Research On Continuous Control Set Model Predictive Control Strategy For Permanent Magnet Linear Synchronous Motor

In modern industrial production,permanent magnet linear synchronous motor(PMLSM)plays a significant role.Compared with permanent magnet synchronous motor,it can produce linear reciprocating motion and does not require intermediate devices such as gears and screws.So it has the characteristics of high speed,high precision,fast response,low noise,etc.,and has been widely used.PMLSM itself is a nonlinear,strongly coupled and multi-variable system,and its mathematical model is difficult to accurately model,so it has high requirements on the control performance of the control algorithm.In addition,there are random disturbances in the actual control system.Unlike the rotating motor,these disturbances will directly act on the mover of the PMLSM without passing through the intermediate links,which will seriously affect the speed and displacement tracking accuracy.The traditional Field Oriented Control algorithm based on proportional-integral controller is sometimes difficult to meet the requirements of some high-performance applications due to its general dynamic performance and anti-disturbance capability.This paper takes the PMLSM speed control system as the research object,aiming at improving the dynamic response of the inner current loop and the anti-disturbance capability of the outer speed loop:First,in order to improve the dynamic performance of the motor,the model predictive control(MPC)algorithm is introduced into the current inner loop design.Model predictive control is widely used in the field of motor control because it adopts control strategies such as rolling optimization,multi-step prediction and feedback correction,has the characteristics of fast dynamic response,strong robustness and can handle multiple nonlinear variable constraints.Considering the finite control Set model predictive control(FCSMPC)algorithm,although its structure is simple and easy to be applied,only one voltage vector is applied in one sampling period,the current harmonic content will be high,and the torque ripple will be too large.In addition,when performing multi-step prediction,FCSMPC needs to traverse all switch states in each prediction step,which will greatly increase the computational burden of the processor.Therefore,this paper introduces the quadratic programming algorithm into the continuous control set model predictive control algorithm to reduce the problem of excessive calculation of multi-step prediction.Secondly,in order to improve the anti-interference ability of the speed outer loop,according to the strong anti-interference ability of the sliding mode control algorithm,combining the MPC method with the sliding mode control,a speed outer loop controller based on the nonsingular terminal sliding mode predictive control method is designed.It not only improves the dynamic response,but also enhances the anti-interference ability of the speed outer loop.At the same time,considering that the disturbance is difficult to be measured directly by the sensor,a disturbance observer is designed to observe the system disturbance,and the observed value is fed forward to the outer loop controller,so that the controller can make compensation for the disturbance,and further improve the anti-interference ability of system.Finally,it is difficult to verify that the proposed algorithm also has good control performance in the actual control system only based on the simulation results.In this paper,a semi-physical and semi-simulation system is built based on d SPACE platform,and several groups of experiments are designed through d SPACE platform.The results show that the proposed algorithm has good control performance and engineering application value.