Research On Predictive Control Of PMSM Based On Load Disturbance Observer

Permanent magnet synchronous motor has been widely used in the fields such as aerospace,railway transportation, and wind power, because of its advantages of high efficiency and high power density. It needed to reach the high position accuracy, high frequency response, low torque ripple and the strong robustness to adapt to different working environment. Then, the traditional control strategies such as PI control can't meet the control needs of high performance.Therefore, it is necessary to introduce advanced control strategy to the permanent magnet synchronous motor control system. Predictive control strategy can achieve fast dynamic response and high-precision tracking control, and has good comprehensive control effect. Thus, this paper mainly researches the application of Predictive Control to PMSM control.The paper firstly establishes the mathematical model of permanent magnet Synchronous motor based on vector control. The inner-loop current controller and the outer-loop speed controller based separately on model predictive control algorithm and deadbeat current predictive control algorithm were designed to form dual-loop predictive control system. In addition, in order to resolve the problem that the speed model predictive control algorithm always rely on machine mathematical model and load disturbances affect the control performance, two different kinds of model predictive control method based on disturbance observer are proposed, viz. predictive control based on the reduced-order Luenberger observer and internal model control (IMC) Observer separately. The two different state observers are designed to estimate the load disturbance, and torque-current compensation is produced as feed-forward of speed loop to attenuate the disturbance. The simulation results show that the proposed method can improve the dynamic response performance and steady-state precision of the control system,and the robustness is greatly enhanced. Secondly, in this paper,and the control performance of two predictive control algorithms based on load disturbance observer are compared and summarized.Finally, the software and hardware of the PMSM vector control system are designed, set up the experimental platform and perform a series of motor start-up,load variation and speed regulation experiments, and demonstrate the feasibility and effectiveness of the PMSM vector control that prepare for the step research.