Three-Phase (LC)(L)-Type Series-Resonant Converter with Capacitive Output Filter

This paper presents a three-phase (LC)(L)-type DC-DC series-resonant converter with capacitive output filter. Operation of the converter has been presented using the operating waveforms and equivalent circuit diagrams during different intervals. An approximate analysis is used, and design procedure is presented with a design example. SPICE simulation results for the designed converter are shown for input voltage and load variations. 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.