lỜi nÓi ĐẦu hệ thống các thiết bị đóng cắt có một ý bảo...

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LI NI U

Trong s nghip cng nghip ha, hin i ha t nc, cng nghip

in lc gi vai tr c bit quan trng, bi v in nng l ngun nng lng

c dng rng ri nht trong cc nghnh kinh t quc dn, vi vai tr nh

vy mt yu cu t ra cho h thng in l lm th no h thng cung cp

in lm vic c tin cy cao p ng mt cch tt nht nhu cu in nng

ngy cng pht truyn ca x hi. H thng cc thit b ng ct c mt

ngha quan trng trong h thng in. N m bo cho cc thit b in ch

yu nh my pht in, my bin p, ng dy dn in trn khng v cp

ngun, cc ng c inv ton b h thng in lm vic an ton, tin cy.

Cc thit b ng ct c nhim v l bo v v ng ct cc thit b in

trong h thng in, kp thi sa thi nhng phn t h thng khi h thng

in x l nhanh chng cc s c. Mt trong nhng s c nghim trng

trong h thng in l cc dng ngn mch, ngoi ra cn c cc s c nh

chm t, mt pha, qu ti

thc hin chc nng ng ct v bo v, yu cu i vi cc thit b

ng ct l lm vic tin cy, nhy cm cao, tnh tc ng nhanh v

bo v c chn lc.

Hin nay, h thng li in Vit Nam ang trn pht trin ha

nhp cng vi cc nc trn th gii nn h thng cc thit b ng ct cng

i mi vi nhiu chng loi mi, cng vi cc cng ngh tin tin ca nhiu

hng nh ABB, Siemens, Schneider Vi nhng l do em chn ti v

Nghin cu my ct thp p dng ln hng schneider ng dng trong

bng in chnh cc trm pht d phng khi ng t ng cc ng c

diesel.

nguyn cu su v cc thit b ng ct, bn n trnh by nhng

ni dung ch yu nh sau:

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Chng 1: Gii thiu chung v thit b ng ct thp p

Chng 2: Gii thiu v ptmt hng schneider

Chng 3: My ct ng dng trong cc bng in phn phi ca cc trm

pht d phng t ng ton phn.

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CHNG 1

GII THIU CHUNG THIT V B NG CT THP P

1.1. KHI QUT V YU CU CHUNG CHO CC THIT B NG

CT

1.1.1. Khi nim

My ct h p (cn gi l ptmt hay my ngt khng kh t ng), l

kh c in t ng ct mch in khi c s c: qu ti, ngn mch, in p

thp, cng sut ngc Trong cc mch in h p c in p nh mc n

660V xoay chiu v 330V mt chiu, c dng in nh mc ti 6000A.

Nhng my ct h p hin i c th ct dng in ti 300 kA.

i khi my ct h p cng c dng ng, ct khng thng xuyn

cc mch in ch bnh thng.

1.1.2. Yu cu

Ch lm vic nh mc ca my ct h p phi l ch lm vic di

hn, ngha l tr s dng in nh mc chy qua my ct lu bao nhiu cng

c. Mt khc tip im chnh ca n phi chu c dng in ngn mch

ln khi cc tip im c th ng hay ang ng.

My ct h p phi ngt c dng in ngn mch ln, c th n vi chc

kilampe. Sau khi ngt dng in ngn mch, my ct h p phi m bo

vn lm vic tt tr s dng in nh mc.

nng cao tnh n nh nhit v in ng ca cc thit b in, hn ch

s ngn mch do dng in ngn mch gy ra, my ct h p phi c thi gian

ct b.

gim kch thc lp t ca thit b v an ton trong vn hnh cn

phi hn ch vng chy h quang. Mun vy thng phi kt hp lc thao tc

c hc vi thit b dp h quang bn trong my ct h p.

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thc hin yu cu thao tc c chn lc, my ct h p cn phi c kh

nng iu chnh tr s dng in tc ng v thi gian tc ng.

Nhng thng s c bn ca my ct h p gm: Dng in nh mc Im,

in p nh mc Um, dng in ngt gii hn v thi gian tc ng.

Thi gian tc ng ca my ct h p l mt thng s quan trng. Thi

gian ny c tnh t lc xy ra s c n khi ngn mch in b ngt hon

ton.

CT: t = t0 + t1+ t2 ( 1 - 1 )

Trong :

+ t0 l thi gian tnh t lc xy ra ngn mch n khi dng in t ti tr s

tc ng I = It. Thi gian t0 ph thuc vo gi tr ca dng in khi ng, v

tc tng ca dng in t

i

d

d ph thuc vo thng s mch ngt.

+ t1 l thi gian t khi I = Itd n khi tip im my ct bt u chuyn ng,

thi gian ny ph thuc vo cc phn t bo v, c cu ngt, kt cu ca tip

im, trng lng phn ng. Nu t1 > 0.01s th my ngt c thi gian tc

ng bnh thng. i vi my ct tc ng nhanh, thi gian t1 = 0.002

0.008s

+ t2 l thi gian chy ca h quang (ph thuc b phn dp h quang v tr

dng in ngt v bin php dp h quang).

1.1.3. Phn loi

a, Phn theo kt cu

+ Loi mt cc

+ Loi hai cc

+ Loi ba cc

b, Theo thi gian tc ng

+ Tc ng tc thi (nhanh)

+ Tc ng khng tc thi

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c, Theo cng c bo v

+ Dng cc i

+ Dng cc tiu

+ ptmt in p thp

+ ptmt dng in cc tiu

+ ptmt bo v cng sut ngc

+ ptmt vn nng (ch to ch to cho mch c dng in ln cc thng

s bo v c th chnh nh c) loi ny khng c v v lp t trong cc

trm bin p ln.

+ ptmt nh hnh: bo v qu ti bng rle nhit, bo v qu in p

bng rle in t, t trong v nha.

1.2. NGUYN L LM VIC CA PTMT

1.2.1. Nguyn l lm vic ca ptmt tc ng theo mc dng

+ Loi dng cc tiu

Hnh 1.1. S nguyn l ptmt dng in cc tiu

Nguyn l lm vic: N t ng ngt mch khi dng in trong mch nh

hn dng in chnh nh Ic. Khi I < Ic, lc in t ca nam chm in 1

khng sc gi np 2 nn lc ko ca l xo 3 s ko tip im ng ra khi

tip im tnh, mch in b ngt. ptmt dng cc tiu dng bo v my

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pht khi chuyn sang ch ng c khi nhiu my pht lm vic song

song, v ptmt loi dng cc tiu c nhiu nhc im nn t s dng.

+ Loi dng cc i

Hnh 1.2. S nguyn l ptmt dng in cc i.

Nguyn l lm vic: ptmt loi dng cc i t ng ngt mch khi

dng in vt qu tr s dng chnh nh Ic. Khi I > Ic, lc in t ca nam

chm in 1 thng lc cn l xo 3, np 2 b ko lm mu gia thanh 4 v n

5 bt ra, l xo ngt 6 ko tip im ng ra khi tip im tnh, mch in b

ngt. pmt dng cc i dng bo v mch in khi b qu ti hoc ngn

mch.

1.2.2. Nguyn l tc ng ca ptmt theo in p

+ Loi thp p

Nguyn l lm vic: N t ng ngt mch khi in p U gim xung

di mc chnh nh Uc. Nu U < Uc. Lc in t ca nam chm in 1

c cun dy mc song song vi li gim yu hn lc ko ca l xo 3 nn

mu gia thanh 4 v n 5 bt ra, l xo 6 ko tip im ng ri khi tip

im tnh, mch in b ct. ptmt in p thp dng bo v mch

in khi in p st qu thp hay khi mt in p ( bo v thp p UTA

85% Um ).

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Hnh 1.3. S nguyn l ptmt in p thp

+ ptmt loi dng in ngc ( cho mng mt chiu)

p

dng

Hnh 1.4. Nguyn l lm vic ca ptmt dng in ngc

Thun dngp

Ngc dngp

Nguyn l lm vic: N t ng ct mch in khi hng truyn dng

in thay i (khi dng in thay i chiu). Nu nng lng truyn thun

chiu, t thng ca cun dy dng in v cun dy in p ca nam chm

in 1 cng chiu vi nhau, lc in t ln hn lc l xo 3, ptmt ng.

Khi chiu dng in thay i (cng sut truyn ngc), lc in t ca nam

chm in t l vi bnh phng hiu hai t thng do dng in v in p

sinh ra, do lc in t gim i rt nhiu, khng thng ni lc ko l xo 3,

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mu gia thanh 4 v n 5 bt ra, l xo ngt 6 ko tip im ng ri khi

tip im tnh, mch in b ngt.

1.3. NI TNG CASCADE PTMT

1.3.1. Ni tng tc ng theo mc dng

K thut ny s dng s phn bc ngng dng tc ng ca phn t tc

ng tc thi kiu t, tnh chn lc tuyt i trong trng hp ny l khng

th c do ISCA ISCB nn c hai CB ny cng tc ng, khi y chn lc l tng

phn v c gii hn theo Irm ca CB nm pha trc, CB pha sau l loi

hn ch dng.

ci thin c tnh chn lc theo gi tr dng nn s dng mt CB hn

ch dng mch pha sau ngha l CB khi xy ra ngn mch pha sau thit b

B, dng hn ch IB s tc ng CB B, song khng A tc ng.

Lu : mi CB m ta xem xt y u c mc hn ch dng no , d

cho chng khng c xp vo loi hn ch dng. iu ny cn lu cho c

tuyn ca CB chun A trn hnh di y. Ch bng cch tnh ton v th

nghim cn thn mi cho php thc thi kiu phi hp ny.

Hnh 1.5. CB B l gii hn dng.

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CB pha trc c dng tc ng nhanh vi tr hn ngn (SD).

Cc thit b ny c trang b b tc ng c gn thm b lm tr c hc

khng hiu chnh. Nh vy tr a vo m bo tnh chn lc vi tt c

CB tc ng nhanh (t pha sau) vi b k dng s c no nh hn Irms.

V d CB A: compact NS250N trang b mt b tc ng SD Ir = 250, gi

tr t b tc ng l 2000A. CB B compact NS100N, Ir = 100A. Sch tra cu

phn phi in Merlin Gerin cho bit gi tr gii hn ca tnh chn lc:

3000A (thay v 2500A nu nh ta s dng b tc ng kiu chun).

Hnh 1.6. S dng mt CB chn lc pha trc.

1.3.2. Ni tng tc ng theo thi gian

S tc ng theo thi gian ca cc CB c tnh chn lc. ng dng ca n

l tng i n gin v n da trn c s lm tr nhiu hoc t thi im m

ca cc CB mc ni tip theo trnh t thi gian kiu bc thang.

K thut ny cn

a vo b nh th trong c cu tc ng

Cc CB c kh nng chu c cc hiu ng nhit v in ng ca dng

trong thi gian tr.

Hai CB A v B mc ni tip (nh vy gi tr dng i qua chng l nh

nhau) s c tnh chn lc nu nh thi gian ct ca B ngn hn thi gian tc

ng ca A

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Chn lc nhiu cp

V d: thc hin vi cc CB Masterpact (bo v in t) (MG)

Chng c th c trang b cc b to tr bn nc iu chnh nh:

- tr (tng ng vi mt nc cho trc) c gi tr ln hn ton b thi

gian ct ca nc thp hn ngay pha sau.

- tr tng ng vi nc u tin c gi tr ln hn ton b thi gian ct ca

mt CB ct nhanh (dng compact) hoc ca cu ch.

