Fractional order calculus,in fact,is the extension of the integer order calculus,which has a wider range of adaptation.With the development of fractional order calculus theory,there are more and more researches on fractional order calculus in the field of control.In this thesis,aiming at the defects of the traditional PI control algorithm of permanent magnet synchronous motor(PMSM),the fractional order PI?controller and the fractional order sliding mode controller are designed by combining the advantages of fractional order calculus and advanced control methods.And they are applied to the speed outer loop control of permanent magnet synchronous motor speed control system in order to improve the performance of the system.Finally,the superiority of the controller designed in this thesis is verified by simulation.The main work of this thesis is as follows:Firstly,the definition of fractional order calculus and the discretization of fractional order calculus operator are introduced.The Bode diagram of indirect discretization of fractional order calculus operator is given,and the approximate effect of different order calculus operator is analyzed and compared.At the same time,the characteristics of the typical links of fractional order calculus are analyzed.The simulation results show that fractional order calculus has more advantages than integer order calculus.Secondly,the basic structure and mathematical model of PMSM are described.And the double closed loop PI control system of PMSM is simulated.The existing problems of traditional PI control method are analyzed synthetically.Then,the fractional order PI? controller is designed for the speed outer loop controller of permanent magnet synchronous motor speed control system.And the parameters of the controller are adjusted by particle swarm optimization algorithm.The superiority of the control strategy compared with the traditional PI control strategy is verified by simulation;Based on the traditional sliding mode control,the fractional order sliding mode controller is designed with fractional order calculus theory.The simulation results verify the reliability of the control method.Compared with the traditional PI control method,it can meet the performance requirements of the speed regulation system.And it can effectively reduce the chattering phenomenon generated by the traditional sliding mode control.Finally,the control strategies of permanent magnet synchronous motor based on two fractional order controllers are compared and analyzed.It can be seen that the system has better control performance under fractional order sliding mode control. |