A Simplified Predictive Current Control of Open-End Winding Permanent Magnet Synchronous Motor

Abstract

Model predictive current control (MPCC) of a 4-level inversion fed open-end winding permanent magnet synchronous motor (OEW-PMSM) using 37 voltage vectors (VV) suffers from the disadvantage of the increased computation burden. A high computation burden on the processor puts a limit on the selection of the minimum sampling time. In this article, a novel method is presented for reducing the computation burden. The proposed method reduces the number of candidate VVs from 37 to a maximum of 4 and a simple cost function is proposed to select the optimal VV. The proposed method calculates the change in stator current (CSC) needed to obtain the required change in the stator flux. The CSC vector is in the direction of the required change in the stator flux, which is used to shortlist the candidate VV for the reduced control set. The required change in the flux is obtained using the reference stator current of the next sample. The multiple predictions of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d-q</i> currents are eliminated and a simple cost function based on the difference between per-unit CSC and candidate VV is used to simplify the calculations. The proposed method is experimentally tested and compared with existing MPCC. The results confirm the effectiveness of the proposed scheme.