Improved repetitive control of single-phase three-level inverter based on PWM voltage feedback

The dead-time effect of driving signal and the lagging effect of digital control have serious implications for the static and dynamic performance of the inverter distortion voltage, the paper makes a research on static and dynamic performance of diode clamp three-level single phase inverter. The paper regards dead-time effect and lagging effect as a periodic disturbance and proposes a lagging improved repetitive control to improve the accuracy of output voltage and reduce voltage distortion caused by dead-time effect. The control strategy does not need to detect the polarity of current and it saves current sensors which are used in traditional current closed loop. The paper also studies the design of repetitive control filter and phase lead component, and the method that deduces lead link k value according to differential equations repetitive control system is proposed. Finally, the validity of proposed control strategy has been verified by simulation and experiment.