fs«'ifif/,»*/«••«/.'!/«• r.ie ii i/rim i''.ff//, t.>i, iit-n hi-iih " •« i m van Ctr T/VtfHMTVDVVHKhaiig Bien Huang dan I k h o n g t h a y doi => Z k h o n g t h a y doi Cdch 2: \ o)iL / = R2 + (02L - Vift N2 • ©10)2 = U Ur VR^.(Z,-ZC)^ , Uc p h i ! thuoc 1/Zc |{R2.Z^)J^ 2Z,-;-.1 V i d y 4: M o t mach xoay chieu RLC noi tiep chi c6 tan so f d o n g dien thay doi d u o c K h i f = 12,5 H z va f = 50 H z thi cong suat tieu t h u ciia mach nhu ' B.15 C.25 _ ^ Zci ZL >2 ^CO s C O bao nhieu Ian c u o n g d o n g dien qua mach bang 0? A 50 theo kieu h a m tarn thuc bac nen: n h a u Thay d o i f cho cong suat toan mach Ion nha't t h i t r o n g t h o i gian r,2 C = ^ ^ ^ ^ = 30(|.iF) ^ Clion B D 75 V i d u 7: Dat m o t dien ap xoay chieu u = Uocos(1007Tt) V vao doan mach RLC c6 U^R P = TR = R2 coL- + t::m COQ = sjo3i(i)2 R = 100\/2 ^ , P p h u thuQC CO theo kieu h a m phan thuc nen: cuon cam thuan c6 t u cam L < l,5/7t H va tu dien c6 dien d u n g C thay d o i dugc K h i dien d u n g t u dien Ian l u g t la Ci = 25/TT (|aF) va (oC '-=> i = yjtj^ C2 = 125/(37i) ((.iF) t h i dien ap hieu d u n g tren tu c6 c i i n g gia t r j De dien ap - ( H z ) T r o n g chu k i d o n g d i e n = hai Ian, ina hieu d u n g tren dien t r a R dat cue dai t h i gia trj cua C la t r o n g s C O 25 chu k i nen so Ian d o n g dien = la 2x25 = 50 Ian = v C h o n A A.50/TT(^F) B 200/(371) (|.iF) thay d o i d u g c ) vao hai dau doan mach g o m d i e n t r a t h u a n R, cuon cam K h i ( = 0)1 hoac co = 002 thi dien ap hieu d u n g giira hai ban tu d i e n c6 cung COQ = 4^x^2 f B 0)g D • theo kieu h a m tarn thuc bac nen: U r - I Z r =• V thuoc R2 + coC coL - UK = max o coC L2CV-2 I L = ,Ucphu Chuy: R 2\ C ' theo kieu h a m tarn thuc bac nen: COQ = Zc diing thi \JQ- => Chon B T h a y d o i C n g u o i ta thay k h i C = 40 jiF va C = 20 yiF t h i v o n ke chi cung trj so' T i m C de v o n ke chi gia trj cue dai 180 C 30 ^F ZQ2 = ZL i': = 100 => C = V I':.: R2+ZL ' 100 CoZr 71 Hu.:.^^^ Z, 2 ' _ T^J.' ,a'J (|.iF) =:>ChonD D 60 ^iF ^ (R2+ZM4 -2ZL-^ +1 ^ ^'Zl: ^Zc theo ZQ Dm vao thi ta se thay: d u n g C thay d o i D u n g v o n ke c6 d i ^ n t r a rat Ian mac vao hai dau tu dien- B 10).iF _ Zci ^) Khi C thay doi dc so sanh cac gid tri Uc c6 the V i dv 6: M o t mach d i ^ n xoay chieu n o i tiep g o m cuon cam va t u di#n c6 dien A.20|aF ZL = 0 ( Q ) 300 R2 + Z ? Huang dan U 'Zc ^CO + 'A) «0 U- "-'zl = i(co?+coi) •, Uc p h u thuoc 1/Zc |(R2+ZM-V-2ZL-^-+1 ^R2+(ZL-ZC)' dai H e thuc lien he g i i i a coi, C02 va coo la C u UZr Ur = m o t gia t r j K h i o) = coo t h i dien ap hieu d u n g giCra hai ban tu dien dat cue +C02) (^F) Zci = - ^ = 0 ( Q ) ; Z c = ^ - = 240(Q) coCi CoCn t h u a n C O t u cam L va tu dien c6 dien d u n g C mac noi tiep, " o i CR^ < 2L cOo = i ( c O ] D lOO/rt Huatig dan V i d u 5: (DH-2011) Dat dien ap xoay chieu u = Uocoscot (Uo k h o n g d o i va ro A C 20/7T (^F) * ZQ canggan ZQQ thi Uc cang Ian, cangxa thi cang be (Zco = 181 Bo trp kien thiic V$t li LTDH tren hcnh VTV2, t^p - Chu z +z UcA = Uc2 = Uc thi Z'X = — V.in BlSn 7-1 + Z ' -1 Zc3e(Zcl;Zc'2)=>Uc3>Uc — Zco =>Uc3 - U c 125"' = 1) Dc so sank Ua va Ua ta c6 the dung phmrng plidp "gidng day" nhw sau: Tit Uc, kc duvng song song vai true hodnh neu Ua trcn day thi Ua > Uc, va ne'u duvi dai/ tin Ua > U^ Chon B V i du 9: Dat dien ap xoay chieu 220 V - 50 H z vao hai dau doan mach noi tie]) nen I' > I =>ChgnC g o m d i e n t r o 50 il, cupn cam thuan c6 cam khang 100 i1 va tu dien c6 d u n g ""^ k h a n g Zc thay d o i Dieu chinh Zc Ian k r g t bang 50 Q, 100 il, 150 Q va 200 Q Vi du 11: D o a n mach noi tiep g o m dien tro, tu d i e n c6 dien d u n g 0,l/7i mF va t h i dien ap hieu d u n g tren tu Ian l u g t bang Uci, Uc2, U c va Uc4 T r o n g so cugn c a m thuan c6 d o t u c a m l/n H Ne'u dat m o t t r o n g cac uien ap xoay cac dien ap hieu d u n g noi tren gia t r i Idn nha't la chieu sau day vao hai dau doan mach tren t h i c u o n g hieu d u n g A Uci C UC3 B Uc2 mach Ion nha't l i n g v o i dien ap nao? D Uc4 A u = U()Cos(105Kt) V Humgdan C u = U()COs(957it)V B u = Uocos(857it) V ^ ^^ V j t r i d i n h : WQ = ^ Zci =50"' =0,02 c dan • = 1007t(rnd/s) vay, ta chi can so sanh hai gia t r i gan d i n h nhat =150"' =0,0067 Ta nhan thay, cang gan d i n h Uc cang Ion ' Ta nhan tha'y, cang gan vj tri d i n h I cang Ion, v i =100"' =0,01 Zc'4 =200"' =0,005 • « D u = Uocos(707rt) V Huang • = " ' Q « 0,008 va nam 7-' 7-' dinh la (O3 = 957t rad/s va true hoanh cat d o t h i tai d i e m t h u hai c6 hoanh va Z^^^^ gan d i n h h o n nen chi thj tai d i e m t h u hai CO hpanh Z't^'j d u g c xac d j n h : hai ben tt)4 = 10571 rad/s Tif I3 ke d u o n g song song v o i yri ' ' " c a n so sanh U^., va U(^3 T u Uc2 ke d u o n g song song v o i true hoanh, eat 182 , Vi du 10: (DH-2011) Lan l u g t dat cac dien ap xoay chieu ui = U V2 cos(1007i:t + dinh nhat bang phuvng phdp "gidng day" A Uc3 At) I co'3 d u g e xac d i n h n h u sau: cO(^=ff)3Co'3 OK =:>(1007t)^ = 957ta)'3 :^co'3 « , t ( r a d / s ) • 183 CtyTNHHMTVDVVHKhang Bo trff kicn Vi thiic VTV2 t^p - Chu V0n BiSn V^t li LTDH tren kenh W4 e [ c o ; a ) ' ] V i d u 14: D o a n mach R L C dat d u o i dien ap xoay chieu o n d i n h c6 tan so f thay n e n I > I => C h o n A doi du'oc K h i tan so la fi va l Z L = =^Zc2 = 12 VR'+{ZL-ZC2)' Hudngddn D o n g dien t r o n g hai t r u o n g h o p lech pha la 2a = — =6,25(ZL-R) R COS(p = ZL Z =^ • D 0,6 D 0,9: C 0,8 Huong dan C = C i =>tan(p5 C = C i =:>tan(pi = ^ t - ^ £ i = t a n | ^ R = Z L - Z c i co,Ltancpj = • C = ^=^Zc2=2,5Za R cojC 3 Z L I - Z Ll ^ CO2 CO1 ^R, _V3=^LI(1L4)^2LI=150(Q) \ J 150V3 =>ChonB ( Z L - Z C I ) +Z2 U, C m a x Z c = 111Tt R 7t R = = > C O S ( p i = COS(P2 (p2 = - a Dong dim hai truvng hap lech pha la la 184 Khi R minh aic cong thuc giai nhanh sau day: thay dot hai gid tri Li vd L2 md co ciing P tin Pmax khi: RQ = ^^1^2 • Khi L thay doi hai gid tri L l vd L l md = = > CO = IOOTI(rad/s) =5 Chon C Chii y: Khi R khong dot va hai gid tri cua L hoac C hoac co ma I, P, UR khong thay dot „ „ tht Z ] = Z2 : Chii y: Chung ta co thechmig * - ^ ra^LCi = Zcj ' Vift * CO Cling 1, Uc, UR, P tht Lnax, Ucmax, URnmx, Pmax khv Lg = CO Cling UL thi Uiimx 2L khi: ^ >v'i'' ^ ' L LQ = - — ^ — ^ L l + L2 Khi C thay dot hai gid tri Ci vd C2 md 185 B d trp ki£n thiic CO Cling CO Cling V^t It L TBIl I, UL, Uc tren kSnh VTV2 t^p - Chu VSn UR, P thi Imax, Ulnmx, L/KIHIIA, Pmax CtyTIVtHMrv C() = C1+C2 b ^ 2a co-^ 2QC2 CQ = till Ucm.u khi: Bicn C I > VIII lihang VIfit 2_ coC C , + C Khi CO thai/ doi hai gid tri MI va coi nih CO Cimg I, UK, Pmax khi: P th'l hu,ix, Unmax, CO Cling Uc thi Ucmx khi: O)Q = CO Cling Ul thi Uijiiax kiii: li^Q = * Ci)(, = ,yo)|Ci)2 ^"^ cothaydoi 0phjiBHD2: • dcu dien dp liieii qiian ;,, ~ •• - doi lien rt ft; ihay L Z\ , • • - Dat osi;) ivv;4 O H = u ^ = u.