Research On Induction Motor To Optimal Direct Torque Control Algorithm Of Electric Vehicle

As a type of new energy vehicle, electric vehicle's development is the mostrapid. The requirements of control effect to motor have become increasingly high.Reliability, efficiency, the user experience and other aspects have proposed morestringent requirements. Based on the above aspects of demand, the induction motorcontrol system is studied in this paper. The tasks have been completed as follow.First of all, Mathematical model have been established for induction machine,the working principle of induction motor have been understand. According to thetorque response speed for electric vehicles have become more stringentrequirements for improving the user experience. Choose the Direct Torque Controlas the main research direction in the paper. Proposed three kinds of optimization forDirect Torque Control to induction motor. Respectively as to the traditional DTC toimprove this sectors,based on PI controller of DTC and predictive DTC.Secondly, in order to achieve the desired effect on the overall control, theaccuracy of the stator flux become particularly prominent. Employ diverse st atorflux observation techniques. Under different environmental requirements, select theappropriate stator flux observation method. Using of full-order flux observerTechnology not only can complete closed-loop stator flux observer, but alsoprovided convenience for speed sensorless technology in the later.Thirdly, because of the actual cost of the project need to be controlled, thissystem requires speed sensorless which need to be designed. This paper presents asimple speed estimation and a speed identification technology based on MRAS. Indifferent conditions present different advantages. In order to further improve thesystem efficiency, presenting a way to reduce system losses by changing theamplitude of the stator.Finally, Basing on predictive DTC, full-order flux observer Technology, speedsensorless technology and optimal amplitude of stator flux can improve DTC moresophisticated.Matlab/Simulink is used to simulate and argumentation. Experiments show theoptimized effect of DTC is very obvious.