a co-simulation such that the electromagnetic part is simulated in the frequency domain while the thermal part resists in time domain. Results: The iteration scheme for the frequency-transient model is convergent for low frequency and high frequency excitation. For su¿cient high frequencies the iteration exhibits a quadratic convergence rate. Conclusions: The frequency-transient model is very e¿cient for coupled heat-electromagnetic simulations since typically the time scales di¿er by several orders of magnitude. For medium frequencies large time steps can be chosen. The analysis shows, that for high frequencies the convergence rate improves further