n Truyn ng in GVHD: Lu Vn QuangNHIM V CA N MN HCHy tnh ton v
thit k truyn ng in cho mt c cu nng h cu trc dng ng c ln lt l:- ng c
in mt chiu kch t song song.- ng c in khng ng b xoay chiu 3 pha
rotor dy qun.Yu cu tnh ton v thit k nh sau:1. ng c m my qua 3 cp in
tr ph, hy tnh in tr m my bit rng ng c ko ti nh mc.2. Tnh in tr ph
cn thit ng vo mch rotor nng ti ln vi tc ln lt l:a. tc nh mc.b. tc
nh mc.3. Tnh ton cc in tr ph cn thit ng vo mch rotor h ti vi tc ln
lt l:a. tc nh mc.b. 2 ln tc nh mc.Bit rng moment cn khi h ti bng
0,8 ln moment nh mc.4. Thit k s nguyn l iu khin ng c khi m my nng
ti v h ti. Bit rng ng c xoay chiu ba pha c dy qun stator v rotor u
c u hnh sao v sc t ng trn stator ln hn rotor 10%.Cc thng s cho
trc:* ng c in mt chiu kch t song song:P (kW) U (V) I (A) IKT (A) N
(vg/ph)101 232 482 4,37 512* ng c xoay chiu KB ba pha rotor dy
qun:P (kW) U1 (V)2p(t cc)N1 (vg) N2 (vg) Kdq1Kdq2m1m246 500 8 28 38
0,966 0,966 3 3R1() R2() X1() X2() pCKpFEI0 (A) cos0,13 0,0284
0,486 0,0913 0,015P 1276 23,36 0,896 0,866Trang 1/65 n Truyn ng in
GVHD: Lu Vn QuangNHN XT CA GIO VIN HNG
DN..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Ngy
.....thng ..... nm 2011 GIO VIN HNG DNTrang 2/65 n Truyn ng in
GVHD: Lu Vn QuangNHN XT CA GIO VIN PHN
BIN..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Ngy
.....thng ..... nm 2009 GIO VIN PHN BINTrang 3/65 n Truyn ng in
GVHD: Lu Vn QuangLI CM N hon thnh n mn hc Truyn ng in th ngoi nhng
n lc ca bn thn, chng em nhn c s gip ca nhiu thy v chng em khng bit
ni g hn ngoi nhng li cm n chn thnh ca chng em n:- Khoa in in t trng
i hc s phm k thut Thnh ph H ch Minh khng ngng cp nht nhng kin thc
mi c gi tr vo bi hc ca chng em trong tt c cc mn hc ni chung v mn
Truyn ng in ni ring, to nhiu iu kin thun li cho sinh vin chng em
trong vn hc tp.- Trng Trung cp ngh Gia Lai to iu kin cho chng em
trong sut thi gian qua.- Thy Lu Vn Quang,ngi truyn t trc tip cho
chng em kin thc qu gi v mn hc ny v thy cng ch dn cho chng em rt
nhit tnh trong qu trnh lm n ny./.NHM SINH VIN THC HIN NTrang 4/65 n
Truyn ng in GVHD: Lu Vn QuangLI M UNgy nay do yu cu v cng nghip ho
v hin i ho t nc nn ngy cng xut hin nhiu dy chuyn sn xut mi c k thut
hin i thay h nhng dy chuyn lc hu, li thi. p ng c nhng yu cu ny th
trc mt l phi o to ngun nhn lc con ngi c trnh v k thut cao ngay t
khi cn hc di mi trng i hc.Trong mt dy chuyn sn xut hin i th khu
truyn ng in gi vai tr rt quan trng, n thc hinc cccng on cuicng camt
quy trnh sn xut v c nh hng ln n vic nng cao cht lng sn phm v nng
sut sn xut. Chnh v vy truyn ng in l mt mn hc khng th thiu i vi nhng
sinh vin khoa in. Mt trong nhng bin php gip cho sinh vin hiu r hn v
mn hc truyn ng in l lm n mn hoc. ti ca n mang tn l: Tnh ton v thit
k c cu nng h cn trc. Ni dung ca n gm 4 chng xoay quanh vn tnh ton v
thit k c cu nng h cn trc dng ng c in mt chiu kch t song song v ng c
in khng ng b xoay chiu ba pha rotor dy qun.Chng I: c tnh c ca ng c
in mt chiu kch t song song.Ni dung ca chng ny gii thiu v c tnh c, c
tnh tc , cc thng s nh hng n dng c tnh c, c tnh c khi o chiu quay,
tnh ton in tr ph m my v vn hm my ca ng c in mt chiu kch t song
song.Chng II:Tnh ton v thit k c cu dng ng c in mt chiu kch t song
song.Ni dung chng ny l tnh ton in tr m my qua ba cp in tr, tnh ton
cc in tr ph nng ti, h ti v thit k s nguyn l cho c cu bng cch dng ng
c in mt chiu kch t song song.Chng III: c tnh c ca ng c in xoay chiu
khng ng b ba pha rotor dy qun.Ni dung chng ny l gii thiu v c tnh c,
c tnh tc , cc thng s nh hng n dng c tnh c, tnh ton in tr ph m my v
vn hm my ca ng c in xoay chiu khng ng b ba pha rotor dy qun.Chng
IV: Tnh ton v thit k c cu dng ng c in xoay chiu khng ng b ba pha
rotor dy qun.Ni dung chng ny l tnh ton in tr m my qua ba cp in tr,
tnh ton cc in tr ph nng ti, h ti v thit k s nguyn l cho c cu bng
cch dng ng c in xoay chiu khng ng b ba pha rotor dy qun.Mc d c gng
ht sc nhng do kin thc cha su, kinh nghim thc t cha nhiu v thi gian
hn hp khng th trnh khi nhng sai lm thiu st. Rt mong nhn c s ng gp
chn thnh ca qu thy c v bn b.NHM SINH VIN THC HIN NTrang 5/65 n
Truyn ng in GVHD: Lu Vn QuangMC LCTrangPhn A: Tnh ton v thit k c cu
nng h cn trc dng ng c in mt chiu kch t song songChng I: c tnh c ca
ng c in mt chiu kch t song song 071. Phng trnh c tnh tc 072. Phng
trnh c tnh c 083. nh hng ca cc thng s n dng c tnh c 094. c tnh c
khi o chiu quay ng c 125. Tnh ton in tr ph m my 146. Hm my 16Chng
II: Tnh ton v thit k 251. Tnh in tr m my qua ba cp in tr m my 252.
Tnh in tr ph cn thit ng vo mch rotor nng ti 273. Tnh in tr ph cn
thit ng vo mch rotor h ti 294. S nguyn l 30Phn B: Tnh ton v thit k
c cu nng h cn trc dng ng cin xoay chiu khng ng b ba pha rotor dy
qunChng III: c tnh c ca ng c in xoay chiu khng ng b ba pharotor dy
qun 321. Phng trnh c tnh tc 322. Phng trnh c tnh c 343. nh hng ca
cc thng s n dng c tnh c 394. Tnh ton in tr ph m my bng phng php th
435. Hm my 44Chng IV: Tnh ton v thit k 481. Tnh in tr m my qua ba
cp in tr m my 482. Tnh in tr ph cn thit ng vo mch rotor nng ti 553.
