Research On Fractional-order Controller For Permanent Magnet Synchronous Motor Control

Permanent magnet synchronous motor has the advantages of small size, high power density, wide speed regulation range and large torque inertia ratio, which is widely used in the field of robot, aviation equipment, national defense and so on. Moreover, the speed controller determines the dynamic and static performance of the system in the control system of AC permanent magnet synchronous motor. So the performance of the speed controller is particularly important.In recent years, with the rapid development of fractional calculus, the application of fractional calculus theory in the design of controller has been paid more and more attention in control field. The dissertation designs the speed controller with the fractional calculus theory in order to improve the control performance of the permanent magnet synchronous motor system. This dissertation researches the aspects of the fractional calculus theory, the design of fractional order controller, the application of fractional order controller in the control system of permanent magnet synchronous motor and the improvement of the fractional order controller. The main contents are below:(1) The fractional calculus theory is introduced, which includes the definition and basic characteristics of fractional calculus. The dissertation analyzes the unit step response characteristics of fractional order integral, and uses the Oustaloup approximation method to design fractional calculus simulation module.(2) The design method of fractional order PI~? controller is introduced. The conventional parameter tuning method and the PSO(Particle Swarm Optimization) algorithm are studied.In the view of the shortcomings of traditional PSO algorithm in parameter tuning, it is improved to make the controller to obtain the better parameters.(3) The vector control method of permanent magnet synchronous motor is researched,and the simulation model of permanent magnet synchronous motor system is established based on MATLAB/SIMULINK. The fractional order PI~? controller is applied in the speed loop of the control system, and its control performance is compared with the traditional PI controller.(4) The fractional order PI~? controller is improved from two aspects. On one hand, in the designs of practical engineering, the output of the speed controller is usually limited, and it may cause the Windup problem. So the fractional order Anti-Windup controller is designed to improve the performance of the control system. On the other hand, the system model and parameters may be changed by the external or internal factors in the practical application. But if the parameters of the controller are fixed, it may make the performance of the control system worse. In order to solve this problem, the fractional order PI~? controller is improvedcombined with the adaptive fuzzy control method, which can make the fractional order PI~?controller adjust its parameters online according to the real-time change of model parameters.Finally, the two improved schemes are compared with the fractional order PI~? controller by simulation.