Simple Predictive Current Control of Asymmetrical Six-Phase Induction Motor With Improved Performance

Despite the intensive research work on the application of model predictive control for multiphase machines, there are many challenges still to be handled such as high circulating currents, variable switching frequency, and high computation burden. This article proposes a simple, yet efficient predictive current control (PCC) for a six-phase induction motor that reduces considerably circulating current, computation cost, and switching frequency. In the proposed method, a group of four candidate voltage vectors (VVs) is formed in each control sample. Unlike similar methods reported in the literature, these candidate vectors are generated based on a simple lookup table and the previous optimal VV. The lookup table is designed such that it allows only one commutation in each control sample. The performance of the proposed method is assessed experimentally using a 1-kW asymmetrical six-phase induction motor. Different performance indices are investigated to compare the proposed method against two different PCC methods in literature at different operating conditions. The experimental results confirm that about a 50% reduction in average switching frequency and 15% in current total harmonic distortion at different speed ranges are observed with the proposed method compared to the conventional one.