-c_ , uSub w o / i v ; v i u'l/;!' '.rnit; \ i ' f a ^ ' i • ' i r i M w ' yv]'-.] j ' ^ y j ' RZ', CM; f!ufil/.;?r L dung Bdi todn: M o t doaii mach dien xoay chieu gom dien tro thuan R , cuon day Thay Zi, = Z^ hay co^ = thuan cam (cam thuan) c6 tu cam L va tu dien c6 dien d u n g C mac noi R^ — ' ^ ' ^ o bieu thiVc Uc ta duoc: k , tiep Dat vao hai dau docin mach tren mot dien ap xoay chieu ma chi c6 tan so goc (0 la thay d o i duoc T i m co de dien ap hieu d u n g tren tu cue dai (Uc) Ucmax Dieu kien dien dp hieu dung tren tu, tren cuon cam cue Dat = L Vc 2) U L CMl: ("C max L to") = max o Zc = Z, ("L max => C to') Uc = dai u I.Zc = • R^ + , '•} (oL = , — =• C - - - - - ( S t 1; i L_R^ 2a L _ R-^2^ ^ £ (i)C b_ -2 Thay Zc = Z , hay co2_C_2 = U (oL c RZ' , K Z L = Z, • = U.- L_R^ Dinh UBHDl: 1) Uc = max « ,.•.sHr•$^,(K- L_R^ goi la tro to U - hoac tren cuon cam cue dai ( U i ) * , B 20000 (rad/s) ' '^ D 10000 (rad/s) ' • 187 B6 trp ki&'n thitc Vpt li L TDH tren hcnh VTV2 t$p — Chu V0n Cty TimnnrvDVVnKhang Bicn Huang dan L R^ C 'l5.10"^ 100^ ~ V 10-^ ULmax « ' C t ' « Z c =Z, =>ChonD • = 100(Q) ' ' Huang dan • „: " j^hi i = 50 H z , thay doi R: UZc "J , Ua=IZc = — = = 100=^(o 100=^(0 = = ^;-^;;^^^ = 10000(rad/s) — coC 100.10" •^5; V J) , n ' ^ • ' B m l i /wan: Khi gidi bSng phieang phnp thi khoi htgng tinh todn dirge gia,,^ 7(R + r ) + ( Z L - Z c ) ' = max: K h i R = 30 Q, thay d o i f: xuong mi'rc "cue ticu" va ta se thd'y dirge hicii qua eiia no ede hai todn eo so lien "khong dcp" Lniax = V i du 2: Cho doan mach k h o n g phan nhanh gom dien t r o thuan 80 Q, cuon - ^ ^ ^ , -^CiionA Uc2 • day C O dien t r o t r o n g 20 Q co t u cam 0,318H, tu dien c6 dien d u n g 15^9 |aF D a t vao hai dau mach d i ^ n m o t d o n g dien xoay chieu c6 tan so' f thay CO gia t r i la A f = 70,45 H z B f = 192,6 H z Huong L I 0,318 C Uc„,x 100^ V 15,9.10"'' 2 C f = 61,3H2 D f = 385,1 H z max (^max' I m a x ) » Cong ~122,5(Q) Ulmax « = 61,3(Hz) Chon C, • = 0,6N/]0U ^/(0 + ) ^ + ( - y L 1800 ^4^5 C = U u.(R + r ) Z \ 40.inVi4 VTl :,1/jju^iJ/iatftig'' L R^ = Z , COcL = ^ | - - - ^ Ucmax dan ' L t6' < ^ Z L = Z , => 27rfL = 2 , ^ f = l^f^ U.60 Chu y: Khi co thay doi tJii d o i dugc K h i dien ap hieu d u n g giua hai dau t u C dat gia t r i cue d a i t h i taVi so'f Vl^t Z c = Z^ hUdng o co^ = L R^ —- : —= COLC VC VC ^ ^/LC VLC VC VLC V i d u 5: M a c h dien xoay chieu RLC noi tiep co tan so'goc co thay cioi, cuon day thuan cam K h i co = V i du 3: M o t doan mach k h o n g phan nhanh g o m : dien t r o thuan 100 Q, cuon IOOTI (rad/s) thi dien ap hieu d u n g tren hai d a u t u dat day thuan cam c6 t u cam 12,5 m H va tu dien c6 dien d u n g faF Dat vao cue dai, k h i co = hai dau mach d i ^ n m o t dien ap xoay chieu co gia t r j hieu d u n g 200 V va c6 cam dat cue dai K h i tan so goc la bao nhieu t h i dien ap h i ^ u d u n g tren hai tan so thay d o i dugc Gia t r i cue dai cua dien ap hieu d u n g tren t u la dau dien t r o dat gia tri cue dai? A.300(V) A 25071 (rad/s) B.200(V) • • f 12,5.1010"^ C lOO(V) Huang dan D 25C (V) H' 100^ ^ ' _ \ %= ^ 4OO71 (rad/s) t h i dien ap hieu d u n g tren l a i dau cuon B 2O07t (rad/s) C 500n (rad/s) f) no > Huang dan ^ ,V%-:\ V^ Chon B dy 6: M a c h d i e n RLC n o i tiep dang xay cong h u o n g N e u eh- g i a m tan so' m o t l u g n g raft nho thi Ucmix = U , Cmax = U ^ t ^ = U - £ - = 200 j^^'^ Lmax 100.100 C O t u cam L = 0,3/7i H co dien tro r = 10 Q va bien t r o R D a t vao dien •iP xoay chieu co tan so f thay d o i K h i f = 50 H z , thay d o i R t h i dien ap hiC"^' d u n g tren tu cue dai la U i K h i R = 30 Q, thay d o i f t h i dien ap h i ^ u du^i^ tren t u eve dgi la U T i so U / U bang •m B.3,15 C 0,79 D 6,29 TJ:U B dien ap hieu d u n g tren dien tro thuan khcing d o i ,r„;T,' r ' v \yx\ A dien ap hieu d u n g tu k h o n g d o i "'""'^— = ( V ) ^ Chon D V i du 4: D o a n mach noi tiep A B gom tu dien co dien d u n g 1/(6?:) mF, cuon cam A 1,58 D 300.T: (rad/s) sS.ti,:; :i : 'x^^'mA •< C d i e n ap hieu d u n g tren tu tang I D dien ap hieu d u n g tren t u giam *• i ,.::r Tu: f C0(2 < COR < COL CO = COL thi Huang dan ^.-UJA ( k h i co = coc t h i Ucmnx, k h i co = Utmav) ta nhan thay, t u v j t r i co = COR COR thi >:/''-'••: URnwx (cong huc^ng), g i a m tan so m o t l u g n g nho thi CO djch ve phia coc m o t l u g n g nho tiic la Uc se tang C h o n C 189 Cty Bo trg hicn tluic V^t li LTBII tren h€nh VTV2 t^p - Chu VMn Bigti V i d u 7: N h a n xet nao sau day la SAl? T r o n g m o t mach d i e n xoay chieu c6 RCL m3c n o i tiep d a n g c6 cgng h u o n g , ne'u ta tang tan so' m a v a n gjf, TNHllMTVDVv'HKhang Vift B 100 V v a 50 V A 107,2 V v a 88,4 V D 50V2 V v a V C 50 V v a 100/3 V n g u y e n dien ap hieu d u n g cua n g u o n dien xoay chieu dat vao mach t h i : Huong dan A D i e n ap hieu d u n g U K giam UwL B D o n g d i e n t r o n g mach t r o nen cham pha h o n dien ap dat vao mach RCL C D i e n ap hieu d u n g tren doan R noi tie'p v o i C se tang = , coL - C ^ - ^ ^=60(Q) -5: 2 D C u o n g d o hieu d u n g mach se giam Huwig L u c d a u ZQ = (oC dan = 0)L = Z L => I = max; U , „ „ , o Z c = Z , =60Q=>co = : : r ^ = - ^ ^ ~ 6 , T t ( r a d / s ) Z,-C = max 100.100 co = 1007r=>U, = Z, - Z r Sau d o tang co t h i ZQ = — < coL = Z L =J> tan(p = — — > =^ u sSm pha hdn i R o)C UKC=IJR' + 100.200 CO = 20071 => U , = (0 = d a u doan mach gc'5m R, L , C mac n o i tiep thoa m a n d i e u k i e n CR^ < 2L Goi 80V2)' = , ( V ) , ' l u g t cac von ke chi gia trj cue dai k h i tang dan tan so'la A Yi, V , V B.V3,V2,Vi C V , V i , V D V i , V3,V2 -'•••Or:,' - /.;r-''v\ ••^••'.••^ Hudvgdan , +(500/3-60)^ b Khi (0 thai/ dot qim hai gid tri wt va (02 va cdc dieu kien khdc lit • } K h i ) thay d o i hai gia t r i coi va C02 ma co cung I , U K , P t h i Li>.,x, URmnx, Pmnx k h i c h o f/c mnx 'o'" lam max COn = JCOICOT = ; =»03iLI = —J - A7; ^ " ' ^ N/LC VCO, ) I C V C O M C ZLI •3; rif> COi CO2 Biet L = C R l D a t vao hai dau doan mach dien ap xoay chieu c^'n dinh, mach CO him thicn tie coi deii coi tlii CO Cling he so cong sua't voi hai gia t r j cua tan so goc SOTI rad/s va 200K de fun ^iii tri Ian nhat nho rad/s H e so cong sua't cua doan mach bang nhat ta so $a)ih gid tri tqi hai B.1/2 A 2/713 dau giai hqn va gid tri tqi '1 dinh V i d u 9: Dat d i e n ap xoay chieu u = 100 V2 coscot V v o i co thay d o i tir IOOT: rad/s • R + co.L - cugn cam t h u a n v o i d o t u cam I/TC H va t u d i e n co dien d u n g O/i/rt m F Dien ap hieu d u n g giij-a hai dau cuon cam co gia t r i Icjn nhat v a n h o nhat tuonj^ • coiL cojC \2 ^••V'' R I o),CJ \ ^ CO] VC ' ' 0.3/^12 Huang dan coscpi =coscp2 0, ' CAI42 R ' = R In V i d u : C h o mach dien xoay chieu R L C mac noi tiep, cuon day thuan cam Chu y: NcU hai todn chi cho iVng la CO- Bay g i o neu cho them dieu kien: ^ = n^R^ t h i choUi^^ax den 2007t rad/s v a o hai d a u doan mach noi tiep g o m d i ^ n t r o R = 80 N/2 C02 Za=R => Chon C ' '/.