地铁轨地过渡电阻及走行轨阻抗在线测量

304Vol.30No.420017JournalofChinaUniversityofMining&TechnologyJul.2001:1000-1964(2001)04-0416-05李　威(,221008):利用解析法讨论了地铁隧道区间中轨地过渡电阻以及走行轨阻抗与轨道电压及流过走行轨电流的关系,建立了解析方程,提出用牛顿迭代法求解方程得出轨地过渡电阻和走行轨阻抗,并在理论上证明了存在有效解.利用单片机的总线通讯手段,在地铁隧道的3个不同地点分别同时自动测量轨道电压、轨道1m电压、负荷电流及机车距变电所距离等参数,并把测量数据送入上位计算机,由计算机完成在地铁正常运营过程中实时在线测量轨地过渡电阻和走行轨阻抗,为减少杂散电流腐蚀提供可靠的依据.:地铁;杂散电流;过渡电阻;轨道电阻;实时测量:U231+.8:A(),,.,,,,[1].,[2],,.,,,.,,,,.11.1.,,,,,.,,,,,,.L,I,is=18IRRgL2,(1):Rg,km;R,/km.(1)Rg,R.2,,,.1.2RgR1[35].:20010223:(1964-),,,,(),.1Fig.1Diagramofprincipleoftherailvoltageandcurrent:u(X)X,V;i(X)X,A;X,km;L,km.(u=0),1bi(X)RdX+u(X)-(u(X)+du(X))=0,du(X)=i(X)RdX.(2)1c:u(X)=di(X)Rg/dX,di(X)=u(X)RgdX.(3)2=RRg,(2),(3)d2u(X)dX2-2u(X)=0.(4)(4)u(X)=AcoshX+BsinhX,(5)(5)A,B,(5)X,(2)i(X)=1RRg(AsinhX+BcoshX).(6)X=0i(X)=IX=Li(X)=I,(6)A,B.A,B(5)(6)u(X)=RRgIsinhX-L2cosh2L,(7)i(X)=IcoshX-L2cosh2L.(8)Xi(X)1mu1(X)i(X)=u1(X)R/1000=1000u1(X)R.i(X)(8)(7)1000u1(X)u(X)=cothX-L2.(9)X,X,Xu1(X),u(X),LI,(9)(8),RRgRRg,RRg.(9),.,,(9)A=xcoth(b-c)x,:A=1000u1(X)u(X)=;b=X=;c=L2=;x==.A=xcoth(b-c)x(A,b,c,bc).1)f(x)=xcoth(b-c)x.a.f(x),y,x0;b.limx0f(x)=1b-c;c.f(x)=1sinh2(b-c)x[cosh(b-c)xsinh(b-c)x-(b-c)x],(x)=cosh(b-c)xsinh(b-c)x-(b-c)x,(0)=0,(x)=2(b-c)sinh2(b-c)x.i)b-c0,(x)0,x0(x),(0)=0,(x)0,f(x)0,f(x).b.f(x)1b-c,limx+f(x)x=limx+coth(b-c)x=1,limx[f(x)-x]=limx+x[coth(b-c)x-1]=limx2xe-(b-c)xe(b-c)x-e-(b-c)x=0,y=f(x)y=x,2a.4174:ii)b-c0f(x)=-xcothb-cx,2b.2Fig.2Atypicalcurveoffunction2)x*A=xcoth(b-c)xy=xcoth(b-c)xy=x.a.A=1b-c,x=0.b.A1b-c0,x*,-x*(x*0),x*A;A,x*A.c.A!1b-c0,:x*,-x*(x*0),x*A;A,x*A.d..3)f(x)=xcoth(b-c)x-A=0,,x0A.4)L1km,c=12L0.5km,A=1000u1(X)u(X)1,Xb=X12L,u(X)0,c,.2,X1mu1(X),u(X),I,L,(9),,RgR.,3,3u1(X)u(X),IL.3.3Fig.3Thehardwareschematicdiagramofmeasuresystem3a,89C51,,u(X),-100100V;1mu1(X),mV.,A/D,.A/D,89C51A/D.u(X)u1(X),,RS485,485,,.3b.I,,,.89C51,,A/D,A/D,,,,.RS485,RS485,,.3c.41830,,L.,.,,;,,.,L.L,,485,u1(X),u(X),I.,,.,3,,,4.-[6],,.,,,,.,,,u1(X),u(X)I,,(9),,RgR.,3,.4Fig.4Schematicdiagramofserialcommunication3RgR,.,,RgR.,,,,,,.,,,.,:1).2),RgR.3),,.4),1km3,RgR.5),RgR,.6),,,,.:[1].[J].,1997,12(5):40-47.[2].[J].,1999,11(6):31-39.[3],.[J].,1997,13(4):49-4194:52.[4].[M].:,1999.425-430.[5]WV.[M].,,,.:,1990.225-235[6].[M].:,1999.210-216.ResearchonReal-TimeMeasurementsofTrackContinuityandTrack-To-EarthResistanceofMetroLIWei(CollegeofMechatronicandMaterialEngineering,CUMT,Xuzhou,Jiangsu221008,China)Abstract:Therelationwasdiscussedbyanalysisamongthetrackcontinuityresistance,track-to-earthresistanceandthetrackvoltage,trackcurrentinundergroundtunnel.Newtoniterationmethodwaspresentedtocalculatethetrackcontinuityandtrack-to-earthresistanceofmetro.Thevalidresultswereprovedintheory.Trackvoltage,1mtrackvoltage,loadcurrentandadistancefromlocomotivetotransformersubstationcanbeautomaticallymeasuredat3differentpointsintunnelbythebuscommunicationofasinglechipmicroprocessor.Measureddataweretransmittedtouppercomputer,andreal-timemeasurementofthetrackcontinuityandtrack-to-earthresistanceofmetrowasperformedontheregularrun,whichprovidesthereliableevidencetoreducetheerosionofstraycurrent.Keywords:metro;straycurrent;trackcontinuityresistance;track-to-earthresistance;realtimemeasurement42030