Analysis and design of interleaved current-fed phase-modulated single-phase unfolding inverter

This paper presents a novel single-phase current-fed phase-modulated interleaved unfolding inverter system for fuel cell applications. Two active-clamped zero-voltage switching (ZVS) current-fed half-bridge isolated converters are interleaved in parallel input and series output configuration. Phase modulation is proposed to control these two converter cells which generate rectified sinusoidal pattern at the dc link. A simple H-bridge unfolding dc-ac inversion is used to produce single phase sine voltage at line frequency switching using square wave control. This not only simplifies the inversion stage in terms of modulation but also reduces the switching losses. Direct front-end current-fed based unfolding inverter is not reported in literature. Detailed analysis and design of the proposed single-phase current-fed unfolding inverter has been presented. Simulation results are illustrated using PSIM9.0.4 to support the analysis and design.