oltc control
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Trm 500 kV Thng Tn
B IU CHNH IN P DI TI MBA AT1(On Load Tap Changer) I. THNG S K THUT : Thit b iu chnh in p l loi lm vic di ti. Thit b ny c th c iu chnh t xa hay ti ch, hoc bng tay quay ti ch. Mi pha c 1 b truyn ng v iu khin lp trong 1 t cnh my bin p. 1- Thng s b iu p - Nc sn xut : Sweden (Thy in) - Nm SX : 2004 - Loi : UCGRE 1050/1050/C - S nc : 17 - Im : 577A - Bc in p : 3608V - Tn s : 50Hz - in tr chuyn v tr : 10,5 m - Tiu chun thit k : IEC 214 (1989-07) 2- Thng s motor b iu p: - Loi : BUE1 - Ngun : 3 ~ 50Hz 380-420V - Tip im : 220VDC 3- Bo dng: - Sau 100 000 ln chuyn nc hoc sau 7 nm vn hnh. - Kim tra 1 ln / 1 nm. II. NGUYN L LM VIC: iu p my bin p nhm mc ch iu chnh in p ra pha trung p 220kV m bo cht lng in nng. Mun iu chnh in p pha trung p cn phi thay i s vng dy, ngha l thay i t s bin k=W1/W2 Do , gia hoc cui cun cao p ngi ta a ra 1 s u dy ng vi cc s vng dy khc nhau. Nu cc u phn p gia dy qun th t trng tn s u v lc in t tc ng ln dy qun s i xng hn. Thc t, i vi my bin p 500kV th cc u phn p cui dy qun th vic cch in s d dng hn. Ngoi ra, cc u dy qun c b tr dy qun cao p, v dy qun cao p dng in nh hn so vi dng in dy qun h p, nn thit b i ni nh gn hn. Thit b i ni phi c cc in tr hn ch dng ngn mch ca b phn dy qun b ni ngn mch khi thao tc i ni.
Thuyt minh mch iu p - Chu Xun Khot
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Trm 500 kV Thng Tn
trnh cho du my bin p khi b bn v ng ct mch in, v h quang chuyn mch, cc cng tc t (cng tc K) c t ring trong 1 thng du ph gn vo vch thng ca my bin p. Gi U1 l in p t vo cun cao p (l in p li pha 500kV) Gi U2 l in p t vo cun trung p (l in p ra pha 220kV) Gi W1 l s vng dy cun cao p (pha 500kV) Gi W2 l s vng dy cun trung p (pha 220kV) Ta c cng thc: U1 U 2 = W1 W2
H? Cao U1, W1 9 v 21 8 7 6 5 4 3 2 1 v 22
Trung U2, W2
Trong , in p li 500kV l U1 v s vng dy pha trung p W2 khng i. Nh vy, mun thay i in p ra pha trung p U2 ta phi thay i s vng dy pha cao p W1. S vng dy cao p W1 tng th in p ra trung p U2 gim v ngc li. Cun dy dng thay i gi l cun dy iu chnh. Ch , khi ta thay i s vng dy cun iu chnh (iu p) phi tha mn nm trong phm vi cho php + 5% ca in p nh mc pha cao p ng vi mi nc (quy trnh vn hnh my bin p). b iu p ti u v tit kim s vng dy, ngi ta khng thit k 17 u ra cun iu chnh (ng vi 17 nc phn p) m cun iu chnh c thit k vi 9 u ra phn p (3 u ra 9A, 10, 9B c cng in p nh mc lm nhim v chuyn mch). Khi iu p t nc 1 n nc 9 tc l im cui ca cun iu chnh, mun iu chnh tip t nc 9 ln nc 17 th ch vic o chiu cc tnh ca cun dy thng qua cc tip im chuyn mch (21,22). 21- Tip im (+) : Cun dy iu chnh c chiu thun cng cun cao p. 22- Tip im (-) : Cun dy iu chnh c chiu ngc vi cun cao p.