Tnh in tr ph cn thit ng vo mch rotor h ti 594. S nguyn l 63Ti liu
tham kho 64Trang 6/65 n Truyn ng in GVHD: Lu Vn QuangPHN ATNH TON V
THIT K C CU NNG H CU TRC DNGNG C IN MT CHIU KCH T SONG SONGChng I:
C TNH C CA NG C MT CHIU KCH T SONG SONG1. Phng trnh c tnh tc
:IIEUm+_CKTIkt- Phng trnh c tnh tc l phng trnh biu din mi quan h
gia tc v dng in phn ng ca ng c:n = f(I)- Theo nh lut Kirchoff 2 ta
c:E= U E = Um RIm: E = Ke.m.nTrong :+ KE= p.N60a: l h s sc in ng*
P: l s i cc t* N: Tng s thanh dn Rotor* a: S i mch nhnh song song
trn Rotor+ m= K.Iktm: l t thng kch t nh mc* Iktm: l dng in kch t nh
mc* K: h s kch t+ n: Tc ng c (vng/pht) Ke.m.n = Um RI mm mE EUR
.In= -K . K . (1)Phng trnh (1) gi l phng trnh c tnh tc t nhin ca ng
c in mt chiu kch t song song (c lp).- Khi I=0 (lc ng c khng ko
ti)mm0EUn= nK .Trang 7/65 n Truyn ng in GVHD: Lu Vn Quangn0: c gi l
tc khng ti l tng- Khi I 0:t: mTNERa =K .: l h s gc ( dc) ca ng t
tnh tc t nhin.mTN TNER .In = a .I =K . : l st p ca ng t tnh t
nhin.nnm= nAnoA12TNoIcIIm3on 1-3 = n0: on t tnh tc khng ti.on 2-3 =
n2 = nm: on t tnh tc nh mc.on 1-2 = n0.n2 = nTN: st tc trn ng c tnh
t nhin.2. Phng trnh t tnh c:- Phng trnh t tnh c l phng trnh th hin
mi quan h gia tc v moment pht sinh ca ng c:n = f(M)- Moment in t ca
ng c:M = KM.m.IVi: MP.NK =2.a: gi l h s moment cn ca ng cmMMIK . ,
thay vo phng trnh tc (1)mm m2E E MURn= - .MK . K .K .(2)Phng trnh
(2) gi l phng trnh t tnh c t nhin ca ng c mt chiu kch t c lp.- Ta
c: Ep.NK =60.aEp.NK =2.a EMK 2 1= =K 60 9,55 M EK =9,55K Thay KM vo
(2) ta c:Trang 8/65 n Truyn ng in GVHD: Lu Vn Quang( )mmm2EEURn= -
.MK .9, 55. K .(3)Phng trnh (3) gi l phng trnh t tnh c t nhin ca ng
c mt chiu kch t c lp nhng khng ph thuc vo h s KM.nA12TNoMcMMm3nm=
nAnoon 1-3=n0: on t tnh tc khng tion 2-3=nA=nm: on t tnh tc nh mcon
1-2=n0.n2=nTN: st tc trn ng c tnh t nhin3. nh hng ca cc thng s n
dng t tnh c:a. nh hng ca in p U:IUIktI+ -CKTE- Vi UKT=Um, = m, Rp=0
th:mm m2E E MURn= - .MK . K .K .U: l in p c ln phn ng.+ mmEUn=K . s
gim theo.+ aNT = aTN = const+ nTN = nTN = const- Kt lun: H cc ng c
tnh c khi gim in p l chm ng thng song song vi ng c tnh t nhin.Trang
9/65 n Truyn ng in GVHD: Lu Vn QuangMcnonU1TN ( Um)oMU2< <
U1U2 Umb. nh hng ca Rp trn mch rotor:CKT+_RpIEUmIktI- Vi: U = Um, =
mmm mp2E E MU R Rn= - .MK . K .K .+- Khi Rp tng th:+ mm0EUn =
constK .+ aNT > aTN+ NT > TN- Kt lun: H cc ng c tnh c l chm
ng thng xut pht t n0.nTNoMRp1>noRp2McRp2Rp1c. nh hng ca t thng
():Trang 10/65 n Truyn ng in GVHD: Lu Vn QuangCKT+ _RCKTIUmIktIE-
Khi tng dn RpKT th:+ Ikt 0+ ET = KE.mm.nT > 0+( )mTEm0 TU EK .I
. n -n 0R R > + MT = KM.m.IT > 0+ m2Em E M mURn .M 0K . K .K
. > T- Trng thing c quay nghch (N): ng c quay nghch khi
Contactor N hot ng, lc ta c:+ U = (-Um)+ nN < 0+ EN = KE.m.nN
< 0Trang 12/65 n Truyn ng in GVHD: Lu Vn Quang+ m mN N-U E -U EI
0R R + < N + MN = KM.m.IT < 0+ mm2E E Mm-URn .MK . K .K . N+0
2E MmRn n . MK .K . +Nnnoo-noMnMnUm-Umb. o chiu quay bng cch o chiu
Ikt:+_IUdmIuEuNB ATTCKTN- Trng thi ng c quay thun (T): ng c quay
thun khi Contactor T hot ng, lc ta c:+ nT > 0+ ET = KE.mm.nT
> 0+( )mTEm0 TU EK .I . n -n 0R R > + MT = KM.m.IT > 0+
m2Em E M mURn .M 0K . K .K . > T- Trng thi ng c quay nghch (N):
ng c quay nghch khi Contactor N hot ng, lc ta c:+ nN < 0+ =
(-m)+ EN = KE.(-m).nN > 0Trang 13/65 n Truyn ng in GVHD: Lu Vn
Quang+ mNU EI 0R > N+ MN = KM.(-m).IN < 0+ mm2E E Mm-URn
.M> 0K .(- ) K .K .( ) N+0 2E MmRn n . MK .K .
