| With the advantages of small volume,simple structure,and small moment of inertia,permanent magnet synchronous motor(PMSM)has been widely used in numerous fields,such as industrial robots,aerospace,locomotive drive.However,considering the existence of factors of motor’s internal parameter such as time variant,harmonic disturbance and dead-time effect of inverter,the deviation is introduced into the estimation process of rotor position.In addition,the resolution and accuracy of the position sensor selected affects the performance of the control system.PMSM is considered as research subject,this thesis focuses on control method of PMSM using short-step optimization based on position state observation.PMSM that meets performance requirement is designed,and the framework of PMSM AC servo control system is built.According to the fundamental model of PMSM,the magnetic simulation and thermal simulation of PMSM are carried out using JAMG-Designer.At the same time,the data such as the cogging force,the characteristics of the air-gap magnetic density,back electromotive force are achieved from JAMG after simulation to testify the rationality of the designed motor.Based on the mathematical control model of PMSM and vector control method,a dual-loop control system of speed loop and current loop is set up,which lays the foundation for the analysis of the control method of PMSM.Enhancing the feedback ability of the position sensor plays a significant role in enhancing the tracking performance of the control system.The magnetic encoder is selected as the feedback device of the control system to analyze the sources of the error of magnetic encoder.There exist low order sinusoidal and cosine signal in phase voltage signal caused by installation error,which are able to be eliminated by the method of cross-interval linear interpolation.In order to solve the issue of multi-pole angle jump point caused by signal noise,a dynamic multiwindow angle short-step optimization algorithm has been put forward,which eliminates the error of angle pole number judgment and improves the resolution effectively.In order to improve the precision of angle value after subdivision,oversampling linear interpolation tabulation method has been proposed.Thus,the high accuracy and resolution of the magnetic encoder are obtained.After the magnetic encoder with high accuracy in the control system is achieved,the disturbance observation algorithm for current loop and speed loop of PMSM is established.The inference that substantial harmonic components are contained in phase current due to the inverter nonlinearity,is analyzed by simulation.On this basis,aiming at the problem of signal feedback lag caused by hardware and software delay,and other issues such as the time-varying resistance value,current harmonic disturbance,the disturbance state observer of current loop and speed loop is established to obtain the feedback value of current and angle.Thus,the observation performance of the control system is optimized.Finally,the software program and hardware system of the control system is developed,and the strong anti-interference ability,excellent tracing performance,good stability and high response of the proposed control algorithm in this paper are verified by loading and no-load experiments on the PMSM test platform.Moreover,the rationality of the proposed strategies is proved further by acceleration,deceleration and load disturbance experiments carried out on the motor with voltage of 80 V and current of 450 A. |
