A coupled inductor buck-boost DC-DC converter with wide voltage conversion range

High efficiency dc-dc converters come in three basic topologies: buck, boost and buck-boost. At extreme duty cycle, the output voltages of these converters are limited due to increase in component stresses. Wide-input-wide-output (WIWO) dc-dc converter is an integration of buck and boost converter via coupled inductor. It has wide step-up and wide step-down capability. By using coupled inductor it is possible to retain the functions of both buck and boost converters, and also can extend the conversion range. In this paper the analysis and design of WIWO dc-dc converter is described. Simulation results reported stand in good agreement with theoretical expectations.