Research For Suspension Control Of Bearingless Induction Motors

The bearingless technique has been developed rapidly recent years,and the research on it has became a focus.The bearingless motor,which combines the drive with magnetic levitation,is a new type of motor.The bearingless induction motor which has the advantage of simple structure and high reliability,was studied earlier than other types of bearingless motors.The bearingless induction motor has great application value in the domain of the electrical drive with high and ultra high speed.The bearingless motor is a new type of motor which hybridizes the motors and the magnetic bearings.The bearingless motor winds the levitation windings together with conventional motor windings to produce radial forces by taking advantages of the similarity between the structure of magnetic bearing and that of the AC motor.The rotor shaft can be successfully suspended by the electromagnetic forces.The bearingless induction motor,because of its simple structure,high reliability,air-gap uniform and easy field weaken,has more value of researchs and applications than other motors. This paper first expounds the basic principle of bearingless induction motor,then analyzes some characteristics of flux orientation control contraposing the mathematical model of bearingless induction motor,a new decoupling control system has been put forward,this approach directly controls rotor eccentric displacement.Based on the analyzing about the fundamental principles of the bearingless induction motor,the motor's mathematical model is derived and the new control system is designed.Then,the control system is simulated with Matlab/Simulink toolbox.The numerical simulation results show that the successful decoupling of radial forces and electromagnetic torque is realized.Finally,the ditigal control system based on TMS320LF2407A DSP for real-time control is designed to relize the measurement of displacement,speed and current.It also provide a reliable experiment environment for suspension operation studying of the prototype motor.The programme in this dissertation is all done by assemble language in the environment of CCs2000 software.Parts of the experiment is finished successfully.