Background: This document presents a dual sliding mode vector control method to estimate speed and position of Permanent Magnet Linear Synchronous Motor (PMLSM).
Methods: Firstly, the motor simulation model is built based on the mathematical model of PMLSM. For the sake of solving the problems of the jitter and position angle deviation in the traditional SMO, the inverse hyperbolic tangent function is used and the software phase-locked loop algorithm is introduced, and the gain of exponential approach rate is improved to change the real-time, so as to eliminate the problems of high-frequency jitter and angle deviation. Secondly, global fractional order integral sliding mode control (GFOISMC) is used to replace PI control to eliminate jitter and improve the robustness to load disturbance. Finally, the dynamic performance of the system under constant speed no-load and constant speed sudden load is simulated.
Results: The simulation result proves a proposed dual sliding mode control strategy combining the improved SMO and GFOISMC that can effectively reduce the jitter and improve robustness.
Conclusion: In this paper, two sensorless control strategies are compared and their robust performance is studied. The two control scheme is simulated in the MATLAB/Simulink environment.
Keywords: Permanent magnet linear synchronous motor, sliding mode observer, PI control, global fractional order integral sliding mode control, speed/position estimated, sensorless.