{- Ian l u g t la cac v o n ke'mac vao hai dau R, L , C K h i tang dan tan so t u gia t r i t h i thay tren m o i v o n ke deu co m o t gia t n cue dai, t h u t u Ian 190 K106,4(V) 100.500/3 50071 => C h o n C ' V i d u 8: Dat m o t dien ap u = Uo cos cot (Uo k h o n g d o i , co thay d o i dugc) vao hni " 80N/2)" + ( 0 - ) ' Mi ' lam «88,4(V) + (100-100)' I = — giam dan;U|{ giam dan Vi , V2, ' CO, R + (09L - (OTC = Z a , | ^ = , / ^ T h a y i ; = ^ R ' thi: (02 VC 191 kien thiic V^t //' LTDII tren kenh VTV2 t^p 2-Chu VSn BiSn R • COSCpi = • VT3 R2 + Rr^-Rp V«i; C02 => Chon A V i d u 2: Cho mach dien xoay chieu RLC mac n o i tiep, cuon day t h u a n cam =>COS(|)i (R + r f + cung he so cong suat 0,35 * 3/N/73 v o i hai gia tri ciia tan so goc (Oi = IOOTI rad/s va C02 Gia t r i C02 A 507trad/s CO ,:: the la B IOOTT/S rad/s C lOOn/? rad/s D 1007t/9 rad/s Huongddn COS R ] = cos 92 R R + cojL _ •=>LC = - R + C02L - - = 0,96 =• Biet L = CW Dat vao hai dau doan mach dien ap xoay chieu o n d i n h , mach c6 + (1)2 Chti y: ^hi huvng That cho biet cam khang, thi Zc,=- vqy: (ofLC - a)iC khang co = coi va co = ^02 mach \: cong Zci 0), 1 -LI IO2 0)2C V i d u 4: D o a n mach R L C k h o n g phan nhanh mac vao m a n g dien tan so coi thi cam k h a n g la 20 (Q) va d u n g khang la 60 (Q) N e u mac vao m a n g dien co + R / ^ - R I ^ 0)2 (0, -\ IOOTC C02 (02 TOOTT >/73 tan so 0)2 = 60 (rad/s) t h i c u o n g d o n g dien cung pha v o i d i e n ap hai dau doan mach Gia t r i 0)1 la A 20 ^/6 (rad/s) | B 50 (rad/s) CO2 =90071 Huang IOOTI =>ChonA (02= — ^^^^^ „ , j - , • - „ i C 60 (rad/s) D 20 S hinh dual dang dieu kien vuong ^ - r ; ) pha Zci tiep A M B D o a n mach A M g o m d i e n t r o R n o i tiep t u dien, d o a n mach M B chua cuon day c6 d i e n t r o r Biet dien ap tren doan A M l u o n v u o n g pha v o i di§n ap tren d o a n M B va r = R V o i hai gia t r i co = IOOK rad/s va co = 56,25:: B.0,85 C 0,91 Huang D 0,82 dan L = CR2 U A M J - U M B =>tan(pAM tan (p^B = - => - ^=-l=> R r C =R^ ® = a),C 0)1 = 0)2 V i d u 3: Dat d i e n ap u = 125 N/2 coscot (V), co thay d o i d u g c vao doan mach noi rad/s t h i mach A B C O cung he so cong suat va gia t r i d o bang (rad/s) dan Z Chil y: Dieu kien ^ = n^R^ cd thctrd 192 0)1 •.(.(f'J'c:- ( x i ) Q r Cong hudng o ft)2L : = • |R2 + A 0,96 dung ±LL = 0)2 1/ Thay C = L/R2 t h i d u a c : C0]L = R => COS 0)2 (O1CO2 =R ;l 0), ©2 Chon A Thay L = CR^ t h i dirge: — \1 => o)i L C = — ^ V i u va i cung pha nen 0)2L = — a)2Cr -CI L C = ©2 / ^Ll ^ -CI (,oj—= 20>/3 (rad/s) 60 Chon D Jill , still''' ,J V i d u 5: (DH-2011) Dat dien ap u = U >/2 cos2Ttft ( U k h o n g d o i , tan so f thay doi dugc) vao hai dau doan mach mac noi tiep gom dien t r o thuan R, cuon cam thuan CO t u cam L va tu dien co dien d u n g C K h i tan so la fi t h i cam khang va d u n g khang cua doan mach co gia trj Ian l u g t la 6Q va 8Q K h i tan so la ii thi he so cong suat cua doan mach bang He thiic lien he giua f i va h la A h = 2(^/ • B h = 0,5fi V3 /^K*: CO, CO, [Z[7 fi Huong C f2 = 0,75f, ' D ta = 4f,/3 dan /6 2fi ^, = / - = : > t2 = - j = => Chon A ' V -CI 193 BS tr^ klSn thtic Vi V^t li LTDH Ircn henh VTV2 t^p - Chii Cty TISHH nrv DVVH lU'L=2U'R Huottg dan K h i f = fo thi d u n g khang: 75 = Z ' c = KhangVlft =>\ = 25v/2(Hz) n-M CO2L _^\ =^L(o)?-a)^) = R V n - l ( c a i + ( ) = > R = - ^ I2 = -(02RVn - ^ 'fcl)''.;: v^ • N e u cho biet C m a k h o n g biet L t h i k h u L : =>ChonD : ;C/»M2/;' Khi i ^ ' ,s thay doi ta)i no ma lien quan den tinh dien np thi ta ap dung dien dp tong clio liai trwang = + (U, - U^)" * Neil f ' = nf tin Z'l = nZi = ul UrLC = U > 3VT45 = |25r^ +100^ {R + 'Vi •R + r = 5r if+Zl Huang dan •r = 50(Q) =>ChonA Nhu c h i i n g ta da biet, " v a n ba't dac d i " m o i phai d u n g den dao h a m de t i m cue t r i ! D o i v a i hai bai toan chi each d u y nhat la di^mg dao ham ( k h o n g each nao khac!) R'+ZL * R' + ( Z L - Z c f C 960 V D.57V , ^ = ^ = = ( V ) C h , „ B ^ £ | L = -^0_+V80^+4.302 -Zc + yZc+4R2 lA.r::, iii' V i du 3: M o t mach dien mac noi tiep theo d u n g t h u t u g o m cuon thuan cam c6 t u cam L = l,5/7i ( H ) , dien t r a thuan R va tu dien c6 dien d u n g C bien thien D a t vao hai dau doan mach m o t dien ap xoay chieu c6 bieu thuc u = U V coslOOTit (V) Thay doi C = Co thay dien ap tren doan mach RC cue dai va gia t r j cue d a i d o bang 2U Co bang Z^+R2 URC-I.ZRC=U V ^'^ Z2 - Z L Z C + (R' + (ZL - Zc)' A 100/71 (HF) + Z^-2ZLZC+(R2+Z[)" B.50/7t()iF) C 75/71 (^F) D 25/7i (^iF) • Huong dan Zl) -2Z,(z^-Z,Zc-R^) Z , V i ^ : 4R^ — ^ — —5- = U => Zc = — ^ Z^^W4Rl^^200Q^C = - ^ (oZc 7t ^ ^ Vi du 4: Dat dien ap u = U ^y2 cosl007rt (V) vao hai dau doan mach mac n o i tiep theo d i i n g t h u t u g o m cuon cam thuan c6 cam khang 120 Q, d i f n t r a thuan UR + R va t u dien c6 dien d u n g C thay d o i K h i C = Co t h i di^n ap h i ^ u d u n g tren 4R^ doan mach chua RC dat cue dai va gia trj cue dai d o bang U D u n g khang CliM y ; Dede nha ta viel chung dot xung L, C nhu sau: K h i L thay d o i : URLmax = UR -Zc + Vz^ -»Z, + 4R^ cua tu liic la Zc + ^/zJ~+ 4R^ - K h i C thay d o i : Upcmax = UR - Z L + 7ZL+4R A 160Q =-C:>Zr = ZL+VZ^+4R2 B lOOQ C Q D 20C Q Huong dan URCmax = 198 ^^^^^ ^ ^^^^ ^_ Huong dan ZL = - -Zc+Vz^+4R^ -ZL+ B 360 V U,,„„ UR RCmax ~ A B no'i tiep g o m cuon cam thuan c6 d o ttf cam L thay d o i , d i e n t r a thuan R •^Z^-2ZLZC+(R'+Z2) K h i C thay d o i : U " Y i du 2: Dat dien ap xoay chieu o n d j n h 120 V - 50 H z vao hai d a n doan mach A 224 V • = U -2Zc(z^Z,Zc-R^) ^ — -— - Z ^ - Z-,L ^ZCr ++{(l R ^ + Z L u RLmax = o ^ ^ o ^ doan mach chua R L dat cue dai Gia t r i cue dai d o la URL=I.ZR , =U •RL Tim.'