直流主轴电动机转速控制系统.pptx

,4.4.2Speedcontrolsystemofd-cspindlemotor（直流主轴电动机转速控制系统）-朱钦松,PPT模板下载：,11,1.给定转速信号2.电流测量和放大3.被控电源24.给定基本转速电势5.电动机6励磁电流测量7.电压测量和放大8.比例放大器9.反电势处理器10.测速发电机11.被控电源1,PPT模板下载：,11,Fig.4.13showsthespeedcontrolloopofad-cspindlemotor,inwhichthe“givenspeedsignal”comesfromCNCunit,“speedfeedbacksignal”comesfromtachometergeneratorandASRisaspeedcontroller.CurrentfeedbacksignalispickedupfromthevoltageofresistanceR1connecteduniaxiallywiththemotorarmature,whichisamplifiedbythecurrentmeasuring-amplifierascurrentfeedbacksignal.,图4.13表示一直流主轴电动机的转速控制回路，其中“给定转速信号”来自计算机，,“转速反馈信号”来自测速发电机，ASR则是转速控制器。,电流反馈信号取自电阻R1处的电压，R1与电动机的电枢同轴连接，,该电压由电流测量放大器放大为电流反馈信号。,PPT模板下载：,11,ACRisacurrentcontroller.The“controlledsource1”11providesthearmaturewithendvoltage,whosevalueiscontrolledbythesignaloutputofACR.Practicalcircuitof“controlledsource1”maybeatransistord-cwavechopper.Partialarmaturevoltage,intermsof,resistanceR2andR3,isamplifiedbyvoltagemeasring-amplifyinglink7andsenttoinversepotentialoperator9.InfactitisaminuscircuitwhichcalculatesinversepotentialaccordingtotheequationE=Ua-IR,ACR是电流控制器。,“被控电源1”供给电枢端电压，,其值由ACR的输出信号所控制。,“被控电源1”的电路可,以是直流晶体管斩波器。,用R2和R3分压的部分,电枢电压，经电压测量-放大环节7放大并传送至反电势处理器9。,它其实是一个减法电路，用以下等式来计算反电势。,PPT模板下载：,where.E-inversepotentialUa-armaturevoltageofmotorI-armaturecurrentofmotorR-armatureresistanceofmotor,式中,反电动势,电动机的电枢电压,电动机的电枢电流,电动机的电枢电阻,AMRisamagnetizedcurrentcontroller.The“givenbasicspeedpotential”referstothegiveninversepotentialatratingspeed,thusthefeedbacksignaltoAMRareoftwosignals,i.e.,theinversepotentialfeedbackandthemagnetizedcurrentfeedback.TwodiodesVD1andVD2areusedtoblockminorfeedbacksignalbutopentogreaterfeedbacksignal.,AMR是一励磁电流控制器。“给定基本转速电势”是在额定转速时的给定反电势,这样，进入AMR的反馈信号有两个，,即反电势反馈信号和励磁电流的反馈信号。,阻止较小的反馈信号但让较大的反馈信号通过。,两个二极管VD1和VD2系用于,11,PPT模板下载：,11,Underratingspeedthegreateroneisthemagnetizedcurrentfeedbacksignal,sothatonlythemagnetizedcurrentfeedbackisactivetoconstructthecurrentclosedloopandperformsconstant-powerspeedcontrol.Uptheratingspeedonlyinversepotentialisactivetoconstructpotentialclosedloopandkeepconstantpotentialthustoperfornconstant-momentspeedcontro