计算答案.docx
电机及拖动(第二版)计算A卷答案一、计算分析题(每题1分)1.°Rj57.5/=R=23x0:©AINUN2301.=n+,=(100+4)=104APQJH=°ii042=1081.6w(1)转速nEa=Un+凡1.=(230+0.1X104)=240,4VC=-=0.1603JnN150()电动机运行:及二UN-R=(220F1x104)=209.6VC=C=-×01603=0.15331.AV2301.e230Ea209.6.n=J=1367rminCt01533(2)电磁功率P=FI=209.6×104=21.798W.ema/a.a(3)电磁转矩2.解:(1)原来高压绕组的匝数UJUinp=NJN1因为630,卢=M,所以n=630匝。4003402v,(2)新的高压绕组匝数因为100003_TVrl43-40所以N=0°°匝_U,v-R/n_220-0.1x158.511N1000=0.204V(rmin)n_URJn_U108RJnlCCv220-0.8x0.1x158.5=1016r/m.n0.2042.UScO8(R+Rs儿=22O-O.8x(O.I+O.3)x158.5=83(WminCv0.2043 .降压瞬间n不突变,Ea不突变,电流突变为:188-0.204x1016=_193A稳态后电流Ia恢复到原来值(0.8In),稳态后转速为:0.204,一R/J88-。.8x0.1x158.5=859“tnin4。根据r,=C丁N1.=G'1。得,=/=-o.8/=/=158.5A1 a,1.a0.8,vu-E“u-c/RaNIN=1251rminUbR/'.220-01x158.5Cl,0.8×0.2044 .解:(1)折算到高压侧的变压器“T”形等效电路参数并画出等效电路图(设RI=R2',X=X2,)由空载试验数据求励磁参数R1.曾吃。%CXn=>Z2tn-R2,n=3.852-0.352=383Q折算到高压侧有:9-77'一)?Zm=kZm=25×3.85=240625,Rn,=kRlt,=25×035=218.75xJ=2X.=252×3.83=2393,75由短路试验数据求短路参数=UOM=WOl逐S-八.43.3=587C,RS=岭噢“94CIs43.3?R=R产;RS=gxl94=097则Xs=JzMK=5/5.87=1.94=5.540x1=x=Xs=554=277折算到高压侧的变压器"T”形等效电路如图JS0307所示:(2)额定负载且cos62=0.8(滞后)时的二次端电压Z=JOoOo/G=i33.3,R*=旦="1=0.0146乙"I.43.3KSZJI33.3密封线*=X1.=也I=OO4I6Q,ASZm133.3AU=X*scos÷*ssin9Ji00%=1×(0.0146×0.8+0.0416×0.6)×100%=3.664%U、=(1-M)U,N=(1-003664)x400=385.3V5.起动电流比为:=工二J=1.7J1R1V2×85.2×0.13各级起动电阻为:Hm=(万一DR”=(1.7-I)XO.13=0.09ICHm=/RM=I7xOO91=O.155CR,3二/Rn=1.7X0.155=0.263C6.解:(1)额定电流j=PNJXIo1NUN230=73.91A(2)电枢电动势F=CZ7v=-11M=×l3×102×1500=241V口UJ6()4"N60lIU7.在固有特性曲线上:=0.41lV(rmin)UbRJN_440-0.38x76一1500Mo=UN.440C.v。411=1070rmin=%=1070-1000=70r/min在降压人为特性曲线上:11n,n="。一=250-70=180rminn7()静差率为:%=<M×100%=-×100%=28%0250在弱磁人为特性曲线上:“=_1.1.l.n°GCe=/=0.293Ia*I22176=106.6AN0.293"maxUkR1.=440-0.38x106.6Ce0.2931363r/min静差率为:B%=nM=I500-1363=93%。15008.解:、Z;=0.045用=4=(:;:;3=00225Xs=0.039(2)=以用CoS%+X;SinO2)=0.0225×0.8+0.039×0.6=0.0414U2=Q-AU)U2n=(1-0.0414)×400=383.44V,n=黑Tg64n15009.解:(1)当输出电流I2=I2N,cos2=0.8(滞后)时的效率n密封线(2、=1Po+'PSN,X100%、BSNCGS,+Po+Psn,(18×12×561=1Xl00%l×5600×0.8+18+l2×56=98.38%(BmSNcos(p?+2P。)