Feasible developments of resonant-pole assisted soft-switching transition PWM DC-DC power converter using transformer parasitic resonant components

This paper describes a fixed frequency resonant pole-assisted soft-switching PWM inverter-fed DC-DC high-power converter with a HV transformer-coupled stage, which operates under ZVS transition principle. The zero-voltage soft-switching operation of this practical power converter circuit using the latest IGBTs as well as its efficacy are evaluated by a trially-produced 50 kW-100 kV converter system operating at 20 kHz/30 kHz. It is proved from a practical point of view that the switching losses of IGBTs and their electrical dynamic stresses as well as EMI noise can be considerably reduced under HF switching-based phase-shift PWM control a wide load range. The structure and the circuit modeling of HV transformers and the power converter using these transformers are discussed. Simulation results are illustrated and evaluated. Power converter performances are compared with those of previously developed resonant converters