Hnh 1.7. Chn lc theo thi gian.

1.3.3. Ni tng kt hp

Hnh 1.8. Chn lc kt hp.

Mt b lm tr thi gian kiu c hc gp phn ci thin c tnh ca chn

lc theo tc ng dng

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Chn lc tuyt i nu ISCB < IrmA (gi tr tcc thi)

CB pha trc c th s dng hai ngng tc ng

Gi tr tr IrmA hoc to b tr kiu in t SD (short delay)

Gi tr tc thi IrmA chun (Compact kiu SA)

1.3.4. Ni tng da trn mc nng lng h quang

H thng ny cho php chn lc tuyt i gia hai CB c cng dng s

c. iu ny t c nh s dng CB hn ch dng v tc ng CB nh cm

ng p sut trong bung h quang ca CB. Mc p sut khng kh b nng ln

tu thuc vo mc nng lng ca h quang.

Hnh 1.9. Chn lc theo mc h quang.

K thut ny dng cho cc mch c dng ngn mch 25In v m bo

tnh chn lc tuyt i gia hai CB c cng dng ngn mch i qua, k thut

ny i hi nng lng lm tc ng CB A trn ngun.

Nguyn tc vn hnh: C hai CB c kh nng hn ch dng, do lc in t

do ngn mch pha di ca CB B lm tip im h quang hn ch dng ca

c hai CB ng thi m. Dng s c s b hn ch nh hai h quang mc ni

tip cng nhit h quang trong mi CB lm khng kh trong cc ngn dp

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h quang n ra v tng p sut. trn mt mc dng no , tc tng p

sut c th dng pht hin v khi ng ct tc thi.

Hnh 1.10. Nguyn tc chn lc theo nng lng h quang.

Nguyn tc chn lc: Nu c hai CB c b ct theo p sut c chnh nh

ng, s chn lc cho hai CB c nh mc khc nhau i hi phi chnh CB

B ct mc p sut thp hn CB A. Nu ngn mch xy ra sau A v trc B,

ch c h quang ca A hn ch dng m thi. Dng trong trng hp ny s

ln hn so vi trng hp s c sy ra sau B. Dng qua A ln hn s sinh p

sut ln hn, lm b tc ng theo p sut lm vic s di y,

dng CB cng ln th CB ct cng nhanh.

S chn lc c m bo nu

+ T s dng nh mc ca 2 CB 2,5

+ T s dng ngt chnh nh > 1,6

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i vi iu kin ngt mch 25 In ta dng s bo v truyn thng nh

cp.

1.4. CU TO CHUNG CA PTMT

1.4.1. t vn

Ngy nay di s pht trin mnh m ca khoa hc k thut nn cc thit

b in c sn xut mt cch n gin, gn nh, cha nhiu tnh nng hn

trc kia rt nhiu v c bit l cc thit b in ngy nay a s l c th

ghp ni c cng vi my tnh, c iu khin trc tip trn my tnh

hoc l iu khin t xa thng qua b iu khin cm tay, ptmt cng l

mt trong nhng thit b .

1.4.2. Phn c kh ca ptmt

Hnh 1.11. Hnh nh ptmt.

1.4.3. Tip im ca aptmt

).

). Nh vy h

quang ch chy trn tip im h quang, do bo v c tip im chnh

dn in. Dng thm tip im ph trnh h quang chy lan vo lm h

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tip im chnh.

g nh Ag-W, Cu-W, Ni...

1.4.4. Mc bo v

, s tc

ng khi mch in c s c qu dng in v st p.

-

.

.

).

.

.

600A.

, cun dy c ny

c qun nhiu vng vi dy tit din nh chu in p ngun.

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1.4.5. Hp dp h quang

Hp dp h quang: ptmt dp c h quang trong tt c cc ch

lm vic ca li in th ngi ta thng dng hai kiu thit b dp h

quang l: kiu na kn v kiu h. Thit b dp kiu na kn c t trong

v kn ca ptmt v c l thot kh.

Hnh 1.12. Cu trc chung ca ptmt.

Kiu ny c dng in gii hn ct khng qu 50kA. Thit b dp kiu h

c dng khi gii hn dng in ct ln hn 50kA hoc in p ln hn

1000V. Trong bung dp h quang thng dng ngi ta thng dng nhng

tm thp xp thnh li ngn. phn chia h quang thnh nhiu on

ngn thun li cho vic dp tt h quang. Hnh dng kt cu hp dp h

quang c trnh by trn. Cng mt thit b dp tt h quang, khi lm

vic mch in xoay chiu in p n 500V th c th dp tt c h

quang ca dng in n 40kA, nhng khi lm vic mch in mt chiu

in p n 440V th ch c th ct c dng in n 20kA.

1.4.6. C cu truyn ng ct ptmt

C cu truyn ng ct ptmt: gm c cu ng ct v khu truyn

ng trung gian, truyn ng ct ptmt thng c hai cch: bng tay v

bng c in (in t, ng c in). iu khin bng tay (nm gt hoc nt

n) c thc hin vi cc ptmt c dng in nh mc khng ln hn

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600A. iu khin bng c in (nam chm in, ng c in, hoc h thng

thu lc) c ng dng cc ptmt ng ct t xa v c ng dng vi

ptmt c dng in ln hn n 1000A. tng lc iu khin bng tay

ngi ta cn dng mt tay di ph theo nguyn l n by. Ngoi ra cn c

cch iu khin bng ng c in hoc kh nn.

Khu truyn ng trung gian dng ph bin nht trong ptmt l c cu

t do trt khp. Hnh 1.13 trnh by mt khu truyn ng trung gian ca

ptmt c c cu iu khin bng nam chm in. Khi ng bnh thng

(khng c s c) , cc tay n 2, 3 c ni cng v tm O nm thp di

ng ni hai im O1 v O2 c ni. Gi 5 lm cho hai n ny khng

t gp li c, ta ni im O v tr cht ( hnh 1.13a )

Khi c s c, phn ng 6 ca nam chm in 7 b ht dp vo h thng

tay n 2, 3 lm cho im O thot khi v tr cht. im O s cao hn ng

ni O1O2, lc ny hai tay n 2, 3 khng c ni cng na, cc tip im s

nhanh chng m ra di tc ng ca l xo ko tip im (hh 1.13b)

Mun ng li ptmt, ta phi ko tay cm 4 xung pha di cho hai tay

n 2, 3 dui thng ra nh hnh 1.13c, sau mi ng vo c

Hnh 1.13. C cu nh khp t do a, v tr dng; b, v tr m; c v tr chun b

ng li.

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1.4.7. Phn t bo v

Cc phn t bo v ptmt gm: bo v qu ti, bo v ngn mch, bo

v st p, bo v dng in d, bo v tng hp bng t hp mch in t.

bo v thit b khi qu ti, trong ptmt thng c phn t bo v

qu ti, kt cu ca n tng t nh mt rle nhit, phn t pht nng ca r

le nhit c u ni tip vi mch in chnh. Khi qu ti, tm kim loi kp

gin n lm nh ri t do m tip im ca ptmt. ng c tnh

ampe- giy ca rle nhit phi nm di ng c tnh ca thit b bo v.

Loi ny c nhc im c qun tnh nhit ln v khng bo v c ngn

mch.

Phn t bo v ngn mch trong ptmt c kt cu tng t nh mt

rle dng in, c cun dy mc ni tip vi mch in chnh (hoc mt phn

dng in chnh i qua cun dy). Khi dng in vt qu tr s cho php th

phn ng b ht, lm nh khp ri t do v m tip im ptmt.

iu chnh vt thay i lc ca l xo phn lc ta c th iu chnh c tr

s dng in ti ng.

Phn t bo v st p c kt cu tng t nh rle in p, cun dy

c mc vo in p ngun, khi c s c st p hay mt in p, lc ht

in t khng sc ht phn ng, l xo phn lc y phn ng, lm nh

khp ri t do v lm m tip im ca ptmt.

Phn t bo v dng in d, cng nh phn t bo v nhiu thng s

c cu to bi cc mch vi in t, trong cc khi o lng so snh,

khuch i v chp hnh.

1.5. LA CHN S B PTMT THNG THNG

1.5.1. t vn

hn ch nhng hu qu nguy him gy ph hng s c qu dng, qu

ti, s c hng cch in, v cch ly phn h hng ra khi li v vy vic la

chn thit b bo v cho mch in ht sc quan trng, v vic la chn

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phi da trn rt nhiu yu t nhng phi ph hp vi cc tiu chun ca tng

thit b, v phi tun th theo tiu chun quc t.

1.5.2. La chn theo mc dng

Vic la chn ptmt ch yu da vo: Dng n tnh ton trong mch,

dng in qu ti, tnh thao tc chn lc. Ngoi ra la chn ptmt cn phi

cn c vo t tnh lm vic ca ph ti l ptmt khng c php ct khi

c qu ti ngn hn thng xy ra trong iu kin lm vic bnh thng nh

dng in khi ng, dng in ng trong ph ti cng ngh.

Yu cu chung l lm vic nh mc ca mc bo v Iptmt khng c

b hn dng in tnh ton Itt ca mch:

Iptmt Itt ( 1-2 )

Ty theo c tnh v iu kin lm vic ca ph ti, ngi ta hng dn

la chn dng in nh mc ca mc bo v bng 125%, 150%, hay ln hn

na so vi dng in tnh ton mch.

Sau cng ta chn ptmt theo cc s liu k thut cho ca nh ch to.

ptmt c la chn t hai h thng: H thng ct mch in v h thng

d tm s c.

+ Chn h thng cch b tr ct mch in

H thng ny gm c lin ng c kh vi cc cc ct dng in v s

c b tr theo cc chc nng sau: S lung cc cc: S lng cc dy dn

ct, in p nh mc (in p s dng), loi dng in (xoay chiu hay

mt chiu).

Dng in Ib: dng in s dng ca mch in, chnh dng in ny cho

php ta xc nh dng in nh mc m ngi ta gi l c ptmt. Dng

in ngn mch Icc: l dng ngn mch m kh c in (ptmt) c th

chp nhn c c th ct tin hnh bo v ngay lp tc cc thit b in

pha sau ca ptmt. Chng ta lun lun phi chn ptmt c kh nng ct

cao hn dng Icc tnh ton pha sau ptmt.

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+ Chn loi h thng m ( hay d tm s c thc hin tc ng m )

S b tr in t - nhit hay in t, thc hin iu khin ca cc cc ct,

c chn theo chc nng: Dng Ib, dng in cc i m n i qua mch

in khi lm vic bnh thng. Dng in t ngt xut hin khi t di in

p (dng in m my). Ty theo gi tr qu dng in ny, ngi ta xc nh

loi ung cong s dng (B, C, D) ca h thng m ca ptmt. (chn

ung t tuyn ca h thng trong catl m cc nh sn xut v vin gim

nh khoa hc k thut gim nh.

Ngoi ra CB cn c la chn tu vo

Cc c tnh in m n c t vo: mi trng s dng ca thit b,

nhit xung quanh, lp t trong t hoc khng, cc iu kin kh hu kh

nng to v ct dng ngn mch.

Cc yu cu khai thc tnh chn lc, cc yu cu nh iu khin t xa,

cc cng tc ph, cc cun dy tc ng ph, c a thm vo h thng mng

tn hiu ni b (thng tin, iu khin, ch th,)

Cc quy tc lp t, c bit l bo v con ngi

Cc c tnh ti nh l ng c, n chiu sng hunh quang, my bin p

Nhng bc tip theo gn lin vi vic chn mt CB trong li phn phi.

