Evaluation of a variable-inductor-controlled LLC resonant converter for battery charging applications

Based on the respective merits of the LLC resonant converter and the VI (Variable Inductor), a new battery charger topology is proposed. This paper presents a design methodology for the LLC resonant converter controlled with a VI. The output of the converter is regulated through a variable resonant tank in order to control the charging process. A small-scale prototype fed by a 50V DC input, with an IGBT based inverter working at 11.3 kHz was built in order to test the proposed control method. Experimental results are presented.