High Frequency Model of a SiC based DC-DC converter for on Board Electric Systems

Isolated DC-DC converters are widely used for electric vehicle applications. The fast power electronic devices based on SiC and GaN technologies enable high switching frequencies, thus reducing the converter size. The high frequency transformer is a fundamental component of these converters since it is used to obtain a high ratio between the input and output voltage. The interactions between the fast electronic devices and the transformer could involve disruptive overvoltage, a reduction of converter efficiency and an output voltage different from the desired one. The paper focuses on the development of a parameter-based model of the DC-DC converter based on SiC devices. A high-frequency model of a transformer and a dynamic model of SiC devices have been obtained from experimental data. The models have been implemented in Simulink, thus taking advantage of the simulations to foresee the behaviour of the converter with the changes of the operating conditions.