Real-time calculation method for single-phase multilevel converters based on phase-shifted carrier pulsewidth modulation

The time delay caused by the digital computation and the update of duty cycle tends to worsen the dynamic performance of digitally controlled power converters. This paper proposes a real-time calculation method for multilevel converters with the phase-shifted carrier pulsewidth modulation (PSC-PWM) to eliminate the time delay of the digital controller without the loss of duty cycle. A proposed sampling method, which samples the current and voltage at the intersections of all phase shifted carriers, is used alternately with the traditional regular sampling method following a selection rule, which is elaborated in theory. Experimental results verify that the proposed real-time calculation method effectively improves the bandwidth of the control system.