+Nnnoo-noMnMnUm-Um5. Tnh Rp m my:CKT+_UmIktII1G 3G 2GRp1 Rp3
Rp2RpIRpIIRpIIIEa. Vn m my:Phng trnh c tnh tc :mEm E mU Rn .IK . K
. - Khi m my n = 0mUIR mmThng R 1 =( )mmUR 0, 04 0, 05I ( )mI 20 25
I mmTc hi ca dng in m my ln:+ Mmm mnhTrang 14/65 n Truyn ng in
GVHD: Lu Vn Quang+ Dng in ln s chy cch in dy qun ng c+ To st p trn
li in+ To lc in ng lm bin dng rnh.Khc phc:+ Gim dng in axmI 2, 5I
mmm+ Mun ImmIcp th phi thm Rp ni tip trn mch RotormcppUI =IR R+mm-
Khi ng c m my th n>0mn , E =K . .n Nn: mpU EIR R+ s gim xung,
trnh ng c lm vic n nh tc thp ngi ta phi ngt dn in tr ph ra khi mch
phn ng.b. Phng php tnh Rp m my:* Cc iu kin ban u: tnh c in tr m my
ta cn phi bit trc cc iu kin sau:- Cc thng s nh mc:m m m m, mP , U ,
I , n- Tr s ti Ic, Mc.- S cp in tr m my m.* Tnh Rp bng phng php
th.nono(II) (I)II1I2ICTNRpIRpIIRpIII abe dchg fbjA(1)(2)(3)- Bc 1:
Ta tin hnh v ng c tnh tc t nhin chn gi tr ln nht v gi tr nh nht cho
php trong qu trnh m my.( )1mI = 1, 8 2, 5 I ( )2mI = 1,1 1, 3 I ,
nu m cI I >, hoc I2 = (1,2-1,3)Ic, nu cmI I >T I1 v I2 dng
hai ng thng song song vi trc tung, hai ng thng ny ct ng t nhin ti
hai im g v h, t g k ng thng song song vi trc I ct I2 ti im f, ni
n0f ct ng (I) ti e. Sau tip tc t e k song song vi I ct ng (II) ti
im d, ni n0d ct ng (I) ti im c, t c k ng song song vi trc I ct ng
(II) ti b, ni n0b ct ng (I) ti a, a l giao im gia trc I v ng (I).-
Bc 2: Tnh Rp m my+ T n0 k ng song song vi trc I ct ng (I) ti im j+
Tnh st p trn ng t tnh:Trang 15/65 n Truyn ng in GVHD: Lu Vn Quang*
T nhin:TN 0 TNEmR .In =n -nK . * Nhn to: pTN 0 TNEmR +Rn =n -n .IK
.Vi cng mt gi tr ph ti th:TN TNpNT p NTn n R= R R 1n R R n 1 1+
](1) pIje-jg egR R Rjg jg 11 11 ] ] (2) pIIjc-jg cgR Rjg jg 11 11 ]
](3) pIIIja-jg agR Rjg jg 11 11 ] ]T ta tnh c:Rp1 = RpIRp2 = RpII -
RpIRp3 = RpIII - RpIIc. Gii thch qu trnh m my:- u tin m my ta a a
in tr ph vo mch phn ng, dng in m my c hn ch xung bng gi tr I1m1mp1
p2 p3UI I (1, 8 2, 5).IR R +R +R +mm-Ti a, docI I
>nnngctngtctrnngs(3), lcnyth n>0, EmE K . .n >0 , nn dng
mp1 p2 p3U EIR R +R +R+gim dn cui cng lm vic n nh ti b. trnh ng c
lm vic vi tc thp ti b th ngi ta tin hnh ng tip im 3G li loi in tr
Rp3, im lm vic chuyn t b sang c ri tip tc tng tc n im d th tip im
2G ng li loi in tr Rp2, ng c tng tc n ng s (1) cho n im f th tip im
1G ng li loi in tr Rp1, im lm vic chuyn t f sang g cui cng lm vic n
nh ti A, kt thc qu trnh m my.6. Hm my:Hm my l trng thi ti tc v
moment ng c ngc chiu nhau. Hm my c dng trong cc trng hp sau:- Hm my
dng trong cc trng hp dng nhanh ng c.- Gi cho mt ti th nng h ti vi
tc khng i.- Gi cho mt ti th nng ng yn trn cao.Trng thi ng c khi tin
hnh hm my:+ n>0+ EmE K . .n>0 Trang 16/65 n Truyn ng in GVHD:
Lu Vn QuangIIEUm+_CKTIkt+ mU EI 0R >+ M= MmK . .n>0 +0 2E
MmRn = n - .M 0K .K .>+ PC m=U .I >0a. Hm ti sinhHm ti sinh l
trng thi hm xy ra khi tc quay ca ng c ln hn tc l tng: n > n0*
Gim tc bng phng php gim in pnnooMnMn(Um)MCMCMMH = MMC(U1)ACB- Ti im
B th:+ nB > 0+ Em 1 Bo1 BK . U EI = = .(n -n ) n01 > 0+ EmE K
. .n>0 Trang 17/65 n Truyn ng in GVHD: Lu Vn Quang+ Em 1 Bo1 BK
. U EI = = .(n -n ) 0 v M0 < ta suy ra Bn01 l on c tnh hm ti
sinh, nm gc phn t th hai.Do hm ti sinh nn khi M n nn phng trnh c
tnh c l:01 2EmRn = n - .M9,55(K . ) Hay 01 2EmRn = n . M9,55(K .
)+Cng sut ng c trn on Bn01:1P=U .I 0+ EmE K . .n>0 + Em 1 Bo1 BK
. U EI = = .(n -n ) 0+ EmE K . .n>0 + Em 1 Bo1 BK . U EI = = .(n
-n )>0R R + M= MmK . .I >0 Kt lun: on n01c l on c tnh ng c
gim tcPhng trnh c tnh tc l:01 2EmRn = n .M9,55(K . )Khi gim in p im
lm vic chuyn t A sang B bt u qu trnh hm ti sinh, do hmtisinh nn tc
ng c gimnhanhv n01M0 do tithnng cntr chuyn ng nn tc tip tc gim v C
ng thi M tng dn n im C th cn bng M v Mc h thng lm vic n nh tc mi.Kt
lun: Khi gim in p gim tc ng c th hm ti sinh nm gc phn t th 2.* o cc
tnh in p t ln phn ng o chiu quay nhm h ti th nng:- Ti im B1 th:+
nB1 > 0+ Em B1E K . .n >0 B1+ m B1(-U ) EI = < 0R B1+ MB1=
MmK . .I < 0 B1Trang 18/65 n Truyn ng in GVHD: Lu Vn
QuangonoMnMn MCMCMMCB B1MnMCMnMCno-no-nE2-nE1E1E2AC(3)B2(2) (1)Mhb1
Mhb2C1 C1D2D1Kt lun: B1 l im bt u hm ngc.- Ti on B1C1 th:+ n >
0+ EmE K . .n > 0 + m(-U ) EI = < 0R+ M = MmK . .I < 0 Kt
lun: on B1C1 l on c tnh hm ngc.Gii thch qu trnh hm ngc: H thng ang
lm vic n nh ti im A, nng ti th ngi ta tin hnh o cc tnh in p t ln
phn ng h ti th nng. Do qun tnh, tc vn quay theo chiu c, im lm vic
chuyn t A sang B1 lc ny dng in phn ng v moment ng c o chiu, qu trnh
hm ngc xy ra lm gim nhanh tc v 0 (C1)- Ti im C1 th:+ nc1 = 0+ EmE K
. .n < 0 1+ 1m m-U E (-U ) EI = =< 0R R+ C + MC1 < 0Kt
lun: im C1 bt u qu trnh m my ngc- Ti on C1 (-n0) th:+ nc1 < 0+
1E 0 C+ 1mmmNUI =- = I < 0R C + MC1 = MmK . .I < 0 Kt lun: on
C1(-n0) l on t tnh ng c quay ngc- Ti im (-n0) th:Trang 19/65 n
Truyn ng in GVHD: Lu Vn Quang+n < 0v 0n = -n+ EmE K . .n < 0
+ m m E m0-U E (-U ) E (K . )I = = = (-n + ) = 0R R Rn+ + M = MmK .
