Ultra-high gain quadratic boost DC–DC converter based on a three-winding coupled inductor with reduced voltage stress for fuel cell-based systems

Abstract

Here, an ultra-high gain quadratic boost DC–DC converter (UQBC) based on the conventional quadratic boost converter (CQBC) and a three-winding coupled inductor (TWCI) has been proposed. It benefits from an extensive voltage gain range and low voltage stress on semiconductors. In addition, the converter requires a reasonable number of components. This structure is suitable for connecting renewable DC power sources like fuel cells to a DC-bus in DC microgrids. Unlike CQBC, the produced conversion ratio has been improved to [1+n+m+d(1+n)]/(1−d)2 thanks to integrating a TWCI into CQBC. As a result, the proposed quadratic boost converter gives a better step-up factor than previously presented quadratic boost converters (QBC). Meanwhile, the employed improvement method has not adversely affected some critical parameters like voltage stress on semiconductors or the input current ripple. This paper presents the mathematical analysis and operating principle of the proposed topology for both continuous and discontinuous current modes (CCM and DCM). Experimental results are represented to validate the converter theory and its performance. Results indicate that a high gain and efficiency have been obtained. Also, the voltage stress on the power switch is reduced by one-fourth by choosing a proper duty cycle and winding coefficient.