.,,, = - C - y - ^ - - = 30 Q va t u dien c6 d u n g khang 80 Q Thay d o i L de d i e n ap hieu d u n g tren K h i L thay d o i : 'co = 27if = 5071 ^ Z L = coL = 0 ( Q ) ; Z c = ^ coC = 200(Q) ^ i:>Ei=200(V) R2 + x Z i - V X / 8V7 ' B no^ = 0,5(ni2 + n22) C no-2 = 0,5(nr2 + nr^) D no = 0,5(ni + n2) Huang ^R^+{z[-Zcf E= / 2^^ + X — V A no = (nm2)0'S Xy A ; n = xni = •3-^ + x V 5^6, (v/s) dan Htiti f = n p => CO = 2ni = 2npn 2x 2V6 = - = > X = • X = xE D a t n = xtt] => I = - Vi Khang V/pt = EQ _ N O Q 72 -co 72 1 Vc 24: N o i hai cue cua may phat dien xoay chieu m o t pha v o i m p t doan R2 + NcDn •Chon B (0 72 -2 , c o L - coCJ D a y la h a m kieu tarn i h i i c do'i v o i L_R^ C +1 CO bien so'l/co^ => CO? m a c h A B g o m R, cuon cam thuan L va C mac no'i tiep K h i l o t o ciia may ' J CO2 • C h o n C quay deu v o i to'c d o Ian l u g t ni vong/phut va m vong/phiit t h i c u o n g Hi t,f" d o n g dien hieu d u n g va tong t r d ciia mach t r o n g doan m a c h A B Ian lupt la I i , Z i va h , Zi Bie't I2 = 4Ii va Z2 = Z i De tong t r o ciia doan mach A B c6 gia trj n h o nha't t h i roto cua may phai quay deu v o i to'c d p bang 480 vong/phut, Gia t r i ciia ni va 1x2 Ian l u a t la BAI ' ^ , jD 240 vong/phiit va 960 vong/phiit • ry dan * Nguon mac - T a i mac T U U P = Pl+P2+P3=I?Ri+liR2+l3R3 V2 A = Pt (02 = 4cO] => n2 = n i (B2C cojC -(OiL=>cof = , LC => n^ = 0,5no = 240 ( v o n g / p h i i t ) ; => C h o n D U , (If N27ifOo CHIEU PHA ngoai D i e n ap d j n h m i i c tren m o i tai U •U = U p 60 C02L- D i f N XOAY D i e n ap day Ud la d i e n ap g i i i a hai dau day n o n g ciia m a y phat d u a v C 360 v o n g / p h i i t va 640 vong/phiit l2=4Ii PHAT D i e n ap pha U P la dien ap g i i i a hai d a u m p t cuon ciia may phat B 120 vong/phut va 1920 vong/phiit E= LIEN QUAN D E N MAY Phuang phdp gidi A ,300 vong/phut va 768 vong/phiit Huang TOAN Nguon mac - T a i mic tam giac LC :> COj = 0,5(0o n = n i = 960 (vong/phiit) U = Ud =Up73 I1 u Zj Z2 ^3 P = Pl+P2+P3=I?Ri+l2R2+l3R3 A = Pt ' > i' • B6 trjf Men thiic V^t li LTBII t h u a n lOO Q mac noi tiep v o l t u dien c6 di#n d u n g 0,l/7i (mF) T i n h c u a n g VTV2 t^p - Chu Vin Bl£n tren henli Nguon mac tarn giac - T a i mac tarn giac d o n g dien d i qua m o i tai U = Ud=Ui I - ^ I - A 4,4 A ^ I - U S3 \\:*ifKVi o:» B V2 A % C >/3 A Huang dan Z C = ~ P = Pi + P2 + P3 = i f R i + I^R2 + I3R3 ^ Nguon mac tam giac - T a i mac 'f^^* Vfeo^ _ U _ UI,N/3 ^ 200^y2^/3 _ 2j3(A) Z Z 100vy2 ^ ^ ^ D 1,8 A • ••„ gti V , ^^i'bm'j^m''ChonB '4 A 183.600 d o n g B 61.200 d o n g C 20.400 d o n g D 22.)50 d o n g >1 Z L =coL~233,24(Q);Z = J R + Z ^ «380(Q) = I2 = I3 = - = ^ 1(A) P = 3I?R = 0 ( W ) = , ( k W ) f: A = Pt = 0,9.8.30 = ( k W h ) dan V i tai d o i x u n g nen d o n g d i e n qua day t r u n g hoa bang i , j R "^ D Iph= 2,9 A ; I.i, =0,25 A toan hang thang (30 ngay) la ii/sq ^f, jj^w = > T i e n d i e n = ( k W h ) x = 183600(VND) ' ' T' => Chon A ^•'=2,9(A) R V i du 5: M o t may phat dien xoay chieu pha k h i boat d o n g , n g u o i ta d i i n g M'l 'v- '''V ^ , , von ke nhiet de dien ap hai dau m o t cupn day t h i so chi ciia no la 127 V V i d u 2: M o t may phat d i e n ba pha mac h i n h c6 d i e n ap hieu d u n g pha N g u o i ta d u a d o n g pha may phat vao b o n g den g i o n g het 127(V) va tan so 50 ( H z ) N g u o i ta dua d o n g d i e n xoay chieu ba pha vao ba boat d o n g v o i d i e n ap hieu d u n g 220 V t h i cac den deu sang K m h t h u d n g tai n h u mac h i n h tam giac, m o i tai c6 dien t r a t h u a n 12Q va d o t u cam Chon p h u o n g an d u n g 51 ( m H ) Xac d j n h tong cong suat ca ba tai tieu t h u A M a y mac h i n h sao, tai mac h i n h • A 991 W B 3233 W t Z L - ( L = 16(fi): ^ ^ =>ChonC Z C 4356 W Huang dan ' Z - R + Z [ =20(Q) Z D.1452W ' P = 3I?R = 4356(W) • V i d u 3: M p t m a y phat dien ba pha mac h i n h phat d o n g xoay chieu c6 tan , •/ • /v„-,,fi') - ^ B M a y mac h i n h sao, tai mac h i n h tam giac C M a v mac h i n h tam eiac, tai mac h i n h •' , , , D M a y mac h i n h tam giac, tai mac h i n h tam giac Huong dan nil _ i-.hi , N e u U = U P t h i de tai boat d o n g b i n h t h u o n g nguon mac - tai mac hoac n g u o n tam giac - tai mac tam giac N e u U = V3 U P t h i de tai boat d o n g b i n h t h u o n g nguon mac - tai mac , so 50 H z , suat dien d g n g hieu d u n g m o i pha la 200N/2 V Tai tieu t h u g o m ba doan mach g i o n g n h a u mac tam giac, m o i doan m a c h g o m d i ^ n tra 213 Neu U = U P / Huang dan t h i de tai hoat d p n g b i n h t h u o n g n g u o n mac tarn giac - ta 22072Z^ mac =i Chon B Ith V i du 6: (CD-2011) T r o n g m a y phat d i ^ n xoay chieu ba pha d a n g hoat dong suat d i e n d o n g tiic t h o i t r o n g m o i cuon day lai c6 Ion bang va bang ;>,t A 0,5Eo V3 B 2Eo/3 liiln niri^iiift'MiCtfixt lif-irl -jtfi.: ej = 62 EQ = EQ 6) 1-2=0 cos cot ^ = E g COS ^ 63 cot + = E() COS ' 2n n U ' , 2n K 22072 R 1- •^1 U T , ^ +^ (cong3 V i du 7: M a y phat dien xoay chieu ba pha mac h i n h d u a van ba tai cung R' 38 h = 2cos(1007rt - 27i/3) ( A ) , b = 2.cos(1007tt + 27i/3) ( A ) D o n g dien chay qua , ;, , / , | D.ith = c o s l 0 t ( A ) Huang dan i,l^=ii '3 , ' 38 + i + i = + Z - | ^+ Z ^ = l iti, - c o s l 0 i t ( A ) V i du 8: M a y phat d i e n xoay chieu ba pha mac h i n h d u a vao ba tai cQng mac h i n h Bie't suat dien d o n g cuon 1, cuon va cuon ciia may phat Ian l u g t la: e i = 220>/2 coslOOTtt ( A ) , e2 = 220 V2 cos(1007t: + 2K/3) (A), 63 = 220 V2 cos(1007tt - 2K/3) (A) va d u a vao ba tai theo d i i n g t i i u t u tren la , d i f n t r o thuan R = 10/ N/3 Q , cuon cam thuan c6 cam khang Z L = 20 Q va tu Cong suat tieu t h u dien: P = P :iu'h HUV*I « K ' I \ ciia day n o i va ciia day t r u n g hoa D o n g dien chay qua day t r u i g hoa c6 gia 214 A 77 ( A ) ? B 33 76 ( A ) ,^ QU Chon D 215 v i d u 2: M o t d o n g ca dien xoay cliieii san mot cong stui't co hoc 10 k W va hicLi theo h i n h sua't 80% d i i o c mac vao mach xoay chieu Xac d i n h dien ap hieu dui-,^ hai dau d o n g co bie'l d o n g dien co gia t r i hieu d u n g 100 ( A ) va tre pha voi dien ap hai dau d o n g co la 7i/3 A 3 V B 250 V D cuon day ciia m a y phat mac theo h i n h sao, cuon day ciia d o n g co mac theo h i n h t a m giac '' t v: dan '/fx/'f:; ' 'i:: '/f.b n\ rt u u • y'^'^'-' D V C 500 V Huong / Huong dan ^A ,;, ^• Theo so lieu U = 220 V, U P = 127 V tuc la U = Ui> M u o n d o n g co hoat d o n g b i n h t h i r o n g t h i n g u o n mac - tai mac tam giac => C h o n D p = ^ = U I c o s ( p ^ U = — ^ • = ( V ) ==>ChonB , H H I cos (p V i du 5: V i d u 3: M o t d o n g co dien xoay chieu san mot cong sua't co hoc 8,5 k W va c6 (CD-2010) M o t d o n g co k h o n g d o n g bo ba pha mac theo kieu h i n h d u g c noi vao mach dien ba pha co dien ap pha Ui'i^ = 220 '^L Cong sua't hieu sua't 88% Xac d j n h dien ap hieu d u n g hai dau d o n g co bie't dong dien ciia d o n g co la 6,6N/3 dien CO gia t r i hieu d u n g 50 (A) va tre pha so v o i dien ap hai dau d o n g co C u o n g d o d o n g d i e n hieu d u n g qua m o i cuon day ciia d o n g co bang 7r/12 A 20 A HtiOfig p = I i = Ulcos(p: H =:>ChonB • dan = 200(V) ' • • Chu y: Khi miic dong ca pha co dien ap dinh mux trcn moi tdi la U oao may pUdl dien xoay chieu pha c6 dien dp pha Id UP tin Hiy vao Ian cua U jd Ui' md yen can miic lunh liny mac hinli tarn gidc Neil U = Ih' vd dong ca hoat dg)ig hinh thwang th'i nguon mac - tdi mac , hoiic }iguon mac tam gidc - tdi miic tarn gidc * Neil LI = Ui'yfs , tarn ClionA ,|, V3 V i du 6: M o t d o n g co k h o n g d o n g bo ba pha mac h i n h vao m a n g dien xoay chieu ba pha mac h i n h sao, co dien ap day 380 V D o n g co co cong sua't 10 KW H e so cong sua't 0,8 C u o n g d o n g dien hieu d u n g d i qua m o i cuon thirang tin nguon mac - tdi nm , , , »Jj ••• •: A 57,0 A B 18,99 A i:\:0'.'