Computationally efficient model predictive control of three-level open-end winding permanent-magnet synchronous motor drive

Abstract

The model predictive current control (MPCC) is popular and widely used method for permanent-magnet synchronous motor (PMSM) and the tuning of weighting factor in classical cost function (CF) of MPCC of PMSM is not required. A three-level inversion-fed open-end winding PMSM (OEW-PMSM) would produce lesser torque and stator flux ripples; however, computation time required for the prediction of control variables is large. This study proposes a control method to three-level inversion-fed OEW-PMSM for reduction of computational time without affecting the performance when compared with conventional MPCC. The proposed method uses a maximum four voltage vectors (VVs) instead of 19 VVs in three-level conventional MPCC. The reduced VVs decrease the number of predictions and computational time for predictions. CF in terms of voltage is used, thereby eliminating the need to predict the currents and faster execution of algorithm is achieved. A higher sampling rate is possible to achieve using the proposed method; thereby, reducing the steady-state ripples in developed torque and stator flux, and improving the percentage total harmonic distortion of stator current. The effectiveness of the presented control method is practically verified after comparing its computational time, steady-state response and dynamic response with that of three-level conventional MPCC.