Applying a modified model predictive current control method to improve surface‐mounted permanent magnet synchronous motor drives performance in transient and steady‐state operations

Abstract

The performance of the conventional model predictive current control (MPCC) method is not without steady-state ripples in electrical drives. Although some recently proposed MPCC methods have succeeded to mitigate this drawback, they have led to reductions in the dynamic speed response inherent to the conventional MPCC method. An improved MPCC is proposed here which would enhance the conventional MPCC method without any side effect on its merits. In this proposed method, three control strategies are presented for transient- and steady-state operations. The first two strategies are applied to improve motor performance in the steady state, through calculating the voltage vector (VV) and its optimal duration to minimise ripples in both d–q -axis currents. The third strategy is applied in the transient-state operation, where, instead of two VVs, an allowable non-zero VV is applied throughout the control cycle to prevent dynamic response reduction caused by zero VV. The experimental results confirm the effectiveness of this proposed method in reducing torque ripples, flux ripples, and the stator current total harmonic distortion in relation to those obtained by the previous MPCC methods.