+ Chn dng nh mc ph thuc nhit mi trng

Dng nh mc ca mt CB c xc nh theo s vn hnh ca thit b

ng vi nhit mi trng cho trc, thng l 300 cho cc CB dn dng,

400 cho CB cng nghip.

S vn hnh cc CB trong cc iu kin nhit khc nhau ph thuc

vo cng ngh ch to b tc ng

+ Cc b tc ng kiu in t nhit khng b

Cc CB vi b tc ng theo nguyn tc nhit khng b c dng tc ng

ph thuc vo nhit . Nu nh thit b c t trong t, hoc trong mi

trng nhit cao th dng tc ng khi qu ti c th b gim xung. C th

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chuyn hng nu CB lm vic vi nhit cao hn nhit chun. V vy,

cc nh thit k phi cung cp bng chuyn hng cho thit b c thit k,

mt khc cc thit b dng mun thng c lp cnh nhau trong t kim

loi c kch thc nh. Tc dng nhit qua li khi c dng, s lm chng

xung hng theo h s 0.8.

Cc b phn ny c trang b mt thanh lng kim b nhit cho php

chn dng hiu chnh Ir ca b phn tc ng theo s thay i nhit trong

phm vi nh sn CB ( 630A ) thng c trang b b phn tc ng t

nhit c b t -50 n +40

0 .

Ghi ch lin quan n vic gim nh mc ca CB

Mt CB c nh mc dng theo nhit mi trng chun (300C) s b qu

nhit khi mang nhit cng dng 500C.

V CB h p c thit b bo v qu dng (nu khng c b) s tc ng

mc thp hn khi nhit cao hn, CB t ng b gim nh mc do b tc

ng qu ti. khi b tc ng nhit c b c th chnh (0.71).In trong

mi trng -50C n 40

0C.

Vi cc CB c b ny trong catalogue thng c gi tr xng hng

ca In nhit trn mc c b, v d nh 500C v 60

0C, nh 95A 50

0C

v 90A 600C cho CB 100A.

+ B tc ng kiu in t

C u im ln v n nh khi vn hnh trong iu kin nhit thay

i. Mc d vy, cc thit b ng ct vn chu nh hng nhit nn nh

ch to thng cung cp di dng biu cc gi tr ln nht ca ngng

dng tc ng cho php theo nhit .

+ Chn ngng ct tc thi hoc c tr ngn

Sau y l bng tng kt cc c im chnh ca b tc ng kiu t hoc

c tr ngn (theo phn loi ca IEC898), bng tc ng tc thi hoc c tr

ngn.

21

Bng 1.1. Bng tc ng tc thi hoc c tr

+ Chn CB theo kh nng ct

Lp mt CB bo v trong mng phn phi in h th cn phi p ng

mt trong hai iu kin sau y:

Hoc c kh nng ct Icu (hoc Icn) t nht c gi tr bng dng ngn mch

gi nh ti im lp t.

Hoc, nu khng phi kt hp vi mt thit b ct khc t pha trc v

c kh nng ct cn thit. Trong trng hp ny c tnh ca hai thit b phi

c phi hp sao cho nng lng i qua thit b pha trc khng ln hn

kh nng chu ng (khng b h hi) ca cc thit b pha sau v ca h

thng dy dn c bo v bng cc thit b ny.

Kh nng tn dng trong:

Dng B tc ng ng dng

Ngng thp dng B My pht d phng

Dy c chiu di ln

Ngng chun dng C Bo v mch: Trng

hp chung

Ngng cao dng D, K

Bo v mch trong

trng hp qu ban

u ln

12In dng MA

Bo v ng c khi

phi hp vi cng tc

t ngt

22

Phi hp cu ch CB

Phi hp CB gii hn dng v CB tiu chun.

1.5.3. Mt s loi ptmt

a) Ptmt vn nng c phn t bo v in t, nhit.

Ptmt loi ny c ch to cho cc mch in cng sut ln, c th

chnh nh c cc thng s bo v trong phm vi tng i rng. Loi ny

thng c bo v ngn mch v bo v mt in p. N khng c v, dng

trong cc trm h p, cc trm phn phi hnh 1.12 trnh by nguyn l cu

to ca ptmt vn nng c dng in nh mc ln hn 200A trng thi

ngt.

Hnh 1.14. ptmt vn nng.

1, Tip im dp h quang 2, bung dp h quang 3, Tip im lm vic

4, Cun dy ng 5, Rle nhit 6,7. C cu t do tut khp 8. Rle dng in

cc i 9, 10. Rle in p 11. Cun dy ct t xa 12 Cn ng ct 13. Gi

ta.

Nu quay tay gt 12 i mt gc n v tr ng hoc iu khin t xa

bng h thng in t 4, thanh 6, 7 s p ln thanh gn cc tip im quay

23

trc O1. Ln lt cc tip im h quang 1 v tip im lm vic 3 ng,

mch in c ng hon ton. Khi c s c cc phn t bo v cn tc

ng y c cu t do tut khi khp (thanh 6,7) l xo 9 s ko thanh gn tip

im ng, ln lt tip im lm vic 3 sau tip im h quang 1 m ra.

H quang xut hin trn tip im 1 v nhanh chng c dp tt nh bung

dp h quang 2.

Cc phn t bo v bao gm: bo v qu ti nh rle nhit 5, 7, bo v

ngn mch bng rle dng in cc i 8 c cun dy (thng l thanh ci

vi s vng w = 1 i qua mch t) mc ni tip vi dng in ng lc, bo

v mt in p bng rle in p 10 c in p mc song song vi hai pha ca

li in, nam chm 11 ct ptmt t xa khi cn thit.

b) ptmt nh hnh:

Hnh 1.15. ptmt nh hnh.

1, u ni 2, 3, Bung dp h quang 4, Tip im tnh 5, C cu truyn

ng 6, Bo v qu ti 7, Bo v ngn mch 8, Nt ct.

Loi ptmt ny thng c dng in nh mc n 1600A, dng cho c

mch xoay chiu ln mt chiu. Hnh 1.15 trnh by nguyn l cu to ca

ptmt nh hnh. Loi ny thng ch c rle nhit v rle dng in cc

24

i bo v qu ti v ngn mch. Tt c cc chi tit u c t trong v

nha kn c kch thc nh, gn, s dng rt tin li, dng thay th cu

dao, cu ch rt tt.

25

CHNG 2

GII THIU V PTMT HNG SCHNEIDER

2.1. T VN

Trong thi i cng nghip ha hin i ha hin nay cc nh my x

nghip, cc th pht truyn ko theo l cc ta nh cao tng, cc khu vui

chi pht truyn mt cch nhanh chng. Vi xu th ko theo s cn

cung cp nng lng in v vic bo tr cng nh vic s dng cc kh c

bo v cc thit b in, s dng chng mt cch hp l qu trnh pht

truyn t nc c nhanh chng v m bo an ton trong khi vn hnh cc

thit b cng nh s dng chng ng vi tc dng ca n l rt cn thit.

2.2. CU TO CHUNG CA PTMT HNG SCHNEIDER

2.2.1. Tip im

Nhng c trng xy dng phn chuyn ng.

Hnh 2.1. Mch chn lc

26

Hnh 2.2. Mch hn ch hin thi.

1. Gi lm bng thp tm.

2. Cm bin dng in tc ng.

3. u ni chng git.

4. u ni nm ngang.

5a. Tip im tnh.

5b. Tip im h quang.

6a. Tip im chnh ( ng ).

6b. Tip im h quang ( ng ).

7. Bung dp h quang.

8. Tip im trt.

9. Cun nh bo v.

10. Cun iu khin ng m.

11. L xo ng.

12. L xo to lc ng.

13. Cn np ct bng tay.

27

14. Thit b ko tho.

15. Thit b ng, m tc ng iu khin.

2.2.2. Phn c kh

Gm cc c cu ca ptmt

Hnh 2.3. phn c kh

(1) Trip bar: Thanh nh l kh ( thanh trung gian ).

( 2) Tripping Actuator: Thit b tc ng to nh.

(3) Unit Case ( n v hp): Khi ngn mch li xy ra, a ch lin lc

c m v h quang c to ra gia cc a ch lin lc. Vo thi im

p lc trong n v cao.

(4) Hole ( l): p sut kh cao thi qua l xoay vp thit b truyn ng.

2.2.3. Dp h quang

Dp h quang bng thit b dp na h dng cho Ptmt. Trong cu

trc ca bung dp h quang c cc thanh thp chia nh dng h quang.

28

Hnh 2.4. Arc Extinguishing Concep

PA t ng-Nc l cng ngh tng b gin on hiu sut bng cch thi

kh. h quang bi gc bn phi. p sut kh c to ra t vt liu polymer

cao c tch ly trong tch ly khng gian, v kh c thi vo cung dp

tt. c bit l cng ngh ny ci thin cao hiu sut ph v in p.

Extinguishing unit : Hp dp h quang.

Movable conductor : Tip im ng.

Unit case : V, hp.

Gas flow : Lu lng kh.

Arc : H quang.

Fixed conductor : Cht dn ( dy dn c nh).

VJC insulation (high polymer materials): Tm cch in nhit s dng

VJC.

(1) Ablation (2) Gas accumulating (3) Gas flow (4) Arc extinguishing : (1)

loi tr -(2) kh ga-(3) lu lng kh-(4) cung dp tt

29

2.2.4. Cc c tnh

2.2.4.1. ng cong chc nng L-I

L: Long time khi dng nh thi gian tc ng chm

S: Short time ct trong trng hp ngn mch vi thi gian tc ng nhanh

I: Iustant time Ct khn cp khi dng ln vi thi gian nh

Hnh 2.5. c tnh ng cong chc nng L-I

2.2.4.2. ng cong chc nng L-S(t=k/I2)-I

Hnh 2.6. c tnh ng cong chc nng L-S(t=k/I2)-I

30

2.2.4.3. ng cong chc nng L-S(t=k)-I

Hnh 2.7. c tnh ng cong chc nng L-S(t=k)-I

2.2.4.4. ng cong chc nng G

.

Hnh 2.8. c tnh ng cong chc nng G

31

2.3. Cc i lng v thng s ca ptmt khi cn tnh ton

a, i lng la chn v kim tra

in p nh mc, kV mmmMC UU ,

Dng in lu di nh mc, A cbmMC II

Dng in ct nh mc, kVA Nmc II

Cng sut nh mc, kA Nmc SS

Dng in ngn mch xung kch cho php, kA

(cn gi l dng n nh ng)

xkm ii .

Dng in n nh nhit

nhm

qd

nhdmt

tii

.

.

Trong k hiu dng bng trn

mmU . in p nh mc ca mng in

cbI Dng in cng bc qua my ct

NI Dng ngn mch. Trong thit k h thng cung cp in coi ngn mch

xa, do III N''

NN UIS 3

xkI Dng ngn mch xung kch ''28.1 Iixk

nhmt . Thi gian n nh nhit nh mc = 5ms hoc 10ms

qt Thi gian ct

b) Tnh chn lc ca ptmt

Thng c mt s thit b bo v ca dng in nm gia ngun v cc

b phn thit b yu cu bo v, cc kh c in ny phi tha mn tnh chn

lc gi hn s c lan rng nh hng n cc b phn khc ca h thng

tnh chn lc c nh ngha:

- Xung dng in bnh thng khng gy ngn mch

32

- Khi vn hnh ng ch thit b bo v gn ch s c nht theo chiu cung

cp mi c tc ng

- Nu thit b ny b hng mt thit b khc mi tc ng cc yu t ch yu

bo v Icp v thi gian Tcp cc Aptomat A1, A2, A3 lm vic. H thng li

in phi c tnh la chn khi xy ra s c.