.I = 0 - Ti on (-n0) E1 th:+n < 0v 0n = -n+ EmE K . .n < 0 +
m m(-U ) E (-U ) EI = =R R + Hay:Em0K .I = .(-n + n ) > 0R + M =
MmK . .I > 0 Khi n n I >0 M >0 Kt lun: on (-n0)E1 l on c
tnh ti sinh.Gii thch: Trn on C1D1 ng c o chiu, do tc dng ca Mc v M
ng c tng tc v lm vic trng thi quay ngc cho n (-n0) th moment ng c
bng 0, nhng do s h tr ca ti th nng nn ng c tip tc tng tc t -n0 n
E1. Trn on n0E1 th moment ng c dng tr li, qu trnh hm ti sinh din
ra, nhng do M < Mc nn nh hng ca Mc ln hn nn ng c tip tc tng tc
cng vi M tng dn tr s cho n im E1 th M = Mc, ti c h xung vi tc khng
i (-nE1).b. Hm ngc:Hm ngc xy ra trn rotor ca ng c do ng nng tch lu
trong cc b phn khi chuyn ng hoc do ti th nng lm cho n quay ngc chiu
vi moment in t lc .* Hm ngc bng cch o cc tnh in p t ln phn ng- Khi
hm ngc bng cch o cc tnh in p t ln phn ng th:n > 0 E > 0 IHN =
0RE ) U (uu dm< Kt lun: M < 0 , B1C1 l on c tnh hm ngc bng
cch o cc tnh in p ln phn ng.Gii thch: Khi h thng ang lm vic nu tin
hnh o cc tnh in p ln phn ng th lc ny do qun tnh tc vn quay theo
chiu c nhng moment ng c o chiu nn qu trnh hm ngc lm gim nhanh tc v
0.Trang 20/65 n Truyn ng in GVHD: Lu Vn QuangM:ImmudmRU[ ]1]1
uu dmuHNRE ) U (I=> [ ] [ ]umm uHNI I > V dng hm ngc ln hn
dng m my nn ngi ta phi tm cch hn ch dng hm ngc khng c vt qu 2,5 ln
dng nh mc. khc phc ngi ta thm in tr ph vo phn ng.dmPHN uu
dmuBHN2,5IR RE ) U (I 1]1
+ Tuy nhin nu thm in tr ph hn ch dng in hm ngc th cui cng ng c h
ti vi tc (-nE2) cao hn yu cu. trnh trng hp ny th khi ng c tng tc n
D2th ta tin hnh ngt in tr ph ra khi mch phn ng, chuyn im lm vic
sang D1 cui cng lm vic n nh ti E1.Phng trnh c tnh c (1) v (2)(1) n
.M) . 9,55.(KR. KU2dm Eudm Edm(2) n .M) . 9,55.(KR R. KU2dm EPHN
udm Edm+* Hm ngc bng cch thm in tr ph vo mch phn ng h ti:* Ti im B:
Khi thm in tr ph vo mch phn ng th:+ IB 0R RE ) U (P uu dm>+ +
MB. KMm. IB > 0Kt lun: M < MC nn h thng gim tc.Gii thch: h ti
ngi ta thm in tr ph vo mch rotor im lm vic chuyn sang B, tc vn quay
theo chiu c nhng lc ny M < MC nn h thng bt u qu trnh gim tc t B
C* Ti on BC th:+ n > 0+ E = KM. m . n > 0+ I0 n) .(nR R. KR
RE UoP udm EP uu dm> ++Trang 21/65 n Truyn ng in GVHD: Lu Vn
Quang+ M0 .I . u dm > Kt lun: BC l on c tnh ng c quay thun gim
tc .- Ti im C: Tc bng 0 nhng trn ng c cn M v MC ngc chiu nhau nhng
v MCc gi tr ln hn nn n ko rotor theo chiu ca n, nh th ti c h xung.-
Ti im CE1 th: + n < 0+ E = KE. m. n < 0+ I =0R RE Up uu
dm>++ M > 0Kt lun: CE1 l on c tnh hm ngc theo in tr ph.Phng
trnh c tnh c l:n = .M) . 9,55.(KR R. KU2dm Ep udm Edm+c. Hm ng
nng:* Hm ng nng kch t c lp+_RHNACKTIktmInE+_BmMCMCnn0AB
B(1)(2)(3)COMcMMHbMnnMTrang 22/65+IktdmEURHNCKTABndm+_IHIu n Truyn
ng in GVHD: Lu Vn Quang- ng c ang lm vic thc hin hm ng nng kch t c
lp ngi ta tin hnh ngt phn ng ra khi li in, cun kch t vn cn c cung
cp in. Lc ta c: + n > 0+ E = KE . m . n > 0+ I0R RE 0HDN uu
0+ E = K. d. n > 0+ I =0) //R (R RECKT HDN uu Rpn = (no n).u2dm
ERM) . 9,55.(K (**)Trang 29/65 n Truyn ng in GVHD: Lu Vn Quanga.
Khi n = nF = 1/2 .nm = 1/2 .512 = 256 (vg/ph)Do h ti nn nF =
-256(vg/ph)V ng biu din c tnh c qua im F nn: MF = MC = 1506 (N.m)
To im F tho mn phng trnh (*) Rph1 = (no nF). uF2dm ERM) . 9,55.(K
Rph1 = [540 (-256)].) ( 909 , 0 024 , 01506) 43 , 0 .( 55 , 92 b.
Khi n = nG = 2.nm = 2.512 = 1024 (vg/ph)Do h ti nn nG = -
1024(vg/ph)V ng biu din c tnh c qua im G nn: MG = MC = 1506 (N.m)
To im G tho mn phng trnh (**) Rph2 = (no nG). uG2dm ERM) . 9,55.(K
Rph2 = [540 (-1024)].) ( 809 , 1 024 , 01506) 43 , 0 .( 55 , 92
Trang 30/65 n Truyn ng in GVHD: Lu Vn Quangn
(Vg/ph)540512256128ATNMc= 0,8.Mm = 1506M(N.m)0-256-1024FGRph1Rph14.
S nguyn l iu khin ng c khi m my, nng v h ti:Trang 31/651G 2G 3G 4G
5G 6G 7GCKTUmB AIRp1 Rp2 Rp3 Rn1 Rn2 Rph1Rph2IktI+-E n Truyn ng in
GVHD: Lu Vn Quang* Qu trnh m my: Da vo th cu 1 ta c th gii thch qu
trnh m my nh sau: u tin m my ta a ton b 3 in tr ph vo mch phn ng,
dng in m my c hn ch bng gi tr I1.Imm = I1 = dmP3 P2 P1 Udm2,5).I
(1,8R R R RU Ti a do I> IC nn ng c tng tc trn ng s (3), lc ny
n>0, =>E= KE n dm nn I = P3 P2 P1 Uu dmR R R RE U s gim xung
cui cng lm vic n nh ti b. trnh lm vic n nh vi tc thp b nn ng c tng
tc n im b th ngi ta tin hnh ng tip im 3G loi in tr Rp3, im lm vic
chuyn t b c ri tip tc tng tc n im d th tip im 2G ng li, loi in tr
Rp2 ng c tng tc n ng s (1) cho n im f th tip im 1G ng li loi in tr
Rp1im lm vic chuyn t f sang g cui cng lm vic n nh ti A kt thc qu
trnh m my. Trong qu trnh m my th cc tip im t 4G n 7G u ng li loi b
cc in tr nng h v h ti, khng lm nh hng n qu trnh m my.* Qu trnh nng
ti: nng ti vi tc bng 1/4 tc nh mc (hoc 1/2 tc nh mc) th ta tin hnh
m tip im 4G (hoc 5G) th in tr Rpn1 (hoc Rpn2) s c ng vo mch rotor
nng c ti ln vi tc c chn theo mong mun. Trong qu trnh nng ti th cc
tip im 1G, 2G, 3G, 6G, 7G u ng li loi b s nh hng ca cc in tr m my v
in tr h ti n qu trnh nng ti.* Qu trnh h ti: h ti vi tc bng 1/2 tc
nh mc (hoc 2 ln tc nh mc) th ta tin hnh m tip im 6G (hoc 7G) th in
tr Rph1 (hoc Rph2) s c ng vo mch rotor h ti ng vi th t cc cp tc c
chn theo mong mun. Trong qu trnh h ti th cc tip im t 1G n 5G u ng
li loi b s nh hng ca cc in tr m my v in tr nng ti n qu trnh h
ti.Trang 32/65 n Truyn ng in GVHD: Lu Vn QuangPHN BTNH TON V THIT K
C CU NNG H CU TRC DNG C KB XOAY CHIU BA PHA ROTOR DY QUNCHNG III:C
TNH CA NG C XOAY CHIU KHNG NG B BA PHA1. Phng trnh c tnh tc :S
nguyn l ng c 3 pha rotor dy qun:Mch in ng tr 1 pha: * Cc thng s lin
quan n ng c in khng ng b xoay chiu 3 pha.Gi:+ R0.X0.I0: L in tr, in
