Complete analysis of steady-state and efficiency considerations in a Forward-Flyback Mixed Converter

This paper presents a novel DC-DC converter where both forward and Flyback actions are mixed. Previously, we proposed this converter that has prominent features of reducing the voltage of main switch and the current ripple of output inductor, and as a result, the high efficiency and the size reduction were obtained as reported in the previous paper. And, this paper presents that this converter has four operation modes when the turns ratio of the second and the third windings of the transformer is set to be a certain value. Furthermore, these operation modes are analyzed through the extended state-space averaging method, and are confirmed by simulation. These characteristics are shown by means of a three-dimensional graphics method. This paper presents the detailed analyses of static characteristics for the four operation mode used three-dimensional expression of load characteristics with another winding turns ratio by the extended state-space averaging method.