Ultralarge Gain Step-Up Coupled-Inductor DC–DC Converter With an Asymmetric Voltage Multiplier Network for a Sustainable Energy System

Abstract

In this paper, a novel ultralarge gain step-up coupled-inductor dc/dc converter with an asymmetric voltage multiplier network is presented for a sustainable energy system. The proposed converter contains one boost converter, one voltage multiplier network, and one passive lossless clamped circuit. In order to achieve an ultralarge voltage gain, one of the two capacitors is charged by the primary side and secondary side of the coupled inductor, then it together with the secondary side of coupled inductor provides its energy for the other capacitor in voltage multiplier network. Besides, the passive lossless clamped circuit not only recycles leakage energy but also effectively reduces the voltage stress on the main switch. By this way, the efficiency of the conversion can be improved. Moreover, the reverse-recovery problem of the diodes in the leakage inductor is alleviated. The operating principles and steady-state analyses are illustrated in detail. Then, the performance of the proposed converter is compared with existing converters. Finally, a prototype circuit at 50-kHz switching frequency with 20-V input voltage, 200-V output voltage, $N = 2$ , and 200-W output power is established in the laboratory to verify the performance of the proposed converter.