khng v dng in trong mch t ho.Trang 33/65N n Truyn ng in GVHD: Lu Vn
Quang+ R1.X1.I1: L in tr, in khng v dng in trong mch stator.+ R2,
X2, I2: L in tr, in khng v dng in trong dy qun rotor quy i v
stator.+ R = R2 + Rp: L tng in tr ca dy qun rotor v in tr ph thm vo
mch rotor quy i v stator.+ U1m : in p dy nh mc+ U1p : in p t ln mi
pha dy qun stator+ E2m : Sc in ng cm ng trn dy qun rotor khi in p
dy t ln stator l U1m, rotor h mch v khng quay.+ KpE 2 dq21
dq12dm1dmN k.N kEU : L h s quy i sc in ng.+ Kp1 qdEK1 : L h s quy i
dng in, t ta tnh c dng in rotor quy i v stator:I2 = KqI.I2+ H s quy
i in tr v in khng:KqR = KqX = qdIqdEKK= K2qET ta tnh c in tr v in
khng rotor quy i v stator:R2 = KqR.R2X2 = KqR.X2+ S = oooo nn n L h
s trt+ no p60f Tc ng b ca t trng (v/p)+ n: L tc ca rotor (v/p)+
9,55n602. : Tc gc (rad/s)+ 602.oo : Tc gc ng b (rad/s)* Phng trnh c
tnh tc ca ng c in khng ng b xoay chiu 3 pha c dng:I22 '2 1211P) X
(XSR'RU+ + ,_
+Trang 34/65 n Truyn ng in GVHD: Lu Vn Quangt Xn = X1 +
X2I22n211PXSR'RU+ ,_
+
(4)Vi 0 < S1nn noKhi m my: n = 0 => S = 1 (max), nn dng in
m my l:I2mm ( )2n211PX R' RU+ +2. Phng trnh c tnh c:* Gin cng
sut:
* Gin moment:* Nu xem 0 0, ms phu th:Mt = Mc = M* T gin cng sut
ta c:Trang 35/65MphPCu1, PstPms, PCu20 n Truyn ng in GVHD: Lu Vn
QuangPt = Pc + PCu2 Mto= Mc.+3R.I22 M ) (o = 3R.I22 M.S. =
3R.I22=> M =o2'2S. 3R'.IThay I2 t phng trnh (4) vo M M 11]1
+ ,_
+2n21 o1P2XSR'R .S .R' 3U M 11]1
+ ,_
+2n21o1P2XSR'R .S.9,55n.R' 3U(5)* Phng trnh (5) c gi l phng trnh
c tnh c ca ng c in khng ng b 3 pha rotor dy qun.* ng c tnh c ca ng
c xoay chiu khng ng b 3 pha c dng ng cong nn ta phi tm to im ti hn
(cc tr). Mun tm to im ti hn (cc tr) th cn c iu kin l:0dSdMT iu kin
trn ta tnh c:Smax n2 21X RR'+t (6)Mmax ( ) [ ]122 1o1P2R R R
.9,552.n.R' 3Ut +t (7)Du + : Khi trng thi ng cDu- : Khi trng thi my
pht* Cch v c tnh c:Trang 36/65 n Truyn ng in GVHD: Lu Vn Quang+ Bc
1: Xc nh to 3 im c bit.- im ng b t trng (0, no), vi p60fno - im ti
hn (Smax , Mmax )- im m my (S = 1, Mmax ), thay S = 1 vo phng trnh
(5) ta tnh c Mmm+ Bc 2: Chn thm cc gi tr ca S trong khong (0 1), t
ta c bng sau:S 0 S1S2SX 1M 0 M1M2MX MmmT cc to X(SX, MX) v 3 im c
bit ni li ta v c ng c tnh c.+ Ly ) 7 () 5 (, v ly du (+) (7) ta c
phng trnh:M maxmaxmaxmax maxaSSSSS) aS (1 2.M+ ++ (8)Vi: aR'R1
;a.Smax n2121X RR++ i vi ng c cng sut ln th: R1 1) ( S ' M2dm2 =
Sm. 0 1 M2> => Phng trnh c 2 nghim:Smax1 = M.Sm + Sm. 1 M2=
Sm. [ ] 1 M2M +Smax2 = M.Sm - Sm. 1 M2= Sm. [ ] 1 M2M Sm = Sm = [ ]
1 M2M t- Moment m my: n = 0 , S = 1Thay S = 1 vo phng trnh (9)
MmmmaxmaxmaxSS12.M++ Bc 2: Chn thm cc gi tr ca S trong khong (0 1),
t ta c bng sau:Trang 38/65 n Truyn ng in GVHD: Lu Vn QuangS 0
S1S2SX 1M 0 M1M2MX MmmT cc to X(SX, MX) v 3 im c bit ni li ta v c
ng c tnh c.Nhn xt: KM= dmmmMM : H s moment m myKM > 1 ng c m my
qu ti cKM = 12- KI = dmmmII = (47): H s dng in m my- ds.dSdM.dSdndM
+ Trng hp 0 < S < 0,4SmaxTrn on ab th: 0 0,4SSmax M
=maxmaxmaxmaxS.S 2.MSS2.M => maxmaxS2.MdSdMm S = o oon1dndSnn n
=>0 cosnt.n S2.Mds.dSdM.dSdSdMo maxmaxab< + Trng hp: S
>> SmaxTrn on cd th: S >> Smax => 0SS0SSmax max MS.S
2.MSS2.Mmax maxmaxmax => 2max maxS.S 2.MdSdM Trang 39/65 n Truyn
ng in GVHD: Lu Vn Quangv S o oon1dndSnn n =>0 cosnt.n S.S
2.Mo2max maxcd> , l bin s3. nh hng cc thng s n dng c tnh c:3.1.
nh hng ca in p:Khi in p U gim th:+ noconstp60f + Smax n2 21X RR'+t
= const+ Mmax ( ) [ ]122 1o'1P2R R R .9,552.n.R 3.Ut +t gim xung+
Mmm11]1
+
,_
+2n2mm1 mmo1P2XSR'R . .S9,55n.R' 3Ugim xungH cc ng c tnh c
U1 < U2 < U33.2. nh hng ca RP (XP) trn dy qun stator:Trang
40/65 n Truyn ng in GVHD: Lu Vn QuangKhi c RP (XP) trn dy qun
stator th theo cc biu thc (6) , (7) , (5) ta c: Smax , Mmax , Mmm u
gim xung.H cc ng c tnh c:3.3. nh hng ca RP trn dy qun rotor:Khi thm
Rp vo mch rotor th:+ Smax tng ln do R tng (suy ra t phng trnh 6)+
Mmax = const (suy ra t phng trnh 11)+ Mmm lun lun bin i(suy ra t
phng trnh 5)H cc ng c tnh c l:Trang 41/65 n Truyn ng in GVHD: Lu Vn
QuangRp2 > Rp13.4.nh hng ca s i cc t p:Ta c: p60fno M: S S)
.(1p60fS) .(1 n nnn nooo T biu thc trn ta thy: khi s i cc t p gim
th tc n s tng ln v ngc li.H cc ng c tnh c l:* i tc moment khng i* i
tc cng sut khng iTrang 42/65 n Truyn ng in GVHD: Lu Vn Quang*i tc
moment cng sut thay i3.5.nh hng ca tn s f:Ta c: S) .(1p60fn , ta
thy khi tn s tng th tc tng theoT (11) ta c: Mmax
no21Pno21P.22f9,552.n3.U.X9,552.n3.U Mmax2n21P.f .229,55.p2.603.UTa
thy khi tn s tng th tc tng theo nhng Mmax gim xung, tc l kh nng qu
ti ca ng c gim xung. m bo kh nng qu ti ca ng c khi tng tn s f th ta
phi tng U1p ln m bo t s:f < fTrang 43/652'1p11pfUfU n Truyn ng
in GVHD: Lu Vn Quang4. Tnh Rpm my bng phng php th:Cc bc tnh RP m my
bng phng php th* Bc 1: V c tnh c t nhin* Bc 2: Chn gi tr ln nht v
nh nht cho php trong qu trnh m my.M1 < 0,85MmaxM2 > (1,1
1,3)MCnu MC > MmHocM2 > (1,1 1,3)Mm nu Mm > MCT M1, M2 dng
2 ng thng song song vi trc tung chng s ct ng c tnh t nhin ti 2 im
g, h. T no k ng thng song song vi trc honh, chng ct ng thng gh ko
di ti t, t l chm xut pht cc tia m my.Trang 44/65 n Truyn ng in
GVHD: Lu Vn QuangNu ng thng cui cng xut pht t t khng i qua a th ta
phi chn li M1 hoc M2 hoc c hai.* Bc 3: Tnh ton gi tr cc in tr m my
- ng vi gi tr moment ln nht => SmaxNT nP 2XR' R' +- ng vi M1
=> STN => SmaxTN = n2XR'- ng vi M1 trn ng c tnh c nhn to ta
c:'P'22NTTNmaxNTmaxTNR RR'SSSS+ RP = R2.1)sS.( R 1SSNTTN2NTTN
1]1
ng s (1) Rp1 = R2.
