Thermal-Electrical Modeling and Simulation of Resonantly Operated DC-DC Converters Based on Extended Describing Function Method

Due to the very large difference between electrical and thermal time constants, stimulation for resonantly operated DC-DC converters using physical or ideal switching model is very time-consuming or impossible with limited computational resources. In order to overcome this problem a novel thermal-electrical averaging model of resonantly operated DC-DC converters is proposed in this contribution. The electrical model is based on extended describing function method. All required parameters for the thermal model can be obtained from datasheets. As examples thermal-electrical models of series-parallel resonant converters with LC- and C-type output filters are given and verified by comparison with a standard simulation tool. The thermal-electrical modeling procedure proposed in this contribution can of course also be applied for other types of resonant converters.