Current Feedback Method - A New Approach of Field-Weakening Control for Surface-Mounted Permanent Magnet Synchronous Motor

In the realm of electric propulsion and industrial automation, the increase in motor performance has led to the development of advanced control techniques. Among these, field-weakening control stands out as a pivotal strategy for extending the operational envelope of electric motors beyond their nominal speed range. This research investigates a simple but effective field-weakening strategy applied for the three-phase surface-mounted permanent magnet synchronous motor (SPMSM) based on the characteristic of q-axis current at a high-speed region. The conventional proportional-integral (PI) controller computes the appropriate reference d-axis current via the error between the reference and estimated values of the q-axis current. In addition, the parameters of the PI controller are determined by the Particle-Swarm-Optimization algorithm concerning minimizing the difference in rotor speed and q-axis current. The performance of the proposed strategy is evaluated by the software simulation in MATLAB/Simulink. The proposed field-weakening strategy can be used in other electric motor types.