A Position Sensorless Vector Control for Permanent-Magnet Synchronous Motor Having High Reluctance Torque Ratio

A position sensorless vector control is proposed for a permanent-magnet synchronous motor having a high reluctance torque ratio. A new evaluation index created by adding the d-axis and q-axis voltages at a specific ratio is introduced to improve the control stability in the proposed control. A theoretical analysis and experimental results are shown to demonstrate the effectiveness of the control.