Analysis and design of isolated high power boost topologies and simulations with quasi-static and quasi-stationary transformer models

Isolated boost full bridge topologies for single phase power factor corrected front ends are introduced allowing one-stage conversion with a simple control and gating scheme. An analysis of the hard switching circuit is summarized for different levels of approximation to account for effects of parasitics on the circuit behavior. Soft switching measures are introduced in order to reduce charge-down losses, high voltage stress on power transistors and HF-oscillations, evaluated by simulations using enhanced MOSFET and diode models and by measurements on 1 kW battery chargers. The deficiency of common static transformer models in commercial simulators are pointed out by comparing simulated results with measurements. They can partly be avoided by application of new transformer models based on quasi-stationary fields implemented in SABER