Design of PMSLM Position Controller Based on Model Predictive Control Algorithm

Zheng Li,Hexu Sun,Qingshan Zhang,Huixian Liu,Jinfeng An

doi:10.1109/access.2021.3083521

Abstract

In order to simplify the permanent magnet synchronous linear motor (PMSLM) system structure, optimize the moving performance of the control system, and further improve the position tracking accuracy of the PMSLM, a PMSLM position controller based on the model prediction algorithm is proposed (PMPC). This paper designs two position model predictive controller schemes: the first scheme is to directly use the linear displacement and q-axis current of the PMSLM to establish a second-order mathematical model, and combine the model predictive algorithm to design the PMPC. The second scheme is to first combine the linear motor motion equation and thrust equation with the model prediction algorithm to design a velocity model predictive controller (VMPC), then on the basis of the VMPC, use the relationship between the PMSLM displacement and the running speed to comprehensively design the PMPC is used as the outer loop controller of the control system. The two PMSLM control methods designed in this paper only need position loop and current loop to achieve precise trajectory tracking. Then, the analysis of the two control schemes shows that the second scheme is superior to the first scheme in terms of control performance. Finally, the PMPC model of the second scheme is built by simulation software to simulate and test. By analyzing the experimental data, it shows that the control method not only simplifies the control system in terms of structure, but also improves the accuracy of PMSLM tracking the direction change of the motion trajectory, and optimizes the control ability of the control system.

Highlights

With the innovation of AC motors and the continuous development of power electronics, DC servo systems are gradually being replaced by AC servo systems [1], [2]
When the linear motor carries a random load, the velocity model predictive controller (VMPC) controller designed is compared with the traditional PI and sliding mode controller (SMC) controllers, which proves the superiority of the speed controller designed in this paper
The results show that the scheme designed in this paper can effectively improve the control function of the control system and improve the position tracking accuracy of the control system

Summary

INTRODUCTION

With the innovation of AC motors and the continuous development of power electronics, DC servo systems are gradually being replaced by AC servo systems [1], [2]. Z. Li et al.: Design of PMSLM Position Controller Based on MPC Algorithm example, uses the stator voltage equation of the asynchronous motor to design a controller based on the model prediction algorithm instead of the traditional current loop proportional-integral (PI) controller, effectively improve the system’s ability to resist external interference and enhance the system’s adjustable performance. Aiming at the phenomenon that PI control can only achieve a compromise control effect between suppressing the overshoot and shortening the overshoot time, the literature [21] uses the model prediction algorithm to design antisaturation permanent magnet synchronous motor (PMSM) speed conversion regulators, effectively suppresses overshoot and shortens the adjustment time of the system. The mathematical model of permanent magnet synchronous linear motor is analyzed, and the first position model predictive controller described in the third section is designed. The second position model prediction controller designed in this paper simplifies the complexity of PMSLM control system, and avoids the situation that the correction link of the controller can’t fully compensate the correction error in the system

PMSLM MODEL

POSITION MODEL PREDICTIVE

POSITION MODEL PREDICTIVE CONTROLLER

PROOF OF CONTROLLER STABILITY

CONCLUSION