Multiphase LCpCs Resonant Converter with Output Current Multiplier for Battery Charger Applications

This paper presents the analysis and design of a multiphase LCpCs resonant converter suitable for high-current low-voltage battery charger applications. In order to reduce the conduction loss, the inverter stage of the converter is obtained from the parallel connection of N class DLCpCs resonant inverters. The effect of the leakage inductance of the transformer on the resonant tank is evaluated. The output stage is based on a multi-winding current multiplier, obtained from the parallel connection of M current-doubler rectifiers. The regulation of the charging current is implemented at constant frequency by modifying the phase displacement of the output voltage of each class D section. The converter is designed for charging high-performance Absorbent Glass Mat (AGM) batteries with a current modulated from 20 A down to 1 A. The maximum voltage is limited to 14.4 V.