Power Regulated Field-Weakening Control Strategy with Adaptive Observers for Permanent Magnet Synchronous Motors

Field-weakening control strategy extends the speed range of permanent magnet synchronous motor (PMSM) drives without modifying hardware, but suffers from complexity and inefficiency. This paper proposes a novel field weakening strategy based on power regulation and an adaptive observer. A power mapping model is formulated to achieve real-time generation of the dq-axis current reference. A discrete state space representation of the power loop demonstrates zero steady state speed tracking error through power regulation, while pole placement analysis provides insights for stability optimization. A speed adaptive observer integrates the sensorless operation and the field-weakening current trajectory generation without additional control loops, improving voltage utilization, while also reducing the torque ripple. Compared with conventional approaches, the proposed method achieves higher DC‑link voltage utilization and improves the load capability. Experimental results on a PMSM test platform validate its effectiveness.