Hnh 2.9. S ni tng ptmt.

V d: khi ngn mach C th ch c ngt ngt in mch ng c

M3 tc cc ptmt khc vn c dng v c cung cp in bnh thng

cho cc nhnh khng s c l la chn tng phn. Nhng v l do no d

m A33 khng lm vic th c cp bo v tip im theo m bo theo i ca

dng in ngn mch t bin p im C th A22 s thc hin cp bo v ny.

l la chn tuyt i.

S la chn trong bo v t c do s khc nhau v thi gian v thi

gian lm vic ca cp bo v c gi l mc la chn theo thi gian

ngha l thi gian lm vic ca cp bo v trc (Vd A22) phi ln hn thi

gian lm vic ca cp bo v sau (A33) ngoi ra cn c mc la chn theo

dng in yu cu l dng in ngt cp I phi nh hn dng in cp i+1 vd

33

A1 c th lm vic im ngn mch a, b A1 thi gian bo v ko di

nhng khi xut hin ngn mch im a c th cn phi ngt mch h hng

sm hn thi gian cho php v s ko di thi gian chy trong mch dng

in ln hn khi ngn mch c th lm cho dy nng ln lm hng dy dn v

thit b do khi dng in ngn mch s ct mt cch t ngt, nhanh chng

nh b ngt dng in.

Tnh chn ptmt

Bo v ngn mch chn lc c phn chia theo thi gian b xung c lp

vi dng in thi gian tng At ca ptmt pha di phi ngn hn thi

gian iu khin cc tiu Tm ca ptmt pha trn, thi gian phn chia gia

hai ptmt vo khong 100ms.

Hnh 2.10. Tnh ton chn lc ni tng hai ptmt.

1 ptmt pha trn

2 ptmt pha di

tm Thi gian iu chnh cc tiu

tA Thi gian tng

kh nng chn lc tA < tm1

Tnh chn lc ca ptmt hn ch dng in cu ch pha trn.

34

Vi cch b tr ny tn ti tnh chn lc nu I 2tAca my ct thp hn gi

tr ti hn ngn nht I2tS ca cu ch.

Tnh chn lc ptmt dng in khng cu ch pha di

Trng hp ny cc cu ch c dng dnh mc ln hn dng nh mc ca

ptmt thi gian ct tng (tS+t1) ca cu ch phi ngn hn thi gian iu

khin nh nht tm ca ptmt.

Tnh chn lc ptmt dng in khng ptmt hn ch dng in pha

di.

Yu cu trong trng hp ny l thi gian ct tA i vi dng in ngoi Ia

ca b hn ch dng in phi ln hn thi gian iu khin ti thiu ca

ptmt pha di.

Hnh 2.11. Tnh chn lc ni tng hai ptmt ct dng in khng b hn

ch dng.

1 ptmt pha trn

2 ptmt pha di

tm Thi gian iu khin nh nht

tA thi gian tng

Kh nng chn lc khi tA2 (IA) < tm1

b) Cc i lng v thng s ca ptmt khi cn tnh ton v la chn

35

2.4. NG DNG CA PTMT HNG SCHNEIDER

2.4.1. Ptmt 1 cc (kiu T3)

RT3.06-40A1P

Hnh 2.12. (6/10/16/20/25/32/40/50/63) 1 Pole ptmt dng ct 6000A.

ptmt tp khi 2P -2E

Vi cng dng bo v mch in chng qu ti v ngn mch, cc dng

sn phm ptmt Roman s mang n cho cng trnh mt gii php bo

v an ton h thng in.

Kh nng chng in git: Khng chm ti cc b phn mng in

Khng bin dng, phng rp di tc ng ca ngoi quan

Sn xut theo tiu chun IEC60898

c tnh k thut

c lm t vt liu chng chy v cch in

Ph hp vi tiu chun IEC 60898

Ngt t ng dng ngn mch khi n va xut hin

Thng s k thut

Dng nh mc 06 - 63A

36

in p nh mc 220/380V AC

Dng ct (IEC 60898): 6.000A

2E c tc dng bo v thit b trn c 2 cc ca ptmt (Khi trng hp b

u nhm dy th ptmt vn hot ng bnh thng l u im vt tri

so vi 1E)

2.4.2. MCCB & ELCB MITSUBISHI

Hnh 2.13. WSS th h mi ( khc larse chm, khng decal )

Sn xut ti Nht

Tiu chun ton cu ( IEC/JIS/EN/GB/UL/CSA )

Ampe Frame hon chnh t 30(32)AF n 1600AF

Chc nng c bn :

MCCB : Cch ly, bo v qu ti, ngn mch.

ELCB : Cch ly, bo v qu ti, ngn mch, dng r.

Cc dng sn phm :

NF/NV- C : loi kinh t

( NF30-CS, NF63-CW, NF125-CW, NF250-CW, NF400-CW, NF630-

CW, NF800-CEW )

NF/NV- S : loi tiu chun ( NF32-SW, NF63-SW, NF125-SW, NF250-SW,

NF400-SW, NF630-SW, NF800-SEW, NF1250-SEW, NF1600-SEW )

NF/NV- H : loi dng ct cao

NF/NV-U: loi hn dng

http://diencongnghiep.vn/vn/San-Pham/Thiet-Bi-Dong-Cat/Mitsubishi-Electric/Mccb/##

37

Ph kin lp bn trong

AL : Tip im cnh bo

AX : Tip im ph

SHT : Cun ct

UVT : Bo v thp p

Ph kin lp bn ngoi

1./ B chuyn thao tc xoay

2./ Ming che v tr ni in

3./ B vn hnh bng motor

4./ Kha c kh lin ng MI dng cho 2 MCCB

( B chuyn ngun MTS, ATS 3P/4P 250A, 300A, 400A, 600A, 800A,

1000A, 1250A, 1600A Mitsubishi )

5./ Kha cn thao tc.

2.5. MY CT THP P HNG SCHNEIDER

2.5.1. Chc nng

My ct in dng ng, ct mch khi c dng ph ti v c khi c

dng ngn mch. My ct thp p l c cu ng m c kh c kh nng

ng, dn lin tc v ct dng in trong iu kin bnh thng v c trong

thi gian gii hn khi xy ra iu kin bt thng trong mch (v d nh

ngn mch). My ct c s dng ng m ng dy trn khng, cc

nhnh cp, my bin p, cun khng in v t in. Chng cng c s

dng cho 2 thanh gp, sao cho in nng c th c truyn t mt thanh

gp ny sang mt thanh gp khc.

My ct c thit k c bit dng cho cc nhim v c bit nh

ng st, s dng li 3

216 Hz phi dp tt h quang di hn (di hn

na sng).

My ct c s dng cho l nung chy c hot ng thng xuyn th

yu cu lc tc ng nh hn v dung lng ct thp hn. Do vy chng t

38

chu mi mn, mc d ch ng m cao v khong thi gian lm vic di.

Yu cu vi chng phi ct nhanh, khi ng/ct khng gy n hoc chy,

kch thc gn nh, gi thnh h. Trong my ct cao p vn dp tt h

quang khi ct ngn mch rt quan trng. Do vy thng cn c phng php

dp h quang phn loi my ct.

Ngt dng in ngn mch l ch lm vic nng nht v c bn. Song

qa in p sinh ra khi ngt dng in b ca my bin p khng ti, ngt

dng in dung ca ng dy di v nhiu trng hp khc cng l iu

kin lm vic nng n cho c h thng ngt.

Trong nhiu trng hp i lng qu in p c xc nh bng s

c bit ca kt cu my ct, cho nn cc yu cu i vi my ct cao p

hin i khng ging nh i vi mt my cch li dng in n gin m

phi yu cu nh thit b ngt mch c dng in khng lm nguy hi cho

h thng v m bo an ton chc chn. Ch to my ct nu ch c tc dng

ngt dng in ph ti th n gin hn.

Theo nguyn tc h thng dn in ca my ct ni tip vi mch in

ca cc thit b in cao p. Khi cc b phn kt cu c bn ca my ct

cn phi chng s tc ng nhit, in t trong khi lm vic bnh thng

cng nh khi ngn mch phi chng trng tnh in tc ng vo cch in

lc in p nh mc v c trong lc qu in p. Trong qu trnh lm vic

ca my ct cn c nhng hin tng sinh ra thm nhiu ph ti nhit, c v

in tc ng vo tng b phn ring ca kt cu my ct (s chy ca h

quang in khi ngt, s tng p sut ca cht kh v cht lng trong khng

gian cng tc, cc b phn c chuyn ng vi gia tc ln v nhiu nhng

hin tng khc). Trong trng hp cc d tr kt cu ca my ct qui nh

khng tng ng vi iu kin cho trc th mi yu t k c th l

nguyn nhn sinh h hng tng b phn hay ton b cc phn ca my

ngt, dn ti ph hng s lm vic bnh thng ca mt khu vc trong h

39

thng in, ngha l dn ti s c. My ct phi t ng hn ch s c trong

h thng, nn cc b phn kt cu ca n phi tuyt i n nh i vi tc

ng nhit v lc in ng, cng nh i vi tc ng ca in p mi gi

tr.

a) Yu cu chung i vi my ct

a.1) S tng ng ca c tnh my ct i vi nhng qui nh cho trc ca

n.

a.2) Tt c cc b phn kt cu ca my ct trong thi gian vn hnh phi lm

vic.

Cc yu cu chung i vi my ct cao p c nu trong cc tiu chun

k thut khc nhau (nh tiu chun Lin X c OCT 687 41 hay cc tiu

chun quc t: IEC, DIN VDE, ANSI).

b) Cc yu cu c bit khc

Ngoi nhng yu cu chung, trong cc trng hp ring cng c nhng

yu cu c bit i vi my ct, ph thuc vo iu kin ring m my ct

lm vic, nh:

b.1) Kh nng lm vic vng m t, nhiu bi bm

b.2) Kh nng lm vic vng rt cao hn mt bin.

b.3) Kh nng lm vic cc thit b di ng

b.4) Thch hp vi iu kin lm vic nhit rt thp.

Do nng lng ngy cng pht trin, v p dng cc phng php hon

chnh trong vn hnh h thng in nn my ct l mt trong nhng b phn

quan trng nht ca h thng yu cu nng cao cc ch tiu k thut vn hnh

nh: tng dng in nh mc, tng cng sut ngt, nng cao tc ng

nhanh, tc ng nhanh nhiu ln ca AB (ng lp li t ng), tng

chng n mn ca cc b phn c v ca cch in; vn chuyn, lp rp, vn

hnh thun tin, an ton v n v ha hon...

Trong khi thit k my ct hin i cn c bit lu n vn nng

40

cao cc ch tiu kinh t k thut, trng lng t nht trong mt n v cng

sut ngt. Kt cu ca my ct cn phi n gin, vng chc, cc chi tit v

cc mi kt cu trong tt c cc loi my ngt phi thng nht v cn phi p

dng cc phng php gia cng tin tin. Trong ch to s dng rng ri cc

nguyn liu c tnh c, tnh in, tnh nhit cao v kinh t nht (cc nguyn

liu tip im c bit, gm c bn cao)

2.5.2. Phn loi

a) My ct nhiu du

Du va l cht cch in ng thi sinh kh dp tt h quang.

b) My ct t du

Lng du t ch sinh kh dp tt h quang cn cch

in l cht rn.

c) My ct khng kh

Dng kh nn dp tt h quang.

d) My ct t sinh kh

Dng vt liu cch in c kh nng t sinh kh di tc dng ca nhit

cao ca h quang. Kh t sinh ra c p sut cao dp tt h quang.

e) My ct in t

H quang c dp trong khe hp lm bng vt liu rn chu c h quang,

lc in t y h quang vo khe.

f) My ct chn khng

H quang c dp trong mi trng chn khng

g) My ct SF6

Dng kh SF6 dp dp h quang.