=1I0.567×5600×0.8+2×18=98.6%m几一小1500146010.Clil="=W1111500R*£=0027x355="6/2N一3×40转速n=1050rmin时的转差率为:SR因为负载转矩不变时,电磁转矩不变)x100%0.0270.13811n1500-1050aq,=!=UJ1111500RC?÷R,即RVs二常数。所以4二空一SNS=1×100%转子回路应串电阻为:R=P,=-1×0.138=1.4八2(0.027)-1(2)效率最高时的负载系数Bm和cos2=0.8(滞后)时的最高效率nmax。11 .SNnN=1500-1460=0271500鼠=SYa÷历斗0627x(2+H)=0.1当Tl=0.8Tn时,在固有特性上运行点的转差率和转速分别为:n=(l-ly)11=(l-0.02l)×1500=l468.5rmin转速降落为:11=电一=1500-1468.5=31.5rmin当频率下降使转速和为:*=100SVmin时,其降频人为机械特性对应的同步转速为:zz1=+i=1000+31.5=1031.5rmin根据频率与同步转速成正比:g=%-Jn%,得频率下降为:f=Mf=WX50=34.4HZj,nNJn1500f恒转矩变频调速时,应保持电压与频率正比调节,即4-=gj-JnUNf得,电压下降为:u=y-fzv=×380V=261AVJN12 .S='"UNn1000-960100o=0.04S,=SN(办÷)=04×(23÷而H)=0.175=0.184将Km=T1.=O.757,Sm=0.175,Tm=XTTN代入实用表达式:Tem=0.757;V=2办7“"%+%s可以解出71=0.75TN时运行点A的转差率为:=0.0291二SNEN=004x164232yv.6x20.6A点的转速为:=(1T)%=(1-鼠)%=(l-0.029)xl000=971rmin反接制动起始点B的转差率为:c=nn=100°971=1.971'B-111ToOo将Tb=-1.87n,5b=1.971代入实用表达式,并注意到反接制动特性对应的最大转矩Tm=XTTk应为负值:-1.8v"ASBISm+SmlSB可以解出反接制动特性上的临界转差率当s'm=095时,应串电阻:Pp9=I-lP,=f-ll×0.184=0.815八2八2Io.)Om'/13 .解:额定电流:InPnJOxIO'UN230=43.48A额定负载时的输入功率:P1=R=J1.=人0.8511.76kW14 .解:(I)UlNP二UIN=3637.3VIin=Sn3Uin=9.16AZin=397.1Xm*=14.259R11>l.23Xs*=0.039Rs*=0.0225(C)(2)u=h*(Rk*cos+Xk*sin)×100%=4.14%U2=(1-u)U2N=383.44V15.解:(1)p2=pN=GkWIr力=竺4Rf177=1.3AP=A=177x1.3W=299WIn6000230A=26.IA乙=八-/=(26.1+1.3)A=27.4APQta=RE=057X27.42W=427.9W所以:Pel=P2Pcua+P/=(6000÷427,9÷299)W=6726.9WP67269T=2_-=_777=M3N7771 em2×145060(2)P.=P,+P陪+PFe=(6726.9+234+61)W=7021.9W=×100%=-×100%=85.45%P17021.916.解:Z;=0.063=渭厂°但X;=依一辰2=。056Z/=1/0.045=22.222R11=Po*Io*2=(1000/180000)0.0452=2.743Xm*=Jzf-2=22.05(2) AU="R;Cosq+X;sin/)=222×0.8+0.056×0.6=5.136%密封线(3)=1'Q-SV,×100%(=1-I-SNCoS化+Po+PsN,X100%1000+052×40000.5X180X103×0.8+1OOO+0.52×400()/=97.3%17.解:(1)输出功率:(小心+&+吃+匕。=6.32-(0.029÷0.045+0.2375+0.1675+0.341)=5.5%W效率:7=oo%=-100%=87.03%Pi6.32(2)电磁功率:Pem=P2+Pad+Pmec+Pcu2=5.5+0.029+0.045+0.2375=5.8115&W转差率:SN=当30.041Pem5811.5(3)转速:n=(1-s)n.=(1-5)=(1-0.041)x50=1438.5r/minP2(4)空载损耗:E)=Ptnec+Pad=0.045+0.029=0.074kWP74空载转矩:=9550=9550=0.49Nmn1438.5P55(5)输出转矩:7;=9550-=9550:=36.5INmn1438.5(6)电磁转矩:Tm=T2E=36.51+0.49=37Nm18.