Study On High Performance Current Control Strategy Of AC Permanent Magnet Synchronous Motor

Currently Permanent Magnet Synchronous Motor(PMSM) has been widely used in advanced manufacture, industry robots and many other applications. To achieve high control performance of PMSM, primary attention should be paid to the dynamic performance of torque current. The torque current dynamic characteristic is closely related to machine parameters, control strategies, project implementation and other factors. Focusing on the delay time in the current control loop, compensation methods through optimization of the current loop implementation sequence and designing of the current control strategy are proposed. The detail research works in this thesis are done as follows.Based on Vector Control theory, the delay property and its effect are discussed firstly in this thesis. To shorten the delay time, three types of current loop implementation sequences are studied and a novel Delay Time Optimization Sequence Strategy is proposed. These different sequences are implemented and compared on Matlab/Simulink, simulation results demonstrate the validity of the proposed sequence strategy.In order to improve the dynamic performance of current loop further, Smith predictor strategy is introduced. The frequency characteristics of the current loop with Smith predict control strategy are analyzed and the implementation of the strategy is discussed. Considering that the design of Smith predictor is related to the model parameters, the influence of parameter perturbation is also studied. The effectiveness and parameter robustness of Smith predict control strategy are vivificated by simulation.Finally, a physical PMSM system based on an ARM cortex-M4 controller is built up and experimental comparison study is conducted. The results show the improvement of current response with the aid of the Delay Time Optimization Sequence Strategy and the Smith predict control strategy.