Steep conversion ration Ćuk, Zeta, and sepic converters based on a switched coupled-inductor cell

Abstract

By replacing the input inductor of the Cuk (respectively Sepic, and Zeta) converter with a cell formed by a coupled inductor and one diode, a new family of converters with high voltage ratio is obtained. The energy accumulated in the leakage inductance is transferred to the load. The voltage stresses across the switching elements are kept at a moderate value. The reverse-recovery problem of the rectifier diode is alleviated. A DC analysis allows for the formulation of the DC gain as a function of the turns ratio and coupling coefficient of the coupled inductor, as well of the load. Experimental results confirm the theoretical expectations.