MC LC 2 CHNG 1 TNG QUAN V CNG TY THY IN TR AN.........................................2 CHNG 2 H THNG KCH T .......................................................................................19 CHNG 3 S MCH LC ...........................................................................................38 CHNG 4 B TO XUNG KCH THYRISTOR AV..........................................................41 CHNG 5 B IU CHNH KCH T T NG AVM.............................................48 KHI IU KHIN D PHNG AVN ..............................................................................101 CHNG 7 CC H HNG TRONG H THNG KCH T.........................................105

_____________________________________________________________________________ TRANG 1

CHNG 1 TNG QUAN V CNG TY THY IN TR AN

_____________________________________________________________________________ TRANG 2

1.1. 1.1.1.

Gii thiu tng quan v Cng ty V tr hot ng ca Cng ty : Cng ty thy in Tr An c thit lp trn sng ng Nai thuc khu vc Huyn Vnh Cu-ng Nai, cch thnh ph H Ch Minh 65 km v pha ng Bc, l khu vc i ni nhng thun tin v ng b v ng sng, vo thng 12/1987 Cng ty a vo hot ng chy t my pht s 1, vi mt din tch tng i ln bao gm khu vc nh khi t my pht v nh lm vic ca cn b cng nhn vin, trm phn phi ngoi tri 220 kV v 110kV cng cc kho vt t v xng sa cha lp rp. Vi 4 t my cng sut 4x100MW Cng ty thuc loi thy in ln khu vc pha nam Vit Nam, nn Cng ty thy in Tr An ng vai tr quan trng trong h thng in quc gia. Mt bng b tr cng trnh chnh ca Cng ty nh sau: Ta nh Cng ty thy in,ca nhn nc, knh dn ra, p sui Rp, p trn, knh ni h chnh v h ph, chn h chnh v h ph.

1.1.2.

Cng trnh chnh ca Cng ty Sng ng Nai bt ngun t bnh nguyn Langbiang. Cc nhnh ca n l sng La Ng, sng B, sng Si Gn, sng Vm C ng.Ton b tuyn cng trnh c b tr lu vc sng ti on thc Tr An bc thang cui cng ca sng. Pha di ch ra sng La Ng 38Km v cch ng ba ca sng 138 km.

1.1.2.1. H cha H cha bao gm h ln v h trung gian vi chiu di n pha thng lu l 43,5Km chiu rng trung bnh l 7,5Km . su ln nht l 28m. Din tch mt thong h cha chnh nh sau: Mc nc khi bnh thng l 323,4Km2 . Khi mc nc cht l 63,1Km2. Dung tch ca h cha: Dung tch ton phn:2,765Km3 Dung tch hu ch: 2,547Km3 Ct nc tnh ton chn Turbine :52m Ct nc khi ln nht l 61,5m, khi nh nht l 44,4m. Vi lu lng nc v v d tr hng nm h Tr An c s gi s dng cng sut t trn 4470 gi (vi nm nhiu nc),cho cng sut pht in t t 1,25t KWh (vi nm t nc) n 2,29 t KWh/nm (i vi nm nhiu nc). Lu lng nc qua Turbine khi pht ht cng sut t 400MW l 880m3/s tng ng 7,92m3 th c 1KW. 1.1.2.2. Ca nhn nc Ca nhn nc dng ly nc t h cha pha thng lu a vo ng ng p lc n Tuabin ._____________________________________________________________________________ TRANG 3

1.1.2.2.1. Ca nhn nc gm : Li chn rc , ca van sa cha,ca van sa cha s c. C 4 ca qua 4 ng ng p lc n 4 t my . Mi ca rng 9m , cao 10,5m. Trong thn cng trnh c cc h khoang gim p v mt hnh lang cao trnh 27m , dng kim tra v a nc thm ra h lu . 1.1.2.2.2. Li chn rc : Li chn rc t cch ca chnh 13m , gm 4 khoang , mi khoang rng 9m v cao 33m . 1.1.2.2.3. Ca van sa cha : Ca van sa cha nm sau li chn rc , cch ly nc thng lu khi kim tra sa cha hoc th nghim ca van sa cha s c . Ca van dng phng , c nng h bng cu chn d. Nhp ca rng 7m , cao 10,5m . 1.1.2.2.4. Ca van sa cha s c : Ca van sa cha s c dng ngn nc vo ng ng p lc khi dng s c cp 3 hay khi cn sa cha ng ng p lc . Van dng phng c gi trt hai bn hng ca , c nng h bng kch thy lc. Mi van gm 2 tht ni tip nhau bng lin ng c kh . np nc ng ng , nng phn trn trc to khe h 120mm , khi nc y ng ng mi nng ht ca van. Ca rng 7m, cao 8,2m. 1.1.2.3. ng ng p lc Gm 4 ng ng bng b tng ct thp cho 4 t my , mi ng ng c : chiu di 81,5m , tit din hnh ch nht : 7m x 6,5m . Nc theo ng ng p lc vo bung xon qua cc cnh hng a nc vo Turbine, sau nc dn ra h lu .Mi t my c 2 khoang ca ra,mi ca c kch thc 7x7m, c ng m bng cu chn d. ng ng p lc c kh nng nhn 220m3 /s khi cc my pht chy vi cng sut t. 1.1.2.4. p trn p trn c nhim v iu tit x l , cng nh tch tr nc vo cui ma l . p trn c 8 khoang, mi khoang rng 15m vi 8 ca van cung c ng m bng cu chn d 2x 125 tn Kh nng x ln nht : 18700 m3/ s Pha thng lu ca p l nn ca knh dn cao trnh 30m, c gia c chc chn v to ng hng nc khi x trn ._____________________________________________________________________________ TRANG 4

Pha h lu c gia c thnh mt nghing xui xung cao trnh 30m, pha y l sn tiu nng c cng dng tiu tn bt nng lng dng nc khi x trn , gim bt s xi l pha h lu. nng cao s gi chy my t sn lng in pht cao Cng ty iu tit h cha theo ma. Tch nc vo ma ma d tr nc vo ma kh, lu lng nc v ln c th x l qua 8 cnh ca van hnh cung p trn. Lu lng nc x ra s c chy qua dng chy t nhin a v pha h lu ca khi t my. Vic thc hin iu tit tt nht s a n sn lng in ln nht.Tuy nhin phi c s iu ha gia cc nh my in v va m bo ngun nc cho nng nghip v giao thng vn ti iu tit tun theo nguyn tc: m bo thc hin mc nc cht ng vo cui ma kh v t c mc nc y vo cui ma ma. Vo ma kh m bo mc nc phi cho cc t my lm vic t lun phin nhau v cng c thc hin trung , i tu cc t my vo ma ny. Vo ma ma cho lm vic ht 4 t my theo lu lng v v gi mc nc bnh thng. Cui ma ma ly nc h cha chy my. 1.1.3. Cc thit b thy lc, h thng du, nc v kh nng h cc ca van nh ca van ca nhn nc ,ca van sa cha s c s c thc hin ng, m nh vo cc xilanh pittong thy lc. Mi b xilanh pittong thy lc c trang b cc van in t iu khin ng m cc ng du p lc phc v cho vic nng h ca van . iu chnh nc qua Turbine bng cch iu chnh m cnh hng bng h thng iu tc, l b iu tc in thy lc dng t ng iu chnh tn s my pht v iu khin tua bin mi ch khc nhau, ng thi dng iu chnh cng sut hu cng t my . 1.1.3.2. Du p lc MHY: p lc lm vic ca du trong h thng iu chnh ng m cnh hng l: (40kg/cm2/4 My pht ) Bnh p lc ch cha mt lng du va iu khin h thng thy lc, th tch cn li c np y kh nn . Sau khi thc hin ng m du c a v ngn gia thng du x, ti y c b lc li, du t ngn gia i qua b lc v c kh bt khng kh trc khi n ngn sch chun b cho chu k. Trn ng ng dn kh p lc 40 kgf/cm2 ni vi bnh p lc MHY c lp van mt chiu, van ny dng ngn khng cho khng kh thot ra t bnh p lc . B iu chnh mc du dng t ng np b sung kh nn vo bnh p lc. Kh nn t h thng 40kg/cm2 qua van tay van mt chiu , b lc kh n b b iu chnh mc du vo bnh p lc ._____________________________________________________________________________ TRANG 5

1.1.3.1. Thit b thy lc:

1.1.3.3. H thng nc: 1.1.3.3.1. Nc lm mt t my. H thng nc lm mt c ly t bung xon qua van truyn ng in, van gim p ,qua h thng lc v van cp nc k thut a n b lm mt du, kh nh. hng turbine my pht. hng my pht. Lm mt gi my pht. 1.1.3.3.2. Nc lm mt my bin p chnh. Nc lm mt my bin p chnh c ly qua ng ng nc cu ha ti 21,9m qua lc v a vo b lm mt du. Khi ng mch my bin th ng thi my bm du tun hon cng t ng ng mch. Nc c a vo b lm mt du ngay sau khi my bm du khi ng. 1.1.3.3.3. Nc cu ha. H thng nc cu ha c ly t 2 ng ng p lc H1 v H4 cao trnh 39,66m qua lc cha chy cho trm phn phi OPY, trm kh nn,kho, phn xng. Trn cc on ng ng c cc v tr ly nc cu ha ti ch. cu ha cho my bin p khi s c v hm cp, sn truyn ti, c ly qua 3 bm t ti cao trnh 1,15m h thng bm to thm p lc cho cha chy. Cc bm s c t ng lm vic khi bo v chnh ca my bin p lm vic. 1.1.3.4. Kh nn: vn hnh cc thit b bng p lc kh ti Cng ty c cc h thng kh nn nh sau: H thng kh nn bao gm: Trm kh nn chnh 40 . Trm kh nn b. Trm kh nn chnh c dng cho cho cc b phn sau: Bnh kh loi 40kgf/cm2 gm c 3 my nn cung cp cho MHY. Bnh kh loi 8kgf/cm2 dng cho o lng, phanh hm . Trm kh nn b c dng cho ch chy b my pht v np kh b sung qua van cu.

_____________________________________________________________________________ TRANG 6

1.2. 1.2.1.

Thit b v kt cu phn in chnh Cc thit b in chnh Cng ty c 4 t my pht c cng sut mi t my l 100MW cc t my c th lm vic 2 ch . Ch my pht. Ch my b. My pht in Turbine nc do Lin X ch to,loi CB3.1230/140-56TB4 trc ng kiu d c cc thng s k thut in sau. Thng s k thut: Cng sut biu kin Cng sut hu cng Trong ch b ng b Qmax = 80 MVAR Qmin = - 40 MVAR in p nh mc stator Dng in nh mc stator in p kch thch nh mc Dng in kch thch nh mc Dng kch thch khng ti Tn s H s cng sut Tc quay nh mc Lng tc S cc t : Us.m = 13,8 kV : Is.m = 4920 A : Ur.m = 340 V : Ir.m = 1200 A : Ir.0 = 670A : f = 50Hz : Cos = 0,85 : nm = 107,1 v/p : nLt = 230v/p : 56 cc : S = 117,6 MVA :P = 100 MW :

1.2.1.1. My pht in:G1.G4

H thng kch thch : Loi t kch bng Thyristor gm hai b chnh lu cu 3 pha ni song song vi nhau, c gc kch t 0o n 150o in . in tr 1 chiu cun dy kch t +15oC l : 0,196 in tr 1 chiu mt pha stator +15oC l in dung mt pha stator i vi my pht in khng :_____________________________________________________________________________ TRANG 7

: 0,0044 : 0,93 F

S ni dy stator: Hnh sao, trung tnh c t bin th kim tra in p Dng in in dung khi mt pha chm t stator : 7A

Dc trc Ngang trc

: xd = 87% ; xd = 27% ; xd = 18% : xq = 58% ; xq = 19%

Th t nghch : x2 = 18,5% Th t khng : xo = 4,6% H s qu ti tnh : 2,5 Momen qun tnh Rotor my pht : 35x 107 kg.m2 ng knh trong stator : 11,6m Chiu cao li t : 1,41m 1.2.1.2. My bin p tng p:T1T4 My bin p chnh c nhim v tng in p my pht t 13,8kV ln 220kV truyn ti v kt ni vi h thng in. My bin p loi T-125000/220 T, 3 pha, 2 cun dy vi cc thng s k thut sau. Thng s k thut : Cng sut biu kin nh mc : Sm = 125 000kVA. in p nh mc : Cao th : UmCA= 242kV. H th : UmHT= 13,8kV. Dng in nh mc: Cao th : ImCA= 299A . H th : ImHT= 5220A. C b iu chnh in th khi my bin p khng ti . Gii hn iu chnh in th :2x2,5% in p tng ng vi cc nc iu chnh: 229,9kV ; 235,95kV ; 242kV ; 248,05kV ; 254,1kV. Tn s T u dy in p ngn mch Dng in khng ti Tn hao ngn mch Tn hao khng ti : 50Hz : Y0 /-11. : Un% = 11 ( 10%) : I0% = 0,55 ( 30%) : Pn = 380kW ( 10%) : P0 = 120kW ( 15%)

Ch lm vic ca trung tnh : Ni t trc tip .

My c lm mt bng h thng du nc loi ( lm mt tun_____________________________________________________________________________ TRANG 8

hon bng cng bc du v nc). Nhit lm mt Lng du trong my bin p : < 330C . : 38 tn

Cc my bin th c t sn cc my bin dng pha in p cao v u ra trung tnh. 1.2.1.3. My ct 13,8KV: 501.504 ng ct, kt ni v c lp my pht vi h thng c s dng my ct u cc ni gia my bin p chnh v my pht. My ct c cc thng s k thut in sau. Thng s k thut: My ct kh SF6 ca hng AlSTOM loi FKG22S. in p nh mc Dng in nh mc : : Um = 24kV. Im = 6300A Ict m= 63kA. Ud = 60KV. tc = 0,029 0,039s t = 0,1 0,115s : : > 10s

Dng in ct nh mc : in p chu ng tn s ngun : B truyn ng ng ct 3 pha. Thi gian ct ca my ct Thi gian tch nng p lc kh nhit 200C : p lc nh mc : Thi gian ng ca my ct :

0,Mpa (7,5kgf/cm2) 0,64Mpa (6,4kgf/cm2) 0,62Mpa (6,2kgf/cm2)

p lc bo tn hiu : p lc kha my ct : 1.2.1.4. My ct 220kV:231234

kt ni gia my bin p chnh v h thng thanh ci 220KV thng qua my ct SF6 , thng s k thut nh sau: My ct loi :LTB245E1 in p nh mc Dng in nh mc Tn s 50Hz B truyn ng ng ct tng pha. Thi gian ct ca my ct : tc = 0,015 0,019s_____________________________________________________________________________ TRANG 9

:Um = 245kV :Im = 4000A

Dng in ct nh mc :Ict m = 40kA

Thi gian ng ca my ct: t < 0,8s p lc kh nhit 200C : p lc kh SF6 nh mc: 0,7Mpa (7kgf/cm2) p lc kh SF6 thp bo tn hiu: 0,62Mpa (6,2kgf/cm2) p lc kh SF6 thp kha mch thao tc: 0,6 Mpa (6kgf/cm2) 1.2.1.5. My bin p t ngu: c cp in p ph hp vi cc ngun ph ti, nh my c trm phn phi ngoi tri OPY 110kV cp in p ny c kt ni vi trm phn phi OPY 220KV bng hai my bin p t ngu 8T v 9T. 1.2.1.5.1. My bin p t ngu: 8T My bin p t ngu do Lin X ch to loi AT 63000/220/110/6,3 85T, 3 pha ,3 cun dy. My c h thng lm mt ( du tun hon cng bc gi ) cc thng s k thut sau. Thng s k thut: Cng sut biu kin nh mc in p nh mc Cao th H th : UmC = 230kV : UmH = 6,3kV : Trung th : UmT = 121kV Dng in nh mc Cao th : ImC = 158A Trung th : ImT =268 301 -342 (A) H th Tn s T u dy: Y0/ --11 Bin iu chnh in p di ti: 8 x 1,5% in p ngn mch :+ UN(C-T) = 11% UN(T-H) = 22% UN(C-H) = 36% Tn hao: Tn hao ngn mch Pn =215 kW Tn hao khng ti P0 = 45 kW_____________________________________________________________________________ TRANG 10

