Speed Sensorless Control of Hysteresis Motor based on MRAS and Luenberger Observer Techniques

Abstract

There is no available sensorless technique for hysteresis motors. This paper presents a comparative study of two different speed observer techniques for hysteresis motor drive. Luenberger observer (LO) and model reference adaptive system (MRAS) techniques 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. Hysteresis motors are super high speed motors that are used in different type of applications such as micro gas turbines, high-speed centrifuges, and machine tool spindle drives. They are basically synchronous motors; however they can also work in asynchronous mode. For some special applications, hysteresis motor may work at asynchronous mode, and knowing the motor's speed characteristics is necessary. Moreover, in these cases, using speed sensors is impossible due to the load and difficulty of installation; therefore, using sensorless methods is the proper solution. Simulation results are presented and discussed.