Application of the current-injected modelling approach to quasi-resonant converters

Until now, the injected current method has been applied only to DC-DC power converters. This paper describes how this method can be extended to quasi-resonant power converters. It is shown that quasi-resonant models are easy to obtain since they are derived directly from the PWM power converter models. These new models result in a unified block diagram from which zero voltage switching or zero current switching transfer functions of the basic topologies such as buck, boost and buck-boost operated in half-wave or full-wave are found. As an application of this method, a zero voltage switching boost power converter and a zero current switching boost power converter are fabricated and tested. Experimental results are compared to computer simulations obtained with this method and with the state-space averaging method