ROTOR POSITION TRACKING AND SPEED CONTROL OF PMSM AUGMENTED WITH NONLINEAR ESTIMATOR UNDER MICROSTEPPING EXCITATION

Abstract

Abstract Stepper motors are the perfect tools where accurate locomotion, movement and positioning are needed. The major applications of permanent magnet stepper motors are in scanners, robotic controls and most widely, these days, in 3D-printers. The accurate rotor position tracking of permanent magnet stepper motor (PMSM) has hence become a very important task. This paper approaches this issue from the process control point of view. Consequently, controlling the rotor position requires complete state information for investigation. The rotor position tracking and speed control of PMSM is advanced from the perspective of Lyapunov-based control method. The nonlinear estimation technique employs a nonlinear observer along with Lyapunovcontroller to estimate accurately the rotor position through the information from motor phase current and angular velocity. The investigation through simulation demonstrates the effectiveness of the estimation technique, as the improved position tracking is achieved upon using Lyapunov-controller in comparison with the current control method under microstepping excitation of the motor.