Interleaved Modulation Scheme With Optimized Phase Shifting for Double-Switch Buck-Boost Converter

Owing to low voltage stresses, wide range of input and the same polarity output voltage, double-switch buck-boost converter (DSBBC) is a popular choice achieve dc/dc conversion in photovoltaic generations (PV), power factor correction (PFC), portable devices so on. Combined control (CC) makes DSBBC operate efficiently, but large ripples are unavoidable during mode transition. With two equal duties, interleaved modulation (IM) inductor ripple current decrease remarkably compared with synchronous (SM) while average still high. By introducing duty offset, declines efficiency enhanced obviously under cycle offset (IMDO). However, 180-degree phase-shifted angle, not enough some cases. Thus, make further improvement on current, an scheme optimized phase shifting (IMOPS) proposed for this paper. Current features, optimal angle (OPSA) operating region IMOPS described meticulously. Besides, theoretical quantitative comparisons different schemes presented, including ratio direct transfer (DPT). Based 150W prototype, feasibility effectiveness demonstrated by experimental results.