PWM control of five-phase five-level inverter based on H-bridge

In this paper, a novel five-phase five-level inverter based on H-bridge is proposed. Then, the PWM control strategies of this inverter are researched. As the five-phase five-level inverter has 3125 space voltage vectors, it makes SVPWM algorithm extraordinarily complex and too difficult to implement. So, it is a feasible control scheme to adopt carrier-based PWM method. According to phase-shift SPWM principle, a new method is proposed which makes both modulation wave and carrier wave phase-shifted. Harmonics of PD-PSPWM and POD-PSPWM are calculated with the double Fourier analysis. Theoretical analysis, simulation and test results confirm that utilization ratio of dc voltage, differential mode and common mode voltage are optimal, while using POD-PSPWM method at alpha=pi and beta=pi.