The Design Of Bruthless Driect Current Motor Drive Its Under The Control Of DSC

Recent years,with the development of Power eleetronic teehnology，motion controltechnolegy,material science technology and computer technology,brushless DC motor,whichworks as a kind of eleetromechanical switching equipment has been developed rapidly.Itsapplication has extended from military to transPortation,gauges,chemical engineering，medical seience and many othera reas.Brushless DC motor has the eability of simplestrueture,operational reliability and excellent speed regulation Performance.Compared to abrush DC motor,brushless DC motor uses electronic commutator to take the Place oftraditional mechanical commutator.This method could avoid the spark coming from theProeess of commutation and the eleetromagneticInterference,and the service life and reliability of the motor has been improved alot.However,the installment for electronic rotor Posture sensor would inerease the burden ofbrushless DC motor,which becomes a certain limiting factortoits apPlication.Asaresult,theProPound of sensorless brushless DC control system with Profound significance has becamea hot research Point reeently.In this Paper,on the basis of dctailed analysis for the struetUre charaetcristic andoperation PrineiPle of brushless DC motor,sensorless brushless DC motor closed loopcontrolsystem is realized.In the aspect of control algorithm,Back Eleetromotive Force(BEMF)is adopted to detect the triPhase back electromotive force zero一crossing and then determinethe Position of the motor rotor,aehieve the commutation Proeess.At the same time,because ofthe stalting Problem brought about by back eleetromotive foree,this Paper Puts forward akind of “,high一frequeney Pulse injeetion method”to deteet the brushless DC motor rotor inthe static Position,along with “three-step startup method” and realize the motor startssmooth without reverse.In this Paper,high-Powered digital signal ProcessorTMS320F28035type DSC Producedby Tl is as the master chip.The experimental results show that the sensoriess brushless DCmotor eontrol system could accurately deteet the initial Position of the motor and smooth start.On the basis of Realizing the correet reversing and closed loop oPeration,the system hasthe funetions of alarm display and double controlled both by keyboard and terminal.All ofthose Proved the feasibility of this system.