Thuyt minh mch iu p - Chu Xun Khot
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Trm 500 kV Thng Tn
1- Qu trnh tng nc:Khi tng nc t 1-2-3-8-9: V tr 20 tip xc vi v tr 21: Gi s ang nc 3 tng ln nc 4 (tc l t v tr 3 sang v tr 4-thun kim ng h). Dng in s c chiu nh sau: A => 11 => 10 => 20 => 21 => 9 => 4 => 30 => 13 => 12 => N. Sau mi ln tng nc, s vng dy cun pha cao p s gim i nn t thng sinh ra trong cun cao p s gim i. Do , dng in sinh ra trong cun trung p s gim i, m cng sut truyn ti khng i nn in p ra pha trung p s tng ln. Qu trnh chuyn mch t nc 9 ln nc 10 v t v tr 21 sang 22: Ti nc 9, khi tip tc tng nc vnh trt V ang v tr 9A-20 s chuyn sang v tr 20-9B. Sau tip im chuyn mch 20 s chuyn t 21 sang 22. Qu trnh o chiu cun dy hon thnh. Nc 9A, 9B v nc 10 l cc nc trung gian c cng in p nh mc. Khi tng nc t 9-10-17: V tr 20 tip xc vi v tr 22: Ti nc 9, sau khi thc hin thao tc chuyn mch thng qua 2 v tr trung gian 9A, 9B, v tr 20 s tip xc vi v tr 22. Gi s tng nc t 11 ln 12 (tc l t v tr 3 sang 4). Dng in s i nh sau: A => 11 => 10 => 20 => 22 => 1 => 4 => 30 => 13 => 12 => N. Sau mi ln tng nc, do cun iu chnh ngc chiu vi cun cao p nn t thng sinh ra trong cun cao p s tip tc gim i. Do , dng in sinh ra trong cun trung p s tip tc gim i, m cng sut truyn ti khng i nn in p ra pha trung p s tng ln.
2- Qu trnh gim nc: Khi thc hin gim nc, qu trnh din ra tng t v ngc.III. MCH IU KHIN NC PHN P:
1- iu khin ti Tapcon (F90-ngn l D06.AA2): - Tapcon (ngn D06-l 231) chn ch iu khin bng tay - Kha Local/Remote ti t iu khin OLTC v tr Remote (c 3 pha). - Cc iu kin khc: kim tra ngun motor, 3 pha ng b, v tr nc 1-17. n nt tng hoc gim nc ti Tapcon, khi r le K423 (gim nc) hoc K424 (tng nc) tc ng, a tn hiu vo mch iu khin khi ng motor iu p. 2- iu khin ti ch bng kha vn (S3): - Kha Local/Remote ti t iu khin OLTC v tr Local. - Cc iu kin khc: kim tra ngun motor, 3 pha ng b, v tr nc 1-17. Vn kha S3 ti t iu khin mi pha MBA sang v tr Raise (tng) hoc Lower (gim).Thuyt minh mch iu p - Chu Xun Khot Trang 4
Trm 500 kV Thng Tn
3- iu khin ti ch bng tay quay: - Kha Local/Remote ti t iu khin OLTC v tr O. - Cc iu kin khc: ngun motor ct, v tr nc 1-17. iu khin ring cho tng pha, quay 25 vng/nc.IV. CC BO V B OLTC: 1- Bo v mc du tt thp: Gi tn hiu vo r le trung gian K609 ngn B03.AF01 (r le ny cng ly tn hiu mc du bnh du ph h thp) => n Oil Level Alarm ngn B03. 2- Van p lc (K hiu F80B loi RS2001) Bo v ngn OLTC tc ng ct my bin p v gi tn hiu vo K311 t B03.AF01 => n Auto Tranformer Trip. Ch l b OLTC my bin p AT1 khng c r le dng du.
Thuyt minh mch iu p - Chu Xun Khot
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