Research On Permanent Magnet Synchronous Motor Control System Based On Improved Sliding Mode Variable Structure Method

PMSM(Permanent magnet synchronous motor)is a strong coupling and complex nonlinear system.It has the advantages of low power consumption,high power density and simple structure.It is widely used in high precision applications.In this paper,the permanent magnet synchronous motor speed control system is taken as the main research object,and the research on sliding mode variable structure control theory is carried out.The traditional motor control algorithm needs handwritten code to develop,which has the defects of low efficiency,long cycle and poor reliability.The software development of the motor control algorithm is realized by MBD(Model based design),and the reliability of the motor algorithm is improved by the effectiveness of the hardware processor verification method.Firstly,this paper analyzes the mathematical model of permanent magnet synchronous motor in different coordinate systems,studies the principle of vector control algorithm,carries out modeling and simulation,builds PMSM vector control system model,and simulates the three-resistance phase current sampling method.This provides a simulation basis for subsequent experimental verification.The simulation results of the simulation model are analyzed,and the anti-interference ability of PI control is insufficient.An improved sliding mode variable structure control method is proposed,and a new sliding mode reaching law is designed.The stability,existence and accessibility of the new approach law are verified.A comparative analysis with the exponential reaching law shows the effectiveness of the novel reaching law.PMSM speed controller based on improved sliding mode variable structure method is designed.Compared with PI controller and speed controller based on exponential sliding mode reaching law,the simulation results show the superiority of the novel reaching law.Secondly,this paper adopts model-based design method to realize the development of permanent magnet synchronous motor software system.Based on the model design method,the improved sliding mode variable structure control model is designed,and the C code generation is completed by MBD method,and the software development of the improved sliding mode variable structure control method is realized.The PMSM vector control system model was designed by MBD method,and the C code which can be directly applied was generated,and the software development of PMSM vector control system was realized.The modules of the permanent magnet synchronous motor vector control system are tested and verified,and the accuracy of the algorithm model is proved.Finally,the experimental platform of the permanent magnet synchronous motor control system is designed.This paper takes TMS320F28335 as the control core.The power supply circuit,DSP minimum application system,current protection circuit,current sampling circuit and PWM interlock circuit are the main control parts to realize the digital development of permanent magnet synchronous motor.The motor load test bench was built,and the experimental analysis was carried out with Nanotec motor,Tamagawa motor and joint motor.The experimental results verify the effectiveness of the improved sliding mode variable structure control method and model-based method proposed.