A Coupled-Inductor-Based Soft-Switching Noninverting Buck–Boost Converter With Reduced Auxiliary Component Count

This letter proposes a coupled-inductor-based soft-switching noninverting buck–boost converter (NIBBC) with reduced auxiliary component count. Instead of using multiple auxiliary passive components to achieve soft switching, the proposed coupled-inductor-based NIBBC uses the coupled inductor as the main inductor, and the auxiliary current generated by the magnetic coupling effect is used to obtain the soft switching for all switches. With simple pulsewidth modulation under fixed frequency, full-load range zero-voltage switching can be obtained under a wide voltage range. Unlike the conventional method utilizing the coupled inductor only to generate nonactive power, the coupled inductor of the proposed converter also takes participant in the power transmission. Besides, the added diode can achieve zero current turn-
off
that avoids the diode recovery issue. The operating principle, the soft switching, and the parameter designs are analyzed in this letter. Finally, experimental results have verified the effectiveness of the proposed solution.