Phase-shift control and harmonics elimination for H-bridge Z-source inverter

Abstract

Phase-shift control is a common approach to voltage control of traditional H-bridge inverters, but this method has not been used to voltage control of H-bridge Z-source inverter (ZSI) so far. This study proposes a new phase-shift control method for H-bridge ZSI, which its main difference with phase-shift control of traditional H-bridge inverters is existence of four shoot-through states (short circuit of the H-bridge) in each switching cycle. One of the advantages of the proposed method is simultaneous elimination of several harmonics by choosing the appropriate switching angles. Moreover, by using this phase-shift control method, the amplitude of low-order harmonics for many values of switching angles is less than the amplitude of low-order harmonics in traditional H-bridge voltage source inverter (VSI). Total harmonic distortion and distortion factor, as two important indexes for quantifying the merits of the proposed method, are calculated and compared with their values in traditional H-bridge VSI. A detailed description of suggested method and comparison with the traditional method are presented in this study. Simulation and experimental results are also given to demonstrate the new features of the proposed method.