Multiphase Interleaved Converter Based on Cascaded Non-Inverting Buck-Boost Converter

This paper introduces an interleaved buck-boost converter with reduced power electronics devices count in comparison with the conventional topology. The proposed converter consists of a single buck converter followed by n parallel interleaved boost converters. The buck switch is gated only if any of the boost switches is gated. In addition to the reduced switches count, the proposed converter offers the following advantages, soft start-up and shutdown capabilities. In addition, the buck stage gives the ability to protect the power electronic devices and to isolate the supply during load failure or overload. Moreover, the proposed converter performs as an interleaved boost converter for high voltage gain requirements with the same switching scheme. Furthermore, it offers fast dynamic performance with smooth transition from the buck mode to the boost mode. This paper investigates the eight different operating zones of the proposed three-phase interleaved buck-boost converter for non-overlapping gate signals operation. The detailed analysis and zones of operation are presented and experimentally validated. In addition, a simple control system is presented to operate the proposed converter as dc-dc converter or ac-dc converter. More study cases are carried out to evaluate the different capabilities of the proposed converter.