: Sm = 63000/ 63000/ 32000kVA :

: ImH = 6,3KV : f = 50Hz

Dng in khng ti :I0 = 0,5% 1.2.1.5.2. My bin p t ngu: 9T My bin p do hng ABB ch to, loi KTRT 245X46 Thng s k thut: Pha,3 cun dy. Sm = 63 000/ 63 000/ 32 000 kVA. Um= 230 / 121 / 6,3 KV. Dng in nh mc Cao th : ImC = 158A Trung th : ImT =268 301 -342 (A) H th Tn s in p ngn mch (%) : UN(C-T) = 11,7 10,7 10,7 UN(T-H) = 20,9 23,8 - 28,2 UN(C-H) = 31,1 Tn tht ngn mch (kW): PN(C-T) = 100,42 112,76 179,56 PN(T-H) = 105,28 115,32 136,29 PN(C-H) = 94,58 Tn tht khng ti (kW) : P0 = 21,57 Dng in khng ti (%): I0 = 0,11 T u dy: Y0TN / -0-11 . B iu chnh di ti : 121 8x 1,5% Kiu h thng lm mt: ONAN/ONAF 1.2.1.6. My ct 220KV: Dng cho ngn l 9T (MC239) thng s k thut nh sau : My ct loi LTB245E1 in p nh mc Dng in nh mc Tn s 50Hz_____________________________________________________________________________ TRANG 11

:

: ImH = 6,3kV : f = 50Hz

:Um = 245kV :Im = 4000A

Dng in ct nh mc :Ict m = 40kA

B truyn ng ng ct tng pha. Thi gian ct ca my ct : tc = 0,015 0,019 s Thi gian ng ca my ct: t < 0,8 s p lc kh nhit 200C : p lc kh SF6 nh mc: 0,7Mpa (7kgf/cm2) p lc kh SF6 thp bo tn hiu: 0,62Mpa (6,2kgf/cm2) p lc kh SF6 thp kha mch thao tc: 0,6 Mpa (6kgf/cm2) 1.2.1.7. My ct 110kV: i vi trm OPY 110kV u c s dng my ct kh SF6,ca hng ALSTOM loi F1/4031/VR v ABB loi LTB 145D1/B Cc thng s k thut i vi my ct ny nh sau: Um= 123kV. Im = 3150 A Ict m = 31,5 kA fm = 50/60 HZ C cu truyn ng ng ct 3 pha. Thi gian ct: tc = 0,019 0,025s Thi gian ng: t 0,04s p lc kh nhit 200C : p lc kh SF6 nh mc: 0,7Mpa (7kgf/cm2) p lc kh SF6 thp bo tn hiu: 0,62Mpa (6,2kgf/cm2) p lc kh SF6 thp kha mch thao tc: 0,6Mpa (6kgf/cm2) Thi gian ct ca cc my ct l 171,138,100B,100A nh sau. Thi gian ct: tc = 0,04s 10% Thi gian ng: t =0,085 s 10% 1.2.2. Kt cu phn in chnh Trm phn phi ngoi tri 220kV v 110kV. 1.2.2.1.1. Trm OPY 220kV: Trm phn phi ngoi tri 220kV c thit k vi 2 h thng thanh gp c thanh gp vng, m bo tin cy cung cp in cao. Trm c 5 ngn l ra ng dy. Trong :_____________________________________________________________________________ TRANG 12

1.2.2.1. S ni in

1 ngn l tuyn ng dy Bnh Ha 1 (273). 1 ngn l tuyn ng dy Bnh Ha 2 (272). 1 ngn l tuyn ng dy Long Bnh (271). 2 ngn ang d phng. Cc ngn khc ca trm dng cho khi t my, my ct kt gin, my ct vng v my bin p t ngu. 1.2.2.1.2. Trm OPY 110KV: Trm phn phi ngoi tri 110kV c thit k vi h thng hai thanh gp c thanh gp vng. Trm c 6 ngn l ra ng dy. Trong : 1 ngn l tuyn ng dy Ph Gio (171). 1 ngn l tuyn ng dy Thnh Ph (172). 1 ngn l tuyn ng dy Kim Tn (176). 1 ngn l tuyn ng dy Tn Ha (173). 2 ngn d phng (174 v 175). Trm kt ni vi h thng thanh gp 220kV bng 2 my bin p t ngu 8T v my bin p t ngu 9T. 1.2.2.1.3. Trm KPYII- 6kV: Trm phn phi trong nh KPYII -6kV c thit k vi mt h thng thanh gp c my ct phn on, ngun ny c ly t cun h p ca my bin p t ngu ,dng ch yu cung cp cho ti a phng. 1.2.3. H thng in t dng Tt c h thng t dng ca Cng ty c ly t 3 my bin p t dng TD1,TD2,TD3 c t cao trnh 23m pha thng lu cng vi my bin p chnh. My bin p t dng c nhim v h in p t 13,8kV xung 6,3kV kt vi trm phn phi KPYI -6kV c lp t ti cao trnh 9,8m. Cc thng s k thut chnh ca my bin p t dng: TD1TD3 My bin p loi TMH 4000/35-TI, 3 pha, 2 cun dy. Sm = 4000kVA Um = 13,8/6,3kV Im SC = 167,3A Im TC = 366,6A_____________________________________________________________________________ TRANG 13

1.2.3.1. Ngun xoay chiu

f = 50Hz T u dy: Y/ -11 Gii hn iu chnh in p di ti: 6 x 1,5% in p ngn mch : UN = 7,5% Tn hao: Tn hao ngn mch Pn =33,5kW Tn hao khng ti P0 = 5,6kW Dng in khng ti :I0 = 1,0% Trm KPY I -6kV c thit k theo dng hp b, lp t trong nh vi mt h thng thanh gp c my ct phn on. Trm c kt ni vi 3 my bin p t dng 13,8/6 kV thng qua 4 my ct 6kV. My bin p TD1 c kt ni ti phn on II qua my ct s 41, my bin p TD3 c kt ni ti phn on I qua my ct s 7, my bin p TD2 c kt ni ti c 2 phn on I v II qua 2 my ct s 19 v 29. Trn mi phn on 6KV c cc my ct u ra c kt ni ti cc my bin p cung cp trm t dng 0,4kV. Cc trm t dng 0,4kV trong Cng ty c cung cp t 2 my bin p 6/0,4kV cho 2 phn on. Cc ngun ph ti t dng 0,4kV bao gm cc trm sau: T dng 4 t my, t dng chung, sn lp rp, trm bm tho kh, trm kh nn, ta nh hnh chnh, p trn. Cc ngun ph ti 0,4kV xa nh p trn v trm bm, chiu sng khu c x, kho xng c truyn ti bng tuyn ng dy trn khng 6kV. 1.2.3.2. H thng in mt chiu H thng in mt chiu ca Cng ty gm c hai cm bnh c quy loi ch pha nc. Mt cm c t phng iu hnh trung tm Cng ty v mt cm c t trong nh iu khin M - 220kV, h thng in mt chiu lm vic ch ph np thng xuyn. Mi cm bnh c qui c kt ni vi mt h thng thanh gp, phn thnh hai phn on. Hai phn on c kt ni vi nhau bng dao cch ly.Trn mi thanh gp c gn thit b ph np thng xuyn t b chnh lu. H thng c quy bao gm 108 phn t, mi phn t c sut in ng 2,15V, sut in ng ton b l 230V DC. Tng dung lng mi cm l 630Ah. Tt c cc ph ti dng in mt chiu c ly t bng in nh sau: Bng in DC M 220kV: dng cung cp cho cc ph ti ngun ng lc thao tc my ct 6KV,my ct 110KV v my ct 220kV .Dng cho mch iu khin my ct ,mch tn hiu v mch bo v ca trm 220KV, 110kV KPY-II 6kV. Bng in DC trung tm: dng cung cp cho cc mch ng lc v thao tc my ct 13,8 kV, my ct 6KV trm KPY I, my ct 0,4 kV trm t_____________________________________________________________________________ TRANG 14

dng. Ngoi ra cn cung cp cho cc ph ti chiu sng s c ,thng tin lin lc ..v.v.. T bng in trung tm h thng DC c cung cp cho cc t my thng qua 2 khi : Khi 1 : Dng cung cp cho cc ph ti mch bo v, iu khin, tn hiu, chiu sng t my H1 v H2. Khi 2 : Dng cung cp cho cc ph ti mch bo v, iu khin, tn hiu, chiu sng t my H3 v H4. Trn mi thanh ci ca mi khi u c ng h kim tra cch in, v in p thanh ci. 1.2.4. H thng iu khin v t ng T phng iu khin trung tm thc hin iu khin t xa cc t my thy lc v cc my ct 220kV ,110kV ,kim tra ch lm vic tt c cc phn t chnh v ch lm vic ca Cng ty ni chung. o lng v kim tra cc phn t thit b in chnh trong Cng ty nh : o dng stato, roto, cng sut P,Q my pht, o dng pha cao p my bin p chnh. Dng v cng sut P, Q tt c cc tuyn ng dy, my ct vng, o in p v tn s trn mi thanh ci , o dng my ct phn on. 1.2.4.2. iu khin v t ng t my S iu khin m bo t ng ha hon ton tt c cc ch lm vic ca tua bin v my pht c thc hin nh sau: Kim tra thng xuyn s sn sng lm vic ca cc t my. Khi ng t my bnh thng, ha ng b my pht vo li, bng phng php ha ng b chnh xc. Chuyn t my vo ch b ng b v ngc li. Dng t ng bnh thng t my. Dng s c t ng k c khi ang chy ch b. 1.2.4.3. iu khin cc thit b ph tr Trong Cng ty s c thc hin t ng ha cc thit b khc nhau: Trm kh nn p lc cao v p lc thp , trm bm tho kh , trm cu ha, thit b ng ng tiu thot nc, h thng thng gi. lm vic m bo tin cy. Mc t ng ha cao,c thu thp thng tin v trng thi ca thit b. Pht tn hiu v bo ng s c n cc t iu khin ti ch v truyn tn hiu s c n trung tm iu hnh. 1.2.4.1. iu khin tn hiu v o lng

_____________________________________________________________________________ TRANG 15

1.2.4.4. Tn hiu trung tm H thng bo tn hiu m thanh v tn hiu nh sng . Tn hiu m thanh bo s c bo ng bng ci v chung t ti phng iu khin trung tm v gian my, cc t iu khin ca khi t my cao trnh 9,98m. Ngt tn hiu m thanh c th thc hin bng tay hay t ng c mc duy tr thi gian. S bo tn hiu bao gm cc thnh phn: Cc my pht in v my bin p khi. Cc my bin p t dng 13,8/6,3kV. Thit b phn phi ngoi tri 220kV-110kV v t ng chng s c. Cc thit b ton Cng ty. 1.2.4.5. Bo v rle ca cc thit b in chnh Bo v cc thit b in chnh trong Cng ty. My pht in. My bin p chnh tng p 13,8/220kV. on ni my bin p vi thanh ci 220kV. H thng thanh ci 220kV. Cc tuyn ng dy 220kV. My bin p t ngu 220/110/6,3kV. H thng thanh ci 110kV. Cc tuyn ng dy 110kV. My bin p t dng 13,8/6,3kV Cc ph ti my bin p 6,3/ 04kV. Ngun t dng 0,4kV. Cc khi bo v my ct tuyn ng dy, my ct phn on, my ct vng ca trm 220kV v 110 kV cng nh l 9T mi a vo c thay th bng rle bo v k thut s .Cn li cc rle bo v cho thit b khc c dng rle in t. 1.2.4.6. Bo v chng st v ni t cho nh my 1.2.4.6.1. Chng st: Bo v chng st qu in p lan truyn bng cc chng st van. Cc chng st van c t u vo v u ra ca my bin p chnh, t ngu, thanh ci ..v.v. Bao gm cc chng st van v v tr lp t nh sau: Chng st van 13,8kV c t pha cun h ca my bin p chnh_____________________________________________________________________________ TRANG 16

chng qu p cho cc thit b nh my pht , my bin p t dng 13,8kV, my bin p TE v cc thit b TV,TI ni trn mng 13,8kV. Chng st van 220kV c t pha cun cao ca my bin p chnh chng qu p cho my bin chnh. Chng st van 220kV,110kV c t trn 2 thanh ci TC1 v TC2 chng qu p cho cc thit b TU, TI ni trn thanh ci. Chng st van 220kV,110kV c t pha cun cao v cun h ca my bin p t ngu 8T v 9T chng qu p cho my bin p. Ngoi ra cn c cc chng st van 6kV c t u vo v trn cc phn on. Bo v st nh trc tip bng cc kim v dy thu st. Cc kim v dy thu st c t trn cc ct , x thanh ci v cc cng vo ca cc tuyn ng dy,ct chiu sng sn c ca trm phn phi. 1.2.4.6.2. Ni t: c thc hin ni t t nhin v ni t nhn to: Cc h thng ni t ca ton Cng ty v trm bin p khng vt qu 0,5. 1.3. QUY TRNH SN XUT IN NNG Cng ty thy in Tr An l nh my pht in vi ngun nguyn liu chnh l nc, cng sut cung cp cho ngun in quc gia l 400 MW. Ngoi ra cng ty cn c th hot ng ch b ng b, c kh nng nhn cng sut phn khng t li v vi gi tr ti a l 43 Mvar/my. Lc ny my pht hot ng ch ng c ng b tiu th cng sut t li l 2 MW. My pht cng c th pht cng sut phn khng ln li ti a l 80 Mvar/my ty theo c tnh lm vic ca my pht. Ch hot ng ca Cng ty tun th theo lnh ca Trung tm iu h thng in min Nam v trung tm iu quc gia. Quy trnh sn xut in nng ca Cng ty c thc hin nh sau: Nc c d tr ti h chnh v dn ti h ph thng qua mt on knh o, h ph ng vai tr knh dn. Cui h ph l cc ca nhn nc a nc t h ph vo ng ng p lc. Cc ca nhn nc c ng m bng cc ca van phng.Cc ca van ny nng h c nh vo b nng thy lc. Ngoi ra trnh rc ni v c rc chm Cng ty cn trang b thm li chn rc . T ca nhn nc c 4 ng ng dn nc vo turbine to thnh mt kt cu thng nht. on u ng ng c nghing nh, on sau nghing tng t ngt lm tng p lc nc lm quay cnh turbine dn n lm quay cc phn quay ca h thng t my. T my thy in bao gm phn lin kt turbine vi my pht c cng h thng cc phn quay, cng trc ng v cc gi . Nhim v ca Cng ty thy in l chuyn thy nng thnh in nng._____________________________________________________________________________ TRANG 17

Cc thit b ch yu phc v cho quy trnh sn xut in nng: Cc thit b thy lc chnh: Turbine v h thng iu tc, my pht v h thng kch t. Cc thit b thy lc ph: Cc h thng m bo s lm vic ca cc t my thy in v cc thit b nng lng khc: cp nc k thut, kho du, trm cha kh nn v cc h thng khc. Cc thit b c kh: Ca nhn nc v b nng thy lc, li chn rc, cc b phn lp t ca chng v cc my khc. Cc thit b in: Cc my bin th, thit b chuyn mch nh my ct, dao cch ly,cc h thng bo v, t ng, iu khin, thng tin lin lc in nng ta thu c ti u cc my pht vi in p 13,8 kV, qua thit b chuyn mch n my bin th tng p ln 220 kV v c truyn ti trm phn phi ngoi tri. Ti y in nng ny s c ha vo li in quc gia,truyn ti ti cc h tiu dng v sn xut thng qua cc tuyn ng dy: ng dy 220 kV: Tr An - Long Bnh (271) Tr An - Bnh Ha 1 (273) Tr An - Bnh Ha 2 (272). ng dy 110 kV: Tr An - Ph Gio (171) Tr An - Thnh Ph (173) Tr An - nh Qun (176) Tr An - Tn Ha (172). Ngoi ra cung cp cho ph ti a phng thng qua 2 ng dy 6 kV n trm 6/15 kV Hiu Lim (trm 15KV).

