Single-Phase Quasi-Z-Source Inverters: Switching Loss Reduction Using a Quasi-Sinusoidal Modulation Strategy

Abstract

Impedance source inverters are gaining higher attention due to their merits compared with the two-stage solution, and among their possible structures, the quasi-Z-source inverter (qZSI) is commonly used due to its simple structure and continuous input current. In this paper, the single-phase qZSI is considered and a quasi-sinusoidal modulation (qSM) strategy is proposed in order to enhance its performance. Unlike the conventional modulation strategies, the proposed qSM strategy has a simpler implementation due to the utilization of only two reference signals, reduced switching losses, and improved energy conversion efficiency as a consequence. The proposed qSM strategy is analyzed and compared with the conventional modulation strategies using PLECS models of a 1.5 kVA single-phase qZSI. Finally, experimental results are shown in order to validate the obtained simulation results, demonstrating higher efficiency under the proposed qSM strategy.