Sensorless Direct Torque Control of Hybrid Stepper Motor Based on MRAS

Abstract

In classical methods only average torque of the stepper motors is controlled which causes high speed and torque ripple. In order to control the torque instantaneously and improve the performance of the hybrid stepper motor, direct torque control strategy is used in this paper. Then by taking model reference adaptive system scheme, which uses the hybrid stepper motor itself as the reference model, speed of the motor is estimated. The sensorless control of hybrid stepper motor based on MRAS is built and simulated with Matlab software. The results show that this control technology is simple and effective and accuracy of the estimation is considerably high.