_____________________________________________________________________________ TRANG 18

CHNG 2 H THNG KCH T

_____________________________________________________________________________ TRANG 19

2.1.

GII THIU CHUNG H thng kch t Tr An l h thng kch t t kch song song , ngun kch t ban u ly t t dng t my v ngun mt chiu t h thng accu ca Cng ty Tr an, h thng kch t to ra dng in mt chiu iu chnh c kch thch my in ng b, to ra dng mt chiu m iu chnh c ngi ta dng hai b cu chnh lu ba pha thyristor lm vic song song, s ng lc h thng kch t Tr An nh hnh 2-1. Cung cp hai b chnh lu thyristor t bin p TE ni vo u cc stator ca my pht c kch thch. to xung kch cho thyristor nh cc b to xung AV-1 v AV-2, thc hin qu trnh iu chnh nh b iu chnh t ng AVM , b iu chnh d phng bng tay AVN v s r le. Bo v cho cc b chnh lu v rotor khi qu in p nh b phng in FV tc ng nhiu ln. Dp t my pht trong ch s c dng my ct dp t QAE. Khi b iu chnh AVM h hng s chuyn t ng h thng iu chnh kch thch sang b d phng AVN v gi nguyn ch kch thch xc lp trc . S nht th v s iu khin c thc hin sao cho khi cn thit c th a mt b chnh lu thyristor ra sa cha m khng cn phi ct h thng kch thch.

2.2.

THNG S K THUT CA H THNG KCH T THNG S in p nh mc (v) Dng in nh mc (A) Cng sut nh mc (kW) in p kch thch gii hn (v) Dng in kch thch gii hn (A) Gi tr kch thch theo in p, n v tng i khi in p cung cp nh mc khi 80% in p cung cp nh mc Gi tr nh theo dng kch thch, n v tng i Cng sut cng hnh(kW) Thi gian cng hnh kch thch(s) S tc ng nhanh khi cng hnh kch thch(s) Tn s in p cung cp (Hz) S thay i cho php ca tn s in p cung cp lu di (Hz) ngn hn khng ln hn 50s(Hz) in p cung cp t dng tn s 50Hz NH MC 400 1600 640 910 2910 2.5 2.0 2 2650 50 0.05 50 +2 ; - 3 +40 ; -10 380 V

STT 1 2 3 4 5 6 7 8 9 10 11 12 13

_____________________________________________________________________________ TRANG 20

14

thay i cho php ca in p t dng 50 Hz(%) lu di. Ngn hn khong 1s. Ngn hn khong 50s

+10 ; -20 + 45 +15

15 16

17

in p t dng mt chiu(v) thay i cho php ca in p cung cp t dng t ngun mt chiu % Cng sut tiu th t dng khi in p nh mc (kW) T li 380V, 50Hz: ch chnh lu thyristor khng ti. ch chnh lu thyristor c ti. Ngn hn trong khong thi gian 15s khi kch thch ban u. T h thng DC 220V: Lu di. Ngn hn khi cng hnh kch thch. Ngn hn khi mt cng hnh kch thch Phm vi thay i gc iu chnh ( in) Hiu sut ( gi tr tnh ton) % n (dB) Kiu lm mt Nhit bnh thng ca mi trng Cng sut tiu th ca AVM (VA) Cng sut tiu th ca AVN (VA) Cng sut tiu th ca bin dng o lng (VA)

220 +10; -15

0.66 0.42 10 0.1 0.42 0.66 1 - 150 97 80 t nhin T 1 - 450C 5 5 5

20 21 22 23 24 25 26 27 2.3.

CC CH LM VIC CA H THNG KCH T Khi ng, kch thch ban u v ng vo li bng phng php ha chnh xc ( t ng hoc bng tay ) trong ch lm vic bnh thng ca li v bng phng php ha t ng b trong ch s c. Ch khng ti v hot ng ca my pht trong li vi ph ti t khng ti n ti nh mc, lm vic theo gii hn ca biu cng sut my pht cng nh khi qu ti theo ng tiu chun (OCT). Dng t my trong ch bnh thng v s c. Ch qu s c nh ngn mch, qu ti v ct ti.

Ch lm vic v cc thng s ca h thng kch thch my pht y khi cc nhnh lm vic song song v khi h hng mt mch trong nhnh cng tn bt k ca cc b chnh lu khi chng lm vic._____________________________________________________________________________ TRANG 21

Cng hnh kch thch theo mt bi s cho trc v ct kch t khi h hng trong li. Ct kch t v dp t khi dng bnh thng my pht bng cch chuyn b chnh lu sang ch nghch lu. Dp t trong ch s c bng my ct dp t. Dng kch thch khi my pht lm vic vi ti nh mc v h s cos = 1 trong trng hp h hng hai mch song song nhnh cng tn bt k ca cc b chnh lu c ni song song hoc l trong trng hp ct mt b chnh lu v b chnh lu cn li cn y cc mch song song. Lc ny phi t ng cm ch cng hnh. iu chnh dng kch thch theo lch v o hm in p, lch v o hm tn s, o hm dng kch thch. Thay i tri s t in p my pht trong gii hn t 80% n 110 %gi tr nh mc. Hn ch dng kch t hai ln nh mc v ng thi hn ch qu ti dng kch thch theo c tnh thi gian ph thuc. Hn ch dng kch thch cc tiu theo tr s t ph thuc vo tr s cng sut thc trong ch tiu th cng sut khng t li. khng. 2.4. Hot ng ca my pht trong ch iu chnh nhm cng sut

C IM CHNH Thc hin theo s t kch song song c bin p chnh lu. B chnh lu theo s cu 3 pha, gm hai b bin i i dng thyristor Thyristor lm mt t nhin B iu chnh t ng AVM dng iu khin bn dn hot ng iu chnh chnh, c khi d phng AVN m bo iu chnh in p khi ct b iu khin chnh Kch t ban u bng h thng mt chiu (accu) hoc xoay chiu t t dng ca Cng ty. B iu chnh tc ng nhanh.

2.5.

C TNH Gn nh, n gin, kinh t, tin cy vn hnh cao

2.6.

IU KHIN KCH T Nguyn l h thng kch thch: S mch lc kch t (hnh 2-1) H thng kch thch thc hin theo s t kch thch song song kiu mt nhm, c hai b chnh lu ni song song. Cung cp cho cc b chnh lu thyristor V1 v V2 t bin p chnh lu TE ni t u ra ca my pht c

_____________________________________________________________________________ TRANG 22

kch thch. ng ct b chnh lu V1 v V2 pha xoay chiu v mt chiu nh cc cu dao tng ng QS1, QS3 v QS2, QS4. Kch thch ban u cho my pht nh thit b kch thch ban u YHB c cung cp t t dng xoay chiu 380V ca nh my hoc t acquy. iu khin t ng v bng tay, bo v, tn hiu c thc hin nh b t ng iu chnh kch thch AVM, b iu chnh d phng AVN v s rle. H thng iu khin AV1 v AV2 c cp in t cc my bin p ring TL1 v TL2 v c m bo bng ngun d phng acquy. Cp in cho AVM ly t my bin p TL1, TL2 v ngun d phng acquy. Dp t trong ch s c nh ptmt dp t QAE. B bo v chm t rotor theo sng xung vung tn s 1-3 Hz (64R). Khi h hng AVM s chuyn t ng h thng iu chnh kch thch sang b AVN v gi nguyn ch kch thch xc lp trc . S mch lc kch t v s iu khin c thc hin sao cho khi cn thit c th a mt b chnh lu thyristor ra sa cha m khng cn phi ct h thng kch thch. 2.6.1.1. Qu trnh kch t ban u S khi kch t ban u nh hnh 2-2 Qu trnh kch t ban u c thc hin khi tc Rotor nRotor 95% nm, my ct 13,8 kV ang m, UMF < 50% Umv c lnh ng kch t t ng hoc bng tay. Khi ng kch t, rle KT1 s kim tra ngun t dng AC nh rle K23 (u tin ngun AC), in t dng AC c chnh lu 3 pha khng iu khin a vo cun dy Rotor; khi khng c ngun AC, rle K23 s tr v tc ng KM2 ng ngun DC t accu Cng ty vo Rotor thc hin kch t ban u vi dng kch t ban u khong 55A. Khi r le K57 s tc ng ng ngun d phng DC cho AV1, AV2, AVM v 2. Khi in p my pht UMF 50%Um, rle KV2 tc ng lm KT1 tr v ct qu trnh kch t ban u. Trong 3s u tin ca qu trnh kch t ban u, nu UMF 115% UMFm th rle KT2 s ct kch t ban u bo v qu p my pht. Nu sau 10s m UMF 82% UMFm, cc khi ngun d phng uc ct ra, b iu chnh AVM lm vic xc lp in p Stator. 2.6.1.2. iu chnh tr s t in p. Khi AVM lm vic, tr s t in p tham gia vo qu trnh iu chnh t ng gi in p my pht n nh; AVM c nhim v so snh Uli (TV14) v Umy pht (TV11) phc v cho vic ha t ng chnh xc t my vo li. - Trong qu trnh ha ng b t my, vi b AVM kch t cho php thc hin theo hai ch ha ng b t ng chnh xc hoc ch ha t ng b t_____________________________________________________________________________ TRANG 23

ng (hin khng s dng ), vi b AVN ch ha ng b bng tay. 2.6.1.2.1. Trong li Ch khng ti v hot ng ca my pht trong li vi ph ti t 0 n nh mc, lm vic theo gii hn ca biu cng sut my pht, cng nh khi qu ti theo tiu chun qui nh. T my hot ng trong li vi b iu chnh AVM, kch t c th thc hin c: Ch kch thch cng hnh vi dng rotor 2400A khi in p gim di 0,85Um v tr v khi in p tng n 0,98Um, ct kch thch khi h hng trong li. Ct kch thch hoc dp t khi dng bnh thng hoc s c. Hn ch dng rotor ty cc trng hp h hng khc nhau ca h thng kch t bng cc ch : - Gim IR n 0,97 IRm khi qu nhit rotor. - Gim IR n khi cos= 1 (Q = 0 ). - Ch OMB: hn ch dng kch thch cc tiu. - Ch cm cng hnh. Thc hin iu chnh kch t theo lch v o hm in p, lch v o hm tn s, o hm dng kch thch. Thay i t xa tr s t in p my pht trong gii hn t 80% n 110% Um. Khi s dng b iu chnh d phng AVN, ch c kh nng thay i mc hn ch dng rotor n IR = 0,75IRm ( trong cc ch cos = 1 ca b AVM ) ng thi b AVN ch thc hin iu chnh kch t theo lch U so vi in p t. 2.6.1.2.2. Dng my Khi dng bnh thng, rle K15 s tc ng i t gc dp t cho cc b bin i V1 v V2 lm vic ch nghch lu gii phng nng lng Rotor ngc v Stator.

_____________________________________________________________________________ TRANG 24

Cc ch lm vic khi h hng trong b bin i: 2.6.1.2.3. Ch cm cng hnh kch t: Xy ra khi: - H hng 1 b V1 hoc V2. - t 2 cu ch trong 2 nhnh cng tn. - Mt dn 1 nhnh ca V1 hoc V2 - R le K42 tc ng gim Q n khi khi OMB tc ng. Khi r le K50 s tc ng n mch cm tng cng kch t trong AVM. Ch gim kch thch n OMB tc ng: dng hn ch Q nhn t li v theo tr s cho php. Khi my pht nhn Q qu tr s cho php, OMB tc ng hn ch kch thch cc tiu, khng cho nhn Q na, lc ny my pht thiu kch thch. Gii tr r le K42 tc ng bng cch n nt SB2 (GCE5). Trng hp ny xy ra khi: - H hng 1 b bin i ng thi xy ra 1 trongcc trng hp sau y: - t 1 cu ch trong b cn li. - t 2 cu ch trong 2 nhnh cng tn ca b cn li. - Mt dn trong 1 nhnh ca b cn li. - Chy 3 cu ch trong 2 nhnh cng tn ca b cn li. - Mt dn 2 nhnh cng tn ca 2 b V1 v V2. Khi K42 tc ng s i gim kch t (K45 tc ng ), tr s t in p ca AVM s c gim cho n khi b hn ch kch thch cc tiu OMB tc ng. Lc ny kch t ang ch cm cng hnh (K50). 2.6.1.2.4. Ch cos = 1. Ch ny a Q v 0, khng cho tng gim kch t. Khi tng gim bng kha tc ng n r le K45, K46 nhng mch s t ko do r le K51. Xy ra trong cc trng hp: - H hng mt b V1 hoc V2. - Chy hai cu ch trong 2 nhnh cng tn. - Mt dn trong mt nhnh ca V1. - Mt dn trong mt nhnh ca V2. Khi ng rle K51 tc ng a lnh n b AVM, AVN gim gi tr t ca AVM, AVN lm gim cng sut Q n 0.

_____________________________________________________________________________ TRANG 25

2.7. 2.8.