-:'.>- ^ c mac Cong sua't tieu tliu ciia doug ca pha: P = 3UIcos(p (I la ctrang Ideu dung (/'"' =^ChonB vd dong ca hoat doug hinh thwang th) nguon mac tarn gidc - tin C 45,36 A Huongdan ^''^ D 10,96 A N g u o n mac - tai mac nen U = U P = U^l/^/3 : P = 3UIcos(p=^I = ' 3Ucosq, V'' Neil U = Ui'/yf} D 35 A v, day CO gia trj bao nhieu? * vd dgiig ca hogt dong Imh Huong P = 3UIcos(p=>I- 0,88.50 cos ' ^ C 105 A N g u o n mac - tai mac nen U = UP: 8,5.i0'^ H I COS (p k W ; he so cong sua't cua d o n g co la 0,5^3 B A D.565 V C.231 V B 200 V A 3 V * C c u o r day m a y phat mac theo h i n h sao, cuon day cua d o n g co mac lO.lO,3 380 — V3 0,8 a 8,99 (A) V i du 7: M o t d o n g co k h o n g d o n g bo ba pha dau theo h i n h tam giac vao mang moi tdi vd cosChonC + 3rr Vi du 11: M o t d o n g co dien xoay chieu co dien t r a day cuo'n la 32 Q, mach dien Vi du 9: M o t d o n g co k h o n g d o n g bo ba pha mac theo kieu h i n h vao mach CO d i e n ap hieu d u n g 200 V t h i san cong sua't co hoc 43 W Biet he so'cong dien ba pha mac h i n h co dien ap pha la 220 V D o n g co co cong suat co sua't cua d g n g co la 0,9 va cong sua't hao p h i nho h o n cong sua't co hoc hoc la k W , hieu suat 80% va he so cong suat ciia d o n g co la 0,85 T i n h c u o n g d o n g d i e n chay qua m o i cuon day cua d o n g CO A 21,4 A Huong P Pj _ 4.10' H • C 0,225 A Huang D 17,3 A dan UIcoscp = Pi-fI^R=> 200.1.0,9 = + 1^32 P h u o n g t r i n h co nghiem: Ii = 5,375 A va I2 = 0,25 A , ta chgn n g h i e m I2 = 0,25 A v i v o i n g h i e m t h u nha't = 5000(W) cong sua't hao p h i Ion h o n cong sua't co ich! 5000 P = 3UIcos(p 3.220.0,85 I = 5,375(A)=^P,,p = I R = , ^ - , W > ( W ) => Chon A ' Vi du 12: (DH-2010) M o t d g n g co dien xoay chieu k h i hoat d g n g b i n h t h u o n g =>ChopD.'' ' Chu i^id tri tire thai ii, i tron;^ moi pha tn viet hieu thi'tc u, i roi can cu ' vao quanhe de tinh • M Vi du 10: D o n g ca k h o n g d o n g bo pha mac h i n h sao, k h i d o n g co hoat d o n g b i n h t h u o n g a d i e n ap 200 V t h i cong sua't tieu t h u ciia d o n g co bang 1620 V2W B 5,375 A * dan 0,8 y: Detinh C u o n g d o d o n g hieu d u n g chay qua d g n g co la A 0,25 A D 8,9 A C 26,7 A B 7,1 A ' voi d i ^ n ap hieu d u n g 220 V t h i sinh cong sua't co hgc la 170 W Biet d g n g CO CO he so'cong sua't 0,85 va cong sua't toa nhiet tren day qua'n d g n g co la 17 W Bo qua cac hao p h i khac, c u o n g d o n g d i e n cue dai qua d g n g co la A 72 A C.2A Huang va he so cong sua't la 0,9 cho m o i pha Pha ban dau ciia d o n g dien (dang h a m cos) cac cuon day 1, va Ian l u g t la 0, 27t/3 va -27r/3 Vao B l A Ulcos(p = Pi +% D 73 A dan => 220.1.0,85 = 170 +17 =i> I = l A = > I o t h o i d i e m d o n g d i e n a cuon co gia trj bang i i = 3V2 A va d a n g tang t h i =>Chon A d o n g dien o cuon va t u o n g l i n g bSng du 13: M o t d g n g co dien xoay chieu k h i hoat d g n g b i n h t h u o n g c u o n g A 1,55 A va A ;v C 1,55 A va -5,80 A A, %: ufi n.^t) B.-5,80 A va 1,55 A • D A va - A ' Huang i i = c o s ( c o t ) ( A ) ; i = c o s cot + • d o n g d i e n hieu d u n g qua d g n g co la 10 A va cong sua't tieu t h u d i e n la 10 / : kVV D g n g co c u n g cap nang l u g n g co cho ben ngoai t r o n g s la 18 k j T i n h tong d i e n t r o t h u a n cua cuon day d g n g co ,', • ^ 162072 = 3.2001.0,9 => , "• A 0 Q B.IOQ C 90 Q Huong I = 3V2 ( A ) ( A ) ; i = 6cos cot 11, • ,• i dan T u cong thuc: P = 3UIcos(p p =l72 = 72(A) 2n (A) P = Pj + l r = > P = + l2rr:>10'* = l ^ ^ D.9C dan + r = > r = 10(Q) ^ChpnB 219 Bdtrgkic'n Ihitc Vfit ULTOlllrcn kcnh VI VJ, t ^ p ^ e - f ^ n u vanm e n Chii y: Ncii doan mqch xony cliicu AB gain inach RLC run tiSp vai dorv^ ca dien pha thi bleu thiic dien dp iren RLC, tren dgng ca Ian linrt la: i = IN/2 cos Wt : •-R ' LC = U K L C ^ C O s ( a ) t L + (pRLc) "-'dong, ) = U ^ / c O s ( ) t + (p) cty R do: C tan(|).ChonD V i du 15: Mot dong co dien xoay chieu san mot cong suat co hoc 8,5 kW va CO hieu suat 85% Mac dong co voi cuon day roi mac chung vao mach xoay cos((p2 , , nr-2 -cpi)\2= 270,6^ +125^ + 2.270,6.125.cos30'' '•:;.^o: r J K t ;rU • hai dau dong ca la n/6 Dien ap hai dau cuon day co gia trj hieu dung 125 ''i - ,.;;iJ< U', : i - Uisincp,+U2sin(pT tan (p = —• 21! i U j coscpj + U C0SCP2 =^ChonC •—I Chu y: Ne'u doqn mqch xoay chieu AB gam mqch R not tie'p vai dong ca dien pha thi bleu thuc dien dp tren R, tren dong ca Ian heat la: UR i = lV2coscot: =URr^COSQ)t I- "d,»i;,',J^ do: P = UI cos cp = - i - vj;, H Dien dp giua hai dm doqn mqch la tong hap cua hal dao dong dim hdx "AB = UR + Lidong_ccJ = UABN/2cos(cot + 9AB)' do: IT2 TT2 ^Tr2 , TT UAB = UR+U +2URUCOS(P; , U^B ^ 345(V) => Chon B V i du 16: Mot dong co dien xoay chieu san cong suat co hoc 7,5 kW va co hieu suat 80% Mac dong co noi tie'p voi mot cuon cam roi mac chung vho mang dien xoay chieu Gia tri hieu dien the hieu dung o hai dau dong co 1'^ U M biet rang dong dien qua dong co co cuong hieu dung I - A va trf 220 220 V - 88 W va hoat dong diing cong suat djnh muc thi l^ch pha giij-a dien ap a hai dau quat va cuong dong dien qua no la 88 = 220.1.0,8 =^ I = , ( A ) ,V U D 267 fi in t^-d iui^i-ih Cdch 1: U^B = U | + U ^ + 2URUcoscp /v Cdch 2: UAB = UR + U U^B = U | + U ^ + 2URUcosq) Un • 380^ - U ^ + 220^ + 2UR220.0,8 UR = 180,337 =^ R = ^ = 361(n) •Chon C 221 VTV2 l.ip-J - Chu V^n Bd trfi klen thiic V$t li LTBll tren kenh Bl&n V i d u 18: T r o n g g i a hoc thuc hanh, hoc sinh mac no'i tiep m o t q u a t d i e n xoay chieu v o i d i e n t r o R = 352 Q roi mac hai d a u doan mach vao d i e n ap P ' = UIcos(p: 80 100 100 = U.0,5cos(p =0 U c o