Abstract
The goal of this paper is use the Luenberger observer to research a new capability of controlling the axial gap self bearing motor, in which an analytical and experimental evaluation of a sensorless speed vector control of a permanent magnet type axial gap self bearing motor is presented. Rotor speed and position are estimated by using a state observer, not by using any shaft mounted position sensor as encoder or resolver etc. The approach is based on the estimation of the motor back-EMF (or induced voltage) through a Luenberger observer with help of measured stator currents and reference voltages. In order to achieve an accurate estimation of the rotor speed and position in all operating range, adaptive gain of observer controller is proposed. Furthermore, due to the change of air gap at the practical experiment, a compensation procedure also assures the system working stably at any axial position of rotor. 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.