BO V H THNG KCH T BO V MY BIN P KCH T 7SJ611(F32)

Rle 7SJ611 nhm 2 (-F32), 7SJ6115-5EB90-1FA0-L0S, v4.7.1Group No. 0214 0209 0276 0201 0280 0251A 0235A 0250A Group No. 0204 0205 0217 0218 Group No. 0210A 0211A 0212

Power System Data 1; Group Power System Settings Value Rated Frequency 50 Hz Phase Sequence L1 L2 L3 Unit of temperature measurement Degree Celsius CT Starpoint towards Line Holmgreen-conn. (for fast sum-iNO monit.) CT Connection IL1, IL2, IL3, (IE) Storage of th. Replicas w/o Power NO Supply Time Overcurrent with 2 phase OFF prot. Power System Data 1; Group CT's Settings Value CT Rated Primary Current 2000 A CT Rated Secondary Current 5A IE-CT rated primary current 2000 A IE-CT rated secondary current 5A Power System Data 1; Group Breaker Settings Value Minimum TRIP Command Duration 0.15 sec Maximum Close Command Duration 1.00 sec Closed Breaker Min. Current 0.20 A Threshold

Group All All All All A11 A11 All All Group All All All All Group All All All

Group Power System Data 2; Group General No. Settings Value 1102 Measurement: Full Scale Current 2000 A (100%) 1107 Motor Start Current (BLK OVL, Start 12.50A Mon.) Group No. 1201 1213A 1215A DMT / IDMT Phase/Earth Overcurrent; Group General Settings Value Phase Time Overcurrent ON Manual Close Mode Inactive Dropout Time Delay DMT Phase 0.00 sec

Group A A

Group A A A Group A A A A A A

Group DMT / IDMT Phase/Earth Overcurrent; Group DMT Ph No. Settings Value 1219A I>>> measurement of Fundamental component 1216A I>>> active Always 1217 I>>> Pickup 6.00 A 1218 T I>>> Time Delay 0.5 sec 1220A I>> measurement of Fundamental component 1214A I>> active Always

_____________________________________________________________________________ TRANG 26

1202 I>> Pickup 1203 T I>> Time Delay 1221A I> measurement of 1204 1205 I> Pickup T I> Time Delay

6.00 A 0.00 sec Fundamental component 3.30 A 12.00 sec Value ON

A A A A A Group A

Group Thermal Overload; Group General No. Settings 4201 Thermal Overload protection

Group No. 4202 4203 4204 4205 4207A 4208A

Thermal Overload; Group Therm Over Load Settings Value K- Factor 0.66 Time Constant 1.0 min Thermal Alarm Stage 90% Current Overload Alarm Setpoint 3.30A Kt-FACTOR when motor stops 1.0 Emergency time 100 sec

Group A A A A A A Group A Group A A

Group Measurement Supervision; Group General No. Settings Value 8101 Measurement Supervision ON Group No. 8104 8105 Measurement Supervision; Group MeasSupervision Settings Value Current Balance Monitor 2.50 A Balance Factor for Current Monitor 0.50

BO V MY BIN P KCH T 7SJ611 (F31) 2.9.Group No. 0214 0209 0276 0201 0280

Rle 7SJ611 nhm 1 (-F31), 7SJ6115-5EB90-1FA0-L0S, v4.7.1

Power System Data 1; Group Power System Settings Value Group Rated Frequency 50 Hz All Phase Sequence L1 L2 L3 All Unit of temperature measurement Degree Celsius All CT Starpoint towards Busbar All Holmgreen-conn. (for fast sum-iNO A11 monit.) 0251A CT Connection IL1, IL2, IL3, (IE) A11 0235A Storage of th. Replicas w/o Power NO All Supply 0250A Time Overcurrent with 2 phase OFF All prot. Group No. 0204 0205 0217 0218 Power System Data 1; Group CT's Settings CT Rated Primary Current CT Rated Secondary Current IE-CT rated primary current IE-CT rated secondary current 1; Group Breaker Value 400 A 5A 400 A 5A Group All All All All

Group Power System Data

_____________________________________________________________________________ TRANG 27

No. 0210A 0211A 0212

Settings Minimum TRIP Command Duration Maximum Close Command Duration Closed Breaker Min. Current Threshold

Value 0.15 sec 1.00 sec 0.20 A

Group All All All

Group Power System Data 2; Group General No. Settings Value 1102 Measurement: Full Scale Current 400 A (100%) Group DMT / IDMT Phase/Earth Overcurrent; Group General No. Settings Value 1201 Phase Time Overcurrent 1213A Manual Close Mode 1215A Dropout Time Delay DMT Phase ON I>> instantaneously 0.00 sec

Group A

Group A A A Group A A A A A A A A A A A Group A Group A A

Group DMT / IDMT Phase/Earth Overcurrent; Group DMT Ph No. Settings Value 1219A I>>> measurement of Fundamental component 1216A I>>> active Always 1217 I>>> Pickup Oo A 1218 T I>>> Time Delay 0.00 sec 1220A I>> measurement of Fundamental component 1214A I>> active Always 1202 I>> Pickup 30.20 A 1203 T I>> Time Delay 0.00 sec 1221A I> measurement of Fundamental component 1204 I> Pickup 2.00 A 1205 T I> Time Delay 0.50 sec Group Measurement Supervision; Group General No. Settings Value 8101 Measurement Supervision ON Group No. 8104 8105 Measurement Supervision; Group MeasSupervision Settings Value Current Balance Monitor 2.50 A Balance Factor for Current Monitor 0.50

2.9.1.

Bo v kch t

2.9.1.1. Bo v chng cng hnh kch t ko di 51E1: 2.9.1.1.1. Cu to: Dng rle loi PT 40/10, k hiu KA3. Ly tn hiu t bin dng TA1 (2000/5). 2.9.1.1.2. Nguyn nhn:_____________________________________________________________________________ TRANG 28

Do kch thch cng hnh ko di n thi gian tc ng. 2.9.1.1.3. Tr s tc ng:It = 1700A t1 = 60s t2 = 65s

2.9.1.1.4. Hng tc ng: Vi thi gian t1 = 60s, bo v gi tn hiu ti rle KT10 i ct AVM. Ko di n t2 = 65s, bo v gi tn hiu n u ra K43, rle K43 c tip im a n mch bo v d phng my pht cng tc ng: Ct MC 13,8kV, khi ng YPOB 13,8kV. Ct kch t. Ct QAE Dng s c t my 2.9.1.2. Bo v qu ti Rotor 51E2: 2.9.1.2.1. Cu to: Dng rle loi PT 40/10, k hiu: KA2. Ly tn hiu t bin dng TA1 (2000/5). 2.9.1.2.2. Nguyn nhn: Do h hng b gii hn cng hnh kch t ca b iu chnh AVM. Do ngn mch pha h p my bin p kch t hoc pha dng 1 chiu. 2.9.1.2.3. Tr s tc ng: It = 2252A t1 = 0s t2 = 1s. 2.9.1.2.4. Hng tc ng: Vi thi gian t1 = 0s tip im tc thi ca KT4, a tn hiu i ct b AVM. Ko di thi gian n 1s, bo v gi tn hiu u ra K43, rle K43 c tip im a n mch bo v d phng my pht cng tc ng: Ct MC 13,8kV, khi ng YPOB 13,8kV. Ct kch t. Ct QAE Dng s c t my 2.9.2. Bo v chm t rotor theo sng xung vung tn s 1-3 Hz (64R) : 2.9.2.1.1. Cu to: - Loi: 7UM6225-5EB91-0CG0-LOS v4.6 (Siemens)TRANG 29

_____________________________________________________________________________

- Chc nng: Bo v chm t rotor (64R,1-3 Hz). - Thit b pht xung vung tn s thp: 7XT71 (c cp bng ngun 1 chiu 220 VDC). - B chia in p 7XR6004 2.9.2.1.2. Nguyn l: y l bo v mi c a vo v thay cho ton b bn t my hin ang vn hnh n nh . Bo v chm t Rotor mi c a vo lm vic vi in p xung vung trc tip (Ug) xp x 50V, c tn s thay i cc tnh i xng t 1 4 ln/giy, ph thuc vo chnh nh. in p Ug c to ra t thit b 7XT71, qua b in tr 7XR6004 (hoc 7XR6003) v cp trc tip ti mch kch t ca rotor my pht, v ng thi c ni ti mch chi than - t (earthing brush in p so vi t) qua mt in khng nh RM. Hai in p iu khin Ucon v in p o pha t qua in khng UMeas c cp ti rle 7UM622 thng qua hai b tranducer TD1 & TD2, c dng so snh pht hin im chm t. in p iu khin Ucon t l vi in p xung vung trc tip Ug c v ln (50V) v tn s. Dng in np pha t (Ig) t b pht xung 7XT71 chy vo rotor qua mch rotor t, tng ng vi in p o phat UMeas.Hnh 2-3-2 Ti mi thi im khi cc tnh ca in p xung vung trc tip Ug i, dng in np Ig c chy qua b in tr (7XR6004) ti mch dung t ca h thng kch t my pht. Dng in Ig ny l nguyn nhn sinh ra in p o pha t UMeas. Ngay khi thnh phn dung dn gia rotor v t thay i (ngha l xut hin vic rotor chm t), dng in np Ig gim xung, vi ln ph thuc vo in tr chm t (c th ti 0 ) (hnh 2-3-1) Vic s dng sng xung vung tn s thp lm gim nh hng ca thnh phn dung dn trong mch rotor v ngn nga cc tn hiu nhiu t cc thit b khc vo h thng kch t.

_____________________________________________________________________________ TRANG 30

Hnh 2-3-2: Hnh dng ca in p xung vung Ug v dng in Ig, UMeas trong cc trng hp vn hnh bnh thng (RE=) v s c RE=5k)

- Khong chnh nh: 6101 Rotor Earth Fault Protection (1-3Hz) ONTRANG 31

_____________________________________________________________________________

OFF Block relay 6102 Pickup Value of Warning Stage Re< 5.0..80.0 kOhm 6103 Pickup Value of Tripping Stage Re 30V( tr s t bo v) th U4 < U5 (D3) U10 dng, nh thng V36 lm V33 m. R40, R38, R36 b ni tt qua V33 lm V32 tt, b n p xung tt, n H1 tt. * Bo v tng in p ngun vo: Lm vic ca bo v ny da trn Zener V35. Khi in p vo tng cao nh thng V35 lm V33 h v tng t nh trn b n p xung ct. Tr s t ca ca bo v ny tng ng vi U ngun vo bng 1,3Um tc 1,3 x 380V = 494V. Ngoi ra trong cn c mch lin ng chng s lm vic sai ca D3. Khi ng ngun cho mch gm C17, transitor trng V38, v transistor V37. Khi ng ngun, C17 np in, lm V38 ngt, cn V37 m, ko u ra D3 xung m trnh tc ng sai ca D3. Sau C17 np y, V38 m v V37 ngt.

5.3.2.

Khi ngun d phng P/A11: Khi P dng cp in cho AVM, khi khi ng v dng, cng nh khi gim in p ca t dng h thng kch t nh hn hoc bng 80% U nh mc hay khi h hng khi ngun chnh . Khi ny cng to ra ngun n p mt chiu 12,6V v 6,5V, ngun cung cp cho khi ny ly t h thng accu nh my, ngun ny s lm vic khi ngun cung cp cho khi ngun chnh gim ti 0,8Um hoc khi h hng khi ngun chnh. 57

Khi ny lun lm vic v bin in p 220VDC t h thng accu thnh in p 35VDC. u ra mch 12,6V mch 12,6V ca qua 2 diode VD31 & VD34. Vi cch mc nh vy, khi Ura < Ura P cng nh khi b ct th 2 diode trn s dn, AVM c cp ngun t Ura P lc ny n H2 ca P sng. n H2 tt khi in p phc hi mc bnh thng. 5.3.2.1. Thnh phn ca P 1. 2. 3. 4. 5. B bin i in p n p xung B phn p t ng B n p 6,5V Mch hn ch ti

5.3.2.2. Nguyn l hot ng 5.3.2.2.1. B bin i in p Nhn ngun mt chiu 220V t h thng in mt chiu bin i thnh in p mt chiu khong 40V. B bin i gm b pht xung theo kiu hi tip bin p gm: UJT, VT5, Transistor VT7, VT8 cc bin p T1 v T2. UJT, VT5 dao ng to xung kch ban u cho mch pht xung khi khi ng. Sau theo mch hi tip qua bin p T1 (cun 9 10) v T2, VT7 v VT8 thay phin nhau dn, to ra xung c tn s khong 26kHz. Qua bin p T2 v chnh lu VD3, VD4 to ra in p mt chiu khong 35V. 5.3.2.2.2. Cc b n p xung b phn p v b n p in p 6,5V v mch hn ch ti trong P lm vic 5.3.2.2.3. Mch hn ch ti (5) Khi tng dng ti, in p ri trn R9 R56 tng, n khi m V14 v V13, theo mch V20 v R19, lm U4(D1) tng, do in p ra ti D1 = 0 ng vi gi tr U25,2 nh hn, lm cho dng ti b hn ch. Khi ngn mch trong ti, V14 m do in p theo dng R14 v R15, lm V13 m, tng t nh trn qu trnh tch thot nng lng trn L1 s din ra vi dng ph ti nh hn. Tr s t ca bo v qu ti l 0,8 1A. 5.3.3. Khi khuch i Y/A8 : Khi Y cng tt c cc tn hiu iu chnh, khuch i v truyn tn hiu n h thng iu khin Thyristor. Cc tnh ca Y ph hp vi cc tnh ca tn hiu vo. u ra ca Y chnh l u ra ca AVM. u vo khi khuch i gm: 58

- Tn hiu o hm in p t khi in p. - Tn hiu lch in p t khi in p. - Tn hiu o hm dng rotor t khi dng in. - in p ra ca khi cng hnh. - Tn hiu lch tn s t khi tn s. - Tn hiu o hm tn s t khi tn s. u ra khi khuych i (cng l u ra AVM) a ti h thng iu khin thyristor, cn a ti khi kim tra h hng AVM v khi ngun c th o in p ra ca AVM trong qu trnh vn hnh nh ng h gn trn khi ngun .

H

YH

T

y3

Y

AV 5.3.3.1. Thnh phn ca Y B ly tng D1

K

My pht sng mang (V10, V31, C7, R22, T1) B iu bin (V5 V8) B khuch i in p kiu vi sai B khuch i cng sut kiu y ko (V14, 17, 18, 21, 22) B gii iu ch tch sng nhy pha (V19, 20, 23, 24) Cc bin p cch ly (T1, T2); Lc C19, 22, R45, cc rle K1, K2 5.3.3.2. Nguyn l hot ng Khi Y thc cht l b khuch i in p mt chiu, c thit k sao cho trong khong in p lm vic 20V vi ti 800, m bo c tuyn tnh. B tng D1: Cng tt c cc tn hiu iu chnh v c o du. in p mt chiu u ra D1 c iu bin thnh in p ch nht. thc hin vic iu bin, cc transistor V5 V8 c iu khin bi b pht sng mang, in p iu bin t cun 6-7-8 ca T1 a n V5 V8. Tn s iu bin khong 5KHz (xc nh bi C7 v R20) Tn hiu u ra b iu bin (C8, C10) l 2 trang in p ch nht ngc pha 59

nhau. Qua D3, hai tn hiu c ly tng D4. Do cch mc ca s D4. Tn hiu ra D4 l nhn i. D5 mc theo kiu vi sai, a tn hiu vo b khuch i cng sut kiu y ko. Tn hiu ra b khuch i cng sut c gii iu ch, bi b tch sng nhy pha. B tch sng cng c iu khin bi 2 xung ngc cc tnh nhau, ly t b pht sng mang. Tn hiu ra c lc bi C22, L1, C19 l 1 chiu. m bo tuyn tnh nh nu trn, thc hin hi tip m su qua R19. K1 dng ni tt u ra AVM khi ha t ng b. K2 dng ni tt u vo Y (b iu bin). K2 ng khi K18 ct. in p ra Y UA c a vo o c, a vo K kim tra s lm vic ca AVM, in p ny cn c a n AVN thc hin vic theo di AVM t AVN. c tnh ca Y c cho trn hnh 5-4-1.

60

K h i k h u c h i U ra = f(U v o )UX V20 18 16 14 12 10 8 6 4 4 3 2 1 2 2 1 2 3 4 -2 -4 -6 -8 3

UX V

UX V

2

UX V

3

Hnh 5-4-1 : c tnh ca khi

5.3.4.