s = ( V ) xoay chieu c6 gia t r j hieu d u n g 380 V Biet quat d i e n hoat d o n g che'dg D i e n ap hieu d u n g tren R : U R = I R = ( V ) d i n h m u c v o i d i e n ap d i n h m u c dat vao quat la 220 V v a k h i ay t h i d o lech T u p h u o n g t r i n h vec to: pha g i i i a d i e n ap a hai d a u quat v a c u o n g d o d o n g d i ^ n qua n o la cf), v o l U A B = U R + U chieu len true hoanh coscj) = 0,8 H a y xac d i n h cong suat d j n h m u c cua quat d i e n A 90W B 6 W t ' U R = , ( V ) => I = 0,512(A) P = UIcos(p = 220.0,512.0,8 = , ( W ) = ^ C h o n A , > V i d u 19: Cho mach d i e n xoay chieu g o m b o n g den day toe mac n o i tiep v o l d g n g ca xoay chieu pha Biet cac gia t r i d i n h m i i c cua den la 120V - 24UW, ' : A (- L A B =17,34" M N ,1) • a , c r ; ! : ,0 ^ ^ |220sin(pAB = + U s i n ( p ^ [ U s i n ( p = 65,574 • " Ket h o p Usincp = 65,574 v d i Ucos(p = 160, suy ra: cp = 22,286^, U = 172,9 V K h i d o n g ca hoat d o n g b i n h t h u o n g : P = U I cos cp 100 = 11 O.I cos 22,286 r=> I = 0,9825 ( A ) d i e n ap d i n h m i i c cua d o n g ca la 220 V K h i dat vao d a u d o a n mach dien T u p h u o n g t r i n h vec to: CFAB = U R + U chieu len true hoanh v a true t u n g ta ap xoay chieu c6 gia t r j h i e u d u n g 331 V t h i ca den v a d o n g ca deu hoat duge: +Ucos(p d o n g d u n g cong suat d j n h m u c Cong suat d i n h m u c cua d o n g ca la UABCOSCPAB = U R A 389,675 W UABsincpAB = +Usincp / B 305,025 W •;•'>•'•• ••••V',-j:\'::i 120 C 543,445 W D 485,888 W Uuongdan •.>: ^ ' U AB = U + U R = > U i s == f220cos(pAB = U R +110.eos22,286 [220sin9AB = + 110.sin22,286 (PAB = 10,93° = > U R = 1 , = > R = ^ » 1 ( Q ) ' I V;?;, De quat hoat d o n g b i n h t h u a n g t h i R tang 116 - 100 = 16Q V i d u 21: T r o n g m o t g i o thuc h a n h m o t hoe sinh m u o n m o t quat d i e n loai 180 + U R + U U R cos (p V - 220 W hoat d o n g b i n h t h u o n g d u o i m o t dien ap xoay chieu c6 gia t r i , , 1417 33r - 220^ +120^ + 2.220.120.cos(p ^ c o s ( p = ^ ^ h i e u d u n g 220 V, nen mac no'i tiep v o i quat m o t bien t r o Ban d a u hgc sinh d o de bien t r o c6 gia t r i 70 Q t h i thay c u a n g h i e u d u n g t r o n g mach la =^ P = UIcos(p = 2 — = 389,675(W) => C h o n A 0,75 A v a cong suat cua quat d i e n dat 92,8% M u o n quat hoat d o n g b i n h V i d u 20: T r o n g m o t g i a thuc h a n h m o t hoc sinh m u o n m o t quat d i e n loai t h u a n g t h i p h a i d i e u c h i n h bien t r a n h u the nao? 110 V - 100 W hoat d o n g b i n h t h u a n g d u o i m o t d i ^ n ap xoay chieu c6 gia A G i a m d i 20 Q B Tang them 12 Q t r i hieu d u n g 220 V , nen mac n o i tiep v o i quat m o t bien t r o Ban d a u hoc C G i a m d i 12 Q D Tang them 20 Q Huang sinh d o de bien t r o c6 gia t r j 100 Q t h i d o thay c u a n g d p h i e u d u n g ^ » p5l.»_^Bq^ ^ dan m a c h la 0,5 A va cong suat ciia quat dien dat 80% L u c d a u , d o n g co hoat d o n g d u o i d j n h muc, cong suat tieu thia cua no: T i n h h§ so cong suat toan mach, he so cong suat cua P ' = UIC0S(p: quat v a d i e n ap h i e u d u n g tren quat liic M u o n quat hoat d o n g b i n h t h u o n g t h i phai dieu c h i n h bien ^• A 92,8 100 -.120 = U.0,75eos(p =t>Ueos(p = , ( V ) t r o n h u the nao? Biet d i e n ap g i i i a hai dau doan mach T u p h u o n g t r i n h v e c t o : U^g = Up, + U s o m pha h o n d o n g dien t r o n g mach chieu len true h o a n h v atrue tung ta Humg dan L i i c d a u , d p n g c a hoat d o n g d u a l d i n h muc, cong sua't tieu t h u cua no: 999 ^ UABCOSCPAB = U R +Ueos(p U A B s i n (PAB = + U s i n (p duge: f220eos9AB ^' =70.0,75 + 148,48 1220 s i n CPAB = + U s i n cp 223 So' tr(> kicn lltuc V^t li^LTDtlJrcn kcnh VTV2 t^p 2- CQ^ T/vmMTVDvvnKhang =:>Usin = 89,482 ket h o p v o i U cosip = 148,48 , suy ra: (p ' V • cosq) = 0,8565 * ' '^JKii K h i d o n g co hoat d o n g b i n h t h i r o n g : P = UIcoscp 120 = 180.1.0,8565 0,5424 rad hay Huang • D irjin „o».; H = : I = 0,7784(A) Pco Ulcoscp-Php P UIcoscp dan 11 = VIft 220.0,5.0,8 = 0,875 = 87,5% =>ChonD d u 24: M o t d o n g co k h o n g d o n g bo ba pha tieu t h u cong sua't la 3,6 k W , Tir p h u o n g t r i n h vec to: U A B = U R + U chieu len true hoanh va true t u n g ta dien t r o t r o n g ciia m o i cuon la Q va he so cong sua't la 0,8 D o n g co mac duoc: h i n h mSc vao m a n g dien mac h i n h v o i d i e n ap hieu d u n g 200 V t h i U A B COS(PAB = 220coscpAB = U K + Ucos(p 220sin(pAB = + 180.sin0,5424 U A B sincpAB = + Usin(p ^ +180.cos0,5424 U , , = 45,25 => R = H i i - 58(n) is:,,,,; dong CO hoat d o n g b i n h t h u o n g Coi nang l u o n g v ich chi toa nhiet cac cuon day ciia stato H i e u sua't d o n g co la A 92,5% U, I = dan Vi du 25: T r o n g d o n g co k h o n g d o n g bo ba pha, goi O la d i e m d o n g q u y cua P-I^r A 86% D 90,625% 'Q ( A j a i r O S S - G i a m d i 70 - 58 = 12 Q =^ Chon C P = UIcos(p=:> I = C 99,7% ^ yA U,U', -1 U,U', ' ' C'm ' D 105 ''P^:' Humgdan r i : Ui N] 220 1100 77^ = r ^ — — - = > - ~ ^ =i>N2 =105 U2 N2-2n 15 N2-3O ^ ^, ^ Chon D • V i d u 3: D a t m o t dien ap xoay chieu u = 200coscot (V) vao hai dau cupn day so V i d u 7: M o t m a y bieh ap v o i cuon so cap g o m 1000 v o n g d u g c mac vao mang cap cua m o t m a y bieh the l i t u o n g t h i dien ap hieu d u n g d u g c a hai dau dien xoay chieu C u o n t h u cap g o m 50 vong Bo qua m g i hao p h i may cuon t h u cap la 10 V2 V N e u dien ap xoay chieu u = 30cosail (V) vao h^n bieh ap C u o n t h u cap noi v o i dien t r a thuan t h i d o n g dien chay qua cuon dau cuon day t h u cap t h i dien ap d u g c hai dau cuon day so cap bang A.300V B.2OOV2V C.3OOV2V D.I50V2V Huaitg dan UiU', IOO72.I5V2 =1 U2U'2 ' ' =1 t h u cap la ( A ) H a y xac d i n h d o n g dien chay qua cuon so cap A 0,05 A B 0,06 A C 0,07 A Huangdau ' D 0,08 A ; ''T ' V i may bieh ap l i t u o n g va cuon thii cap noi v o i R nen ta ap d u n g cong U'2 = I50V2 ( V ) => C h o n D« 10^/2U'2 V i d u 4: M a c cuon t h u nhat cua m o t may bieh ap l i t u o n g vao mg^ nguoV diC'^ xoay chieu t h i suat d i e n d g n g hieu d u n g cuon t h u hai la 20 V, => Chon A ' v-v Chu y: Nc'u cuon thu cap cm may bieh ap not vai RLC: " V ioK cuon t h i i hai vao n g u o n dien xoay chieu t h i suat dien d g n g h i ^ u d^-f' t r o n g c u o n t h u nhat la 7,2 V T i n h d i e n ap hieu d u n g cua n g u o n dien A 144 V B.5,2V C 13,6 V U2 = : ^ -12 = U2 N2 D.12V , ^R2+(Zi_-Zcf • W '•' M r.: M > j'' n Huang dan UiU'i U,U', =1 E.E P, U,I, = ^ E = 12(V) ^ C h o n D 20.7,2 227 Ir^t hit^n I