Comparison of multiresonant half-bridge DC-DC converters for high voltage and high output power

Two multiresonant zero voltage switching (ZVS) half-bridge converters for high input and output voltages are compared: the multiresonant, series-loaded, half-bridge converter and the series-parallel-loaded, multiresonant, half-bridge converter. Both converters use capacitive output filters, solving the problem of high reverse recovery losses associated with hard turn-off transients of the rectifier diodes. The comparison is based on a state space analysis of the converters. The effects of the parasitic switch capacitances are considered. Optimum design criteria for minimum component stress of both converters are derived. Thus, the ratings of all components are minimized and the efficiency of the converters is enhanced considerable. The advantages of the converters are compared using voltage gain characteristics and stress characteristics. Practical applications of both converters are presented and verified in experimental prototypes