Khi t trc in p - YH /A2: 61

Khi YH dng thay i tr s t trc ca in p my pht. Phn t chnh ca YH l mch nh lu Thay i tr s t l thay i in p trn t nh, khi c cc lnh u vo khi YH. u vo khi t trc in p gm: - Lnh thay i tr s t v pha ln hn ti ch hoc t xa. - Lnh thay i tr s t v pha nh hn ti ch hoc t xa. - Lnh iu chnh nh t ng tr s t in p t khi ha ng b. - Lnh gim ti v cng my pht. u ra ca khi t trc in p a n khi in p. 5.3.4.1. Thnh phn ca YH Thit b thay i tr s t: T nh C2, cc Transistor trng V4, V5, vi mch D2, rle K2, vi mch D3 v phn t chng tc ng sai ca khi khi kch t ban u. Thit b thay i tr s t khi ha ng b v gim cng sut v cng khi cm tng cng v khi dng my: vi mch D6. Thit b bo hiu: V17, V18, n H1, H2. 5.3.4.2. Nguyn l hot ng ch ban u, u vo ca D2 c cn bng bi R28, U10 D2 = 0. Khi c lnh thay i tr s t, ti u vo D3 xut hin cc tnh dng, rle K2 ng, ni u vo YH vi t nh C2. Tu thuc vo cc tnh ca tn hiu a vo t C2 m n c t in p m hoc dng. Thay i tr s t trn t C2 c din ra cho n khi khng cn tn hiu u vo t C2. in p ra D2 tng ng vi in p trn t C2. y chnh l in p ra ca khi YH. Sau khi h mch K2, in p trn t C2 c gi khng i cho n khi c lch tip theo u vo YH. Gi tr gii hn ca tr s t trc c bo bi H1, H2. 1. 2. H1 n max Uy m cc i H2 n min Uy dng cc i

Uy: in p tr s t - K46, K45 l kha tng, gim tr s t t xa - , M l kha tng, gim tr s t ti ch. - Cc u vo theo 5A, c rle K51 l lnh gim ti v cng khi cm tng cng v rle K58 lnh gim ti v cng khi c lnh dng my. Khi c lnh gim ti v cng, u vo o D6 ni vi PT1, tn hiu t PT1 lm cho u ra D6 m, qua R5 tip im K2 ni vi t C2. Kch thch my pht gim cho n khi tn hiu u ra PT1 = 0. Tc l khi cng sut v cng bng khng. 62

Lnh iu chnh tr s t khi ha ng b, c thc hin da trn hiu UR-UC t YH. Hiu s ny qua R84 vo u khng o D6. Ty thuc vo du ca tn hiu ny m tr s t thay i v hng tng hay gim lm tng hay gim kch thch my pht cho n khi UR-UC = 0.

5.3.5.

Khi in p H/A3 : Khi H dng o lng in p my pht, to ra tn hiu lch in p my pht khi tr s t trc: U v tn hiu U u vo khi in p gm cc tn hiu sau: - in p phn cc (in p ta), xc nh in p t trc ca my pht.

63

- in p my pht so snh vi in p ta, in p ly t my pht qua cc my bin p trung gian. - in p ra ca khi tr s t in p. - in p ra ca khi dng khng. - in p ra ca khi gii hn dng kch thch cc tiu. in p ra khi in p cung cp cho: - Khi khuch i ly tng vi cc tn hiu khc v khuch i. - Khi ngun kim tra s hot ng ca khi in p. - Khi cng hnh, khi ha ng b v khi kim tra cho s hot ng ca chng. 5.3.5.1. Thnh phn khi H a. B ly tng in p D3 b. Knh o lng c qun tnh, lch in p my pht (o lng in p my pht) D8, D9 c. Knh o lng khng qun tnh, o lng in my pht: D1, D2, D6, cc Tr V12, V13, V20, b tch phn, cc kho b nh V18, V19, V21, cc b nh C36 C38, cc b lp V22, V23, V24. d. e. f. B cng D10 B khuch i: D12 B vi phn D11

5.3.5.2. Nguyn l hot ng 5.3.5.2.1. B so snh tng D3 u vo D3 a n cc tn hiu nh trn hnh D3 c h s khuch i bng -1. Cc tn hiu trn thay i v hai pha s lm thay i tr s t trc ca in p. u ra D3 c a n knh o lng tc ng nhanh v knh qun tnh. 5.3.5.2.2. Knh o lng tc ng nhanh Knh ny o lch ca gi tr tc thi o lng in p my pht vi tr s t trc cho trc. Thnh phn gm 3 b ging nhau, ng vi 3 pha .Mi b gm cc thit b theo s khi nh sau: (hnh 5-6-1)

64

Ur

atric p M F in

Bin i sin thnh vung

T o xung rng cua

T b ly t ng T ch ph n

K ha V 18 --V 21

B nh nhanh

B l p

R R 55 B t ng

Hnh 5-6-1 : S khi knh o lng tc ng nhanh Xt s lm vic ca 1 b: (b 1) * attrit in p my pht: Bin th T1 nhn tn hiu in p my pht 100V t TV11 v gim p * B bin i D1: to xung vung * B vi phn C7: bin i in p xung vung thnh rng ca 2 cc tnh. * Kha transistor V12: c m bi xung rng ca cc tnh dng 1 ln trong 1 chu k, phn cn li V12 tt. * B tch phn D4: Ti u vo o ca D4, in p ra D3 c ly tng vi cc in p trn t nh qua R55 v b lp V22. u ra D4 s c in p nu UR38 UR55. Lc qu trnh tch phn s din ra cho n khi no UR38 = UR55. Khi V12 m th V18 tt, thng tin khng truyn vo b nh. ng vi 3 pha lch nhau 1200, nn vic x l thng tin truyn vo b nh 3 ln trong mt chu k. y chnh l ngha ca knh o lng tc ng nhanh. in p my pht c o lng, nhn bit trong mt chu k. in p ca thit b nh nhanh t b lp qua R78, R79, R80 (3 b), a n u vo b cng D10. Theo knh ny c h s khuch i bng:

65

K =

R89 3.R 89 3.20 K = = 1 R 78 // R 79 // R 80 R 78 62 K

K = 15.3.5.2.3. Knh o lng qun tnh Knh ny o lch gi tr trung bnh in p chnh lu 3 pha ca my pht so vi gi tr cho trc. in p u ra D3 qua b lc RC: R44, R55, C18 n u vo b tch phn o D9. Hng s thi gian ca b lc l T = R44.C18 = 105.0,47.10-6 = 0,047s = 47ms 2,5 chu k p my pht y chnh l c im ca knh o lng qun tnh 5.3.5.2.4. B tng D10 Ti u vo D10, cng cc in p ra ca 2 knh: thit b nh nhanh v o lng qun tnh, to cho c tnh iu chnh ca AVM l phi tnh. Tc l cc xo trn bn ngoi lp tc c nhn bit bi thit b nh nhanh v tc ng n u ra H. 5.3.5.2.5. B khuch i D12 Khuch i cui ca H H s khuch i = -R101/R22 = -1. in p ra D12 l in p ra ca H (U). c tnh cho trn (hnh 26) 5.3.5.2.6. Khi hi tip : Khi gm R103, kha S3 v R76. Khi hi tip a vo to c tnh ca AVM l tnh. H s tnh c xc nh bi v tr ca S3 (KU), tc l xc nh bi mc hi tip. 5.3.3.2.7. B vi phn bao gm cc phn t : C48, D11 v S1 B vi phn to ra tn hiu U, h s khuych i theo knh ny c th thay i nh kha S1. * Khi a in p my pht bng tr s t trc th U = 0 (tr s c chnh nh l 95V) U c a n Y cng vi cc tn hiu khc v khuch i. U Y Ngoi ra U : Ch th YH YH

66

UD 12 V6

4

2 80 90 100 -2 -4 110 120

U V

-6

Hnh 5-6-2 : c tnh khi H /A3

5.3.6.

Khi dng phn khng - PT1/A4 : Khi PT1 dng b chnh st p trn my bin th chnh ca my pht v truyn thnh phn khng ca dng in my pht vo khi OMB. Lc i ni c t KIQ u vo khi dng khng gm c: - in p UA, C ca TV11. - T my bin dng pha B qua cc bin p trung gian ca TA3 (mch lc kch t ). u ra ca khi dng khng a ti: - Khi in p b chnh st p trn my bin p chnh. - Khi t trc in p t ng thay i tr s t. - Khi hn ch dng kch thch cc tiu OMB.

5.3.6.1. Thnh phn PT1 - B so snh (khuch i D1). - Chnh lu nhy pha D3 - B tch phn iu khin c D5 - B lc ng b gm: t nh nhanh C21, V19, V20, D7 67

- attrt xung ng b iu khin b nh: D2 - attrt xung ng b iu khin b tch phn: D4 5.3.6.2. Nguyn l hot ng 5.3.6.2.1. B so snh D1 Nhn in p my pht: UAC t T4, qua D1 in p sin c bin i thnh dng xung ch nht. 5.3.6.2.2. B chnh lu nhy pha bn k dng ca in p sin: U10D1 0 Khi my pht mang ti dung Ura D5 < 0 5.3.6.2.4. Thit b nh nhanh D7, C21, V19 Xung rng ca u ra D5 c np vo thit b nh nhanh qua kha V19, V20 v c iu khin bi attrt xung ng b D2 qua transistor V22. 5.3.6.2.5. attrit xung ng b iu khin b nh Tn hiu ra D1 (xung ch nht) qua vi phn C4, V2, R10, to thnh xung rng ca 2 cc tnh. Xung dng c a vo u o D2 qua R9, to thnh xung gn cc tnh m c rng xc nh bi C7, R18. V22 b tt bi xung ny. Khi V19 m, tn hiu t V5 c a vo b nh C21. Khi in p u ra D7 c gi tr m bng vi in p u ra D5 thi im nhp thng tin. Nh vy b nh ghi nhn v gi in p bng in p ng ra D5. Gi tr ny c gi cho n ln tt tip theo ca V22. Lc khi dng khng my pht thay i th mt thng tin mi c np vo b nh. 5.3.6.2.6. attrit xung ng b iu khin ca b tch phn in p ra D2 c a qua D4. Vi phn C8, V10, R24 to tn hiu rng ca cc tnh dng. Xung ny c a qua ng o D4, to xung ch nht cc tnh m. Xung ny lm tt V18 v m V17, lc C20 c ni tt phng in qua V17. 68

Nh vy V17, V19 m 2 ln trong mt chu k. Trong V19 thng trc tm tn hiu vo b nh, sau V19 tt v V17 m xo tn hiu trn C20, chun b cho chu k tch phn mi. * u ra D7 a n con ni SX1 dng b chnh dng do st p trn my bin th chnh v a vo khi in p H. Tn hiu a vo D6 o u a n khi OBM thc hin vic hn ch kch thch cc tiu. a n khi in p H ch th IQ a n khi t trc in p YH thay i tr s t khi gim ti v cng.UD7 V10 9 8 7 6 5 4 3 2 1 1 2 3 4 5

1

2

3

4

5

IQ A U27A V

Hnh 5-7-1 : Khi dng khng PT1 (S ph thuc ca Ura vo Uvo)

69

UD 2

0

T

0UD 4

T

0

T

UD 5

0

T

UD 6

0

T

Hnh 5-7-2 : th in p khi PT1

5.3.7.

Khi dng in - T /A5:

70

Khi T dng o dng roto v stato my pht, to o hm I' E v to in p t l vi dng roto a vo cc khi hn ch qu ti , OP. u vo khi dng in: - T bin dng in TA11( sau bin p kch t TE) qua cc my bin p v chnh lu thnh dng mt chiu a vo D1. u ra D1 a vo khi vi phn D5; khi IRotor tng nhanh th D5 C xu hng ko li km hm s tng ca IRotor - Khi IRotor = 1200A th u ra D1 = -5A. - T bin dng in stator pha B. Khi IStator = 4920A th u ra D2 c in p l: +5V. u ra khi dng in: - Tn hiu o hm dng rotor a ti khi khuych i. - Cc mc tng ng vi dng rotor cung cp cho khi hn ch dng cng hnh. - Tn hiu dng stator a n khi hn ch cng hnh. Trong khi ny c kha KIE gm 10 v tr lch nhau khong 0,3V (V tr lm vic t nc s 9). 5.3.7.1. Thnh phn khi T a.Thit b o dng stator: chnh lu V7, V10 v khuch i D2. b. d. Thit b o dng roto: b chnh lu v khuch i D1 B khuch i in p D3 c.B chn dng: ch chn dng pha roto e.B lp D4 f. B vi phn D5, C13, R47 g. Cc b so snh in p D6, D7 5.3.7.2. Nguyn l hot ng 5.3.7.2.1. Thit b o dng stator Dng stator ly t bin dng stator pha B,qua bin p T8, qua b chnh lu V7, V10 c lc bi C2, a vo D2. in p ra D2 t l vi dng stator. a vo ch th. R6: chnh in p ra D2, tng ng vi dng stator khi nh mc ch -5V.

5.3.7.2.2. Thit b o dng rotor T cc my bin dng kch t qua cc bin p trung gian T5, T6, T7 qua chnh lu V1 V6, lc bi R7, C1 a vo D1. in p ra D1 t l vi dng roto v c chnh bi R5. in p ny a n ch th. Khi dng roto l nh mc 200A, ch -5V 71

5.3.7.2.3. Khuch i in p D3 Do khng s dng b chn dng nn dng t ngun dng V17 chy qua V15, V18, R26 s to in p u vo D3 bng in p ti u ra D1, do D3 ch ng vai tr o du tn hiu t D1, a n v OP. 5.3.7.2.4. Vi phn D5 Tn hiu t D1 qua b tch phn gm C13, R47, D5 tao thnh I'E v qua kho S1 a vo Y. Khi chuyn my pht t AVM AVN, I'E c ni tt loi tr tc ng sai ca n. 5.3.7.2.5. B lp D4 D4 ng vai tr b lp li in p ra D1 a vo cc b so snh D6 v D7 5.3.7.2.6. Cc b so snh D6 v D7 ch lm vic bnh thng ca my pht , u ra D4 = 0 in p u ra D6, D7 c xc nh bi phn lc dng ti u vo o ca n bi hi tip m sau qua R62, R63 nn c gi tr m. Khi IE > IEm Ura D6, Ura D7 = 0 Khi gim dng roto (do tc ng ca OP) n 0,97Im in p u ra D6 t gi tr m gii hn. Khi tc ng n OP, in p ny s chuyn b tch phn ca OP sang ch nh. Tr s ny c xc nh bi R50. i vi D7, Ura D7 = 0. Khi dng IE > 0,93IEm, v t gi tr m gii hn khi gim dng IE < 0,9IEm.

5.3.8.

