Modeling of ZCS multiresonant series-parallel converters using energy concepts

Energy and physical concepts are used in this paper to find the steady-state characteristic equations of an ideal multiresonant series-parallel power converter (MRSPC). The converter has a capacitive output filter, and operates in an under-resonant regime. In this regime zero current switching (ZCS) is possible, which reduces the tailing current problem of bipolar power devices. This converter can be used for capacitor charging in laser power supplies and pulsed power applications. A closed form solution, based on state-space analysis, is found for this converter. This approach simplifies the mathematical operations and reduces the computation time in simulation and optimization routines. Based on the model, the steady-state characteristics of the converter are derived by a simulation program, and compared with the series resonant half-bridge converter (SRHC). These characteristics can be used for the optimum design of the converter for a given input voltage and load range. The output current characteristics in discontinuous current regime are also discussed, which provide design guidelines for capacitor charging applications