Steep conversion ratio buck converter based on a switched coupled-inductor cell

Abstract

By replacing the input inductor of buck converter with a cell formed by a coupled inductor and one diode, a new converter with low voltage ratio is obtained. The energy accumulated in the leakage inductance is transferred in a non-oscillatory manner to the load, thus avoiding a voltage overstress across the transistor. The DC gain expression and experimental results show its dependency on the coupling coefficient of the coupled inductor k, the turns ratio n, and the load. © 2010 IEEE.