Study Of Improving Fluxweakening Control Of Permanent Magnet Synchronous Motor Based On Single Current Regulator

Permanent magnet synchronous motor(PMSM)has remarkable advantages of high efficiency and energy saving,so it has been widely used in many fields,such as rail transit,aerospace,household appliances,electric vehicles and others.Especially in recent years,with the development of power electronics technology,microcomputer control technology and the theory of its control,the motion control system of permanent magnet synchronous motor has been attracting more and more attentions of domestic and foreign scholars.This paper conducts a more in-depth analysis and study of reaches of(PMSM),both at home and abroad,and summarizes their advantages and disadvantages.Secondly,mathematical models of vector control of PMSM is established,and the principle,realization and working range of flux-weaken control are deeply analyzed theoretically.Then the steady-state working model of PMSM is obtained.It provides a theoretical basis for the subsequent improvement of the flux-weaken control method is deduced.Based on TMS320F28035 control card,Texas instrument motor control kit and servo control motor,the experimental platform of permanent magnet synchronous motor(PMSM)is established,which provides experimental support for subsequent research.The traditional double current regulator flux-weaken control system has advantages of simple control,good robustness etc.However,the parallel connection of the two current regulators can easily generate saturation of the current regulator.The system tends to lack good control stability.Because there is only one current regulator in the current loop of the single current regulator flux-weaken control system,the q-axis voltage is determinate directly by the controller.Therefore,the saturation problem of double current regulator does not exist in the single current regulator flux-weaken control system,and the control stability is better in the high speed flux-weaken region.The conclusion is verified by simulation and experiment.The traditional single current regulatory control system has limitations that it is difficult to consider both the strong load capacity and the high light load efficiency.In this paper,the load line of the motor is modified by means of virtual impedance,so that the motor works near the optimal efficiency point under light load.With the increase of load to work near the maximum electromagnetic torque,the efficiency of the motor under light load is improved without reducing the load capacity of the motor.The feasibility and effectiveness of the algorithm are verified by simulation and experiments.