Khi o qu ti /A6: dng o qu ti roto ca my pht, hn ch thi gian qu ti, ph thuc vo trng thi nhit ca my pht. Hn ch ti trong ch ngui dn ca my pht khi cm qu ti lp li. S lm vic ca a trn hm hyperbol, gn ng vi c tnh qu ti ca my pht. 72

u vo ca khi o qu ti l tn hiu dng rotor t khi dng in. u ra ca khi o qu ti rotor a ti khi hn ch dng rotor v bo tn hiu qu ti rotor thng qua r le trung gian. C 2 bo v qu ti Rotor: 1. ng) 2. Trong khi ny c: Khuch i D1 ghi nhn qu ti nh v khi qu ti my pht n c a vo lm vic u tin. Khuch i D10 ghi nhn qu ti trung bnh Khuch i D9 ghi nhn qu ti ln nht, gm c qu ti rotor trong ch cng hnh. Khuch i D5 m hnh nhit ly tch phn nhit rotor (stator) my pht khi qu ti, kim tra mc pht nng ca my pht v khi qu ti cao hn cho php n s ng b ghi nhn pht nng (D7 v t nh C21) Tn hiu vo ly t TA1 qui i ra in p. Khi IE = IRm th Uvo = -5V. 5.3.8.1. Thnh phn ca B ghi nhn qu ti: D1, D9, D10 ni theo s iod l tng. M hnh nhit (b vi phn v nh v t nng) Tn hiu qu ti: D2, V12, K1 5.3.8.2. Nguyn l hot ng 5.3.8.2.1. B ghi nhn qu ti D1, D9, D10 c cc h s khuch i khc nhau. Cc h s c th thay i nh cc bin tr tng ng R4, R100, R106. u vo mi b khuch i c 2 in p: in p t l vi dng roto (t T) v in p t hay cn gi l in p phn cc. Tr s t ca mi b c th chnh nh, nhm chnh nh tr s qu ti, nh cc bin tr R5, R56 v R3. D1 dng ghi nhn tr s qu ti b cn D9 dng ghi nhn tr s qu ti ln nht, k c qu ti trong ch cng hnh. Bin tr R5 c chnh nh sao cho khi in p a vo 2A l 5,3A tng ng vi dng IE = 1,06IEm, in p u ra D1 0 v c xu hng m. Bin tr R4 chnh sao cho IE = 5,5V tc IE = 1,1IEm, UraD1 = 10. Bin tr R3 t v tr sao cho khi IE = 6V tc IE = 1,2IEm, D10 c xu hng dng v 0. Bin tr R106 t sao cho khi U5A = 8V tc IE = 1,6IEm, UraD10 = 2V Bin tr R56 t v tr sao cho khi U5A = 8V tc IE = 1,6Im, UraD9 c xu 73 Bo v bng khi Bng rle ly trc tip t bin dng (12s tc

hng dng v 0. Bin tr R100 t v tr sao cho khi U5A = 10V tng ng vi IE = 2Im, UraD9 = 10V. u ra ca b ghi nhn qu ti ni vo m hnh nhit qua cc R30, R99, R31. D1 ni vo m hnh qua D3. c R101 chnh nh s tri im khng ca b ghi nhn qu ti. Bin tr R101 c chnh sao cho khi ct cc tn hiu vo 2A, 5A, UraD5 = 0 5.3.8.2.2. M hnh nhit Bao gm: B tch phn iu khin D5, C15, V13, V14 B ghi nhn t nng: D7, C21, V18 B so snh D4 B a hi n n D6, D8 Cc rle K1, K3 Mch m hnh nhit hot ng theo nguyn tc ca thit b trn cc phn t tng t. B tch phn kim tra mc t nng roto khi qu ti trong ch t nng v ngui dn. Trn u vo D5 c transistor trng V13, V14 c cng cch ly tng in tr trong mch t phng ca C15. V13, V14 mc theo s vi sai gim nh hng ca nhit trong s lm vic ca b tch phn. B ghi nhn t nng l thit b nh lu, dng kim tra trng thi ban u ca my pht khi qua nhit v khi ngui dn. T u ra D7 n u vo D8 c mch hi tip m R18. N c a vo lm vic trong ch ngui (khi tip im K1(1-2) ng v c iu khin bi D2. R18 c chn thi gian ngui dn ca my pht t 15 n 30 pht. iu khin b tch phn thc hin bi D4, D6, D8, rle K2, K3. u vo D4 l in p ra D5, so snh vi in p ta cc tnh m trn bin tr R36. R35 c chnh sao cho D4 tc ng thay i cc tnh t dng sang m xy ra khi UraD5 l 10V. (-10V ch t nng v +10V ch ngui). Thay i cc tnh in p u ra D4 s to tn hiu khi ng cho b a hi i D6. Trn u ra D6 xut hin xung ngn cc tnh (+). Lc transistor V20 m, K2 tc ng, tip im K2(2-3) ni nhanh u ra D5 vo b inh v t nng D7. Thng tin c truyn vo D7. Thi gian ng K2 c xc nh bi thng s ca hi tip mm R69, C23. S thay i cc tnh trn u ra D6 t (+) (-) to tn hiu khi ng D8. u ra D8 xut hin xung ngn cc tnh dng, V26 m, K3 tc ng. Tip im K3(2-3) ngn mch nhanh b tch phn qua R33, UraD5 = 0. Thi gian ni D5 xc nh bi R81, C38 (lm V26 m dn n K3 tc ng ni ttb tch phn 74

D5 qua R33 ). - Nu dng roto tng n tr s vt qu tr s t ca b nh v qu ti b D1. u ra D1 xut hin in p m, cn u ra D3, D2 in p dng, V12 m. K1 tc ng, H1 sng, ct mch hi tip qua R18. M hnh nhit lm vic ch t nng. in p dng u ra D3 tng ln, np cho t C15, tc ng n cc cng V13. iu ny lm u vo o D5 c in p dng, in p u ra D5 t gi tr gii hn (-10). u ra D4 nhn c in p m gii hn, qua t C18 to xung a vo u o D6. Lc K2 tc ng khi. UraD5 vo b ghi nhn t nng D7. in p m UraD5 qua tip im K2(2-3), t vo C21 v cc cng V18. Transistor V18 kha, Ura o D7 c gi tr m. Kt qu l in p trn t C21 v u ra D7 tng ln mt gi tr xc nh gn bng 0,1V. Sau nh ni trn, sau 1 thi gian ngn K2 ct, K3 tc ng ni tt b tch phn, t C15 phng in qua R33. in p trn b tch phn bng 0. Khi xung trn u vo D8 gim xung K3 ct. Lc ny nu qu ti vn cn, in p trn D5 li tng ln tr s gii hn m, K2 tc ng truyn thng tin vo D7 v C21. in p dng trn C21 v D7 tng cn 0,1V. Qu trnh m thc hin khong N = 93 ln, cho n khi in p trn D7 t gi tr khong 10V ( tng ng vi s pht sng cho php ca roto my pht. Lc in p u ra D7 truyn vo OP thc hin lnh hn ch dng roto. S chu k t nng c th chnh nh nh bin tr R22. - Khi dng roto gim n gi tr cho php (do tc ng ca OP, hoc sm hn do b ghi nhn ca OP ghi nhn c s qu nhit), UraD1 = 0 (UraD2 thay i cc tch t (+) (-). R le K1 ct, tip im K1(1-2) ni u ra D7 n u vo D3 qua R18. Lc ny kim tra trng thi nhit roto ch ngui dn. Tn hiu qu ti ct. UraD3 < 0, a n C15 v cng V13. Lm cho in p u ra D5 l cng gii hn (+10V) - UraD4 < 0, UraD6 > 0. V20 m, K2 tc ng ni m hnh nhit vi b nh v t nng. in p dng u ra D5 t vo C21 v V18. dn V18 thay i, u ra D7 c gi tr dng, kt qu l gim in p trn t C21 v D7 mt gi tr 0,1V. Khi in p xung m trn u o D6 gim thp hn tr s t, UraD6 < 0 cn UraD8 > 0, r le K2 tt, tip im K2(2-3) h mch, r le K3 tc ng ni tt b tch phn D5. Khi in p m trn u o D8 gim thp hn tr s t UraD8 < 0, K3 tt. Do UraD7 gim nn ni tip qua R18 gim. UraD3 gim, sau K3 ct UraD3 tng ln tr s gii hn nhng nh hn tr s trc. Qu trnh trn lp li 93 ln cho n khi in p ra trn D7 gim n 0, nhng chu k in p trn D5 tng n tr s gii hn ngy cng ln ln. Thi gian 75

ngui ca roto my pht din ra theo hm m. Khi my pht ngui hon ton th tn hiu qu nhit trn khi hn ch dng rotor OP tt, r le K1, K2, K3 ct. Nu qu ti lp li trc khi my pht ngui th m hnh nhit li a vo lm vic ch t nng v b nh v t nng s tnh ton trng thi nhit ch trc .

IE IE N 2.0 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 20 40 6080 120 160 200 240 T S

c t n h g i i h n

Hnh 5-9-1: c tnh gii hn

5.3.9.

Khi gii hn dng roto OP/A7 Khi OP dng hn ch dng roto my pht ch qu qu ti, khi qu nhit v gii hn 2 ln dng roto trong ch tng cng 2 ln dng kch t. u vo khi hn ch dng rotor gm: - Tn hiu dng rotor t khi dng in to ra. - Tn hiu cm cng hnh khng cho vt qu dng Irotor nh mc t s r le bn ngoi. - Tn hiu dng stator t khi dng in to ra. - Tn hiu cng hnh t khi cng hnh. 76

- Tn hiu qu ti t khi o qu ti rotor. u ra ca khi ny a ti khi kim tra v gii hn gi tr u ra ca AVM gi tr tnh ton, ng thi a tn hiu ra ngoi qua r le trung gian khi khi hn ch lm vic. 5.3.9.1. Thnh phn OP B ghi nhn qu nhit D1 Thit b bo tn hiu qu nhit D2, V13, K3 Thit b thay i tr s t in p D5 Thit b thay i tr s t dng roto 2 IEm Thit b cho php qu ti trong ch ngui khi ngn mch D4, D7. 5.3.9.2. Nguyn l hot ng D1: B so snh in p c hi tip dng cng R21, R22 trn u vo o D1 c cc tn hiu: Qua R1 lnh hn ch qu ti t (7-5) KT10 (tn hiu dng) Qua R2 in p ra D6 ca T Qua R3 in p t l t nng roto UraD7 ca (tn hiu dng) Qua R8 in p ta t l vi gii hn cho php ca nhit roto (tn hiu m) in p ra D1 >0 nu cc tn hiu a vo nh hn in p ta v ngc li. u ra D1 ni vi baz V9 (qua V5, R20) Trn chn Baz ca V9 cn c in p dng khng i R100 v in p ra t D7 /T V9 iu khin s lm vic ca thit b thay i tr s t, V9 m khi c in p m t ln baz ca n, lc K1 tc ng, ni b nh v qu nhit n thit b thay i tr s t. * Thit b tn hiu qu nhit: Lm vic nh b so snh in p D2 c hi tep dng cng R25. u vo o D2 qua R5 ni vi u ra D7 l in p t l vi t nng, u vo thun ca D2 qua in tr R6 l in p u ra khuch i D1, t l vi qu nhit. Tng cc in p ny so snh vi in p ta (-)qua R11 u vo o 4 D2. UraD2 0, U10D2, U10D3 >0, U10D5 = 0. V13 ct, K3 ct, khng c tn hiu qu nhit. U10D4, U10D7 = 0 U vo D8 ch a n gi tr in p m ca n. V vy U10D8 >0. V25, V27, V42, V40 kha. OP khng nh hng n ch ca h thng kch thch. * Khi c qu ti, nhng khng dn n qu nhit: U4D1 = 0. Ch ca D1 khng i. U10D1 > 0. in p trn baz V9 bng khng (t D7 ca T) V9 m, K1 tc ng, u ra D1 ni vi D5. Ch ca D2, D3, D4, D5, D6 v D8 cng khng thay i. Trong trng hp ny OP cng khng nh hng n ch lm vic ca h thng kch t. * Khi qu nhit my pht: UraD7 > 0, a vo u o ca D1, D2, D3 (17A), gi tr ny ln hn tr s t D1 ( U10D1 < 0, U10D2, U10D3 < 0. Lc V9 m, K1 tc ng. Tip im K1(2-3) ni u ra ca b nh v qu nhit vo tch phn D5. Qua R5 U4D5 < 0 nn U10D5 > 0. T C11 c np in. in p dng u ra D5 a n u vo H qua R102 gim tr s t AVM. in p m u ra D2 lm m V13, K3 tc ng n qu nhit sng, bo hiu qu nhit. Qu trnh tng in p trn D5 v gim tr s t AVM din ra cho n khi IE < 0,97IEm. Khi u vo D1 qua R2 a n ip p m (T), lm thay i cc tnh D1, U10D1 > 0, K1 ct, ct thit b thay i tr s t D5 khi b nh v qu nhit. (Tch phn D5 lm vic ch nh. in p trn u ra D5 v trn t C11 xc nh tr s t ca AVM tng ng vi dng IE = 0,9EIEm.Transistor V16 s gi khng cho C11 phng in, my pht ngui dn tr s ny) 78

Ngoi ra khi qu nhit, UraD6 >0, qua R74 gim tr s t D8, t gi tr IE = 2IEm n IE = IEm. Khi ang ngui (my pht cn nng) UraD2 < 0 v vy K3 cn ng, n qu nhit s tip tc sng cho n khi my pht ngui hon ton. * ch ngui dn: nu X6-X7(SX1) ct ra, qu ti lp li khng cho php, loi tr qu ti trong qu trnh ngn mch. Khi ct X6 X7(SX1), UraD3 0, v th tr s t iu chnh dng (tr s t D8) s t dng nh mc, qu ti lp li b loi tr (tc l dng roto) bi b iu chnh dng D8, V25, V27 s duy tr gi tr nh mc. Nu qu ti my pht gy ra bi s ngn mch, th u vo 3A ca khi ny s a n in p m (u ra 16A ca ) cn 2A a n in p ca T nn UraD4 > 0 ( UraD6 = 0. Tr s iu chnh dng t phc hi gi tr qu ti trc , tc l ch ngn mch s cho php tng dng roto cao hn nh mc. in p dng trn u ra D4 din ra cho n khi in p u ra D7 tng n tr s xc nh qua R55 lm gim u ra D4 n C v duy tr gi tr ny. Khi in p dng c phc hi.

5.3.10. Khi hn ch kch thch cc tiu OMB/A13 : Khi OMB dng hn ch cng sut khng do my pht ly t mng in tr s cho php, ty thuc vo cng sut thc, bng cch hn ch dng kch thch cc tiu ca my pht ch km kch thch. u vo khi ny gm: - in p pha B ca stator my pht. - Dng in pha B ca stator my pht. - Tn hiu dng cng sut khng t khi dng khng. - Tn hiu o hm dng rotor t khi dng in. u ra khi hn ch dng kch thch cc tiu a ti u vo khi in p, v i bo tn hiu thng qua r le trung gian. Khi my pht nhn cng sut khng t li gi tr nh hn cho php th khi ny khng nh hng n dng kch thch my pht. 5.3.10.1. Thnh phn OMB Thit b o thnh phn thc: gm D1, kho V13, chnh lu nhy pha D4, tch phn D6 v b nh tc ng nhanh (C26, V24, V26, A7). Cc b so snh D3 v D5 iu khin kha V24 ca b nh v kha V22 ca b pht dao ng phi tuyn. 79

B to nghing c tnh: gm b so snh in p D2 ni theo s diode l tng, b khuch i tng D2. Thit b tn hiu OMB gm D9, K1 v n H1 Kha chuyn mch S1 "KQ" 5.3.10.2. Nguyn l hot ng * Thit b o thnh phn thc S lm vic ca thit b o thnh phn thc ging nhau nh o thnh phn khng (m t khi dng phn khng PT1). S khc nhau l khi OMB ly in p pha B cn PT1 ly in p AC. in p trn u ra D7 t l vi dng in p B * Bin tr R62 dng t sao cho khi u vo OMB bng O, in p u ra D7 = 0. thc hin iu ny khi chnh cng sut my pht, ta ni X2 xung im O ca ngun. * Bin tr R15 dng t dng stato my pht, t (0,5 1) I m v cos = 1, in p u ra D7 tng ng t 0,5 1 khong in p ca khuch i D7. Thnh phn khng v thc cng trn u o D8. in p t l vi thnh phn khng ly t PT1 qua (R60) in p t l vi thnh phn thc: u ra D7 Qua R55, R57 hoc R80 ph thuc vo gi tr ca dng thc, trn u vo D2, so snh in p cc tnh dng ly t D8 vi in p cc tnh m ly t bin tr R2. u ra D2 l u ra ca OMB c a n H. * Khi my pht khng kch thch hoc kch thch ban u, loi tr tc ng sai ca OMB bng b kha V40 (transistor trng ). Khi kch thch my pht tiu th cng sut khng t li khng qua tr s cho php, u vo D2 c cc tnh m, u ra D2 = 0. Khi OMB khng nh hng n dng kch thch. Nu my tiu th cng sut khng t li vt qu tr s cho php, in p m trn u vo D8, lm cho u vo D2 c cc tnh dng. UraD2 m. in p ny qua kha S1 "KQ" a n u vo H, lm tng tr s t tng, kt qu l lm tng kch t, gim cng sut tiu th t li. Khi OMB lm vic UraD2 < 0. Trn u ra D9 s c in p dng qua n p V35 lm V37 m, K1 tc ng, tip im (3-4)K1 lm H1 sng, bo hiu OBM lm vic, ng thi tip im (2-3)K1 a qua r le K7/P bo tn hiu ra ngoi bng c hiu (KH34/GCE5) ca h thng kch t. Khi OMB lm vic, dng kch t c tng ln cho n khi u vo D2 gim n 0. Khi cng sut khng tiu th gim, in p vo D4 dng. Khi ti thc bng 0, in p u ra D8 t l dng khng, trng hp ny OMB lm vic ch gii hn dng kch t nh nht tiu th cng sut khng cho php l ln nht. Khi tng ti thc, OMB s lm vic gim tiu th cng sut khng. 80

nghing c tnh on 1, c xc nh bi R65 l khng thay i, n c la chn khi hiu chnh OMB. nghing on 1, 3 c th thay i bi R92, R93. im gy ca c tnh, gia on 2, 3, thay i bi R73, R77. R73 chnh im gii hn lm vic ca on 2, im A t to A1. Chnh R73 sao cho in p trn n bng in p trn V31 v khi H1 sng. Gim in p trn u vo 26A (nh hn 4V) nhn c ta A2 ca A (khi H1 tt) Bin tr R92 xc nh nghing ca on 2. t R92 ti v tr sao cho cng sut thc im B1, cng sut khng tng ng lm n H1 tt. R77 t im gy ca c tnh on 3, im B. R77 t sao cho in p trn n bng in p trn V32 v lm sng n H1. Gim in p trn 26A nhn c to B2 im B (khi H1 tt) R93 t nghing on 3 R93 t sao cho khi in p vo 26A = 0 v in p trn 27A = 10V lm n H1 tt. Trn u vo o D8 t 25A qua R97 l tn hiu I' E t T, tng n nh ca h thng t ng khi OMB lm vic. Kha S1 dng tch OMB ra (v tr O) v cc v tr khc dng thay i h s truyn t theo OMB a vo H.

