Model predictive combined vector and direct torque control of SM‐PMSM with MTPA and constant stator flux magnitude analysis in the stator flux reference frame

Abstract

This study presents a combined vector and direct torque control (CVDTC) for surface-mounted permanent magnet synchronous motor (SM-PMSM). The CVDTC method has a fast dynamic torque response without requiring any conventional PWM signal-generators. Besides, it provides low-speed control and standstill operation, torque and flux ripple reduction, minor switching frequency variations, and low computational burden. In this study, CVDTC is mathematically analysed in the stator flux reference frame and then both DTC and CVDTC are simulated and compared for SM-PMSMs. To further reduce torque and flux ripple, model predictive combined vector and direct torque control (MPCVDTC) with the finite control set is analysed and proposed in the stator flux reference frame. Moreover, maximum torque per ampere (MTPA) and constant stator flux magnitude analysis for SM-PMSM are explored in the stator flux reference frame. Simulation and experimental results substantiate the effectiveness and performance of the CVDTC and MPCVDTC methods over a vast speed range.