Model predictive control for Cascaded H-bridge multilevel inverters with even power distribution

Cascaded H-bridge inverters are commonly controlled using linear control and Phase Shifted Pulse Width Modulation, since it allows an even power distribution among the cells, which reduces the harmonic distortion by means of isolation phase-shifted transformers. Recently, predictive control schemes for power electronic converters have been developed, featuring its simplicity, flexibility using different control objectives and an improved dynamic performance. However, for multilevel inverters, high amount of calculations is needed in order to make predictions, making difficult the implementation of this control strategy in a standard control platform. This paper proposes a modified predictive control algorithm for a Cascaded H-Bridge inverter that considerably reduces the number of calculations for the load current control, while improves the power distribution among all cells of the converter and, consequently, the harmonic quality of the input current. Simulation results are presented to validate the proposed method.