,_
1]1
gjeg. Rgjgj ej2ng s (2) Rp2 = R2.
,_
1]1
gjcg. Rgjgj cj2ng s (3) Rp3 = R2.
,_
1]1
gjag. Rgjgj aj2Rp1 = RpIRp2 = RpII RpIRp3 = RpIII RpII5. Hm
my:5.1. Hm ti sinh:* Trng hp 1: Gim tc bng cch tng s i cc t m bo
cho moment khng i th hm ti sinh nm gc phn t th hai ca h trc to
n0M.Trang 45/65 n Truyn ng in GVHD: Lu Vn Quang- on Bno2 l on c tnh
hm ti sinh- on no2C l on c tnh ng c quay thun gim tc* Trng hp 2: H
ti th nng bng phng php o th t 2 trong 3 pha ngun a vo ng c, hm ti
sinh xy ra gc phn t.- on BC: on c tnh hm ngc- on C(-no): on c tnh
ng c quay ngc- on (no)D: on c tnh hm ti sinh5.2. Hm ngc:* Trng hp
1: Hm ngc bng cch o th t 2 trong 3 pha ngun a vo ng c h ti th nng.
Hm ngc xy ra gc phn t th 2 (on BC hnh trn)* Trng hp 2: Hm ngc bng
cch thm in tr ph vo mch rotor, hm ngc xy ra gc phn t th 4 (ng s 1
hnh trn), t hnh trn ta xc nh c :+ on EF: l on c tnh ng c quay thun
gim tc+ on FD: l on c tnh hm ngc khi thm in tr ph RpTrang 46/65 n
Truyn ng in GVHD: Lu Vn Quang5.3. Hm ng nng:* Hm ng nng kch t c
lp:* Hm ng nng kch t dng t:- Hm ng nng kch t dng cu chnh lu:Trang
47/65H n Truyn ng in GVHD: Lu Vn QuangDiode Mmax 1.3 Mmax 2.41-2 :
Khc nhau v dng IDC khi thc hin hm ng nng1-3 : Cng dng in mt chiu
IDC, khc nhau in tr ph trn mch rotor (ng s 3 c thm in tr ph)1-4 :
Khc nhau v IDC v RP trn mch rotor.CHNG IV:TNH TON C CU NNG H DNG NG
C AC KB 3 PHA1. Tnh ton in tr m my qua 3 cp in tr ph bit rng ng c
ko ti nh mc:Trang 48/65 n Truyn ng in GVHD: Lu Vn Quang tnh in tr m
my cho ng c in khng ng b xoay chiu 3 pha rotor dy qun ra c nhiu cch
tnh. n gin khi tnh in tr ph m my ta dng phng php th.* Phng trnh c
tnh c t nhin ca ng c khi lm vic ti nh mc:11]1
+ ,_
+2N21o21PXSR'R .9,55.S n3.R'.U* V phng trnh c tnh c t nhin ca ng
c in khng ng b xoay chiu 3 pha c ng biu din l ng cong c im cc tr,
nn khi v c tnh c ca n ta cn xc nh 3 im c bit:+ To im tc khng ti l
tng khi M = 0 , no = (v/p)p60f+ To im cc tr (Mmax, Smax)+ To imm my
(Mmm, S = 1)* Xc nh to im no = 750(v/p)460.50p60f * Xc nh to im
(Mmax, Smax)- H s quy i sc in ng:0,73638.0,96628.0,966.K N.K
NEUKdq2 2dq1 12dm1dmE - H s quy i in tr v in tr khng:KqR = KqX =
K2E- in tr rotor quy i v stator:R2 = R2.KqR = 0,0284.0,7362 = 0,015
()- in tr ngn mch:RN = R1 + R2 = 0,13 + 0,015 = 0,145 ()- in khng
rotor quy i v stator :Trang 49/65 n Truyn ng in GVHD: Lu Vn QuangX2
= X2.KqX = 0,0913 . 0,7362 = 0,049 ()- in khng ngn mch:XN = X1 + X2
= 0,486 + 0,049 = 0,535 ()- Tng tr ngn mch:ZN =0,55( , 0,535 0,145
X R2 2 2N2N + +- Dng in stator nh mc (I1dm):Ta c: Pc = Pm = .PM: P
=3 .U1m.I1dmCos I1dm = 68,45(A).500.0,866 3 0,896.46.000Cos .U 3
.P1dm.dm Do stator u Y nn : I1dm = I1pm= I1m = 68,45 (A)- Dng in
qua rotor (I2m)Ta c sc t ng: F = N.IDo sc t ng pha stator ln hn pha
rotor 10% nn:F1 F2 = 0,1F10,9F1 = F2 0,9 I1pm N1 = I2Pm.N2I2m =
45,4(A)3828 0,9.68,45.N.N 0,9I21 1pdm Do rotor u Y nn : I2dm = I2Pm
= I2m = 45,4 (A)- Dng in rotor quy i v stator:I2m = KI.I2m
61,6(A)0,73645,4KIqdE2dm - H s trt ch nh mc:T phng trnh c tnh tc
(4) ta c:I2 2N211PXSR'RU+ ,_
+=> R1 + 2N2'221PXIUSR'
,_
Trang 50/65 n Truyn ng in GVHD: Lu Vn Quang=>
2N2'221PXIUSR'
,_
- R1=> S12N2'21PR XIUR'
,_
- ch nh mc th Rp = 0 R = R2 v U1p = U1pm = 3Udm Sm 12N2'2dm1P'2R
X.I 3UR
,_
0033 , 013 , 0 535 , 06 , 61 . 3500015 . 022
,_
- Tc nh mc ca ng c:Smodm onn n nm = no(1-Sm) = 750(1-0,033) =
747,5 (v/p)- H s trt nh mc:Do ng c c cng sut ln nn t biu thc (9) ta
c:MSSSS2.Mmaxmaxmax+=> Mm dmmaxmaxdmmaxSSSS2.M+=> (*)
2.M2.MSSSSMdmmaxdmmaxmaxdm +T (10) => Smax
0,0280,5350,015XRXR'N'2N => n = no(1-Smax) = 750(1-0,028) = 729
(v/p)Thay Smax = 0,028 v Sm = 0,033 vo phng trnh (*) ta c:Trang
51/65 n Truyn ng in GVHD: Lu Vn Quang=>
4,30,00330,0280,0280,0033.21M ,_
+ M : Mm = 9,55587,7(N.m)747,546.0009,55nPdmdm - Moment ti hn ca
ng c:Mmax = MMm = 4,3.587,7 = 2527 (N.m) to im ti hn l : (2527 ;
0,028)* Moment m my ca ng c : khi m my Smm = 1=> Mmm
141,4(N.m)0,0280,02812.2527SS12.Mmaxmaxmax+++ Mt s im cn thit khi v
ng c tnh c:- Khi S = 0,005 => n = no(1 - S) = 750(1 - 0,005) =
746 (V/p)M874,6(N.m)0,050,0280,0280,052.2527SSSS2.Mmaxmaxmax++- Khi
S = 0,01 => n = no(1 - S) = 750(1 - 0,01) = 743
(V/p)M1600(N.m)0,010,0280,0280,012.2527SSSS2.Mmaxmaxmax++- Khi S =
0,02 => n = no(1 - S) = 750(1 - 0,02) = 735 (V/p)M)
2390,4(N.m0,020,0280,0280,022.2527SSSS2.Mmaxmaxmax++- Khi S = 0,035
=> n = no(1 - S) = 750(1 - 0,035) = 724 (V/p)M)
2465,3(N.m0,0350,0280,0280,0352.2527SSSS2.Mmaxmaxmax++- Khi S =
0,05 => n = no(1 - S) = 750(1 - 0,05) = 713 (V/p)M)
