Research On Model Predictive Control For Permanent Magnet Synchronous Motors Drive System Based On Fraction Order Speed Regulator

In terms of permanent magnet synchronous motor(PMSM)drive system,the traditional control methods mainly are vector control and direct torque control.The vector control system based on stator current has slow response because of its inherent current loop;Although direct torque control system has fast response,its large torque ripple leads to bad operating performance.Finite control set model predictive control(FCS-MPC)is a high performance control algorithm in recent years.FCS-MPC is a kind of online optimization control algorithm which is based on model predictive control theory.The method is simple in concept but has strong constraint handling ability.Traditionally,the speed loop of the PMSM FCS-MPC system uses a conventional PI speed regulator,and it has bad control accuracy and robustness.Therefore,it is important to use advanced control strategy to design PMSM speed regulator.Fractional order controller is popular studied in recent years.Fractional calculus theory is an extension and expansion of the integer order calculus theor,which has following advantages:(1)The fractional calculus is global;(2)The fractional calculus can describe the dynamic behavior of actual system more precisely,and its mathematical modeling is closer to the actual system;(3)The fractional calculus operator has memory and genetic.In recent years,fractional order theory is applied to modern control theory to produce fractional order regulator.Fractional calculus controller has advantages of traditional controller and overcomes defects of traditional controller.Therefore,the designed controller has dual advantages of traditional controller and fractional order controller.The main research contents are as follows:(1)PMSM model predictive current control system is designed based on the traditional PI speed regulator and compared with the traditional vector control system.(2)Fractional order integral sliding mode speed regulator and fractional order terminal sliding mode speed regulator are designed based on PMSM model predict current control system.Then,fractional sliding mode controller and integer order sliding mode controller are compared and analyzed in sliding mode arrival time,converge time and decrease the chattering.(3)Extended fractional order sliding mode observer is designed by considering the variation of the motor parameters and the uncertainty of the external disturbance.The designed observer and fractional order terminal sliding mode speed regulator are a compound controller(4)A current observer is designed based on fractional order adaptive law with only one phase current sensor to accurate estimate the other phase current and stator resistance online.