The Research Of PMSM Vector Control System Based On Sliding Mode Variable Structure Control

Currently, Permanent Magnet Synchronous Motor (PMSM) with its the advantages of compact structure, high efficiency, high power factor, easy to heat elimination and maintenance, has been widely used in many fields. With further research, technology innovation and introduction of new materials, PMSM has vast prospect. Because of the advantages of Sliding mode control (SMC) theory is not sensitive to robustness, fast response and easy to realize the benefit is being applied in the field of power transmission. With the Permanent Magnet Synchronous Motor (PMSM) as the executive component the work focus on study of space vector control and sliding mode control by combining theoretical analysis with Matlab/Simulink tool.First of all, this paper reviews the historical development of Permanent Magnet Synchronous Motor (PMSM), introduces current situation and control strategies of PMSM. Secondly, the structure and type of PMSM is studied, and vector control theory, then mathematical model established by the coordinate transformation and the theory of vector control which laid a theoretical foundation. Then analysis of PMSM control for several control strategies and detailed analysis of the voltage space vector theory. On this basis, the rotor field oriented vector control of id = 0 and voltage space vector pulse width modulation are chosen, then combining Simulink and M-functions establish PMSM simulation system. The result preliminarily proves the control program feasibility. In view of the traditional PI regulator overshoot to the system with load disturbances and the chattering of traditional sliding mode controller, this paper proposes a method of dynamic sliding mode. The control signal produces an effective chattering reduction after integrations. The comparison of PI controller and dynamic sliding mode controller indicates that the robustness with load disturbances and parameters of outside interference, the dynamic and static characteristics are quality and to a certain extent decrease the chattering. After carefully analyzing the variable exponent reaching law method, a variable exponent reaching law velocity controller is presented. After simulation, the comparison of variable exponent reaching law controller and dynamic sliding mode controller shows that the method adopted to improve the system quickly and decrease chattering and the robustness too, verify the correctness of the policy. Then,a speed controller for PMSM based on fuzzy sliding-mode was designed. The proposed strategy could reduce chattering compare with conventional sliding-mode control. The simulation results show that the controller can realize the speed tracing, dynamic and static performance and good robustness. At last, this thesis contstructed the control system with DSP, the thesis designed the hardware, and analyzed the electrocircuit in detail for system establishment, did start work.