2154,5(N.m0,50,0280,0280,052.2527SSSS2.Mmaxmaxmax++- Khi S = 0,07
=> n = no(1 - S) = 750(1 - 0,07) = 698 (V/p)Trang 52/65 n Truyn
ng in GVHD: Lu Vn QuangM)
1742,7(N.m0,070,0280,0280,072.2527SSSS2.Mmaxmaxmax++- Khi S = 0,1
=> n = no(1 - S) = 750(1 - 0,1) = 675 (V/p)M)
1312,2(N.m0,10,0280,0280,12.2527SSSS2.Mmaxmaxmax++- Khi S = 0,3
=> n = no(1 - S) = 750(1-0,3) =525
(V/p)M467,6(N.m)0,30,0280,0280,32.2527SSSS2.Mmaxmaxmax++- Khi S =
0,5 => n = no(1 - S) = 750(1-0,5) =375 (V/p)M(N.m) 1 ,
2820,50,0280,0280,52.2527SSSS2.Mmaxmaxmax++- Khi S = 0,7 => n =
no(1 - S) = 750(1 0,7) = 225
(V/p)M201,8(N.m)0,70,0280,0280,72.2297,3SSSS2.Mmaxmaxmax++Trang
53/65 n Truyn ng in GVHD: Lu Vn Quang- T 3 im c bit v cc im cn thit
v ng c tnh c ta c bng sau:S n(v/p) M(N.m)0 750 00,0033 747,5
587,70,005 746 874,60,01 743 16000,02 735 2390,40,028 729 25270,035
724 2465,30,05 713 2154,50,07 698 1742,70,1 675 1312,20,3 525
467,60,5 375 282,10,7 225 2011 0 141,4* Do khi m my S =1 => I2
rt lnI2 ( )521,9(A)0,535 0,015 0,13 . 3500X1RR . 3U2 22N2'211p+
++
,_
+* hn ch dng m my ngi ta ng thm in tr ph vo mch rotor trong qu
trnh khi ng ri sau ngt dn in tr ph ny ra theo tng cp.- Chn gi tr
trn v di cho php trong qu trnh m myM1 = 0,835Mmax = 2110 (N.m)M2 =
1,105Mm = 649,4(N.m)MC = Mm = 587,7 (N.m)Trang 54/65 n Truyn ng in
GVHD: Lu Vn Quang- T M1, M2 dng 2 ng thng song song vi trc tung
chng s ct ng c tnh t nhin ti 2 im g,h. T nok ng thng song song vi
trc honh, chng ct ng thng gh ko di ti t, t l chm xut pht cc tia m
my.n (vg/ph)M (N.m) 2527 2527649,4587,7 141,1750t0SA
hfdbigeca(3)(2)(1)- Tnh ton gi tr cc in tr m my+ ng vi cc gi tr
moment ln nht => SmaxNT = n'P'2XR R ++ ng vi M1 => STN =>
SmaxTN = n'2XR+ ng vi M1 trn ng c tnh c nhn to ta
c:'P'2'2NTTNmaxNTmaxTNR RRSSSS+ Rp = R2 .1)SS.( R 1SSNTTN2NTTN
1]1
T th ta o c:jg = 1,7 mmeg = 5,3 mmcg = 22,2 mmag = 85 mmT ta tnh
c cc gi tr in tr ph :Trang 55/65 n Truyn ng in GVHD: Lu Vn QuangRPI
= R20,088( ,1,75,30,0284.jgegRjgjg je21]1
1]1
1]1
RPII = R20,37( ,1,722,20,0284.jgcgRjgjg jc21]1
1]1
1]1
RPIII = R2) ( 369 , 17 , 185. 0284 , 02 1]1
1]1
1]1
jgagRjgjg jaRp1 = RpI = 0,088 ()Rp2 = RpII - RpI = 0,37 - 0,088
= 0,282 ()Rp3 = RpIII - RpII = 1,369 - 0,37 = 1,000 ()2. Tnh ton in
tr ph cn thit ng vo mch rotor nng ti vi cc tc ln lt l 1/2nm;
1/4nm:Khi 1 c cu cu trc nng h th khng phi lc no cng lm vic vi mt tc
nht nh m chng ta thng xuyn thay i tc ca n p ng nhu cu ca qu trnh sn
xut. Do mun thay i tc p ng quy trnh sn xut th phi mt thm in tr ph
vo mch rotora. Nng ti vi tc : n = 1/2 nm=> n = 21.747,5 = 373,75
(v/p)* V ng c c cng sut ln: P = 46(KW) nn: Mm
dmmaxmaxdmmaxSSSS2.M+Trang 56/65 n Truyn ng in GVHD: Lu Vn
Quang* H s trt khi nng ti: S oonn n V ng biu din qua im B nn:SB
0,5750373,75 750nn noB o* Phng trnh c tnh c khi nng ti vi tc n =
373,75 (v/p)Do ng c lm vic ch nh mc v ng biu din qua im B nn MB =
Mm = 587,7 (N.m)Hay MB = Mm
BmaxBmaxBBmaxSSSS2.M+=> BmaxBmaxBmaxBBM2.MSSSS +BmaxB
maxBmaxB2 2BM2.M.S SS S+ S2maxB 2.SB.0 S .SMM2B maxBBmax + S2maxB
2.SB.0 S .S 2B maxB M +t X = SmaxBiu kin: X > SB = 0,5=> X2
2.0,5.4,3.X + 0,52 = 0=> X2 4,3.X + 0,25 = 0 = (-4,3)2 - 4.0.25
= 17,49 = 4,18=> X1 = SmaxB1 =4,2424,18 4,3) (2.a b+ + => X2
= SmaxB2 =0,0624,18 4,3) (2.a b (loi)T biu thc (10) ta c:SmaxB1 =
N'pn1'2XR R + RPn1 = SmaxB1.XN + R2 = 4,24.0,535-0,015 = 2,25
()Trang 57/65 n Truyn ng in GVHD: Lu Vn QuangM RPn1 = K2E.RPn1
=> RPn1 4,15(,0,7362,25KR2 2E'Pn1 b. Khi nng ti vi tc : n = 1/4
nm=> n = 41.747,5 = 186,8 (v/p)* V ng c c cng sut ln: P = 46(KW)
nn: Mm
dmmaxmaxdmmaxSSSS2.M+* H s trt khi nng ti: S oonn n * V ng biu
din qua im C nn:S0,75750186,8 750nn noC o* Phng trnh c tnh c khi
nng ti vi tc n = 186,8 (v/p)* Do ng c lm vic ch nh mc v ng biu din
qua im C nn MC = Mm = 587,7 (N.m)Hay MC = Mm
CmaxCmaxCCmaxSSSS2.M+=> CmaxCmaxCmaxCCM2.MSSSS +CmaxC
maxCmaxC2 2CM2.M.S SS S+ S2maxC 2.SC.0 S .SMM2C maxCCmax + S2maxC
2.SC.0 S .S 2C maxC M +t X = SmaxCiu kin: X > SC = 0,75=> X2
2.0,75.4,3.X + 0,752 = 0=> X2 6,45.X + 0,5625 = 0Trang 58/65 n
Truyn ng in GVHD: Lu Vn Quang = (-6,45)2 - 4.0.5625 = 39,35 =
6,27=> X1 = SmaxC1 =6,3626,27 6,45) (2.a b+ + => X2 = SmaxC2
=0,0926,7 6,45) (2.a b (loi)T biu thc (10) ta c:SmaxC1 = N'pn2'2XR
R + RPn2 = SmaxC1.XN R2 = 6,36.0,535 0,015 = 3,387 () RPn2 =
K2E.RPn2 => RPn2 6,25(,0,7363,387KR2 2E'Pn2 Tm li: Khi nng ti vi
tc n = 1/2 nm th Rpn1 = 4,15(), cn khi nng ti vi tc n = 1/4 nm th
Rpn2 = 6,25 ()n (vg/ph)Rpn1186,8A587,7 2527
M(N.m)373,75BC0Rpn2750Trang 59/65 n Truyn ng in GVHD: Lu Vn Quang3.
