A new class of quasi-square wave resonant converters with ZCS

A new class of a single-switch zero-current switching and clamped current (ZCS-CC) DC-DC power converters are proposed. These power converters can be realized by connecting a resonant tank inductor and a diode in series with the active switch in a conventional PWM power converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the freewheeling diode. All the semiconductors in these power converters switch at ZCS with minimum current stress, while the freewheeling diode turns-on at ZVS. Moreover, the variation in the semiconductor voltage stresses are relatively low at either full and minimum load. The steady-state characteristics for the complete power converter class are analyzed and verified.