Inductor-capacitor gain cell-based non-isolated high step-up converter for DC microgrid

In this paper, a high-gain DC-DC converter with an ultra-step-up voltage gain value of 20 is introduced. The proposed converter is synthesized using two stages – stage 1 yields a voltage gain which is double that of a classical boost converter (CBC) and stage 2 employs an inductor-capacitor gain cell (ICGC) to obtain a quadratic voltage gain function. Since a voltage gain extension technique is employed, the voltage stress on the switches in stage 1 is significantly reduced. The proposed gain extension hypothesis is experimentally validated through a 20 V to 400 V, 200 W prototype converter that operates at 94.5% full-load efficiency. The proposed converter regulates the output voltage to 400 V over a wide range of input voltage and load current variations with minimal overshoots and undershoots. Further, the maximum voltage stress on two switches switch is only 10% of the output voltage. Due to the interleaved mechanism employed in stage 1, the input current is smooth and ripple-free. Based on the comparison with several state-of-the converters, the unique advantages of the proposed converter are clearly validated and found suitable for DC microgrid application.