P PN 1 B 2 A Q QN U26A V 1 A 2 B2 -0.4 -0.2 -4 -2 A1 0.4 0.2 0 B1 0.8 0.6

U27A V 10 8 6 4 2 0 A Q QN 1 U26A V A 2 B2 -0.4 -0.2 -4 -2 2 3 B

P PN D 1 B1 0.8 0.6 A1 0.4 0.2 0

U27A V 10 8 6 4 2 0

0

0

81

Hnh 5-11-1 :c tuyn khi OMB

5.3.11. Khi tn s v bo v - 3 /A14: Khi 3 dng to tn hiu t l vi lch tn s f = fMF- fMFm, to o hm f' a vo khi khuch i Y, nhm to s n nh trong h thng cc ch qu . Phn bo v thc hin vic ct f v f' khi tng ng thi in p my pht v tn s cao hn mt gi tr nh trc, cng nh khi tng in p hoc tn s cao hn gi tr cho trc. 5.3.11.1. Thnh phn ca khi 3 5.3.11.1.1. Thit b tn s B lc tn hiu vo (R1 R4, C3, C4) B so snh D1 Cc b vi phn attrit xung ng b Mch pht dao ng (tch phn D3) Thit b iu khin b tch phn D6 Cc b khuch i lch tn s v o hm bc nht tn s D8 D13 5.3.11.1.2. Thit b bo v B so snh in p D2, D10 S logic AND D5 Rle K 5.3.11.2. Nguyn l hot ng 5.3.11.2.1. Thit b tn s a. B lc v so snh 82

in p my pht pha AB qua bin p o lng n bin p trung gian T11, qua b lc gm R1 R4, C3, C4 n D1, kt qu l u ra D1c tn hiu xung ch nht. Phn cc tnh dng c a qua V7 v c n p bi V8. ng thi u ra a n attrit xung ng b D4 v a n D6 to xung iu khin b tch phn D3. b. B tch phn D3 A3 c iu khin bi V16 v V32 1/2 chu k m ca in p U10D1>0 lm U10D6 c gi tr dng, lm V32 m, V16 tt, D3 ch tch phn o, U10D3 < 0 v tng theo thi gian ph thuc vo R23, C18. 1/2 chu k dng ca in p, V32 tt, V16 m, C18 c phng in, U10D3 = 0 Nh vy, tn hiu u ra D3 l in p rng ca cc tnh m. Chu k ca in p my pht c bin i thnh in p t l vi n. c. Thit b nh D7, C29 v V27 in p u ra D3 c truyn vo b nh C29, thng qua kho V27. Ti u vo khng o D4 qua b vi phn (C13, R22) D4 1 xung ngn cc tnh m. Xung ny lm tt V18, lm m V27, lc ny thng tin u ra A3 truyn vo b nh. Do tnh cht ng b ca xung u vo D4, D6 vi in p my pht m khi thng tin truyn vo b nh th V16 m, ni tt t C18. Vic x l thng tin truyn vo b nh din ra mt ln trong mt chu k in p my pht. d. B so snh khuch i lch tn s my pht Tn s my pht c so snh vi mt tr s dt trc f m, trn R53 c tr s dng. Ty thuc vo tn s my pht m ti cc cng V29 s xut hin hiu in th c gi tr: = 0 khi fMF = fm > 0 khi fMF> fm < 0 khi fMF < fm V29 lm vic theo s lp li nn in th ti cc ngun bng in p ti cc cng. * Khi fm < fn Ura D7 > 0 v bng in p Ura D3, vo thi im truyn thng tin vo t C29. Sau in p u ra D7 vn gi khng i v V29 c cng cch ly. Gi tr ny c gi khng i cho n ln tt V18, m V27 tip theo. Khi Ura D7 > 0 cc u ra D8, D10, D11, D12 s dng cn D9, D13 m. Kt qu ngc li khi fm > fn. in p u ra A8 l in p t l vi lch tn s my pht v tn s fn. R28 chnh nh h s truyn ca knh lch tn s f. 83

u ra D8 a n D12 v D9 khuch i v lc a vo Y. Kha S2 chnh h s khuch i ca AVM theo knh f. e. B vi phn to f' lch tn s c a n b vi phn C47, R101, R102, D11 c o du D13 a n Y qua kho S1, Kf', chnh h s khuch i ca AVM theo knh f'. 5.3.11.2.2. Thit b bo v Dng ni tt cc u ra f, f' trong cc ch khng bnh thng ca my pht. Bo v khi tng ng thi in p v tn s

Bo v ny xy ra trong trng hp ct ti u vo o D2 cp vo in p t l vi in p my pht, t bin in p qua cc bin p trung gian T1, T2, T3 v chnh lu bng V1 V6. in p ny so snh vi in p trn R11. R11 c chnh nh sao cho khi Umf 110V. U raD2 chuyn t dng sang m. Nu tn s my pht cng tng ng thi vi in p U raD13 m xung, khi tc tng dn ln, tr s m D13 lm cho tng cc in p t vo u o ca D5 m, UraD5 dng, V30 m, K1 tc ng, ni tt ng ra f', f. Bo v khi tng tn s Tn s ny c chnh khong 52 53Hz. UraD8 > 0 lm UraD10 < 0 lm D5 chuyn t m sang dng lm rle K1 tc ng. Bo v khi tng cao in p my pht c chnh khong 120 125V. in p trn R9 khi ln nh thng V24, V25 K1 tc ng

84

U V

D7

3

1

2.5

2 2

1.5

1

0.5

49

50

51

f Hz

-0.5 2 -1 1

1. U 2. U

D13 D9

= f(f) = f(f)

-1.5

Hnh 5-12-1: S ph thuc ca in p ra vo tn s

5.3.11.3. Khi iu chnh tr s t - YH/A16 : Khi YH dng phi hp vi YH: lm thay i tr s t in p my pht, khi ha chnh xc, ha t ng b, hoc khi chuyn kch thch t b AVN sang b AVM. y ta ch xt qu trnh khi ha ng b chnh xc. 5.3.11.4. Thnh phn YH 1. 2. 3. B so snh in p li v my pht khi ha chnh xc D2 B khuch i lch in p D1 Cc r le in t v bn dn thc hin qu trnh

5.3.11.5. Nguyn l hot ng 5.3.11.5.1. Khi ha chnh xc Khi c lnh ha, tip im rle K49 ng rle K2, K3 ca YH. Rle K3 ng ngun 12,6V cho cc phn t trong khi YH. in p my pht ly t bin in p qua T12 v cc diode V1, V3 in p li ly t bin in p qua T10 v cc diode V2, V4 Cc in p ny c a vo D2 to ra Ur UC. Hiu s ny c th c iu chnh bi bin tr R11. Qua tip im rle K2(3-2), hiu s UR UC c a n khi YH thay 85

i tr s t. ng thi tip im rle K4(5-4) ct UK khi khi K khi UR UC = 0 thay i tr s t chm dt. Lnh ha chm dt khi my pht c ng vo li 5.3.11.5.2. Khi chuyn t AVN AVM Khi b AVN lm vic, theo tip im K18(10-14), lm rle K1 c in. U c a vo D3. ng thi in th ti cc C ca V13 m, lm V22, V27, V28 m, rle K5 c in, tip im rle K5 a n thay i tr s t, v ni tt u ra b iu chnh AVM. Nh vy khi b AVN lm vic, b iu chnh AVM vn nhn bit v thay i thng xuyn tr s t. Khi chuyn sang AVM, lnh ny c xa. - Lc ny iu chnh Q bng kha iu khin.UMF UL H(U) Khi ct AVM AVN ang lm vic

YH B ho MF Ni t AVM

YH

Np gi tr Q cho H

5.3.12. Khi cng hnh - /A12: Khi dng kha lin ng s iu chnh gim kch t theo o hm bc nht in p my pht vo thi im ct ngn mch. u vo khi cng hnh l lch in p t khi in p, khi c ngn mch trong li, lch in p c gi tr m ln vt gi tr t th u ra ca n c gi tr mt in p (-) khng i, in p ny a ti khi khuych i v i cng hnh kch thch my pht. Sau khi ct ngn mch v phc hi in p n 0,98 tr s t in p, cng hnh kch thch c ct vi thi gian duy tr khong 0,2s qui nh bi hng s thi gian do t in v in tr trong mch. Trong mch c 2 kho: S1 (KE): c 10 v tr tng ng vi tng cp in p (+) a vo D1 (thng v tr 0.85); mi nc ca S1 l 0,01Um. S2 (KUE): dng thay i h s hi tip theo in p rotor my pht. 5.3.12.1. Thnh phn B so snh in p D1 Thit b duy tr ct cng hnh (R12, R13, R23, C3, V8, D2) Chuyn mch S1 (KE) thay i tr s khi ng. 86

5.3.12.2. Nguyn l hot ng : Ti u vo o D1 a n: in p t khi ng rle (in p phn cc) c th thay i nh S1 lch in p my pht U ch bnh thng my pht U = 0 U4D1 >0 UraD1 bo h hng AVM. Khi khng bo h hng AVM khi: 1. 2. 3. 4. Chuyn ngun, s dng ngun d phng U = 0 Cc i lng f, f . . . ca khi Y thay i Tn hiu cm cng hnh t khi OP (kha u vo D4).

5.3.13.1. Thnh phn K: B khuch i D1 Cc phn t logic D2 (AND), D3 (NAND) B so snh (khuch i D4 vi hi tip dng). Tch phn D5 Rle K1

5.3.13.2. Nguyn l hot ng: u ra UC t H n K qua YH (tip im K4 ca YH) lin ng trong trng hp ha t ng b. 88

u ra D1 ni vi D2, D3 in p UA n: u o D2 (+) u khng o D3 (-) u ra D2 v D3 ni n u o D4. y in p dng c so snh vi phn cc m (t R43). in p ra D4 ni vi b tch phn D5. Khi UraD5 >0 V14, V16 kha, K1 ct (H2 sng, bo AVM h hng). Khi UraD5 0, U10D5 0, 0, UraD5 < 0, H1 sng bo AVM tt Hoc khi U < 0, UA > 0, UraD2 = 0, UraD3 < 0 nn UraD4 > 0, UraD5 < 0, H1 sng bo AVM tt. * Nu AVM h hng: Ng vo: UC 0, cn UC = 0. khi UC> 0 UraD1 < 0, UraD2 < 0, UraD3 > 0. khi UC < 0 UraD1 > 0, UraD2 > 0, UraD3 < 0. in p dng ti u ra D2 hoc D3 lm thay i cc tnh D4 t dng sang m. UraD5 > 0 v tng ln n khi nh thng V13, V16 ct, K1 ct. H2 sng bo AVM h hng. Trong iu kin vn hnh bnh thng , in p m t khi in p H /A3 vo qua in tr R40, san bng in p dng ly t R42. Nu ko H ra khi ngn t, in p dng t R42 a vo D4, dn n bo AVM h hng. * Trong ch qu ti roto, tn hiu m t khi hn ch dng rotor OP/A7 qua V8 v R36, to ng ra D5 in p m, Bo AVM tt. Khi h hng t hoc P (ngn mch cc ng ra) Ngun cung cp cho K3 P ly t ngun n nh, khng lin h vi cc ng ra , P, nn K s bo h hng AVM. 5.3.14. Khi rle trung gian P/A18: Khi P dng cch ly v in cc mch tn hiu ca AVM, vi cc mch in p thao tc 220 ca h thng rle. Cc tn hiu a ra ngoi t qu trnh x l ca AVM l: 89 UA

- Bo h hng AVM. - Bo tn hiu sang bng in p my pht v in p li a ti b ha ng b chnh xc. - Bo qu ti rotor khi 1,1Im. - Bo qu nhit rotor. - Bo khi hn ch dng rotor 2Im lm vic. - Bo gii hn dng kch thch cc tiu lm vic. Trong P c 7 rle - K1, K3: bo hiu s lm vic ca AVM tt hoc h hng Lin h vi K v Y - K2: Lin h vi YH, kt thc qu trnh iu chnh tr s t (K4) - K4: Lin h vi OP; khi qu nhit, K3 (2-3) - K5: Lin h vi , khi qu ti K1 (5-6) - K6: Lin h vi OP hn ch qu ti OP, (2-3) - K7: Lin h vi OBM hn ch kch thch cc tiu K1 (2-3) Cc rle c cung cp ngun 27V, ngun ny c ly t mch 45V Khi ngun chnh hoc khi ngun d phng P qua b n p t 45V 27V 5.4. BO V H THNG AVM: H thng AVM c ct ra trong cc trng hp sau:: - Bt ptmt SF1 trong t TV11 ( 5m). - Bt ng thi 2 ptmt ngun chnh SF7 v SF8 / GCE5. - Cng hnh kch t ko di 60s, I = 2IRm. - Qu ti rotor ko di 10 pht, I = 1,1IRm. - Qu dng cng hnh I > 2IRm. - Qu in p kch thch (kh t bng rle K20 v K21), U >1,15U m lc cha ng MC 13,8kV. - H hng bn trong khi AVM. S khi s c ct AVM nh hnh 5-17.

90

5.5.

