Zero-Voltage Transition Nonisolated Bidirectional Buck-Boost DC-DC Converter With Coupled Inductors

This article presents a new zero-voltage transition (ZVT) pulsewidth-modulated (PWM) bidirectional dc-dc buck-boost converter. The main features of the suggested converter are simple control, simple structure, and the reduction of stresses on the power switches. In this converter, only two auxiliary switches, two snubber capacitors, one diode, and one coupled inductor are used to create zero voltage switching (ZVS) condition for all switching components in both power How directions. The limited number of elements and the ZVS condition make a high-efficient converter that can be applied in many industrial applications. The proposed converter has the efficiency around 97% at full load in both boost and buck modes. Hence, the suggested soft-switching cell is in such a way that it can be applied in other basic non-isolated bidirectional converters such as cascade buck-boost, buck-h(x)st/buck-boost, single-ended primary-inductor converter (SEPIC)/Zeta, and Cuk/Cuk. The confirmation of the theoretical waveforms and analysis of the suggested topology is done by the experiments carried out on a hardware prototype of a 100-W converter.