Predictive current control for multilevel active rectifiers with reduced switching frequency

In this paper, a new low-frequency predictive current control is proposed for a single-phase cascaded H-bridge multilevel rectifier. The control method has been fully investigated with theoretical analysis, simulation, and experiments on a laboratory prototype with five series-connected H-bridges. However, the analysis and technique are valid for any general N-level structure. The simulations and experimental results presented demonstrate the excellent performance of the predictive control in terms of ac current waveform quality, power factor, and reduced switching frequency of each bridge, in comparison to traditional control schemes. Index Terms--Active rectifiers, multilevel converters, predictive control, pulsewidth modulation (PWM).