A novel high step-up converter, which is suitable for a renewable energy system, is proposed in this paper. The proposed converter is composed of the dual switches structure, three-winding coupled inductor, and two voltage multiplier cells in order to achieve the high step-up voltage gain. The dual switches structure is beneficial to reduce the voltage stress and current stress of the switch. In addition, two multiplier capacitors are, respectively, charged during the switch-on period and switch-off period, which increases the voltage conversion gain. Meanwhile, the energy stored in the leakage inductor is recycled with the use of clamped capacitors. Thus, two main power switches with low on-resistance and low current stress are available. As the leakage inductor, diode reverse-recovery problem is also alleviated. Therefore, the efficiency is improved. This paper illustrates the operation principle of the proposed converter; discusses the effect of the leakage inductor; analyzes the influence of parasitic parameters on the voltage gain and efficiency, the voltage stresses and current stresses of power devices are shown; and a comparison between the performance of the proposed converter and the previous high step-up converters is performed. Finally, the prototype circuit with input voltage 20 V, output voltage 200 V, and rated power 200 W is operated to verify its performance.
Liu et al. (Thu,) studied this question.