Performance Enhancement of Salient Permanent-Magnet Motors over Wide Speed Range Based on Finite-Set Model Predictive Control

The key downside of the interior permanent magnet synchronous motor (IPMSM) is the torque reluctance because the stator inductance across the air gap is not equal, which increases the difficulty of regulating the motor currents. In this paper, an improved model predictive control (MPC) is proposed to achieve better drive performance of the IPMSM operating in the region of flux-weakening under sudden torque turbulence and different speeds. The emphasis of the proposed strategy is on the cost function section, which reduces the error between predicted velocity and reference velocity. Meanwhile, a modified low-pass filter flux observer is proposed to complete the velocity prediction by the torque value. For flux-weakening operation, the d-Axis reference current is computed based on machine parameters. Moreover, the finite control set is implemented as an optimizer instead of a modulator. Finally, comprehensive simulations are presented to verify the proposed strategy.