Sensorless Speed Control of Axial Gap Permanent Magnet Motor Using Sliding Mode Observer

Abstract

The permanent magnet synchronous motor drive system incorporates magnetic bearings to perform high speed control and balance rotor control between the two stators. The paper designed a system to perform adjusting motor speed sensor-less based on measured current, axial position and voltage reference components. The electromotive force (back-EMF) generated in the stator is estimated by a Sliding mode observer. The angular position and velocity rotor is calculated through the α-β com-ponents of the back-EMF. An improved phase-locked loop to correct the estimated angular position to exactly follow the true value. The motor drive is built in a vector control structure based on field-oriented control. The simulation results show that the proposed phase-locked loop-coupled observer is fully capable of meeting system control requirements in the medium speed range and above.