High Step-Up Interleaved dc–dc Converter With Asymmetric Voltage Multiplier Cell and Coupled Inductor

In this article, a novel high step-up interleaved dc–dc converter is presented, which is composed of an interleaved structure, an asymmetric voltage multiplier cell (AVMC), and a passive lossless clamped circuit. Compared to the classical interleaved boost converter, the proposed converter has a higher voltage gain owing to the employment of the AVMC and the coupled inductor. In addition, the input current ripple is limited to low values with the help of the interleaved structure, which gives more lifetime to the input power source. The voltage stresses of main switches are substantially low so that the MOSFETs with low voltage rate and ON-resistance ( $R_{\textrm {DS}(\mathrm{ON})} $ ) can be used. In addition, the voltage stresses and the reverse recovery problems of diodes are improved dramatically. Moreover, the zero current switching (ZCS) turn-on of switches and the ZCS turn-off of the clamp diodes are realized to reduce the switching losses. The leakage inductor energy is recycled and the voltage spikes are improved greatly by the passive lossless clamped circuit so that the efficiency can be upgraded further. Finally, a 400-W, 40-V-input, 400-V-output prototype is established to demonstrate the performance of this converter. The highest efficiency is about 97.3% and the full-load efficiency is approximately 97%.