Sensorless Control Based on PMSM Linear State Observer

PMSM is widely used in the industrial manufacturing field. In order to reduce costs and get rid of the dependence on position sensors, this paper proposes an enhanced linear extended state observer (E-LESO) position free control method. By using an extended state observer, the characteristics of disturbances can be accurately estimated. The rotor position information can be treated as disturbances, and based on this, the back electromotive force can be expanded twice to increase the system order, alleviate phase lag, and improve the dynamic performance of the system, thereby estimating the back electromotive force. In addition, using phase-locked loops to replace inverse trigonometric functions further improves observation accuracy.