2.5.3. Cc thng s chnh ca my ct

+ Um l in p dy ln nht m my ct c th lm vic bnh thng tin

cy trong thi gian di.

+ Im l dng chy lu di qua my ct m khng lm qu nhit v khng

41

gy h hng, (lin quan kch thc cc chi tit trong my ct).

+ Im l dng n nh ng nh mc.

+ Inhm l dng n nh nhit tng ng thi gian n nh nh mc tnh .

+ Icm l dng ct nh mc chnh l dng ngn mch ba pha hiu dng ton

phn ln nht my ngt c th ct c m khng gy h hi g cho my ct.

Icm xc nh t thc nghim.

Cng sut ct nh mc: Scm = 3 Um . Icgh (2-1)

+ Icgh: dng ct ln nht cho php khi U < Um.

+ tt: khong thi gian tnh t khi c tn hiu ngt n thi im h quang b

dp tt trn c ba pha.

- Tc ng nhanh tt= (0,02 0,06)s.

- Tc ng trung bnh tt = (0,15 0,1)s.

- Tc ng chm tt = (0,15 0,25)s.

Ngoi ra yu cu my ct c kh nng ng mch ngay c khi ang c dng

ngn mch m cc u tip xc khng h hi g.

2.5.4. My ct khng kh h th (ACB)

2.5.4.1. Nhng tnh nng chnh:

Hnh 2.14. My ct khng kh h th( ACB ) do hng Schneider sn xut.

42

Di dng ct ln n 6300A t 65-130kA ti 500V AC vi tm iu chnh

rng.

Chc nng c bn: Cch ly, bo v qu ti v ngn mch.

C 2 loi: Kiu lp c nh - FIX, Kiu ko ra DRAWOUT.

Ph hp cho mi ng dng.

Np bng tay (Cu hnh c bn):

Cun l xo NG/CT c np nng lng bng cn gt tay. My ct

c NG khi nt ON c nhn v CT khi nt OFF c nhn.

Np t ng (Cu hnh t ng):

Cun l xo NG/CT c np nng lng bng motor np. My ct

c NG khi nt ON c nhn v CT khi nt OFF c nhn, hoc

iu khin qua PLC.

Size I (Icu=Ics: 65KA): AE630-SW, AE1000-SW, AE1250-SW,

AE1600-SW, AE2000-SWA.

Size II (Icu=Ics: 85KA): AE2000-SW, AE2500-SW, AE3200-

SW, AE4000-SWA.

Size III (Icu=Ics: 130KA): AE4000-SS, AE5000-SS, AE6300-SS.

p ng cc tiu chun ton cu nh: IEC 60947-2, EN 60947-2 (CE), JIS

C 8201-2, GB 14048.2 (CCC)

Khi rle in t ETR:

WS1,WS2: bo v ti cng nghip

WM1, WM2: bo v my pht in

2.5.4.2. Cc ph kin lp thm cho ETR:

G1: Bo v chm t

E1: Bo v dng r

AP: Cnh bo sm

N5: Bo v cc trung tnh 50%

EX1: Khi m rng cho ETR

43

VT: Bin p

DP1: Mn hnh o m a nng (lp trn ETR)

DP2: Mn hnh o m a nng (lp trc mt t)

TAL: Cnh bo nhit ca tip im lm vic

BIF-CC, BIF-PR, BIF-MD, BIF-CON, BIF-CL: Cc ph kin

dng cho nhng ng dng ni mng.

2.5.4.3. Cc ph kin lp thm cho ACB:

1. Motor Drive (MD): MD-AD250-W (200~250V AC-DC)

2. Closing Coil (CC): CC-AD250-W ( 100~250V AC-DC)

3. Shunt Trip device (SHT): SHT-AD250-W (100~250V AC-DC), Cn

dng km vi AX.

4. Under Voltage Trip device (UVT): L thit b t ng CT my ct

khi in p ca ngun qua my ct thp hn in p nh mc. B bo v

thp p (UVT) ny bao gm cun tc ng v b iu khin. C 3 loi thi

gian tc ng tr khi thp p: INST, 0,5s v 3.0s.

5. Auxiliary switch (AX): AX(0A,0B), AX(1A,B), Max.AX(5A,5B)

6. Mechanical Interlock (MI): Thit b ny dng phng trnh kh

nng thao tc cng lc 2, 3 my ct. c dng kha lin ng c kh

trong cc ng dng chuyn i ngun in (ATS). Cc ng dng c

nng mc an ton cao hn nu kt hp vi kha lin ng in (bng

cch lin ng cc SHT, CC ca cc my ct vi nhau)

7. Cc ph kin khc:

BC-L: kha nt nhn

CNT: m s ln thao tc

DI: kha lin ng ca

CL: tip im v tr (dng cho drawout)

. COT: cp ngun SHT khi mt ngun

44

CHNG 3

MY CT NG DNG TRONG CC BNG IN PHN

PHI CA CC TRM PHT D PHNG T NG

TON PHN

3.1. T VN

Cc thit b ng ct v bng phn phi c s dng cho vic phn phi

in cc trung tm iu khin ng c chng cha thit b bo v ng ct

bin i iu khin v o lng cc cu trc v t hp kh nhau c dng

cho nhng ng dng v yu cu khc nhau v cng vic thao tc do cng

nhn thc hin cc thit b ng ct v bng phn phi c a vo cc tiu

chun v quy nh trong IRC.

Cc h thng theo modul vi kch thc cng sut tiu chun c

thit lp rng di cho vic lp rp kh c theo cc iu khon ca nh sn xut

v c im thc t, nhng iu khon ny phi c hiu qu c cho d n ban

u v cho c cc thay i m rng sau ny.

Bng in phn phi l ni tp trung nng lng nhn t cc my pht

thng qua cc cu dao chnh ACB (Air Circuit Breaker) phn b n cc

ph ti. Ti c b tr trn ton b cc trm pht nhng chng hoc trc

tip, hoc gin tip u c cung cp t thanh ci bng in chnh thng qua

cc cu dao ph ti CB ( Circuit Breaker ). Trn bng in phn phi v c

bn c mt s thit b v h thng in c thit k tch hp nhm mc

ch to nn mt ni d tr nng lng p ng y cng sut cho ph ti

ton cu vi tin cy cao, hot ng an ton v giao din thn thin vi

ngi s dng. Vi chc nng nh vy, bng in phn phi phi bao gm

mt s thit b: o lng, kim tra, kh c phn phi v bo v, thit b iu

chnh, iu khin, cc nt n, cng tc, mn hnh cm ngBng in phn

45

phi hin nay cng c bc nhy ln v cng ngh, c tha hng cc

tinh hoa k thut cao vi kh nng iu khin, iu chnh, thu thp v s l,

trao i thng tin ln. Bng in phn phi l mt phn khng th thiu c

trong cc trm pht d phng ton phn.

3.2. BNG IN CHNH

3.2.1. Cu trc chung ca bng in chnh

Bng phn phi v bng o lng nh

Cc bng phn phi nh vi kch thc theo DIW VDE 871 c cha

ptmt, cu ch v cc ph kin c dng nh mc ti 63A chng c kch

thc chiu rng*chiu cao = 250.150 v phi c cch in hon ton.

Cc phng php lp t c th l: Lp trn mt, lp phng

Cu to: C loi khng c v tho lp hoc khng c ca, c ca tho lp

hoc c v

Cc bng phn phi lp trong tng c k hiu H

T hp thit b ng ct h p.

Thut ng t hp thit b ng ct h p bao trm tt c cc cu hnh c

Um xoay chiu n 100V tn s 100Hz hoc 1500V in p mt chiu tr

cc bng phn phi nh chng gm phi hp ca thit b in c v in t c

loi hon ton thit b in t. Da vo mc an ton t hp ny li c phn

chia thnh t hp thit b ng ct kiu in t nghim tng phn nh ch to

c th la chn cch th nghim da vo iu kin sn xut hoc kinh t.

iu kin th nghim cn phi chng t c yu cu sau:

a vo nhit gii hn trn

bn in mi

Cng ngn mch

Ni cn thn gia cc b phn ca thit b ng ct v dy bo v bng quan

st hoc o in tr

Cng ngn mch ca dy bo v

46

Hinh 3.1. Bng phn phi nh vi dng c o c t bn trong

v.

Khong cch phng in b mt in mi v khong cch cch in

Chc nng c kh

Cp bo v.

Bng in chnh nhn v cu trc c tp hp bi mt s panel ring r

(hnh 3.1). Mi mt panel c tnh nng v yu cu s dng ring, cng chnh

v l do ny m v cu to cng nh hnh thc chng c c im cch bit.

Tuy nhin, trong thit k tng th, ngi ta bao gi cng thc hin to dng

vi trnh m thut cng nghip nht nh c c mt sn phm cng

47

nghip va hin i, va hon m v hnh thc. Vi mt bng in chnh

thng thng bao gi cng c tch hp bi cc panel c bn sau.

3.2.1.1.Cc panel dng cho cc my pht- Generator Panel

S lng panel c quyt nh bi s lng cc my pht c trong trm,

nu trm c hai my pht th cng s c hai panel, nu trm c ba my th

cng phi c ba panelcc panel ny c tch hp bi:

Thit b o lng: bao gm cc ng h o in p Voltmeter, o dng

in Ammeter, o tn s FM Frequency meter, o cng sut phn

khng KVA ( nu c), o h s cng sut Power Factor(cos) (nu c);

Thit b ng ct: cu dao chnh Air Circuit Breaker (ACB);

Cc thit b bo v: Rowle cng sut ngc, Reverse Power Relay

(RPR), Rle qu ti Ovr Current Relay (OCR);

Cc cng tc chuyn mch v iu khin: Cng tc dng cho o in

p cc pha ca my pht v ca li in (Bus); Cng tc chuyn mch

o dng in cc pha ca my pht IR, IS, IT; cc nt n dng khi

ng hoc dng t xa cc ng c diesel lai my pht; Chit p iu

chnh in p khng ti cho my pht (nu c);

Cc n bo hiu: my pht hot ng ( running), ACB ang m, ACB ng.

48

Hn

h 3

.2.

MS

B v

i

cc

pan

el v

b

ng

s

mt

dy

.