hut V^t l i Lmil l i c n hcnl, VTV2 - Chu t4ip Van c i y innn nrv own Blin Huang dan d\ 8: Cho m o t m a y bien ap c6 hieu suat 80% C u o n so cap c6 100 vong, cuon t h u cap c6 200 v o n g M a c h so cap l i t u o n g , dat vao hai d a u cuon so cap d i e n ap xoay chieu c6 gia t r j hieu d u n g 100 V va tan so 50 H z H a i dau cuon t h i i cap n o i v o i m o t cupn day c6 dien t r o 50 Q, d p t u ce,m 0,5/7t ( H ) C u o n g d p d o n g dien hieu d u n g mach so cap nhan gia t r i : 100 •0,8 = Uili P,,=P„^UiIi=U2l2+U3l3=:>Ii = , 5 ( A ) = > C h o n C d a u v o i m o t d i e n t r o R' = 10 Q Coi d o n g d i e n va d i e n ap l u o n c u n g pha = 2^^(A) C u o n g d p d o n g d i e n h i ^ u d u n g chay t r o n g cupn so cap la 8.50 Chon A •Ii=5(A) 100.1 A 0,150 A B 0,450 A la C u p n t h u cap n o i v o i tai tieu t h u c6 dien t r o 200 Q, c u p n S T cap n o i v o i U2 cupn SO cap la C 0,5 A D 0,8 A s-i • U, I, 1, Ni N, I1 = N2 N, = 0,5(A) Chon A dau ra) va cdc dau noi voi R tin ap dung cong thuc: Psc=P.c=>UiIi=U2l2+U3l3i Kl- • , ^ „ - U2 I, N2 Neu ap dung cong thuc —^ U i = -iI2 = —^ Ni U2=40(V)=>l3 = R 40 U3 40 R', 10 = 0,5 ( A ) = 4(A) • 400.Ii = 20.0,5 + 40.4 => I i = , ( A ) N2 „ , U = — ^ U i => I2 = hu y: Dot voi may him ap ly twang ma cuon thw cap c6 nhieu dau (chang hqn c6 I, = Ni 100 sau: P, = I ^ R = 300^90 U2R 90^+120^ — P2 = P = ( W ) =>U2 =300(V) ~ 400 U2 Huong dan = 360(W) U2 rfiii 1/: Ne» m(ic/i thu cap ndi cdc bdni^ den , , (^fJ'' * P C h o n A Binh luan: Nm dp dung cong thuc ~ - //;; t'nn kct qua sai ii = (A) 96% C u o n g d o hieu d u n g qua cuon so cap va t h u cap Ian l u o t la A 1,5625 A va 7,5 A B 7,5 A v a l , A C A va 1,5625 A D 1,5625 A va A Huong P2 =n.mP,, = - ( W ) I'll • "••"CI • U j dan ' 1100 N, U 1, U2 N2 48 ' 220 P2 P, U = n U , , =4.12 = ( V ) U ,I M I _ • 0,96 = Ui=240(V) 360 2401, • l i -1,5625(A) => Chon A CM y: Nell mach thu cap mi voi dong co' dim (P = UIcos(p) bhih thiraiig thi N, P2=P l2=I U2 = N2 Ucoscp u, =u 396 W , CO h | so cong sua't 0,8 Ne'u d o n g co hoat d o n g b i n h t h u o n g thi c u o n g d o hieu d u n g t r o n g cuon so cap va tlui cap Ian l u o t la 7^0 Biet d i e n ap hieu d u n g giua hai d a u cuon so cap la 1000 V va he so'cong sua't ciia cuon t h u cap la 0,8 Ccuig sua't nhan duc^c cuon t h u cap va c u o n g hieu d u n g t r o n g cuc)n t h u CcYp Ian lucrt la A 9600 W va A B 960 W va 15 A C 9600 W va 60 A D 960 W va 24 A Huang U, N, U, N, C 0,8A va 2,25A D A va 2,5 A 1000 6250 1250 _ U2I2COSCP2 r • va t h u ca'p 2,5 N g u o i ta mac vao hai dau cuon t h u cap m o t d o n g co 220 V - B 1A va 1,6A 6250 v o n g va 1250 vong, nhan c(";ng suat 10 k W t u m a n g d i e n xoay chieu j_j^P2 Ujli V i d u 15: M o t m a y ap hieu sua't 90% co t i so g i u a so v o n g day cuon so cap A 0,8A va 2,5 A coscp = Vi d u 17: M o t may bien the hieu sua't la 96'}.' so'vong cuon so cap -'a t h u cap la H Ui «• 12 Tronu;!f Uj •"60' n-1 Ni U2 N2 v , f K i i , n ti>g> • 1000 4-1 40 N2 N2 = 2000 Chon A C/iM y: Nha lai trieang hop may bien dp hai cuon day hodn doi vai trb ta da Huang dan N i = Nab = 1000 N2=Nbc=N,b-N3,=640 ^ rut cong thitc: Cdch 1: U2 N2 220 1000 U2 640 _U2l2gOS(P2 _ PI N2 _N2 UjU'i =U2U'2 N U2 =^U2 = a ( V ) 1= n-1 140,8.14,08.1 Ii=9,0112(A) 22O.I1 Uili > C h o n C U2 Tuang tu vai bien dp co n loi thep: A> , U2 Ui U'l = U2U'2 n-l'n-1 n-l_N2 1000 Ui l2 _ Ni 14,08 Cdch 2: ^ = ^ = •II =9,0112(A) U2 II ii N2 Ii 640 CM y: Binh thirang may bien dp c6 hai loi thep va cuon sa cap quan tren mot loi, cuon thie cap quan tren loi Iqi: = j-, ^ V i d u 20: M o t m a y b i e n ap co l o i d o i x i i n g g o m n h a n h n h u n g chi co hai n h a n h d u p e quan hai cupn day K h i mac m o t cupn day vao dien ap xoay chieu t h i cac d u o n g sue t u no sinh k h o n g bj thoat ngoai va dupe chia deu cho liai n h a n h lai K h i mac cupn vao dien ap hieu d u n g 120 Neu may bien dp co n loi thep va cuon sa cap va thit cap dime quan n loi , thi tit thong a cuon sa cap (p ditoc chia deu cho (n - 1) loi lai Tir thong qua cuon thu cap Id ij^(n - 1) nen dien dp tren cuon thie cap gidm (n - 1) Ian Ta co the V t h i cupn k h i de h a co dien ap hieu d u n g U2 K h i m i i c cupn v o i dien ap hieu d u n g 3U2 t h i dien ap hieu d u n g a cupn k h i de h o la A 22,5 V B 60 V xem nhu dien dp tren cuon sa cap chia deu cho (n - 1) nhdnh va moi nhdnh cJu U2 N2 e2=-N2 thuan thi c6 the xem dien dp vao N (n-l)dt 232 l U U = ^ ^ | ^ = U2U2 n-1 ' ^ 5-1 5-1 e2 U'2 = 2 , ( V ) = > C h o n A va coi tie thong Id khep kin Neii cuon thie cap deha cuon sa cap co dien tra dt D 45 V Chu y: Khi dp dung cac cong thiec tren tin dien tra cua cdc cuon day hhong ddng ke CM: Suat dien dong a cuon sa cap va thie cap Ian Iwat Id: ei = - N u Huang dan n-1 ' nhdn duvc phan: C.30V - l(n-l): N2 phdn bo tren tren R va tren cuon cam thuan (n-1) N, L: U i = U R + U L = ^ U f =U^+Ut R U R J 233 Cty Chi CO llidnli plum Ui.^^ih/ hicn tuang cam I'nig dien tiv ncn cd)ig thiec may bien au luc nail la: —— = —^ U2 ,'• • N2 • • hao phi) m o t d i e n ap xoay chieu co gia trj hieu d u n g k h o n g d o i t h i d i e n ap ' hieu d u n g giua hai dau cuon t h u cap de h o la 0 V Ne'u g i a m b o t m o t Vi d u : C u o n so cap cua m o t may bien ap l i tucVng cuon so cap c6 N i = 1100 phan ba t o n g so v o n g day cua cuon t h u cap t h i dien ap hieu d u n g giira hai ;!;'v6ng va cuon t h u cap c6 N2 = 2200 v o n g D u n g day d a n co t o n g dien t r o R dau de ho cua no la de noi hai dau cuon so cap cua may bien ap v o i dien ap xoay chieu co gia t r i A hieu d u n g on d i n h la U i = 82 V t h i k h i k h o n g noi tai d i e n ap hieu d u n g giua hai B 0 V 100V A 0,19 • B 0,15 - D 0,225 _ N| U2 U? = U? + UL 1100 160 2200 ul => 82^ ^itU2 = ( V ) Ni Khi may hicn ap co ao'vbng day a cum sa cap thay dcTi ta diing: u, U'2 : N] ±n N2 [U'l 110V dan j u d l o M ( f I O £ - F i G ) jYS jyb Ni - n N2 ^ = N2-n ^ => n = N2 • Chon B N, U' N2+3n Ul i ] INN = U' INN, J Ul = — = : > U ' = 200(V) Ul I* d i e n ap xoay chieu co gia t r j hieu d u n g k h o n g d o i t h i d i e n ao hieu d u n g § giD-a hai d a u c u o n t h u cap de h o cua no la 100 V Ne'u chi tang them n vong day cuon day so cap t h i dien ap hieu d u n g giira hai dau de h o cua cuon -i t h u cap la U Ne'u chi g i a m d i n v o n g day cuon day so ca'p t h i d i e n ap hieu d u n g giii-a hai d a u de h o ciia cuon t h u ca'p la U Ne'u chi tang t h e m 2n N2 u D ''Vi d u 25: Dat vao hai dau cuon day so cap cua m o t m a y bien t h e ' l i t u o n g mot N2 Ni ^ Khi may bien dp co so vong day a cum thie cap thay doi ta diing: 2U • C 2 V N, u/ U^^N2 U2 v^>: Huong =•'^'^^-jij"^.' ^ dnl'o %j H ^.' .M B 0 V \J_ ±n N2 Ni v o n g day cuon so cap thi dien ap hieu d u n g g i i i a hai d a u cuon t h u cap de h o la A.50V »34 'UJ dien ap hieu d u n g giua hai dau cuon t h u cap de ho la 0 V O cuon t h u C u o n so cap co d i e n t r o thuan Q va cam k h a n g Q D i e n ap hieu d u n g N2 f.'