解:一=3二2,0二2pImp2×3×3pX360_3×3603630考号K、=Si畔×90)=sin(×90)=0.966,Kih.qa.2×30sin二一sin2=2.«r30sm-2sin0.966Kw=KvKa=0.966X0.966=0.93360/60×50.nA-nni=1OOOr/min,Sn=-P3%.XlO'55l()3100q-97q0.03100oN一石U7nCOS0n-石X380x0.915X0.88NP33=1O3.8A19.解:(1)额定转差率:6=60x50=1000r/ninn.-n100O-950=0.05I(XX)(2)转子铜损:PMEC=Pn+PmeC+=28×103+800+50=28850WPC“2_SNPMEC1一$Pcu2=JJPYEC=0'°5×28850=1518AWSN1-0.05(3)定子电流:P1=Pn+Prnec+Pcu2+Pre+Peul=28×IO3+800+1518.4+500+1000=31868AW6也UNCOS必31868.4323×380×0.88二55AP28000(4)效率:/XlOO%=×100%=87.86%R31868.4(5)转子电流频率:f2=SNyi=005×50=2.5Hz20 .解:(1)高压侧额定电流:SN20=1.16A低压侧额定电流:,SN二20”疯AN3×0.4=28.87A(2)求电压高压侧额定相电压:TT=UIN_J_9_U'NP-33=5.774匹低压侧额定相电压:02NP=1.=°231BZ(3)求匝数低压侧绕组的匝数:因为U*Uj8二NU2npUJMN2所以N?="U2,Y=04x3300=132匝1N2Un1。21 .解:(1)额定负载时的输入功率:P17P=J=20.48&WCZ1.O.83(2)额定电流:22 .1.直接起动电流和起动电流倍数分别为:2.IstUNR2200.067A=3283.6A1.=3283.6=15.8倍R=2201.5x207.5-0.067=0.6423.(1)直接起动时,电源容量对电动机的起动电流倍数要求应满足下式:3÷¾klf3÷三电动机容量J4(55)=5.3而电动机的k=7>5.3,故不能采用直接起动方法。2)当采用Y降压起动时,起动转矩为:Tfl=Txl=IKTN=*TN=。67TN即TJTN,所以也不能采用丫一降压起动方法。(3)若采用自耦变压器降压起动则:起动转矩:n=vz=v为了使Tl>7,自耦变压器的变比应为女<近,即抽头比应为:->-!=70.72%,取1.=73%k2k此时电动机的起动电流为:几=3乙=;左/=0.727/“=3.73人KK起动电流与额定电流比为:女3=3.73<5.3IXt可见采用抽头比为73%的自耦变压器进行降压起动时,起动转矩大于满载转矩,起动电流倍数满足电源要求,故可以采用此方法起动。24 .解:N=2NyZ=2×5×16=160E3分琴鲁"IA25 .解:(1)额定电流=11320APn_300x1()66UNCoSoV-318×103×0.85(2)额定功率因数角n=arccos0.85=31.79°有功功率PN=300MW无功功率Q=Pvtann=300×0.6197=186fvar26.解:(1)见JS0303(2)Rs=R1+k2R2=2.48+(1000/3230)2×0.4=5Xs=X1+k2X2=3.22+(1000/3230)2×0.6=7Zs=啊+X;=52+72=8.603IlN=Sn3Uin=IOX1O33X1000=5.774AUi=Usn=InXZs=5.774×8.603=49.7V27.(1)0.041500=0.166-1_n11N_1500-1440(2)T=95502=9550X=49.74Nm1.N11n1440Tlll=ATTN=22x49.74=109.43Nm机械特性实用表达式为:2x109.43218.86s0.166s0.1664H0.166S0.166S(3)当n=1300rmin时的转差率为:S=旦口="出U29=0.133加1500对应的电磁转矩为:=106.9Vw_218.86_218.86Iem=0.166=0.1330.1664H0.166S0.1660.133(4)s=O-l范围内取不同值代入机械特性实用表达式,算出对应的Tem值,可画出机械特性曲线。(绘制特性曲线略)28解:UNP=UN8=4o°H=23W京QP=UNP+jXjnp=231Oo+72.38x37.5-31.79。=278+775.86=288.215.26°(1)E=/EOp=GX288.2=499.W“15.26。