Mojtaba yavari - Department of Electrical Engineering, University of Kashan, Kashan, Iran
Abolfazl Halvaei Niasar

Hysteresis motors are super high speed motors that used in industry such as micro gas turbines, high-speed centrifuges, machine tool spindle drives and etc. They are basically synchronous motors; however they can works in asynchronous mode. For some special applications, hysteresis motor may work at asynchronous mode, and knowing the motor's speed is necessary. Moreover, in these cases, using speed sensors is impossible due to load and difficulty of installation, and so using sensorless methods is proper solution. Unfortunately there isn't any sensorless technique for hysteresis motors. This paper presents a comparative study of two different speed observer techniques for a hysteresis motor drive. Luenberger observer (LO) and model reference adaptive system (MRAS) theories are considered. The speed estimation algorithm based on both techniques are derived and implemented in Simulink. The robustness of both speed estimation algorithms against load torque changes is investigated. Simulation results are presented and discussed.

hysteresis motor; sensorless control; speed estimation; luenberger observer; MRAS