Multiphase resonant converter for battery charger applications

This paper presents the analysis and design of a multiphase configuration of resonant converter suitable for high-current battery charger applications. The inverter stage of the converter is obtained from the parallel connection of three class D LC_p resonant inverters, increasing the output current capability of the circuit. The regulation of the charging current is implemented at constant frequency, modifying the phase displacement of the drive signals of one inverter with respect to the others. The battery charger is designed for high-performance Absorbent Glass Mat (AGM) cylindrical battery; at present, widely used in micro-hybrid vehicles.