Design Optimization of High-Frequency WBG-Based LLC Resonant Converter for Telecom Applications

Nowadays high efficiency and power density are desired for designing a power electronic converter. Technology advances in power semiconductor devices, makes it possible to design converters for operation in higher frequencies to reduce size of the converters. As the frequency is increased, switching losses and temperature is also increased, so designing a converter for high frequency operation needs some tradeoffs. In this paper a multi-objective design optimization procedure with regard to efficiency and volume has been carried out for an LLC resonant converter used in telecom applications. This optimization algorithm results in the best set of operating frequency, dead time and suitable choice of wide bandgap switches for the primary bridge and the synchronous rectifier in the secondary side. Finally, a 400V to 48V, lKW LLC resonant converter is designed by the proposed algorithm and a full load efficiency of 96% at 775kHz is obtained.