n.,一严EoUN一03×288.2x231.PP=-sinAk=sin15.26(3) remr2tUN2.38=22.087ZW(4) =3.8SinbNsin15.26,29.解:(1)额定转速nN电磁功率:Pem=P2+Pad+pmec+pcu2=10000+200+77+314=10591W额定转差率:S'=£皿二一0。3Pitn10591同步转速:巧=里也=6050,OOF/mi11P2额定转速:n=(1-5,)n1=(1-5n)l=(1-0.03)><5()=1455.5r/minP2(2)额定运行时的电磁转矩、输出转矩和空载转矩输出转矩:T、=9550%=9550当”=65.6INmn1455.5P+p77+2(X)空载转矩:Tli=9550*”=9550=.S2NmnN1455.5电磁转矩:=65.61+1.82=67.43MTZ30.解:电磁功率:P=p+pem1.N1.necPad+PM=10+0.175+0.102+0.314=10.59MW转差率:5=p42ptw=0.341/10.591=0.0296额定转速:为=(1S)甩=(I-0.0296)1500=1455.5rmin额定电磁转矩:TJ1.en10.591x1()3211150067.4Ntn6031 .解:(1)额定负载时电枢电动势:Ed-RJaN=(220-0.26×75)V=200.5V因为额定负载时电磁功率:儿=E/.=200.5X75W=15037.5W所以额定负载时输出功率:=(15037.5-2589冲=12448.5W所以额定负载时输出转矩为:T2=B=“448.5Nm=Io(X)X24纵/60118.93Nm(1)励磁电流因为所以输入功率:P1=Uk+1.n)=22。X(75+2.42)OZ=17,03KW所以额定效率:=PjP1=12.45/17.03=0.73=73%32 .解:当B=I时,U2=U2N,U=0,则:4cos2÷*ssin)=0XSNS而短路参数为:Z=以=2616=6.33乙,lsp92.3RsPs_530003/r3x92.3?=2.07X5=7Zs-s=716.332-2.072=i6.2所以2.07216=-0.128夕,=-7.3"为阻容性负载33 .解:额定电流,“去M=3额定励磁电流也3加Rf20.1=5.72A额定电枢电流Io=In+I3435+572=310.7A额定电枢电动势EUN=UN+RfIaN÷2(7z,=115+310.7×0.0243+2=124.5V额定电磁功率pn=EjN=124.5x310.7=38682.15W额定电磁转矩=254.75Nm,=P*38682.15加一区一27x1450/6034 .解:电动机的输入功率:720P=°=80(WC0.9母线上总有功功率:P1=2000+800=2800W同步电动机补偿有无功功率:PvCoS0=f-Jp-Q=PTano=2(XX)Xtan53.=2666.67kvar0.8=2800728002+(2666.67-t.)2解上式得:Q=566.67%Var同步电动机的功率因数:CoSe=/80°=0.816(超前)8002+566.672同步电动机的定子电流:P1800邪UNCGS(PV3×6×0.816=94.3A35 .解:(1)额定电流In600×106网UNCoSJV320×103×0.9=19245A额定功率因数角n=arccos0.9=25.840(2)有功功率PN=600MW无功功率Q=PNtann=600×0.4843=2906Mvar(3) Eo=U+JInx1=1.0+Jl×1.946Z-25.840=2.55Z43.460功角:Sn=43.46°36.过载能力:A=SinbNsin43.46°=1.454=ZJqq0-97q=0.Q311l0+0.03×-1=0.11532zv6x210=0.02转子回路串入0.8Q电阻时,人为机械特性上的临界转差率为:_R+R0.02+0.80.02×0.115=4.715将Tem=TN,S%=4.715,Tm=入TTN代入机械特性实用表达式:T=TN=-Om可以解出转子回路串入电阻R=0.8Q电阻时运行点的转差率为:s=,a±7IFi)=4.715x(2.05+73i)=4.715x(2.05±1.79)解得:S=I8.1,52=,226两个解中,52=1.226<m=4.715是稳定运行点的转差率,而5=18.l>ym=4.715是处在非线性段上的不稳定运行点的转差率。所以取s=1.226°对应的转速为:11=(l-5)21=(l-1.226)×1000=-226rmin电动机处于倒拉反转运行状态,即匀速下放负载。37.