A Wide Input Voltage Range Unidirectional Resonant Switched‐Capacitor Converter for Fuel Cell Applications

This paper introduces a full bridge high voltage gain resonant switched capacitor converter (SCC) providing soft switching conditions for all power semiconductors above and below the resonant frequencies. The proposed unidirectional converter operates effectively both above and below the resonant frequencies, which extends its practical range of applications. Its output voltage can be regulated by different methods such as phase‐shift, PWM and frequency modulation techniques. Frequency modulation enables output voltage regulation across a wide input voltage and load range with minimal switching frequency variation. Symmetrical structure, small input‐output filters, compact passive components, low switching losses and reduced EMI noise, input‐output common ground, simple control circuit and high voltage gain make the proposed converter suitable for various applications. In addition, the state space trajectory, mathematical analysis, design approach and simulation results of the converter are described in detail, which are also verified by implementing a 60–120 V to 400 V, 200–1370 W prototype converter in practice.