49

3.2.1.2. Panel ng b - Synchronizing Panel

Mi bng in chnh thng ch c mt panel ha ng b, panel ny c

chc nng thc hin vic ha ng b cc my pht vi nhau. Ha ng b

cc my pht c th thc hin bng tay hay t ng th vn cn phi c cc

thit b phc v cho cng vic ny. Hin nay, trong mt s trm pht gim

kch thc cho bng in chnh ngi ta c th thit k panel ha ng b

ghp chung vo cc panel cc my pht, tuy nhin nh vy vic thao tc v

theo di s gp kh khn hn rt nhiu c bit l vi nhng ngi vn hnh

khng quen, mi vo ngh hoc l t trnh k thut. Panel ha ng b

c tch hp mt s thit b sau:

Thit b o lng: bao gm cc ng b o cng sut tc dng ca cc

my Wattmeter (trm c bao nhiu my th by nhiu ng h o cng

sut trn panel ny)

Cc cng tc chuyn mch v iu khin: cng tc dng cho vic ha

ng b SYS Synchroscope Switch; cng tc la chn ca tng my

pht CS Control Switch; cc cng tc iu chnh ng c tr ng

iu tc diesel lai my pht GS- Governor Motor Control Switch;

Cc thit b ch bo: ng h ha ng b SY- Synchrocope dng

hin th qu trnh ng b gia cc my hoc gia mt my pht vi

li khi thc hin ha ng b bng tay hoc t ng. Vic a ng

h ha ng b vo hot ng c la chn bng tay, y l loi thit

b lm vic ngn hn nn sau khi thc hin ha xong cn phi cho thit

b ngh. Hin nay c nhiu loi ng b k nhng ph bin nht vn l

hai loi: ch th bng kim v ch th LED ( Light Emitor Diod), hai loi

ny c cu to hon ton khc nhau; B n ha ng b SYL-

Synchronizing Lamp gm ba n hot ng theo nguyn tc n tt

hoc n quay. Thng b n cng vi ng b k to nn tin cy

cao cho thit b ha, chng i km nhau v b xung cho nhau; cc n

50

bo hiu chnh qun l: Cch in thp, mt ngun iu khin sn sng

khi ng, iu khin t xa

3.2.1.3. Panel tch hp cc khi ng t cho cc ph ti quan trng-

Group Starter Panel

y l cc module cha cc hp khi ng cho cc ph ti quan trng ly

in trc tip t bng in chnh. Ty tng tu vi cc ph ti nhiu hay t m

s lng cc khi ng t t trn cc panel ny s c phn chia theo

nhm. V d i vi mt con tu trng ti 15.000 T trn bng in chnh s c

hai panel dnh cho cc ph ti ny, trong mi panel c gi l mt nhm,

nhm khi dng s 1 ( No 1 group starter) bao gm:

Bm nc bin lm mt my chnh s 1 ( No 1 Cool S W Pump)

My nn gi khi ng s 1 (No 1 Main Air Comp)

Bm nc ngt lm mt my chnh s 1 (No 1 Cool F. W. Pump)

Bm cp du FO cho my chnh s 1 (M/E FO Supply Pump)

3.2.1.4. Panel cp ngun cho ph ti ng lc-440 V Feeder Panel

y l ni cung cp nng lng cho ph ti hoc cc nhm ph ti ng

lc thng qua cc cu dao ph ti CB. Ty vo tnh cht v tm quan trng

cng nh cng sut ph ti m chng s c cung cp trc tip hoc thng

qua cc bng in ph trung gian. Trn panel ny ch yu b tr cc CB,

ngoi ra c thm mt s thit b o lng nh ng b o in tr cch in

M, cc n ch th cch in ch yu kim tra trong li ng lc.

3.2.1.5. Panel cp ngun cho ph ti sinh hot 220 V (hoc 100 V) Feeder

panel

Nhm ph ti sinh hot c cp ngun ti panel in p thp ring r

ly t h thanh ci ph trn bng in chnh. Ngun cp cho h thanh ci ny

c ly t bin p chiu sng 400/220 V hoc 440/100 V , vi tu thy th

in p chiu sng cng c cung cp bng in p dy ( khc vi li in

dn dng dng in p ba pha) iu ny i hi cc thit b lm vic trong

51

li chiu sng, sinh hot trn tu thy cng c c th ring, c bit l vn

an ton cho thit b, ngi vn hnh v s dng h thng. 220 V Feeder

Panel hoc 100 V Feeder Panel ch yu l cc CB ph ti. y cc CB s

dng ch yu l loi mt pha ( hai cc). Cng nh 440 V hoc 400 V Feeder

Panel cc CB thng c la chn vi phn bo v ngn mch thc hin

bng tc ng do t trng dng ngn mch to nn (dn dng thng la

chn tc ng bo v ca cc CB trn nguyn l pht nhit) v vy kh nng

phn ng vi dng ngn mch nhanh v chnh xc hn. Tt nhin la chn

no th ph tn y vi loi CB ny gi thnh ln hn rt nhiu. Trn panel ny

cng trang b cc n bo cch in cho li sinh hot, ng h o in tr

cch in, cc ng h Voltmeter v Ammeter o in p v dng in cho

li sinh hot.

3.2.2. Cc thit b c tch hp trn bng in chnh

Bng in chnh nhn t kt cu c m t nh vy. Tuy nhin, cu to

chi tit cc phn t th bng in chnh c th c nhn nhn l h thng tnh

c tch hp cc thit b v l thuyt l tnh song thc cht cc qu trnh vt

l trong n th khng h tnh ti, ngc li n rt ng.

3.2.2.1. Thanh ci

T s khai, bng in chnh l ni tp trung nng lng in nn thanh

ci l mt trong nhng thit b c mt u tin. Kt cu, hnh dng, cht liu

lm nn thanh ci cng tri qua rt nhiu thay i v n nay nhng tiu

ch v thanh ci cng khng phi l thng nht ton b gia cc nh ch to.

Tuy vy, c mt s tnh nng k thut th bt c nh sn xut no cng

u hng ti l: Kh nng dn in tt, c bn c hc, d gia cng

ch to, tui th cao, gi thnh h. Chnh t nhng yu cu ny m thanh ci

lun c ch to bng ng nguyn cht. Tuy nhin, hm lng tp cht c

trong ng nguyn cht th mi nh ch to mt khc v cng l ch tiu

cnh tranh trn th trng m con ngi s dng cn lu v d th no th

52

hm lng ng nguyn cht ti thiu cng phi t c khng di 97%.

Khi trm pht cn dng cc my in mt chiu cung cp dng mt chiu cho

cc ph ti th thanh ci c hai, nhng khi trm pht l cc my pht in

ng b th thanh ci ph bin bao gm ba thanh, c mt vi trm c th th

thanh ci gm bn thanh. Nh vy, v s lng th trm dng dng xoay

chiu tng thanh ci thm ch gp i. Hnh dng v kch thc ca thanh

ci cng rt a dng. Kch thc thanh ci hon ton ph thuc vo cng sut

ca trm, cn hnh dng dng th c nhiu la chn mi nh thit k. Hin

nay, hnh dng thanh ci vn ph bin dng mt ct ch nht, t l gia chiu

di v chiu rng ca mt ct cng c ty chn. Chnh iu ny lm nn

tnh a dng, tuy nhin ti u nht ngi ta vn chn mt chiu gp t 5-10

ln chiu kia c ngha rng tit din thanh ci thng l ch nht vi chiu

di ln gp 5-10 ln chiu rng. C nhiu trm pht thanh ci c thit k

kp, mt pha c th dng hai thanh ci chy song song v st nhau, tt nhin

l tng tit din ca thanh ci kp cng ch bng tit din trong trng hp

thanh n ( cng dung lng). Hnh 3.2 trnh by tit din ca thanh ci bng

in chnh lp t trn tu Vnh Thun, Vnh An, Vnh Hng vi dng tnh

ton 1060A.

6

75

Hnh 3.3. Kch thc thanh ci chnh trn bng in vi dng tnh ton

1060A.

53

Thanh ci trong bng in chnh cng c phn ra thanh ci chnh v

thanh ci ph. Kch thc cc on thanh ci ph thng nh hn thanh ci

chnh. Thanh ci ph thng l cc on phn nhnh trong h thng thanh ci

hoc thanh ci cho panel phc v sinh hot. Thanh ci c lp trong bng

in nh cc gi , vic tnh ton khong cch cc gi trn c s tnh

ton ngn mch tm ra lc in ng v tn s dao ng c hc. Ngi ta

c th tin hnh trit tiu dao ng c hc bng vic thay i khong cch cc

gi cho thanh ci. Gi thanh ci thng lm bng vt liu cch in c

nh hnh vi kh nng cch in tuyt i v bn c hc cao. Gi

thanh ci cng a dng v hnh dng v kch thc, hnh dng kch thc ca

gi cn ph thuc vo ngi thit k lu chn t thanh ci ng hay

nm.

Thanh ci trn bng in chnh c th c phn on hoc khng phn

on ty vo yu cu thc t ca trm pht. Thng thng nht ngi ta vn

thit k thanh ci c phn on khi trm c t hai my pht tr nn, lm

nh vy trong qu trnh khai thc khi cn sa cha cc thit b thuc phn

on no th ct phn on ra, khng lm nh hng n vic cp ngun

cho cc ph ti quan trng theo yu cu cp in ca cc h tiu th u tin,

loi mt. Cu dao phn on l loi cu dao khng thc hin ng m khi c

dng, v vy tip kim v kinh t ngi ta c th la chn loi cu dao

phn on ging vi cc cu dao cch ly, khng phi c cc tip im h

quang, tip im ph v thit b dp h quang. Trong nhng trng hp c

bit cc tu chuyn dng hoc qun s c yu cu cch ly thanh ci trong

trng thi c dng th ngi ta phi la chn cu dao phn on nh cc my

ct.

54

Hnh 3.4. Cu dao phn on trn thanh ci.

Mu sc ca thanh ci cng c thc hin theo nhng cch khc nhau,

ngi ta c th dng sn mu phn bit cc thanh ci. Vi thanh ci trm

mt chiu thng ngi ta dng hai mu tiu biu: mu cho thanh ci cc

tnh dng, mu en cho thanh ci cc tnh m. Vi trm xoay chiu dng ba

thanh ci th cc pha thanh ci c sn cc mu cho pha R ( Vit Nam

thng gi l pha A), xanh cho pha S (B), vng cho pha T (C). Vi bng in

dng bn thanh ci th thanh ci trung tnh (Neutral) c th c sn thm

mu xm. Sn dng cho thanh ci l loi c kh nng dn nhit tt gip

cho vn truyn nhit ra mi trng xung quanh thun li. Nu dng loi

sn thng thng th ngi ta ch sn tng on mt cch nhau m khng sn

ton b. Mt s bng in ngi ta dng bng dnh cch in mu qun

ln phn bit cc pha nhng vi cch ny th bng dnh ch qun cch qung

to iu kin ta nhit trong qu trnh lm vic.

Vic ghp ni cc thanh ci cng c thc hin ht sc cn thn. Tip

xc l tip mt, dng tip xc c nh nn b mt tip xc bao gi cng c

gia cng chnh xc. ai c ghp ni dng bng ng vi loi ng hp

kim c bn c hc cao, c kh nng chu ko v nn. Cc long en ca ai

c ng vai tr ht sc quan trng, n thng c lm bng ng to

kh nng tip xc cho b mt tip gip. Ngi Nht vi tim lc kinh t cao,

55

ngi ta vn s dng cc ai c bng st ghp ni cc thanh ci nhng

long en th hon ton dng bng ng.

Hnh 3.5. Cu dao chnh

3.2.2.2. Thit b ng ct

Thit b ng ct trn bng in chnh tu thy phn ln l loi thit b

in p thp, ph bin in p s dng khng vt qu 1000V, xut pht t

vn an ton nn ch nhng tu c bit hoc tu qun s ngi ta mi s

dng in p trung p. V chng loi, thit b ng ct dng trn tu thy

cng s dng ht sc hn ch: Cu dao chnh ACB, cc cu dao ph ti CB,

cu dao cch ly, cu dao phn on v mt s thit b ng ct cng sut rt

nh.

