Research On Position Tracking Control Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has become the major actuator in servo system,with its advantages of small size,high power density and efficiency.And it is widely used in industrial fields.With the continuous development of the industry,people’s demand for the performance of the position servo system is also increasing.The PMSM is a complex control object with multivariable,nonlinear and strong coupling.Besides the position tracking performance is easily affected by load torque disturbance and motor parameter perturbation in actual operation,the traditional control method is difficult to achieve high-precision performance.Therefore,the design of high-performance position tracking controller is of great significance to improve the performance of position servo system.Taking the PMSM position servo system as the research object,the control strategy of the PMSM position servo system is studied deeply in the thesis.In order to improve the performance of PMSM servo system,an improved nonlinear backstepping active disturbance rejection control(ADRC)method is proposed in this thesis.Firstly,in order to promote the limited convergence performance of traditional ADRC method,the feedback control law is improved based on backstepping control theory and continuous smooth nonlinear function;Secondly,aiming at the problem that the actual control gain must be known in the design of traditional ADRC and the limited performance of the equivalent disturbance estimation method,an observer based on Landau adaptive method is designed to identify the external disturbance and equivalent rotational inertia of the system online,based on which the control output is compensated in real time.Simulation results demonstrated that the proposed method can effectively improve the position tracking speed and accuracy of the system,and enhance the adaptive ability to parameter uncertainties and disturbances.In addition,a PMSM position servo system hardware platform based on TMS320F28335 is built.The hardware platform consists of a driving board and a control board,mainly including power supply circuit,IPM power drive circuit,current sampling circuit,DSP peripheral circuit,AD conversion circuit,and conditioner circuit for encoder.The control system,and modules programs such as SVPWM,position and rotational speed calculations,and the proposed control algorithm are designed and debugged on CCS6.0.Then the position tracking control achieved.Finally,the experimental verification of the proposed control method in this thesis is carried out using the established hardware platform.The step and sinusoidal position tracking results under no-load and load conditions is compared and analyzed,the experimental results show that the proposed method can overcome the effection of the system perturbation,and improve the position tracking speed and tracking accuracy,which further verify the effectiveness and practicality of the proposed method.