Tnh ton in tr ph cn thit ng vo mch rotor thay i tc khi h ti vi cc
tc ln lt l: n = 1/2nm, n = 2nm:n (vg/ph)nondm0 ndm2 ndm Rph1Rph2Mc
Mmax M (N.m)Khi ng c h ti ta phi ng thm in tr ph vo mch rotor c tc
theo mong mun, khi ng c s quay theo mt chiu ngc li h tiKhi ng c h
ti th moment cn bng 0,8ln moment nh mc nn:MC = 0,8Mm = MD =
0,8.587,7 = 470 (N.m)a. H ti vi tc : n = 1/2 nm=> n = 21.747,5 =
373,75 (v/p)* H s trt khi h ti vi tc n = -373,75 (v/p)S oonn n * V
ng biu din qua im E nn:SE
1,5750373,75 750nn noE o+* Phng trnh c tnh c khi h ti vi tc n =
- 373,75 (v/p): V ng c tnh c i qua im E nn:Trang 60/65 n Truyn ng
in GVHD: Lu Vn QuangME = MC = 0,8Mm = 470,1 (N.m)Hay ME
EmaxEmaxEEmaxSSSS2.M+=> EmaxEmaxEmaxEEM2.MSSSS +=> EmaxE
maxEmaxE2 2EM2.M.S SS S+=> S2maxE 2.SE.0 S .SMM2E maxEEmax +t X
= SmaxEiu kin : X > SE = 1, 5=> X2 2.1,51 , 4702527X + 1,52 =
0 X2 16,1.X + 2,25 = 0 = (-16,1)2 - 4.1.2,25 = 250,2 = 15,8=> X1
= SmaxE1 =15,9215,8 16,12.a b++ => X2 = SmaxE2 =06 , 028 , 15 1
, 16. 2 ab (loi)T biu thc (10) ta c:SmaxE1 = N'Ph2'2XR R +RPh1 =
SmaxE1.XN - R2 = 15,9.0,535 0,015 = 8,49 ()M RPh1 = K2E.RPh1 =>
RPh1 ) ( 15,670,7368,49KR2 2E'Ph1 b. H ti vi tc : n = 2.nm=> n
=2.747,5 = 1495 (v/p)* H s trt khi h ti vi tc n = -1495 (v/p) S
oonn n *V ng biu din qua im F nn:Trang 61/65 n Truyn ng in GVHD: Lu
Vn QuangSF
2,997501495 750nn noF o+* Phng trnh c tnh c khi h ti vi tc n = -
1495 (v/p): V ng c tnh c i qua im F nn:MF = MC = 0,8Mm = 470
(N.m)Hay MF FmaxFmaxFFmaxSSSS2.M+=> FmaxFmaxFmaxFFM2.MSSSS
+=> FmaxF maxFmaxF2 2FM2.M.S SS S+=> S2maxF 2.SF.0 S .SMM2F
maxFFmax +t X = SmaxFiu kin : X > SF = 2,99=> X2
2.2,994702527X + 2,992 = 0 X2 32,15.X + 8,9 = 0 = (-32,15)2 -
4.1.8,9 = 998 = 31,5=> X1 = SmaxF1 =31,8231,5 32,152.a b++ =>
X2 = SmaxF2 =0,325231,5 32,152.a b (loi)T biu thc (10) ta c :SmaxF1
= N'Ph2'2XR R +RPh2 = SmaxE1.XN R2 = 31,8.0,535 0,015 = 17 ()M RPh2
= K2E.RPh2 => RPh2 31,3(10,73617KR2 2E'Ph2 Trang 62/65 n Truyn
ng in GVHD: Lu Vn QuangTrang 63/65 n Truyn ng in GVHD: Lu Vn
Quang4. S nguyn l ng c khi m my, nng v h
ti:Rp1Rp1Rp1Rpn1Rpn2Rph1Rpn2L2 L3 L1DC 3 phaG1G2G3G4G5G6G7* Qu trnh
m my: Da vo th cu 1 ta c th gii thch qu trnh m my nh sau: khi m my
ta tin hnh m cc tip im 1G, 2G, 3G, cc tip im cn li u ng li. ng c lm
vic xut pht t im a v tng tc dn trn ng c tnh c nhn to s 3, moment ng
c gim dn ; n tip im b th ta tin hnh ng tip im 3G li loi in tr RP3ra
khi mch rotor im lm vic chuyn sang c. C tip tc nh vy ta s ln lt loi
c in tr RP2, RP1ra khi mch rotor im lm vic chuyn sang im g trn ng c
tnh c t nhin. ng c tip tc tng tc n im A th: M=MC nn h thng lm vic
vi tc n nh.* Qu trnh nng ti: nng ti vi tc bng 1/2 tc nh mc (hoc 1/4
tc nh mc) th ta tin hnh m tip im 4G (hoc 5G) th in tr Rpn1 (hoc
Rpn2) s c ng vo mch rotor nng c ti ln vi tc c chn. Trong qu trnh
nng ti th cc tip im 1G, 2G, 3G, 6G, 7G u ng loi b s nh hng ca cc in
tr m my v in tr h ti n qu trnh nng ti.* Qu trnh h ti: h ti vi tc
1/2tc nh mc (hoc 2 ln tc nh mc) th ta tin hnh m tip im 6G (hoc 7G)
th in tr Rph1 (hoc Rph2) s c ng vo mch rotor h ti ng vi th t cc cp
tc c chn theo mong mun. Trong qu trnh h ti th cc tip im t 1G n 5G u
ng li loi b s nh hng ca cc in tr m my v in tr nng ti n qu trnh h
ti.Trang 64/65 n Truyn ng in GVHD: Lu Vn QuangTI LIU THAM KHO1.
Truyn ng in ca Bi Quc Khnh, Nguyn Vn Liu Nguyn Th Hin ca NXB khoa
hc v k thut H Ni2. C s truyn ng in t ng ca Bi nh Tin Phm Duy Nhi ca
NXB H Ni nm 19833. in t cng sut ca Nguyn Bnh ca NXB H Ni nm 19934.
RailwayTractionPoweredbySynchronsmotorsSuppliedThrought Natunal
Comutation Inventers ca Albert Wiart and Tean Hamel.Trang 65/65