Cu dao chnh (Air Circuit Breaker-ACB)

Cu dao chnh khc vi cc cu dao ph ti do yu cu v c tnh nng k

thut, tin cy, tnh an ton v kh nng lm vic v vy tm quan trng

ca ACB l rt cao. Chnh v l do ny m trong thit k tnh ton cng nh

khi la chn thit b bao gi ngi ta cng rt ch n thit b trng yu

ny. Hnh 3.4 gii thiu mt ACB ca hng Terasaki loi AME4B v hnh 3.5

gii thiu cu to bn trong ca loi ACB ny. AME4B l thit b c th ng

56

ct bng tay v bng ng c, dng in nh mc Im = 400A, kh nng ct

ti 16 KA.

Hnh 3.6. Cu to bn trong ca ACB loi AME4B.

Trc ht v dung lng ACB bao gi cng c la chn dng nh

mc ca thit b lun ln hn dng nh mc tnh ton vi h s k=1.1-1.75

trong di dng in c kh nng la chn bo v phi rng, tuyn tnh.

Dung lng dng ct ca ACB cng ln hn dng nh mc cng tt. Thng

thng dung lng dng ct c th gp 10 n 50 ln dng nh mc. V d

dng nh mc ca mt my pht tnh ton l 385 A, la chn ACB loi

AME6B c dng nh mc l 630A kh nng ct ca cu dao ny c th t

6160 A. Vi gi tr dng ct ny, sau tc ng bo v ACB vn hot ng tr

li bnh thng khng b bt c mt li k thut no.

Mi c tnh k thut ca ACB l c tnh ampe-giy (A-s) c sai s nh

hn cc CB thng thng, iu ny ni n tnh chnh xc ca ACB trong

hot ng tc ng bo v hay ni cch khc l cng ngh ch to i hi cao

hn, gi thnh t hn.

57

Mt c tnh k thut na cng phi k n l kh nng tch hp cc

tnh nng trong mt ACB cao hn rt nhiu. Mt ACB phi bo v c ngn

mch vi cc nc tc ng: Long Time Delay, Short Time Delay, Instant

Trip; bo v qu ti vi cc kh nng ct u tin nhiu nc, vi vic ct qu

ti nhiu thit k trong trm pht cng phn vng tc ng cho bn thn ACB,

cho r le qu ti Over Current Relay (OCR), ct my pht; Bo v thp p vi

thit b UVC- Under Voltage Coil; Bo v cao p Over Voltage Coil- OVC;

Bo v cng sut ngc vi Reverse Power Relay (RPR)

Hnh 3.7. c tnh A-S ca ACB vi cc mc dng tc ng I1, I2, I3.

Hin nay cng ngh thng tin pht truyn, ACB thng c thit k mt

my tnh nh tch hp trong n thc hin thm mt s chc nng ngoi

mt s chc nng kinh in: Tham gia iu khin ng, ct cho chnh ACB.

o lng cc i lng v hin th o lng cc i lng v hin th o

lng. Ci t mt s i lng v thng s cho gim st v iu khin gim

st. Ghp ni vi cc h thng lin quan thng qua mng truyn thng cng

nghip v gi cng nh nhn cc lnh iu khin t xa qua cc ng truyn

ni b.

58

c tnh A-S ca ACB c trnh by trn hnh 3.6, y l ng xy

dng theo l thuyt vi Long Time- Delay Trip Pick-Up Current I1, Short

Time Delay Trip Pick - Up Current I2 v Instantaneous Trip Pick - Up

Current I3.

Hnh 3.8. c tnh A-S ca ACB vi cc mc dng tc ng I1,

I2, I3.

Cc ng cong ny trong cc ACB thc t bao gi cng c mt gii dung sai

dao ng trong khong t 5 25%, y l cc sai s cho php v vi dng I1

th vic t dng vi dung sai cho php ( Pick- Up Current Setting Tolerance

%) l 7,5 %, vi I2 th dng t vi dung sai 15 % v vi I3 th dung sai l

20 %. Vi tng ACB c th chn cch tnh gi tr dng I1 ( Pick- Up

Current Setting- LTD) theo mt trong 5 cch sau y:

I1 = Im (0.8-1.0-1.15-1.125) (3 - 1)

Gi tr dng I2 (STD) c tnh nh sau:

I2 = Im (2.0-2.5-3.0-3.5-4.0) ( 3- 2)

59

Gi tr dng I3 (INST) c tnh nh sau:

I3 = Im (4,7,12,15) (3 - 3)

3.2.3. Vn iu chnh, iu khin trn bng in chnh

Hin nay mc t ng ha bung my trong c t ng ha cc

qu trnh cho i tng l h D-G trm pht cng ngy cng tr ln hin i

hn. Vic tch hp cc phn iu khin cho i tng ny c th thc hin

c v c ci t trn bng in chnh, nh vy trn cc panel my pht

thng c thm cc chc nng iu khin. Vic iu khin cc diesel t bng

in chnh cng phi c thit k trn c s cc thit b phn cng ca cc

nh ch to cc t hp ny.

3.2.3.1. iu khin cc t hp diesel generator

Hin nay, cc thao tc khi ng cc diesel lai my pht u c thit

k c th thc hin iu khin ti ch hoc iu khin t xa. Trong vic thc

hin cc iu khin ny cng lun c hai ty chn: thao tc bng tay v thao

tc t ng. Vic iu khin bng tay thng n gin thng qua cc cng tc

hoc nt n, cc thao tc phi thc hin tun t m trong ngi vn hnh

phi nm c th t thc hin. Khi s dng phng thc hot ng t ng

th trong thit b c thit k cha ng mt chng trnh iu khin

thay con ngi.

Hnh 3.8 trnh by lu khi ng cho diesel lai my pht v chng

trnh a hai my vo hot ng song song.

Hnh 3.9 l lu thut gii iu khin qu trnh tch hai my khi ng

b v thut gii dng my. Vn phn phi ti tc dng trong trm pht in

hin nay thng c thit k hot ng t ng, trong kh nng phn

chia ti cho cc my pht c tnh ton theo nhiu phng n khc nhau.

Vi nhng trm pht thng thng, trong tnh chn ngi ta thng la chn

hai my lm vic song song v c cng cng sut, iu ny cng to iu kin

60

thun li cho vic iu khin t ng phn chia ti tc dng . V thit b, hin

nay cc hng cng c nhiu gii php k thut thc hin mc ch ny.

Cc h thng c thit k t cc thp nin cui th k hai mi thng thc

hin bng cng tc t, rle hoc s dng cc mch in t c np rp t

cc linh kin ri rc.

61

Hnh 3.9. Thut gii khi ng D-G v ha song song cc my pht

62

Hnh 3.10. Thut gii tch hai my khi ng b v dng my

63

Hnh 3.11. Cch ly tn hiu dng in tc dng phn phi ti

Hin nay, vic iu chnh cng sut tc dng thng c cc hng thit

k v ch to bng t hp vi mch hoc chip iu khin vi chng trnh ci

t sn trn c s iu khin chung ca PLC vng ngoi. V nguyn tc, cc

thit k u phi xut pht t vic o dng in tc dng ca my pht, c rt

nhiu cch thc hin cho mc ch ny, mt trong nhng cch mang tnh kinh

in l s dng chnh lu nhy pha nh trn hnh 3.11a. T hnh v thy

rng in p:

URA = U5 U4 ( 3-4 )

Vi s nh hnh 3.11a th in p U5 v U4 l in p mt chiu

nhn c sau chnh lu, vic to nn kh nng cm nhn v pha ( tnh cht

ti ) li c thc hin trn chnh lu nhy pha. th vct biu in trn

hnh 3.11b, cc gi tr in p mt chiu nhn c sau chnh lu c th vit

nh sau:

U5 = U2 + U3 .Cos ( 3-5 )

64

U4 = U1 U3 .Cos ( 3-6 )

Khi thit k la chn bin p TR1 c cc cun dy th cp vi hai na

hon ton ging nhau nn in p U1 = U2 v vy:

URA = U5 U4 = 2U3 .cos = k1 .I .cos = k1Itd ( 3-7 )

Trong : Dng Itd l dng in tc dng v k1 l h s bin dng.

Tn hiu sau b chnh lu nhy pha ny c a n thc hin tc

ng n b iu tc ca ng c diesel lm thay i lng nhin liu a

vo ng c v thc hin c vic thay i kh nng nhn ti tc dng cho

my pht. Tt nhin l khi cc t hp D-G lm vic song song vi nhau, vic

t hp ny nhn thm cng sut th t hp khc phi gim bt cng sut i (

phn phi theo t l cng sut ) gi cho tn s trong h khng b thay i

trong qu trnh iu chnh.

3.2.3.2. iu khin qu trnh ngt u tin khi xy ra qu ti

Khi xy ra qu ti trn trm pht, an ton khai thc trm pht, v

nguyn tc h thng phi t ng sa thi tng bc cc h tiu th ra khi

li in. Vic ct cc h tiu th km quan trng ra khi li vi cch thit

k kinh in lun c mc nh trong qu trnh thit k h thng ch khng

phi c tnh ton ti thi im tc thi. Hin nay, cng vic ny c th

hon ton thc hin c theo hm ngu nhin, tuy nhin vn do s kin

khng qu quan trng v cng do yu cu kinh t m ngi ta khng p dng.

Trong thc t cc trm pht c nhng s l khc nhau vi cc mc qu

ti v cc nhm ph ti. Vn iu khin cng ty thuc vo quan im ca

ngi thit k. Vi nhng trm pht c cng sut khng vt qu 1 MW,

thng vic ngt tng nc cc ph ti khng quan trng c thit k do r le

qu ti ( OCR- Over Current Relay) iu khin. c im ca hnh thc

khng ch ny l h thng n gin, hot ng tin cy m gi thnh cng

khng cao, chnh v l do ny m cho n nay phng n dng r le qu ti

vn c p dng. Vi trm c cng sut ln, vic phn vng qun l cho

65

ACB v r le qu ti c p dng, v nh th kh nng ct cc ph ti tr ln

linh hot hn, c bit l hin nay kh nng tch hp cc phn mm iu

khin, gim st trn cc ACB hon ton tin ch vi cc giao din thn thin

hn. Tuy nhin, vi phng n ny h thng tr nn phc tp hn v thc t

vi nhng trm c cng sut nh vy vn phn phi v theo di gim st

ton b cc thit b cng yu cu vi dung lng cao hn.

3.2.3.3. iu khin khi ng tun t lc c in tr li sau khi xy ra

mt in ton trm

Trong qu trnh khai thc trm pht in, hin tng mt in t ngt

ton trm v mt l do ngu nhin no c th xy ra. Vi tnh hung trm

pht d phng hoc trm pht s c phi thc hin nhim v duy tr ngun

nng lng ti thiu cho hot ng thit yu ca trm. S c phi c nhanh

chng khc phc. Khi ngun chnh c cung cp tr li th cc ph ti s

ngay lp tc c khi ng do ang s dng. Vic cc ph ti ng lot

khi ng tr li c bit l cc ng c khng ng b ba pha s lm st p

cc b ti thi im ban u , nu cc ph ti cng sut ln ng lot khi

ng s gy nn tnh trng qu ti v nguy c mt in tr li l rt cao.

trnh hin tng ny ngi ta phi thit k thm cc b timer khng ch thi

gian khi ng cho tng ph ti phn theo mc quan trng nhiu hay t

cho php thc hin khi ng tun t trnh s c khng cn thit xy ra. Cc

b timer ny c np trn tng b khi ng ca cc ph ti lp trn bng

in chnh ( Group Starter Panel ) v c n nh s giy tr cho php khi

ng tr li khi xy ra mt in cho tng ph ti.

