Three-phase (LC)(L)-type series-resonant converter: Design and experimental results

This paper presents the design and experimental results of a three-phase (LC)(L)-type DC-DC series-resonant converter with capacitive output filter. Based on an approximate analysis a design procedure is presented with a design example. Intusoft simulation results for the designed converter are presented for input voltage and load variations. Experimental results obtained in a 300 W converter are presented. It was observed that the magnetizing inductance is low enough eliminating the need for external parallel inductance. Major advantages of this converter are the leakage and magnetizing inductances of the high-frequency transformer are used as part of resonant circuit and the output rectifier voltage is clamped to the output voltage. Also, the converter operates in soft-switching for the inverter switches with a narrow frequency control range and the tank current decreases with the load current.