PHNG PHP HIU CHNH CC KHI CA AVM:

Kim tra AVM - c tin hnh bn th nghim - Vic kim tra cc khi hnh khi ko tt c cc khi ra khi ngn v tin ca AVM. - Trnh t kim tra v hiu chnh cc khi AVM cn phi thc hin theo ng th t cc mc di y : 5.5.1. Kim tra khi ngun 1/ Tho tt c cc khi tr ra khi ngn AVM 2/ Trn u ra ca (cc im o +12V, -12V) ni bin tr 95; 2,1A. 3/ Kim tra in p ngun 12,6V khi ti bng 0,5A. Tr s in p ra khong bng 25,2V (chnh bng R16) v i xng xo vi im khng. 4/ Kim tra ngun 6,5V khi ni ti 1K vo ngun ny. Tr s o c khong 6 6,5V 5/ Kim tra in p gia 4a, 7b. in p ny khong 45V. 6/ Kim tra bo v qu ti : Tr s bo v : Iti max = 1,0 1,2A Khi Rti = 0 th Iti < 0,4A 7/ Kim tra s lm vic ca mch n p : Khi thay i U ngun t 300 n 450V vi dng ti Iti = 0,5A, in p ra thay i vi Ura < 0,1V. 8/ Kim tra bo v in p ngun tng cao : Tr s bo v tc ng : U ngun max = 570V (chnh bng V35) o tr s bo v tr v. 91

9/ Kim tra bo v in p ra tng cao : iu chnh in p ra bng R16. Tr s bo v tc ng khong 30V (chnh bng R49 hoc R50) 10/ Chnh in p ra bng 25,2V nh R16. 5.5.2. Kim tra khi 1/ Tt c cc khi, tr v , tho ra khi ngn AVM. 2/ Trn u ra ca (cc im o +12V, -12V) ni bin tr 95V, 2,1A. 3/ Cp ngun mt chiu 220V cho AVM.t Iti = 0,4V o in p ra khi ngun (khong 24 0,2V, chnh bng R26) o in p 12,6V so vi 0. o in p 6,5V so vi 0. (khong 6,0 6,5V) 4/ Ly c tnh ti Ura = f (Iti) 5/ Kim tra bo v qu ti : Tr s bo v Iti max = 0,7 0,8A Khi Rti = 0 th Iti < 0,3A 6/ Kim tra s chuyn mch ngun t sang v ngc li. 5.5.3. Kim tra khi 1/ Chnh khng khi . - Ni ti 820 vo u ra Y (1:X21 v 2:X21) - Tho tt c cc khi tr , , . - Ni 5A, 6A, 7A, 10A, 11A, 12A, 13A n 1A (im 0) - o in p ra vi tiu chun UA 0,25V - o gn sng nh - nh ca in p ra vi tiu chun UL

0,5 0,5

1,0 1,0

2- Kim tra mch theo di AVN khi ct AVM. a. Ni mch 5A vi in p -12,6V to gi lnh ct AVM. b. Thay i UMF, o tr s U khi tn hiu Uo bt u thay i. Tr s ny khong +0,2V (chnh bng R1). 5.5.13. Kim tra khi 1- Kim tra s tc ng ca mch cng hnh khi gim thp in p my pht ng vi mi v tr ca kha KE. 2- Kim tra thi gian tr ca mch tr v trng thi ban u khi tng in p my pht (khong 100ms, chnh bng t C3) 5.5.14. Kim tra khi K 1- Kim tra s hon ho mch tn hiu K/A15. 2- thi gian duy tr bo h hng (khong 0,8s) 3- nhy ca khi theo knh U (khong 0,5V) 4- Kim tra n HG sng khi : - Thay i UA t -20 +20V, con ni SX1/H/A3 tho v U=0 - Khi thay i U trong ton gii hn c th v ni SX1/H /A3 - Khi chuyn ngun t sang /A11. /A1 5- Kim tra mch kho K/A15 khi : - Khi OP/A7 lm vic . - Khi ni 17A/ K/A15 vi -12,6V 5.5.15. Kim tra khi - Kim tra c kh relay - Kim tra in p ngun vi tiu chun Uob-9a= 27 28V - Th lin ng vi tn hiu tc ng cc khi , , , . ,

100

Phc trnh tp s

____________________________

Chng 6 KHI IU KHIN D PHNG AVN

CHNG 6 KHI IU KHIN D PHNG AVN

101

Phc trnh tp s6.1. CHC NNG

_________________________

Chng 6 KHI IU KHIN D PHNG AVN

B AVN l b iu chnh in p my pht d phng, dng iu chnh bng tay t xa b chnh lu thyristor. AVN c a vo lm vic khi h hng b iu chnh chnh AVM. Theo lnh ng kch t AVN tc ng nng in p my pht ln nh mc Tham gia iu chnh in p ca h thng khi my pht trong li. Khi ct ti AVN t tr s cc tiu loi tr Ustato tng vt Cc ch lm vic: Ty thuc vo AVM ng hay ct m AVN 2 ch theo di hoc iu khin S khi AVN c v trn hnh 14 Trong : - T2: atrit in p stator: nhn ngun t bin p TV12 qua SF3, T2 gim p a vo BM. - BM: B chnh lu v lc: in p ra ca BM khong 13 14V khi UP = UFm. - H2: Ngun n p: H2 nhn ngun 15V t -2, n nh 12,5V cung cp cho cc ngn K v P. - K: B nh: K nhn tn hiu in p my pht t T2, in p ra AVM (U50) v mch hi tip (U8) t ngn P. ng thi K nhn cc lnh logic t K18, K45, K46, K14 xc nh ch lm vic ca AVN. - P: Ngn iu khin: so snh, khuch i, to in p ra ca AVN (U42). Tr s ny c a n Y-2 ca AV1, AV2 trong ch iu khin H thng kch t bng AVN. ng thi ngn P xc nh phm vi iu chnh ca b AVN.

6.2.

NGUYN L LM VIC CA AVN B iu khin d phng AVN lm vic hai ch : theo di v iu chnh

6.2.1.

Ch theo di B iu chnh AVN thc hin ch theo di khi r le K18 ng (tc l b AVM ng) Ch theo di ca AVN l ch m n to ra in p U42, gn bng in p ra ca AVM (U50), khi cn thit chuyn t AVM sang AVN, in p ca my pht vn khng thay i thi im chuyn i. Mch 40 t attrit in p cung cp cho K. K c h s khuch i bng -1 nn U = -U15 khi tho dy ni XP1 XP2. U10A1 ngn P 0 Khi a vo XP1 XP2, do c c mch hi tip U8 t P qua K, so snh vi

102

Phc trnh tp s

_________________________

Chng 6 KHI IU KHIN D PHNG AVN

U50 ca AVM, trn A2(K) nn u ra ngn P (U8) U50. Khi c s sai lch gia U8 v U50, qua A2 (K) a n u vo A1(K) lm thay i in p trn t C12, dn n U15 thay i. Lc qua A1, A2 ca P, U8 s c ko v bng U50. 6.2.2. Ch iu khin B iu chnh AVN thc hin ch iu khin khi K18 ct (tc l b AVM ct). Lc ny r le K1(K) ng, ct u ra b khuch i A2, ng thi tch t C12 khi u ra b khuch i A1(K), a vo in tr R18. Lc in p trn t C12 gi khng i nn U15 khng i nn in p my pht gi nguyn gi tr trc . By gi b AVN tin hnh ch iu khin. Do U15 = const (hng s), nn in p my pht c iu chnh theo U42. Lc ny K1 trong P ng U42 a n khi AV iu khin thyristor. * Tng, gim kch t: R le K45, K46 lm ng K2 hoc K3 trong K, s lm np v x t C12, lm U15 thay i, s lm tng hoc gim in p ca my pht. * Khi my ct 13,8KV ct: Khi chuyn kch t t b AVM sang b AVN, cng nh khi ng kch t bng AVN, m K14 ct, rle K4(K) ng t C12 x, a diode VD14 vo mch, lc ny in p my pht UMF c ko v tr s nh xc nh bi VD14. Do c t C19, sau r le K4 c ct ra, khi ta c th iu chnh AVN bng K2, K3. * Phm vi iu chnh ca b AVN: Tr s cc tiu xc nh bi R9 (ngn P). Khi U15 < U16 c ly t R9, U42 c xc nh theo U16, khong 0,82 0,85 Um Tr s cc i xc nh bi R2 ngn K c chnh t 108 110% Um. * Ch cos = 1: Khi K42 hoc K51 ng lm K2 ng (ngn P). VD2, VD3 b ni tt. Lc ny U42 c a v tr s sao cho dng roto ln nht ng vi cng sut thc bng m v cng sut khng bng 0. * Hn ch IP = 1,1IPm: Xc nh bi VD2, VD6 v R11. Khi in p vo A1 vt qu ngng ca VD2 VD6 s a R11(63) so vi R6(62) gim nh h s khuych i ca ngn P.

6.3.

KHI KIM TRA K-2 V KHI NGUN -2 103

Phc trnh tp s

_________________________

Chng 6 KHI IU KHIN D PHNG AVN

Khi -2 kim tra dn ca cc nhnh trong 2 b chnh lu v s t cu ch ca cc khi T 6.3.1. KIM SOT DN Tn hiu kim sot dn cc nhnh c ly t bin dng cc nhnh ca b chnh lu, qua b chnh lu cu 1 pha thnh in p mt chiu vo ngn KT1, KT2. y in p c so snh vi in p ta nhn bit dn ca cc nhnh K-2 c th bo mt dn mt nhnh hoc hai nhnh cng tn. S mt dn s c cc rle trung gian, a tn hiu ra s bn ngoi. trnh s bo sai ca mch mt dn, khi khi ng v dng K-2 a n tn hiu t bin dng roto TP. Theo mch ny, mch bo mt dn ch lm vic khi dng roto 550A. 6.3.2. KIM TRA CU CH Khi t cu ch trong cc khi T, cc tip im cu ch ni ngun 24V qua cc in tr RL a n ngn ca K-2, tc ng mch t cu ch. Mch t cu ch c th bo t mt cu ch, 2 hoc 3 cu ch 2 nhnh cng tn. Tn hiu ny c bo ti K-2 bng diod quang nh cc rle trung gian a tn hiu ra s bn ngoi. Ngun cung cp cho K-2 c ly t khi -2 6.3.3. -2 KHI NGUN Khi ngun -2 cung cp cho khi K-2 v b iu chnh d phng AVN Khi ngun -2 nhn ngun xoay chiu 3 pha 380V t p t mt SF9 v ngun mt chiu 220V t p t mt SF10. in p xoay chiu qua bin p T, gim p a vo ngn 2 chnh lu. Cc ngn CT2-1, CT2-2 v CT3 to ngun n nh in p 15V v 20V Cc ngn VT1, Y, 1 v Y dng to ngun t ngun mt chiu 220V, khi cha c in p xoay chiu, hoc khi in p xoay chiu gim nh hn 0,8 gi tr in p nh mc.

104

Phc trnh tp s

____________________________Chng 7IU KHIN V BO V H THNG KCH T

CHNG 7 CC H HNG TRONG H THNG KCH T

105

Phc trnh tp sCHNG 7 CC H HNG TRONG H THNG KCH T

7.1.

CC H HNG THNG GP TRONG H THNG KCH T :

ST T

01 02

THIT B H HNG B V1,V2 lch dng V1(400); V2(700) Kzp tc ng ct QAE Khi ca b AV1

NGUYN NHN H HNG Bulng ni nhnh BT5 vo thanh ci tip xc khng tt Nc ma lm chm mch Rotor (Rcc ) Mt 01 pha, do ngn mch qua v bin p TP1 Tip im khng tip xc, khng khi ng c P

BIN PHP KHC PHC Ct b V1, tho cc khi BT5 xit li Thi kh nc, lm sch bi in tr Rcc Lt tm cch in di bin p TP1, ng thi lm cho tt c cc bin p cn li Tng cng thm cc tip im ni //, tng tin cy cho mch khi ng P Thay th t in v in tr Hn li mch Thay th t tt Thay Zener V31 trn tm Thay diode VD3 Ct u cp a vo Shunt a u cp vo hng kp ni chung vi dy a ln ng h dng Rotor GCE4 t li v tr cc diode

GHI CH

H1 H1

03

H1

04

R le K57 ng h V1, V2 dao ng

H1

05 06 07 08 09

-H hng bin tr R/HC1 -H hng t C1/VT2-2 Khng ch th trn ng Khi /AVM h do t mch Chy in tr T in trong mch b b lc RC chp OMB tc ng ri c Khi OMB, hiu KH37 do h hng /AVM Tm KT2/ - Bo mt dn V2, cc tc ng sai nhnh vn bnh thng ng h dng Rotor GC4 lch so vi GCE4 Cp 2183 t GCE4 n ng do tip xc gia cp v u Shunt khng tt h dng Rotor/GC4 Khi -, KH17 bo mt dn nhnh V2 Diode VD9 chm v gy ngn mch u ra

H1 H2 H2 H2 H2

10

H3

11

H3

106

Phc trnh tp sCHNG 7 CC H HNG TRONG H THNG KCH T ST T

THIT B H HNG Mch iu khin kch t / AVM /AVM /AVM

12

NGUYN NHN H HNG Mch 397;398 lin ng my ct khi 220KV chm t

BIN PHP KHC PHC B mch lin ng vi my ct khi, thc hin theo s mi ch lin ng vi my ct 13,8KV

GHI CH

H3

13 14 15 16

17

Ct AVM qua KV1, K20

18

/AVM in p ra 12,5V khng n p

19

HTKT KV1 (115Um)tc ng ct K15,AVM

20

Khng tc ng , Sa cha li rle PB do PB b kt, gy H3 cht Bo qu nhit Rotor Thay vi mch D4/ H4 Bo qu ti Rotor, Thay vi mch A3/ Vi mch A3 khng H4 n nh in p rotor dao Thay vi mch khuch i D7 v ng ,h hng vi H4 t C20 mch v t in p u ra my Thay V1(KT808) bng pht tng cao Transistor 2N3055 (15KV) Thay V2(KT602) bng Do diode V2/ khi lm Transistor H1061 vic pht nng H2 chm vo 02 dy V3, V4 lm V1(KT808) cht dn n cc ngun chm nhau Do transistor Thay bng Transistor C2383 V8(KT608 thng ) Thay D1 iu chnh in p kiu Kh lm in p trn i DF xung qua cun dy L bng V10 ng kch t khng a mch lin ng ti t t thnh cng (do h ng vo hng kp mch t iu kin H3 tc my pht t 95Um) Do u nhm mch u li mch p TV12 p TV12 H3

107

LI CM N

Trong thi gian tp s va qua, c s quan tm ca Lnh o Phn xng in - T ng to iu kin cho ti c hc tp, nghin cu v tm hiu cc thit b ca Cng ty Thy in Tr An,c bit l H thng kch t ca t my. Nhng kin thc thc t qu bu l s b sung, hon thin cho nhng l thuyt c trang b trong nh trng v s p dng vo thc t cng vic. Qu trnh thi gian tp s ti Cng ty ngoi vic nghin cu ti liu ti cng hc hi c rt nhiu t nhng anh ch T Th Nghim v c bit l cc anh trong Nhm Kch t, Phn xng in -T ng . Nhng ngi lun sn sng gii thch nhng thc mc ca ti. Qua y ti xin gi li cm n ti cc Anh. Xin c gi li tri n ti anh Bi Chnh ch, ngi trc tip hng dn ti hon thnh Phc trnh tp s ny. Tuy c nhng c gng nhng khng trnh khi nhng thiu st, rt mong s ch bo ca cc Anh, cc Ch b sung thm nhng kin thc qi bu ti c lm vic tt hn trong thi gian ti. Mt ln na ti xin chn thnh cm n Lnh o Cng ty, Lnh o Phn xng in-T ng quan tm to iu kin ti hon thnh Phc trnh tp s trong thi gian qua. Tr An, thng 05 nm 2009 Ngi vit Nhn xt ca ngi hng dn: Huy Sn ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ...................................................................... ......................................................................

*Nhn xt ca T Trng T Th nghim :

*Nhn xt ca Qun c Phn xng in- T ng :

.