Analysis and Design of a New Ultra-Step-Up DC–DC Converter with Reduced Voltage Stress for Renewable Energy Systems Applications

A new non-isolated high-gain high-efficiency interleaved DC–DC converter with low voltage stress is introduced in this paper, which is suitable for renewable energy sources applications. It utilizes coupled inductor (CI) and built-in transformer (BIT) to achieve an ultra-step-up voltage ratio. In such a case, a more flexible voltage gain is provided through the turn ratios of CI and BIT. Through the interleaving effect, the input current ripple is minimized and also equal current sharing performance is realized between the interleaved phases. Moreover, the implementation of low voltage MOSFETs is facilitated by reducing the voltage stress across which consequently decreases the conduction losses. Meanwhile, the leakage inductances of the magnetic devices provide zero current switching of the semiconductors, and reverse recovery losses of diodes are diminished, as well. Finally, a 1 kW 20–400 V prototype is fabricated to examine the conducted steady-state analysis and to demonstrate the merits of the proposed converter.