Design of two-winding voltage step-up/current step-up constant-frequency DC-to-DC converters

This paper presents procedures for designing the transformer for a two-winding energy-storage dc-to-dc power converter in which the power transistor is pulsewidth modulated by means of a constant-frequency type of controller. The presence of the second winding provides an additional degree of freedom in the design procedures beyond those for single-winding converters and leads to a number of design options for achieving specific performance characteristics. Ten options are provided: four relate to conditions that may be imposed on the duty cycle, four to maximum stress on the semiconductors, and two to the transformer turns. The design algorithm has been implemented in a computer program to automate the design procedures and to provide an evaluation of the converter circuit for each of the transformer designs.