Research On Control Strategy Optimization Of Permanent Magnet Synchronous Motor Speed Servo System

With the development of permanent magnet materials,permanent magnet synchronous motors have attracted attention for their outstanding advantages such as simple structure,high power density,reliable operation,strong overload capability and high efficiency.The use of AC motors instead of DC motors in high-performance speed control systems has become a consensus in the industry.However,in engineering applications,as the servo system improves the control performance requirements,the limitations of the traditional PI controller control performance become more obvious.Therefore,this paper uses a surface-mount permanent magnet synchronous motor to study and optimize the control strategy of the current loop and speed loop of the speed servo system.Firstly,the parameters in the current loop PI controller are designed by analyzing the current loop transfer function and combining the actual parameters of the motor used in this paper.Aiming at the cross-coupling phenomenon of current loop-to-straight axis current caused by motor back electromotive force,combined with current feedback decoupling algorithm,a composite decoupling controller is proposed to improve the current control performance.Then,Combined with the mathematical model of the permanent magnet synchronous motor speed loop,a standard speed loop linear ADRC controller is established,and the parameter design rules of the extended observer in the ADRC controller are analyzed.In order to improve the observation speed of the external observer of the extended observer,based on the analysis of the construction principle and structural characteristics of the extended observer,this paper proposes an extended state observer with velocity observation error feedback,and gives the specific parameter design.Increased the observation speed of the expansion observer to the external disturbance of the system.Aiming at the influence of the moment of inertia on the dynamic performance of the speed control system,this paper analyzes the characteristics of the on-line identification of the moment of inertia based on the least squares method and the model reference adaptive method.Finally,the inertia of the model reference adaptive servo control system is selected..Finally,based on Matlab/Simulink,the simulation model of speed servo control system is built.The experimental platform was designed and fabricated,and the control algorithm was written.The correctness of the proposed control algorithm was verified by simulation and experiment.