等效电阻的几种计算方法

朱卫萍*(武汉电力职业技术学院电力工程系,湖北武汉430079):归纳介绍并讨论了串联并联电路的等效电阻计算方法;按两种情况介绍了复杂混联电路等效电阻的计算步骤;对于星形与三角形联接的电路介绍了星形三角形等效变换公式与方法;讨论了平衡电桥的等效电阻计算;进而引申出具有对称结构的电路等效电阻的简化计算方法:电工;等效电阻;简化;计算方法:TM11:B:2076/ZY(2010)03-0022-05,,,,,3,1图1串联电路图,,:R=R1+R2+R3+,+Rn=Enk=1Rk(n):(1),;(2),R=nR12图2并联电路图,,:1R=1R1+1R2+1R3+,+1Rn=Enk=11Rk:(1),,;(2),R=R1n(n);(3),R=R1R2R1+R2:(1),3,:R=3,,R1=128,R2=68,R=3=123=48#22#83Vo.l8No.320109JournalofWuhanElectricPowerTechnicalCollegeSep.2010*:2010-09-02:朱卫萍(1960-),女,大学,武汉电力职业技术学院电力工程系副教授?34,,n,12848382818(34612),?:n,:R=n+1(n),(2),,R1=18,R2=1008,R=R1R2R1+R2=1@1001+100=100101=0199U18,,,,,1.电阻之间联接关系比较容易确定:,,,,,,3,ab,R1R2,R3R4,,R5(b),,,:Rab=R1MR2+R3MR4图3混联电路图:,,,,3,ac,R1R2,R3R4,(R3+R4),,:Rac=R1MR2,bc,R1R2(),R3R4,:Rbc=R3MR42.电阻之间联接关系不太容易确定4,,,,,,图4复杂的串并联电路图:(1),,5图5寻找节点:,,c,,#23#83:(2),6a#c#d#b#图6各节点画在一水平线上:,,6ab(3),,,,,7图7节点命名法的新电路图(Y)(v),,8图8星形与三角形联接电路图,R1R2R3vY,9v-Y:Ra=R1@R2R1+R2+R3=40@5040+10+50=208Rc=R1@R3R1+R2+R3=50@1040+10+50=58Rd=R2@R3R1+R2+R3=40@1040+10+50=48图9等效互换后的新电路图ab:Rab=Ra+(Rc+R5)M(Rd+R4)=20+60@4060+40=448R3R4R5Y,R1R3R4v(R2R3R5v)1.电桥的概念:4,58,,a-cc-bb-dd-a,c-d,,2.电桥平衡及平衡条件,10,,Vc=Vd,图10电桥电路图,?,,,,8#24#20109,R4R5258208(11),,R1@R5=R2@R4,R1R4=R2R5,,图11平衡电桥电路图3.平衡电桥电阻计算,,,:(1)cd(Ucd=0),,12,图12等电位点短接后的电路图Rab=50M40+25M20=33138(2)cd,Icd=0,,,13,图13桥支路断开后的电路图Rab=(50+25)M(40+20)=33138:,,,14,,,15:Rab=1M1+1M1M1M1+1M1M1M1+1M1=0.5+0.25+0.25+0.5=1.58,14,,(1),,16,,:Rcabc=1+(1+1)M(1+1)+1=38,:Rab=Rcabc2=1.58(2)(下转第32页)#25#83:[10]王颖娴.高职院校精品课建设的思考[J].新课程研究.2009,(1).[11]何树全.高校精品课程建设创新体系初探[J].福建论坛.2009,(2).Practice&FeedbackofComputerNetworkQualityCourseConstructionLIUHairong(HuanggangPolytechnicCollege,Huanggang438002)Abstract:NetworkQualityCoursespromotionandapplicationarethemaincontentofteachingreformofhigheruniversitiesandcolleges.Combinedwithcourseconstruction,thisthesishasputforwardComputerNetworkQualityCoursesteachingtastsaftercarefulteachinganalysisandsystematicdesign,anditalsohasdiscussessuchrelavantissuesascourseteachingcompetencesystem,teachingmethods,practicalteachingdesigningconcepts,websiteconstructionandteachigstaffresourcescomposingandsoon,whichhaspositiveinfluencetocomputerbasisteaching.Keywords:computer;network;highereducation;qualitycourse(:黄逵中:杨上游)(上接第25页)图16取12部分的电路图,,,17Rab=Rae=1+1M1=1.58图17取14部分的电路图,,,,,,,,,,,(:李火元:朱德康)#32#20109