Switched-Capacitor and Coupled-Inductor-Based High Step-Up Converter With Improved Voltage Gain

Abstract

Based on a hybrid technique of coupled inductor (CL) and switched capacitor, a high step-up dc–dc converter is developed in this article. It consists of one active switch, one CL, four diodes, and four capacitors. The active switch withstands low voltage stress and all diodes’ voltage stresses do not exceed half of the output voltage. Simple structure and low-voltage-rated switches contribute to high efficiency of the proposed converter. The converter provides the ideal voltage gain of ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 + 2\,\,n) /(1 - d)$ </tex-math></inline-formula> , here <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> represents the turns’ ratio of the CL and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$d$ </tex-math></inline-formula> is the duty ratio. Its circuit configuration and operation principle are introduced. Effects of leakage inductance of the CL and parasitic resistance of components are analyzed in detail. The experimental results demonstrate the effectiveness of the proposed converter and the maximum efficiency is above 97%.