A ZVS High Step-Up DC–DC Converter With Three-Winding Coupled-Inductor Assisted Voltage Multiplier Cell Suitable for Renewable Energy Systems

Ever-increasing usage of renewable energy sources such as photovoltaic and fuel cell, calls for high-gain dc–dc converters with high efficiency and low input current ripple. To deal with this issue, this article focuses on the proposition of a step-up dc–dc converter. The proposed converter is equipped with a three-winding coupled-inductor, which not only extends the voltage gain through the tertiary winding mixed within a voltage multiplier cell; but also, participates in achieving zero voltage switching (ZVS) for the main switch through the connection of its secondary winding in series with an auxiliary power switch in a soft-switching cell. Fortunately, ZVS of the main switch in a wide load range along with zero current switching of the auxiliary switch and diodes, minimizes switching losses, and diminishes reverse recovery issues. Moreover, the leakage energy is absorbed by the passive clamp avoiding high voltage spikes. Low input current ripple and low voltage stresses are other merits of the proposed converter. The operating principle along with the steady-state analysis is presented and the proposed converter is compared with similar counterparts. Finally, to evaluate the effectiveness of the proposed converter a 200 W 48 V–400 V prototype is developed and tested.