电气工程及其自动化专业英语

电气工程及其自动化专业英语

　　应该注意：一个理想电压源(独立或受控)可向电路提供任意电流以保证其端电压为规定值，而电流源可向电路提供任意电压以保证其规定电流。Adifferentclassofrelationshipoccursbecauseoftherestrictionthatsomespecifictypeofnetworkelementplacesonthevariables.Stillanotherclassofrelationshipisonebetweenseveralvariablesofthesametypewhichoccursastheresultofthenetworkconfiguration,i.e.,themannerinwhichthevariouselementofthenetworkareinterconnected.一种不同类型的关系是由于网络元件的某种特定类型的连接对变量的约束。

　　另一类关系由于网络结构，即网络的'不同元件互相连接的方式所产生的相同形式的一些变量间的关系。1.Aresistorwhoseresistancesvarywithitscurrentisknownasanonlinearresistor.

　　2.Anopencircuitisacircuitelementwithresistanceapproachinginfinity.

　　3.3.Anelectricheaterdraws10Aforma120Vline.Theresistanceoftheheateris12.

　　4.Anidealdependentsourceisanactiveelementinwhichthesourcequantityiscontrolledbyanothervoltageorcurrent.

　　5.Anindependentvoltagesourceisatwo-terminalelement,whichmaintainsaspecifiedvoltagebetweenitsterminals.

　　6.Accordingtothepassivesignconvention,ifthepowerhasaplussign,powerisabsorbedbytheelement.

　　7.Electriccurrentisthetimerateofcharge,measuredinamperes.

　　8.ForacircuitcontainingNnodesandMbranches,therewillbeN-1independentnodevoltage.

　　9.Foravoltagesource,itsterminalvoltageisknownbutitscurrentmustbedeterminedbytheexternalcircuitconnectingwithit.

　　10.Ifinanacbphasesequence,Uan=100-20,thenUbnis100100.

　　11.Itisconventionaltotakethecurrentflowasthemovementofpositivecharges.

　　12.Kirchhoffslawsarethatarebasedonthetopologyofthenetwork.

　　13.Kirchhoffscurrentlawcanbestatedintwoways.

　　14.Kirchhoffscurrentlawisbasedonthelawofconservationofcharge.

　　15.Kirchhoffsvoltagelawisbasedonthelawofconservationofenergy.

　　16.MeshanalysisappliesKVLtofindunknowncurrentswhicharemeshcurrents.

　　17.NodalanalysisisbasedonasystematicapplicationofKCL,andsatisfiesautomaticallyKVL.

　　18.Nodalanalysismethodischoosingnodevoltagesascircuitvariables.

　　19.Ohmslawstatesthatthevoltageacrossaresistorisdirectlyproportionaltothecurrentflowingthroughtheresistor.

　　20.Resistorsarepassiveelements.

　　21.Theplus(+)andminus(-)signsinanelectriccircuitdiagramareusedtodefinevoltagepolarity.

　　22.Therearefourpossibletypesofdependentsource.

　　23.Thecircuitelementusedtomodelthecurrent-resistingbehaviorofamaterialistheresistor.

　　24.Thealgebraicsumofallvoltagearoundaloopiszero.

　　25.Thepotentialatreferencenodeordatumnodeiszeroinnodalanalysis.

　　26.Theenergyrequiredtomoveaunitchargethroughanelementisvoltage.

　　27.Thevoltageacrossaninductoreadsthecurrentthroughitby90.

　　28.Thevoltageacrossancapacitorlagsthecurrentthroughitby90.

　　29.Thethree-phasesourceandthethree-phaseloadhavefourpossibleconnections.

　　30.Thethreevoltagesthathavethesameamplitudeandfrequencyandareoutofphasewitheachotherby120aresaidtobebalancedthree-phasevoltage.