Sensorless Speed Control of a Permanent Magnet Type Axial Gap Self-Bearing Motor

This paper presents an analytical and experiment evaluation of sensorless speed vector control of a permanent magnet type axial gap self bearing motor, in which rotor speed and position are estimated by using state observer, not by using mechanical encoder or resolver... The approach is based on the estimation of the motor back-EMF (or induced voltage) through a state observer with help of measured stator currents and reference voltages. In order to achieve an accurate estimation of the rotor speed and position, adaptive gain of observer controller is proposed. The experiment is implemented based on dSpace1104 with two three phase inverters. Results confirm that axial force and rotating torque can be controlled independently and motor can get the good performance in steady state at the average and high speed range. <