解:SN=3Xl=3kV-AUIN=6×220=380VU2N=IioVI1N=Sn3×Uin=3×1073x380=4.56A12N=Sn3×u2n=3×1q73×110=15.75A4.5×103=10.68A38.解:(1)定子电流:Y接时:Un=380V'JNrINCoS皿V5×380×0.8×0.8接时:Un=220V1N=18.45APN_4.5x103ViaVNCOS必V3×38O×O.8×0.8(2)因为nNnlP60/60×50K145()=2.07取P=260/6()×5()1.n11./1,=1500r/mnP2(3)额定转差率:SN=勺二曳=5001450=0.0333nl15(X)39.T=95502=9550×-=146.9Nm1N%715Tl=I.8TN=I.8X146.9=264.4Nm_nr11NSN=Hl750-715r=0.047750146.9二2220.047x264.4校验T22(l.l1.2)T1.=(1.l1.2)X98=(107.8U7.6)Nm7岂=空I=U5.96N7>1.17122.28ll凡=*=*察=°°94C各级转子回路电阻:Rp=0R=2.28X0.094=0.214Rp2=O?R?=2.282X0.094=0.489Rp1.卢R1=2.283×0.094=1.114各级起动电阻:RM=RPrR?=0.214-0.094=0.12Rm=Rp2-R,=0489-0.214=0.275R“3=火尸3R/,2=1.114-0.489=0.62540.解:该厂电力设备从电源取得的有功、无功及视在功率:jp=1200ZrWS=P1CoS夕1200_0.65一1846.2ZVAQ=SlSin夕=1846.2x0.76=1402.99Zvar同步电动机从电源取得的功率:P=-=526.32&Wr20.95P2526.32cos/,0.8=657.9WA=S2sin=657.9X0.6=394.74kvar装设同步电动机后的全厂负荷及功率因数:P=P1+P2=1200+526.32=1126.32kWQrQcQ.=1402.99-394.74=1008.25&varS=帆+Q;=1726.322+1008.252=1999.19kVACOS±=窄=0.864(滞后)单位姓名考场号考号密封线所以,全厂的功率因数为0.864(滞后),变压器不过载。41.1.Ea=Un-RJa=220-0.4×53.4=198.64VPem=EaIa=198.64×53.4=10607.4WTem=9.55塌=9.55X"比。7"=6753Nme,nnN1500P10×IO3Ty=9.55上=9.55X=63.67TVmnN1500T0=Tem-T2=67.53-63.67=3.86Nm2.GY=鬻=。侬4UNGQN220=1662"min0.1324,R“TI,”0.4×3.86-CznQ=%s-或=16627=1653rminCeCr%9.55×0.132423.%-05ZA=220-05x534x04=58gmE0.13244.“-纥=UN-G/=220-01324xl600=24Ra0.442.解:(1)磁极对数:"n4=现P60/60×50o1,由Op匕=3.16取p=395()同步转速:=x=100Or/minP3户y1000_950_额定转差率:=一=.¥¥、=0.05nlI(XX)(2)总机械功率:Pmec=Pn+Pmec=28+1.1=29kW转子铜损:与空=/一PMEC1-$Npcu2=PYEC=005X291=1.532Wcu2If1-0.05(3)输入功率:P=Pn+Pmec+Pcu2+PiPcu=28+1.1+1.532+2.2=32.832kW定子电流:Ixn=-r-=1.S?.?_=56.684KUNCOS必3×38O×O.88(4)效率:=殳100%=3100%=85.3%Pi32.832(5)转子电动势频率:=Z=0.05×50=2.5ffi43.(1)_750720SN=一750=0.04(%+MT)=0.04×(2.4+2,42-l)=0.183P75T=955Oa=9550X=994.8NmiN11n720T111=%Tn=24x994.8=2387.5Nm(2)实用表达式为:2x2387.547750=50.1830.183、S(绘制特性曲线略)一见一外,_1500147044.1500起动时,尸1,£尸2人,代入上式可求出转子串电阻人为机械特性上的临界转差率为:S,n=16=0.02=2%:TNXlSm机械特性近似公式为:T转子每相应串入的起动电阻为:Rl=-1j×0.08=20.1)(Sr-1R2=S"1>45.