Coupled inductor based high gain current-fed DC-DC bridge converters

High boost DC-DC converters find wide variety of application in industry such as solar photovoltaic systems, fuel cell systems, UPS, micro-grids to name a few. Low component count, continuous input current, high boost operation at non-extreme duty ratio, etc. are some of the desirable features of a high gain DC-DC converter. In this paper two coupled inductor based novel high gain DC-DC converters are presented which are derived from current-fed DC-DC bridge converter. The proposed converters require only one capacitor and one coupled inductor in its structure. While both the converters present a linear gain - turns-ratio characteristics, one of the converters presents a unique feature of very small turns-ratio range of the coupled inductor. This helps in requirement of less windings turns and consequently reduced losses. The operating principle of the converters is discussed in details along with their steady-state analysis. The theoretical analysis is verified using experimental prototypes.