Permanent Magnet Synchronous Motor Index Type Of Fractional Order PI Speed Control

Permanent Magnet Synchronous Motor(Permanent Magnet Synchronous Motor)is a kind of AC motor which develops rapidly.It has the features of low cost,high power density and high energy density.It is widely used in industry and life,such as electric vehicle,vehicle traction equipment,wind power control,navigation ship power propulsion devices.However,in the actual operation,the external environment interference and motor interference,such as external temperature anomalies,input voltage fluctuations,load changes,motor internal parameters perturbation and other factors,will have a number of adverse effects on the normal operation of PMSM,from Motor control performance is reduced,so it is necessary to design a controller with strong robustness.In this paper,the basic structure and working principle of PMSM are introduced firstly.Then three mathematical models are built according to the working principle of PMSM.The advantages and disadvantages of each model are analyzed,Considering synthetically,the mathematic model is set up under dq axis coordinate system,the relationship between the motor flux linkage,voltage and torque is simpler.A simulation model is built in MATLAB.The PI controller is used to control the speed controller.The uncertainty factor of the torque coefficient is added to the speed loop controller.The experimental results show that,given a stepped angular velocity input signal,the system overshoot fluctuation increases and the robustness is poor,which makes it difficult to satisfy the control requirements of the control system under the condition of the torque coefficient perturbation.Aiming at the weak robustness of traditional PI speed control to PMSM parameter perturbation,an exponential fractional PI(FO[PI])controller is applied to the velocity loop control.Then the parameters of the FO[PI]controller are set according to the phase angle margin,amplitude condition and robustness condition.Then the approximate approximation of the FO[PI]controller is realized by the impulse response invariant discrete method.According to the approximate function in Matlab/Simulink simulation,Simulation results show that FO[PI]controller is superior to traditional PI controller in parametric perturbation robustness.When the parameters are adjusted by using the phase angle margin and amplitude condition,a suitable phase angle margin and gain crossover frequency should be selected for the PMSM open-loop system,After a number of simulation experiments show that:the combination of different phase margin and gain crossover frequency for the speed loop control is very different,and even some phase margin and gain crossover frequency combination in this method can not find the response ratio Coefficient,integral coefficient and fractional order.Therefore,in this chapter,we discuss the feasible region of phase angle margin and cutoff frequency for the simplified control object.Finally,some experiments are carried out on the experimental control platform with TMS320F28335 DSP as the core to verify the effect of the FO[PI]controller in the real system,and give the experimental results and some codes.Simulation and experimental results show that the proposed FO[PI]controller pair is valid and makes the PMSM speed servo system obtain better speed regulation performance.