Model predictive current control with a finite set of novel voltages and modulator in permanent magnet synchronous motor drives

Finite control set model predictive control (FCS–MPC) has been deployed extensively in electric motor drives and power electronics applications. Many advantages, including fast transient response, have been reported. However, the improvement of its steady-state performance, that is, suppression of current ripple, is one of the main problems of a conventional FCS–MPC strategy. This article presents a current control strategy based on FCS–MPC using the concept of variable voltage smoothing. In the proposed method, a finite set of novel voltage vectors, produced by the smoothing process, are introduced as candidate control input candidates, and the controller generates the optimum output voltage using a modulator integrated with the FCS–MPC scheme. Thus, the voltage candidates are generated flexibly, and a suitable voltage for acceptable steady-state performance is determined as the control input. In addition, the smoothness in the proposed concept can be updated automatically depending on the drive situation, that is, transient, or steady-state operation, thus avoiding degradation of dynamic performance. Simulation and experimental results obtained with a permanent magnet synchronous motor drive system demonstrate that the proposed control strategy is effective to achieve current control with fast tracking performance while suppressing current ripple.