:1003-0794(2004)12-0054-03(,150027):针对单闭环调速系统的组成和基本性质,研究了这种调速系统存在的问题及解决办法。通过实验提出了一种有效的单闭环调速系统-带电流截止负反馈的转速负反馈直流调速系统的原理及应用。:单闭环;直流调速系统;电流截止;负反馈:TM33:A1 “”“”。,,,。-(V—M)。2 。SF,UfUd,ΔU,FD,CFUk,,1。1 Fig.1 SinglereturncircuitDCadjustdrivingsystemofadoptrotateoppositefeedback,,。1KZ,、,、、、。CF。3,,,,,,,、、。ERP、ASP,,。,。:[1],,.:ERP、SCM[M].:,2002.[2],,.[M].:,2002.[3].[J].,2003,(3).[4],,,.[J].,2001,25(2):105-106.:(1974-),,,,:.Tel:0554-6632216.:2004-07-18Enterpriseweb-procurementmodelHUANGShao-fu(AnhuiUniversityofScienceandTechnology,Huainan232001,China)Abstract:Web-procurementisdevelopingincreasinglywiththeinformationtechnicmakingprogress.Severalmodelsofweb-procurementaresummarized.Theadvantagesanddisadvantagesofmodelareanalyzed.Thedevelopmentdirectionisforecastatthesametime.Vendorandenterprisemaybewintowinviaweb-procurement.Keywords:web-procurement;model;on-linebusiness·54· 200412 DOI:10.13436/j.mkjx.2004.12.029,,。L,。, Ud0=E+IdR(1)Ud0———,Ud0=AU2cosα;E———,E=Cen(n);Id———;R———。3 ,,,:(1),K,,, Δnb=IdRCe(1+K)(2)K=∞,Δnb=0,。,。(2),,。,。(3),,。。,,。4 。(1)-,,。,,,。,,U,,+4.2~-0.7。(2),,。-,,。2,Ui。2 Fig.2 Oppositefeedbackofcurrentdeedline5 5.1 电流脉动的影响及抑制措施m=2,3,6,12,…,,。,L=∞,,:(1),;(2)(),,。,,:(1);(2)。5.2 引入滤波器保证交流分量正常工作,。,,,,。,。5.3 电压负反馈调速系统中的电压隔离变换器,,。。,,。,,,,。5.4 直流调速系统中的限幅电路,,、αmin。,PI,。,·55· 200412 ——— :1003-0794(2004)12-0056-02(,150027):提出利用超高速机床主轴前后两转切削振动轨迹的相位差ψ来预报切削颤振的新方法,并且提出了利用等工件转角间隔采样,通过计算工件前后两转切削振动信号的互功率谱密度函数,精确确定相位差ψ的算法。通过理论分析,提出了超高速机床颤振预报方法的可能性,可望在实际中推广应用。:切削振动;预报;相位差:TG502.14:A1 ,,,,。,,[1~3]。、[4],、。,,,。,。2 。,。a0,y(t-T)y(t),1。a(t)=a0+μy(t-T)-y(t)F(t)=kcb[a0+μy(t-T)-y(t)]kc———;b———;μ———。y(t-T)=Ai-1sin(ωt+ψ)y(t)=AisinωtAi-1———;Ai———;ψ———。E=∫2πw0F(t)cosβdy(t)=kcbAiAi-1μπcosβsinψ,。,,。6 、,,,。。,,、。:[1],.[M].:,1998.[2],.[M].:,2001.[3],.[M].:,2003.:(1977-),,,2001,,4.Tel:0451-89671699,E-mail:lihaiyan1977@126.com.:2004-08-02StudyofDCadjustdrivingsystemofsinglereturncircuitLIHai-yan(HeilongjiangInstituteofScienceandTechnology,Harbin150027,China)Abstract:ThispaperaimsforcomposeandbasiccharacterofDCadjustdrivingsystemofsinglereturncircuit,studiesthesystemexistquestionandresolvemethod,andthenthroughexperimenting,raiseakindofeffectiveprincipleandap-plicationofDCadjustdrivingsystemofsinglereturncircuit-DCadjustdrivingsystemofsinglereturncircuitwithrotateoppositefeedbackofcurrentdeedline.Keywords:singlereturncircuit;DCadjustdrivingsystem;currentdeedline;oppositefeedback·56· 200412