解:(1)n1=60f1p=60×50/3=1000rminSn=(11i-11n)/n=0.038f=Sn11i-1.9HzPQ=P2+p÷p=7500+45+80=7625WPcu2=301.2WPlN=P2÷Pcul+PFC+Pcu2÷pQ+p=8630.2Wn=75008630.2=87%(3) In=15.85(4) T=Pm/=75.73Nm46.解:(1)电枢绕组为单叠绕组a=3密封线Tem=C"忐I×2.1×12×1O=13.317Vzz2×3.14×3u(2)电枢绕组为单波绕组a=lT=CJ=里I=3X398×2.1×12×10=39.937Vz7z1 em5la211ala2×3.14×1v47.解:电磁功率:pm=p-pcul-Pf=60-0.6-0.4=59W总机械功率:PMK=(I-S)PM=(I-0.03)x59=57.23ZW转子铜损耗:Pe=SP=0.03X59=1.77RV-CuZem48.1.Cv220-0.91x22.311N1000=0.2UNRa+RbTCV-cC代入已知数据:1000=-2200.2()91+99.55×0.221CmB可以解出制动瞬间电磁转矩为:T4-0.81NmentD-220091+92 .由O=-Tr得n=0时的电磁转矩:T=-42AN-m0.29.55×0,221emclemc3TN=G/n=955Cv/n=9.55x0.2x22.3=42.6M根因为IT<,所以不能反转。IemCN49.解:(1)由空载试验数据求励磁参数励磁阻抗:7*=二=15.38励磁电阻:乙tnJ0.0652=600/100x10142,nf20.0652励磁电抗:X>z;/-,2=15.382-1.422=15.31由短路试验数据求短路参数:短路阻抗:Z;=U;=°05短路电阻:R=尸;V=A=18003=0.018SS"SN100×10短路电抗:X;.=Zs2-Rs2=0.052-0.0182=0.467(2)AU=从R*SCoS2+X*'sinOJX100%=1×(0.018×0.8+0.467X0.6)=4.24%0,=(1-ASU2N=(l-00424)400=383V=1Po+"PSN,×100%BSNsS?+Po+Psn,(l600×fX1800)八l×100×10×0.8+600+l2l800/=0.577×1003×0.4=83.3A=97.1%×100%额定转差率:SN¾1_1(X)0-960(KSNCGS%+2Pq)=flx100%0.577×100×103×0.8+2×600j=97.5%50.解:Pad+Pmec=pn×2%=10XlO3×2%=200WPmec=Pn+P+Pad=10×°+2OO=10200W同步转速:nx三=x50=100OrZminpcu2=SnPem=OQX10625=425WpI(W=9550A=9550=101.46Mnnl100O511.C,aUN-RjN_220-0.8×12,5=0.14V(r/min)当转速n=1200rmin时,电动势为:Ea=C“=014x1200=16W21N此时进行能耗制动时,应串入制动电阻为:凡=2-R=3-0.8=5.92。密封线2.TI=O."NP25×IO3=0.9×9.55口=0.9X9.55X=14.3NmIIN1500当忽略空载转矩时,Tem=T1.将已知数据代入能耗制动机械特性:Ra+RbCC:-120=一一08-×14.3解得:9.55×0,U2RB=OmQ当考虑空载转矩时,Tem=T1.+To。额定电磁功率:p#ElN=Cn"nn=°14x1500x125=2625W空载转矩:Tn=TTZ=9.55PMPN=9.55×26252500=86yvm制动时电l0'"WIN%1500磁转矩:Tem=Tl+TO=09J+TO=09X955X+0.86=15.2N加AOiO由能耗制动机械特性:-120=-“l5.2解得:?=0.689.55×0.142八852.解:励磁电流:=0.5A'Rf440励磁损耗:尸W=RJj=*=端=IlOW空载时输入功率:P=U0=220X2=440W励磁功率:P,=IlOW电枢铜损耗:PcuaRaIa-Ra0/)=IxlS=2.25W电刷接触损耗:PCUh=2fJz=2×l×1.5=3.0W附加损耗:Pud=O则.Pmec=PFePPfPCuaPCubPad=440-110-2.25-3.0=324.75W当la=1OA时,I=Ia+If10+0.5=10.5Ap=W=220x10.5=23IOWP=R72=×n2=oow输入功率:rcuaKalaiuPy=IlOlVPCJ2AU=2xlxlO=2OWP?=Pl*=Pl-Pclta-Pf-PCHPM+PFeJ输出功率:=2310-100-110-20-324.75二1755.25WP175525效率:7=S100%=X100%=75.98%P1231053. CN=UIRJN=