A High Step-Up/Step-Down Input-Parallel Output-Series ZVS Bidirectional Converter With Coupled Inductors

Abstract

This article introduces a nonisolated bidirectional converter with high-voltage conversion ratio. In the proposed converter, by integrating the two-phase low-voltage-side (LVS)-parallel high-voltage-side (HVS)-series bidirectional converter with the coupled inductors, features, such as high voltage gain, low voltage stresses, current sharing, and current ripple cancelation, are achieved. Due to the proposed converter's operation in triangular conduction mode, the desirable benefits of zero voltage switching, diode reverse recovery elimination, and reduction of converter filter inductors and, consequently, leakage inductors are obtained. To recycle the leakage inductors’ energy and to solve the related difficulties for both operation modes, a simple passive clamp with the minimum number of elements is utilized. Also, to improve the light-loads’ efficiency, the variable frequency control is developed. The proposed converter is comprehensively analyzed, and to verify the analysis, the experimental results are provided.