Research On Threshold Suppression Strategy Of Permanent Magnet Synchronous Linear Motor

Permanent Magnet Synchronous Linear Motor(PMLSM)eliminates the intermediate mechanical transmission link and speeds up the system response.It has the advantages of simple structure,high precision,large thrust,high speed and direct drive.In recent years,with the continuous deepening of the research on motor manufacturing and control technology,great efforts have been made in the development and application of CNC machine tools,rail transit and other fields.However,because of the cancellation of the intermediate mechanical transmission link,the disturbance caused by its own structural and external factors will directly act on the PMLSM itself during the operation of the motor,resulting in unstable operation of the motor and greatly increasing the control difficulty of the system.Therefore,the suppression of PMLSM thrust fluctuations has gradually become an important research direction for the majority of scholars.This thesis takes PMLSM as a research object for the suppression of thrust fluctuation,and analyzes and studies the two aspects of the motor's own structure and control system.This thesis first briefly introduces the structure and working principle of PMLSM.At the same time,the three-dimensional model is built in Ansoft Maxwell 3D and dynamic finite element analysis is carried out.Combining with the simulation results,it is analyzed that the main cause of thrust fluctuation is magnetic resistance.For the generation of magnetic resistance,by optimizing the structure of the motor and comparing it with experimental simulations,proper optimization of the motor structure can suppress the magnetic resistance and reduce the generation of thrust fluctuation.Secondly,the mathematical model of PMLSM on dq axis is established.According to the principle of direct torque control(DFC),the PMLSM DFC simulation model is established in Matlab/Simulink software.The simulations show that the traditional direct torque control system has large fluctuations in thrust and proposes the introduction of particle swarm optimization(PSO)and fuzzy control algorithm(Fuzzy Control).Through simulation analysis,it has been found that the thrust fluctuation has been effectively suppressed,confirmed the feasibility of the control program.After analyzing and researching the PMLSM control system,the servo control system based on DSP+FPGA+IPM is designed.The main hardware modules and software modules are introduced in detail.