Speed Control of Surface-Mounted PMSM Using the Gain-Schedule PI Control Method

Surface-Mounted Permanent Magnet Synchronous Motors (SMPMSMs) are increasingly favored in a variety of motion control applications, ranging from robotics to electric vehicles and industrial automation. This is due to their high efficiency, reliability, and power density, fast response speed, and high efficiency. The fixed-gain characteristic of traditional PI controllers causes them to operate less than optimally under a variety of operating conditions, even though they are widely used and simple to understand. Achieving outstanding control performance is still challenging, though, because of the PMSM's dynamic complexity. To address this limitation, the proposed Gain-Schedule PI control method dynamically adjusts the proportional (P) and integral (I) gains based on real-time speed conditions, thereby enhancing the controller's adaptability and performance. The study begins with the mathematical modeling of the Surface-Mounted PMSM, capturing its electrical and mechanical dynamics. The Gain-Schedule PI controller is then designed, where the gain scheduling mechanism is formulated to adaptively modify the PI gains in response to predefined speed thresholds. Extensive simulations are conducted using MATLAB/Simulink to evaluate the controller's performance under different operating scenarios, including changes in speed setpoints. Simulation results demonstrate that the Gain-Schedule PI controller outperforms the traditional fixed-gain PI controller, showing significant improvements in speed regulation, reduced overshoot, faster settling times, and robustness to operating point variations.