| Permanent magnet synchronous motor has the advantage of high torque current ratio, strong environment adaptability, high efficiency, high reliability, high power density, et al. So far, permanent magnet synchronous motor has been widely applied in the industrial fields. During the speed control of permanent magnet motor, there are internal model perturbation and external disturbance, and the widely used double closed loop PI controller cannot meet the requirement of the system robustness. It is significant to utilize the modern robust control theory to improve the dynamic performance of permanent magnet synchronous motors. In this thesis, we use the Hamiltonian system method and the passivity property of the permanent magnet motor to investigate its robust control problem and design a robust controller which can utilize the internal structure of the system. The works done in the thesis can be summarized as follows:(1) Noting that permanent magnet synchronous motors always suffer to the disturbances of un-modeled dynamic and external world, we put forward an uncertain dynamic model of the system and discussed its passivity property. A dissipative Hamiltonian realization was completed as well.(2) We put forward a double-loop robust control the permanent magnet synchronous motors based on the Hamiltonian system theory. First, in the inner loop we design a feedback controller to realize the assignment of structure matrix, Hamiltonian function and equilibrium point and to enhance the dynamic performance of the system. Then, we put forward an outer loop robust controller to improve the robustness to external load disturbance.The robust controller proposed in the thesis can extensively utilize the internal structure of the permanent magnet synchronous motors, so the controller structure is simple and easy to complete. Simulation comparison with the traditional control scheme demonstrates the effectiveness of the proposed robust controller. |
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