/l cap, ne'u g i a m bot n v o n g day t h i dien ap hieu d u n g g i u a hai d a u de h o cua 2200 v o n g N o i d a u cua cuon so cap v o i dien ap xoay chieu 40 V - 50 H z U2 liK;^ (bo qua hao p h i ) m o t dien ap xoay chieu co gia trj hieu d u n g k h o n g d o i thi i"-' Vi d u 22: M a y bien the ma cuon so cap co 1100 v o n g day va cuon t h u cap co _ Ni ^ IK.V Vi d u : ( D H - ) Dat vao hai dau cuon so cap cua m o t m a y bien ap if t u o n g Chon D UL r/i C N Ni ,D UI i 2N, = - = ^ - ^ = -=>U'2 U' ^ U, j^juvii.iu'i R N, ,!/ dan J (;.» C 0,42 C 2 V Huong dau cuon thi'r cap la U2 = 160 V T i so giOa d i ^ n t r o t h u i i n R va cam k h a n g Zi, ciia cuon so cap la Vift y{ d u 23: Dat vao hai dau cuon so cap cua m o t may bien ap l i t u a n g (bo qua : • - K : TNHH NTV D VVH Khang B.60V C.IOOV D 120 V 235 Bo ttp klen thurc V$t li LTBH trgn kinh VTV2 t^p - Chu Van ~ C i y JTV/i/r nrv Bien Huang dan Dvvn'Knaag^vifsr' BAI TOAN LIEN QUAN DEN TUYEN TAl DI|N phuang phdp gidi 100 AP=I^R N2 t'.i.mdi :;\rfij5 0';.*: N i + n U " N2 U, U] _ N i - n 2U N, =>2 = N j +2n U' N2 N +n Ni-n 5Ni 3N2 Ni => n = —- U _ Ui U ' 3100 ^ Chon B Cuong hieu dung chay tren duong day: I = U ' = 60(V) A U = IR = Thong thi/ilng xem cosy^l •>AU = PR ; u • R.; Cong suat hao phi tren duong day: AP = I^R = thu cap 60 vong thi di^n ap hieu dung thu cap la 25 V Neu giam so vong l^Ucoscp Dien nang hao phi tren duong day sau thoi gian t: AA = APt day thu cap 90 vong thi dien ap hieu dung thu cap la B 12,5 V C 17,5 V Huang dan AP Phan tram hao phi: h = — D.15V U, N, Ui Ni 25 N2 +60 U ' _ N - _ 240-90 _ 150 N2 U ' _ 150 20 U, Ul Ni 240 Nt 240 U l ap 5000 V tren duong day c6 dien tro tong cong 20 Q va he so cong suat =:>U' = 12,5 bang Do giam the tren duong day truyen tai la: A 40 V day ciia cuon so cap gap hai Ian so' vong day cua cuon thu cap Do so suat nen cuon thu cap bj thie'u mot so' vong day Muo'n xac djnh so' vong day thie'u de quan tie'p them vao cuon thu cap cho du, hoc sinh dat vao hai dau cuon so cap mot dien ap xoay chieu c6 gia tri hieu dung khong doi, roi dung von ke'xac djnh ti so dien ap cuon thu cap de ho va cuon so cap Liic dau t i so' dien ap bang 0,43 Sau qua'n them vao cuon t h u cap 24 vong day thi ti so dien ap bSng 0,45 Bo qua moi hao phi may bien ap De dugc may bien ap dung nhu d u dinh, hoc sinh phai tie'p tuc ( quan them vao cuon thu cap i A 40 vong day B 84 vong day N, = U, •N2=0,43NI N1 Ul => Chon D f C 100 vong day D 60 vong day , ,,.iyi: A N2 + 24 + n = 0,5Ni => 516 + 24 + n = 0,5.1200 => n = 60 D 800 V Huang dan " ' ' ' i u 2: Mot may phat dien xoay chieu c6 cong suat 1000 KW Dong dien no phat sau tang the'duoc truyen di xa bang mot day dan c6 tong chieu dai 200 km c6 duong kinh 0,39 cm va lam bang hgp k i m c6 dien tro suat bang 1,8.10'' (Qm) Biet he so cong suat duong day bang Tinh cong suat hao phi tren duong day neu dien ap dua len la 50 kV ' - •' A 0,16MW D 0,12MW B.0,03MW i i; C 0,2 MW Huong dan Dien tro duong day: R = p— = p — j = 1,8.10 -8 Tir jNi=1200 i N2 + 24 = 0,45Ni J ^ |N2 = 516 ' C 80 V 200.10-^ 20 = 800(V) =>ChonD -R = AU = I R = Ucos(p" 5000.1 Sfi'fcui Huang dan B 400 V ' ' V i du 27: (DH-2011) Mot hoc sinh quan mot may bien ap voi d u dinh so'vong \i \ Vi du : Nguoi ta can truyen mot cong suat dien 200 kW t u nguon dien c6 dien => Chon B I (Ucoscp)2 • Di?n tro tinh theo cong thuc: R = p N2 Ni Ni PR Hieu suat truyen tai: H = - h 20 _ N2 236 PR Ucos(p cupn so cap thi di?n ap hi^u dung thu cap la 20 V Neu tang so' vong day A lOV < Ucoscp Dp giam the tren duong day: V i dy 26: Khi dat mot dien ap xoay chieu c6 gia tri hieu dung khong doi vao r: (y\0*2i 200.10^ •*301(Q) 7i(0,195.10~^y Cong suat hao phi tren duong day: A2 AP = U cos ^ R = 1000.10,3 ^ 50.10^.1 j 301 * 0,12.10*^ (W) => Chon D ' J'^ lit • 237 Bo' t r p hien tltitc V^t l i L T O I I trcn kcnh VTV2 t a p J - LHU VJH BISH V i d u 3: n o i phat n g u o i ta t r u y e n cong sua't t r u y e n tai dien nang la 1,2 MVV d u o i dien ap k V Dien tro cua d u o n g day truyen tai t u noi phat den noi tieu thu la 4,05 i l He so cong suat cua doan mach 0,9 Gia dien lOOo , J dong/kWh t h i t r u n g b i n h t r o n g 30 ngay, so tien khau hao la A 144 trieu d o n g ; C 110,16 trieu d o n g Ucoscp B 150 ho dan 168 ho dan ^ 1,2.K/^ ^ 6.10^0,9 4,05 -200.10-'(W) D i e n nang hao p h i tren d u o n g day sau 30 rciii •'•I'.i i P >1I C h o n A Chii y: Khi con^ suat dim Icn duvng day khmg doi, dien ap tang n Ian thi cong sufn hao phi giani nK = 150Pi Cdch 2: K h i U tang gap d o i thi hao p h i giam Ian nghTa la phan dien nang c6 ich tang t h e m 3AP/4 = 144Pi - 120Pi rr> AP = 32Pi K h i U tang Ian t h i phan dan •;; ' ' ' - V i du 6: M o t d u o n g day c6 dien t r o tong cong Q dan m o t d o n g dien xoay chieu m o t pha tir n o i san xuat den n o i tieu d i i n g D i e n ap liieu d u n g ciia mach dien la cosc|) = 0,8 Co bao nhieu p h a n tram cong sua't b i ma't mat tren d u o n g day toa nhiet? A 1,6% I B 2,5% Huong N e u d u n g may bien ap ccS t i so v o n g day cua cuon t h u cap va cuon so cap la 10 t h i tai noi sir d u n g cung cap d i i diijn nang cho 95 may hoat d o n g Neu AP - I^R = dat x u o n g san xua't tai nha may dien thi cung cap d i i dien nang cho bao nhieu may? -''B.IOO C.85 Huong D 105 dan G o i P, A P va P I Ian l u o t la cong suat nha may dien, cong sua't hao p h i trcn d u o n g day k h i chua d i m g may bien the'va cong sua't tieu t h u ^-iia m o i ma) x u o n g san xuat , P - ^ = 80P, 25 AP 100 •P = 100Pi ^ Ucoscp = 95P, V i dy 5: ( D H - 2012) Dien nang tir m o t tram phat dien d u o c d u a den m o t kb^' tai d j n h c u being d u o n g day truyen tai m o t pha Cho bie't, neu dien ap dau t r u y e n d i tang tir U len U thi so ho dan d u o c tram cung cap d i i d'^'^ R=^h = D 10% ) dan AP PR 400.10^.4 P U^cos> 10^0,64 - , = 2,5% Chon B V i du 7: T r u y e n tai m o t cong sua't dien ( M W ) den n o i tieu t h u bang d u o n g day p h % dien ap hieu d u n g dua len d u o n g day 10 ( k V ) M a c h tai dien c6 he so cong sua't 0,8 M u o n cho ti le nang l u o n g mat mat tren d u o n g day k h o n g qua 10% cong sua't t r u y e n thi dien t r o ciia d u o n g day phai c6 gia trj thoa m a n -j^ f t , A R