A modified duty-modulated predictive current control for permanent magnet synchronous motor drive

Abstract

Predictive current control (PCC) is a promising technique for adjustable speed drives due to its intuitive features such as quick response, easy inclusion of non-linearities and constraints as well as multi-variable operation. The conventional predictive current control (C-PCC) employs a cost function to choose the optimum vector, which reduces the error between the reference and the predicted current. Even though the C-PCC can achieve excellent dynamic performance with a single active voltage, the steady-state performance is affected with larger torque and flux ripples. When two voltage vectors are applied in a control interval, the steady-state performance is improved. This paper proposes a modified duty-based PCC for permanent magnet synchronous motor (PMSM) drives, employing an active and null vector in control interval, where the duration for which the optimal active vector is applied is based upon a simple error based calculation. The proposed duty calculation requires a simple constant and eliminates the need for current slope calculation, which results in parameter insensitive operation. The proposed method is compared with C-PCC and recently published works based on duty calculation. The simulation and hardware experiments conducted on a PMSM drive confirm the effectiveness of the proposed method with reduced torque and flux ripples.