A Zero Current Ripple Bidirectional DC–DC Converter With High Voltage Gain and Common Ground for Hybrid Energy Storage System EVs

In this article, a novel nonisolated bidirectional dc–dc converter (BDC) consisting of a quadratic voltage cell, a switched-capacitor (SC) cell, and a zero current ripple cell has been proposed for hybrid energy storage system (HESS) in electric vehicles (EVs). The converter presented combines the advantages of high voltage gain, wide voltage gain range, low voltage stress across power switches, zero current ripple, and common ground between both sides. Besides, synchronous rectification technology is applied to achieve higher efficiency of the converter. The comprehensive analysis of the operation principle, the characteristics analysis, and the efficiency analysis of the converter in a continuous conduction mode (CCM) are presented in detail. This article also develops a 1-kW scaled-down prototype, which validates the effectiveness and feasibility of the proposed BDC. The maximum efficiency of the converter under full load is 95.09% in the step-up mode and 95.24% in the step-down mode.