Design of a 5 kW high output voltage series-parallel resonant DC-DC converter

This work presents a comprehensive procedure for designing a high output voltage series-parallel resonant DC-DC converter. The system output voltage control is by a combination of duty-cycle and switching frequency variation, where soft-switching is preserved over the entire operating range. The basic principle of operation of the converter is described and an analytical model is established which does provide a basis for the numerical calculation of the stresses on the power components. Furthermore, a control strategy for minimizing the no-load conduction losses is proposed and the transient behavior in case of load steps including output short-circuit is discussed based on digital simulations.