Finite Control Set Model Predictive Control with Feedback-Based Flux-Weakening Operation for PMSM Drives

Finite control set model predictive control (FCS-MPC) has gained widespread application in permanent magnet synchronous motor (PMSM) drives, especially for the operations below the base speed. In this paper, a novel voltage feedback-based flux-weakening control scheme is proposed to enable FCS-MPC to extend its operation above the base speed. In this method, an extended state observer (ESO)-based ultra-local model is employed as the prediction model to reduce parameter dependence. To realize flux-weakening operation, PMSM's steady-state voltage drop is estimated using the information from ultra-local model. And the magnitude of steady-state voltage drop is then used as the feedback variable to reconstruct a novel voltage control loop. The output of voltage controller automatically modifies the d-axis current reference when motor operates above the base-speed. With the help of voltage control loop, a smooth and automatic flux-weakening operation can be achieved without requiring the motor parameters. The proposed method is verified experimentally under various speed and load conditions. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.