Research On Predictive Current Control Of Permanent Magnet Synchronous Motor Without Speed Sensor

Permanent magnet synchronous motor(PMSM)has become the focus of research at home and abroad because of its advantages such as large torque,high efficiency and simple structure.In recent years,with the rapid development of domestic industrial automation,the control performance of permanent magnet synchronous motor(PMSM)is more and more high.The conventional PID control method is difficult to meet the control requirements.The speed control system is a traditional mechanical encoder system for speed measuring device,will inevitably lead to problems,reduce the reliability of the system of the motor cost increase,so the design of speed sensorless is particularly critical.The main works in this thesis are listed as follows:(1)Speed control system of permanent magnet synchronous motor based on model predictive current control often exits unstable operation and speed fluctuate under the external disturbance.We propose a discrete sliding mode control for permanent magnet synchronous motor model based on predictive current control with load disturbance observation.Based on the study of the current model predictive control algorithm for the surface permanent magnet synchronous motor,the discrete sliding mode speed controller is designed to replace PI regulator,and the controller suppress the overshoot and improve the starting performance of the system.Discrete sliding mode perturbation observer is proposed and used for feed-forward compensation,and the observer suppress the external disturbance effectively and improve the robustness of the system.(2)The traditional ADRC system usually has many problems with adjustable parameters and complex setting,and the sliding mode control is robust,but there is chattering phenomenon.In order to improve the robustness of the conventional model predictive current control method,a sliding mode based on active disturbance rejection speed controller is designed.The sliding mode control method is used to improve the structure of ADRC.The controller introduces sliding mode reaching law in ADRC structure and improves ESO and NLSEF in ADRC.Based on retaining the original performance of ADRC,the controller simplifies parameter setting and improves the response speed and robustness of the system,and the stability was proved by using lyapunov theory.(3)A novel cascaded sliding mode speed observer is proposed to estimate speed and rotor position,which overcomes the time delay caused by the low-pass filter.A front current sliding mode observer that estimates the EMF of the motor in the ?-? axis,a back EMF sliding mode observer that estimates the speed and rotor position,and we prove the stability of the algorithm.In this paper,TMS320DSPF2812 is used as the core control chip.The PMSM vector control is verified by the construction of related drive circuit,protection circuit and the compilation of vector control algorithm.The experimental results show the feasibility of the proposed method.