Two-phase motor drive systems with Z-source inverter and hybrid PWM

In this paper is proposed a drive system for a symmetrical two-phase motor using Z-source inverter. The modulation technique applied to proposed system combines the theory of space-vector PWM with the ease of implementation of a triangular-comparison PWM, including the shoot-through zero vectors inherent of Z-source inverter. Such strategy reduces the effort of algorithm calculation. The introduction of the distribution ratio allows the development of a systematic approach in which both converter efficiency and THD of the motor voltages are affected by that distribution ratio. Also, the paper proposes a simple software algorithm to generate the hybrid modulation of Z-source inverter with the introduction of the “virtual” dc-link zero point. Simulated and experimental results demonstrate the validity of the proposed system.