3.2.3.4. iu chnh ng c tr ng servo motor

Vic iu chnh ng c tr ng thc hin gi tn s li in theo

gi tr nh mc khi my lm vic c lp cng nh vic phn phi ti tc

dng cho cc my khi chng lm vic song song. Hin nay trn cc trm pht

hin i, cc thao tc ny c thc hin theo hai phng thc bng tay v t

66

ng. Ty chn ny hon ton theo mun ca ngi vn hnh. Thc hin

bng tay thng qua thao tc ca ngi vn hnh tc ng vo Governor

Switch, y l cng tc loi t hon nguyn c lp t trn gen.panel.

Hnh 3.12. Mch iu khin Servo Motor.

Hnh 3.12 trnh by s ca mch iu chnh ny vi GS11 l cng tc

iu chnh bng tay ca my 1 v GS21 l ca my 2. ng c tr ng trong

s ny dng ng c xoay chiu ba pha nn vic o chiu ng c c

thc hin thng qua cc cng tc t hng 115R, 115L, cho my 1 v 215R,

215L, cho my 2. Khi la chn ch t ng th lc tn hiu iu chnh

do b iu khin cng sut PWC thng qua cng 00 v 01 gi n 65RX v

65LX ca b s l tn hiu ICU-GP1 iu khin hai cng tc t 115R,

115L. Tng t nh vy tn hiu t cng 02 v 03 ca PWC gi n 65RX v

65LX ca b x l tn hiu ICU-GP2 iu khin hai cng tc t 215R v

215L.

3.2.3.5. Mch sy cho my pht lc ngng hot ng

Vic gi cho nhit my pht khi ngng hot ng m bo cho

cch in ca my pht khng b gim xung do hi nc xm nhp l mt

vic lm thng xuyn trong qu trnh khai thc my pht ng b trn trm

67

pht. Trong thit k ngi ta cng cho php thc hin thao tc ny bng tay

v t ng, vic t ng cung cp ngun cho b sy thng ly thng qua

tip im ph thng ng ca cu dao chnh ACB, mi khi turn off cu dao

chnh ACB l mch sy c cp ngun t ng nu nh cng tc ngun

ng.

V d hnh 3.13 trnh by s mt mch sy my pht trn tu VinaShin

Sun vi congtactor 188 v 288 cp ngun, mch iu khin cc cun dy ca

hai congtacter ny thng qua cng tc sy SHS11 v SHS21 v hai tip im

thng ng ca r le trung gian 152B v 252B khng ch qua hai tip im

thng m ca ACB1 v ACB2. in p sy s dng li sinh hot.

Hnh 3.13. Mch sy cc my pht

68

3.2.3.6. Mch iu khin ng m ACB

iu khin ng m cho cu dao chnh ACB l mt cng vic quan trng

v n nh hng trc tip n an ton khai thc ca con tu. V ACB c lin

quan n rt nhiu chc nng iu khin v bo v khc nhau nn bn thn n

cng lc l phn t thc hin ca nhiu h thng. Chnh v l do ny nn

ACB lun c la chn cn thn v cc yu cu v quy phm k thut cng

kht khe. Do c tnh ca ACB nh vy nn trn n c tch hp kh nhiu

cc chi tit, thnh phn cc thit b t c kh chnh xc n cc linh kin in

t hin i v hin nay vi cc ACB c dung lng ct ln th ngi ta thit

lp c mt my tnh mini iu khin cho qu trnh ng, ct, o c, kim

tra, bo v v thc hin rt nhiu chc nng khc na. iu khin cho ACB

c th thc hin bng tay n thun nhng ng thi cng thc hin t ng

trn c s cc chc nng c sn hnh 3.2. gii thiu mt mch iu khin cho

ACB lp t trn tu Vinasin Sky trong trn ACB c tch hp mt s

cun thc hin: UVC, OPEN, CLOSE, RESET. Mch ngoi vi phc v cho

iu khin bao gm cc thit b : cng tc ng (m) bng tay CS21, cng tc

la chn ha SYS, mch tch hp ICU- GP2, cc r le trung gian 252A,

252B, 252CX, 252TX, r le thi gian 284T ( cc s 2 y l ch s ch cho

my s 2 nu l my 1 th cc s 2 ny c thay bng s 1 th cc s 2 ny

c thay bng s 1), tip im r le in p li 27B1, tip im r le iu

kin 225X1, tip im r le kha chuyn 91Z, tip im r le kha chuyn

ca ngun in b SCX, tip im b ha t ng ASD

Trc tin, ACB c th hot ng c th ngun iu khin phi

c cp in AC110V t mch 24V. Khi c ngun, ngay lp tc r le 284T

c in, r le thi gian ny c t thi gian tr l 1 S ( trong trm nu c

hai my pht th lm vic t thi gian cho 184T ca my s 1 v 284T ca

my s 2 phi khc nhau, lc r le no c thi gian tr ngn hn th s

dnh quyn thc hin vic ng in ln li trc trong trng hp trn li

69

khng c in), sau qung thi gian ny tip im thi gian 284T (1-3) s b

ng li. Nu nh trn li cha c in (m cng tc iu khin CS21 ang

t v tr OPEN ) th lc r le 27B1 s ng tip im thng ng

27B1(71-72) v 252CX c in cung cp cho cun ng CLOSE v ACB s

hot ng ng ngun ln li ngay cn nu m cng tc CS21 ang trng

thi CLOSE th khng cn phi ch 284T hot ng, cun CLOSE cng

c cp in thng qua tip im CS21 (2-4) qua 27B1 (31-32). Nu iu

gi thit trn m khng c th ACB s ph thuc vo hai mch iu khin: th

nht, mch nhn t ng ASD (015-016) vi 225X1 (8-12) v th hai mch

nhn ca hi v tr tay iu khin CS21 (2-4) vi SYS (21-23) thao tc ny s

ph thuc vo ty chn.

Hnh 3.14. Mch iu khin ACB (AME TYPE).

Thc hin m ACB cng c hai phng thc: hoc iu khin bng tay

CS21 t trng thi OPEN v CS21 (5-7) thng mch cp in cho cun

252TX hot ng tc ng vo cun OPEN trong ACB hoc mch th hai

thao tc thng qua hai tn hiu ni tip 291X1 (8-12) vi 91Z (6-10).

Cun UVC c cp in thc hin gi khi ACB2(a2-c2) ng.

70

Hnh 3.15. Mch iu khin ACB (Schneider).

Vi loi ACB ny mch iu khin c thit k kh n gin: MHC l

cun dy ca ng c cp ct, XF l cun ng ca ACB, MN cun in p

(UVC), S041-2 l cng tc ng ACB bng tay, S042-2 cng tc nh bng tay

ACB, S-K061 l tip im contactor in b, K011 v K012 l tip im ca

contactor li in, RPR l tip im ca r le cng sut ngc. Thc hin

ng m ACB c th bng tay, t ng tip im K081 l tip im ca ng

h ha, gip cho ngi vn hnh ho my thp phng thc bn t ng tc

l con ngi tham gia vo qu trnh iu chnh cc i lng: in p v tn

s cn vic chn thi im ha l do thit b thc hin t ng b h

synchroscope. Vic ha t ng thng qua b auto.synchroscope mang tn

T45-2, khi s dng thit b ny th vic ha t ng hon ton do my thc

hin khng cn con ngi tham gia bt c vic g.

71

3.2.4. Phng php tnh chn my ct

Tiu ch la chn my ct ca my pht ngoi in p nh mc, tiu ch

quan trng nht l dng in v dng ct nh mc. ABB cung cp vi kiu

my ct cho my pht c th c s dng tu vo cng sut ca my pht.

Hnh 3.16. Bng la chn my ct cho my pht.

Mt mt l cc my ct SF6 kiu HECS v HCE 7/8 (c v) v kiu HGI

v HECT (khng v), mt khc l my ct chn khng kiu VD4G

in p nh mc (IEC)

VD4G 17,5 kV

HGI 17,621 kV

HECI 25 kV

HECS 23/25 kV

HEC 7/8 30 kV

3.2.5. Cc ch khi thit k, lp rp, s dng my ct.

3.2.5.1. Cc h hng thng gp, kim tra v s l

Khi khng ct my ct c trc ca vn hnh nhanh chng kim tra tn

hiu t trang Alarm trn mn hnh my tnh, n tn hiu trn thit b RTK ti

72

cc t iu khin v bo v phn 500kV. T tn hiu ny trc ca phn on

nguyn nhn v khoanh vng kim tra.

a) khng ct c ti ch ( c hai mch ct 1 v 2)

Cc h hng

Cch kim tra v khc phc

My ct ang

v tr ct

- Kim tra trng thi my ct.

- Nu my ct ang trng thi ng th kim tra tip im

trng thi my ct

S1(1-2, 3-4) 3 pha mch ct 1 b h mch khng.

S01(9-10, 11-12) 3 pha mch ct 2 b h mch khng

Kh SF6 khng

-Kim tra ch th p lc kh SF6 trn ng h ti my ct.

- Nu p lc kh SF6 < 7,1 Bar th bo lnh o trm v cng

ty bit x l.

- Nu p lc SF6 ( > 7,1 Bar - p lc SF6 kha mch thao

tc) th kim tra r le K16, K6 ti t QF01 c lm vic khng.

- Nu cc r le trn khng lm vic th kim tra tip im

K16(3-

11), K6(3-11) t QF01 c b chp khng

p lc du thy

lc khng

- Kim tra ch th p lc du thy lc trn ng h ti my

ct.

- Nu p lc du thy lc < 21,5 Mpa th bo lnh o trm

v cng ty bit x l.

- Nu p lc du thy lc ( > 21,5 Mpa - p lc du thy

lc kha mch ct my ct ) th kim tra r le K5, K15 ti t

QF01 c lm vic khng.

- Nu r le trn khng lm vic th kim tra tip im K5(3-

11), K15(3-11) t QF01 c b chp khng.

73

Mt ngun iu

khin mch ct

Mch ct 1:

- Kim tra ptmt cp ngun cho mch ct 1 l Q805 t

B03.AA2.

- Nu Q805 ng m vn khng c in p trong mch ct

th c th ptmt h hng v phi kim tra in p ngay ti

chn ptmt Q805

- Nu ti chn ptmt c in p th kim tra (+) ngun ti

chn 13 ca kha ct ti ch S4. Kim tra (-) ngun ti chn

14 ca kha ng ti ch S4.

- Nu ti kha S4 khng c in p th kim tra tt c cc

chn hng kp ngc v pha ngun Q805.

Mch ct 2:


B03.AA2.



chn ptmt Q808

- Nu ti chn ptmt c in p th kim tra (+) ngun ti

chn 23 ca kha ct ti ch S4. Kim tra (-) ngun ti chn

24 ca kha ng ti ch S4.

- Nu ti kha S4 khng c in p th kim tra tt c cc

chn hng kp ngc v pha ngun Q808

Lnh ct ti ch

khng c tc

dng.

- Kim tra li nt n ct my ct S4 ti t my ct b h hng

hoc do tip im nt n S4(13-14) v S4(23-24) khng khp

mch trong qu trnh n nt.

H hng r le ra

lnh ct

- Kim tra cun dy ca r le ra lnh ct c b chy khng K4

i mch ct 1, K14 i mch ct 2. Nu chy bo lnh o

74

trm, cng ty bit x l.

- Kim tra trng thi tip im ph r le ra lnh ct K4(3-

11);(4-12);(5-13) khi r le tc ng c 3 pha i mch ct 1.

- Kim tra trng thi tip im ph r le ra lnh ct K14(3-

11);(4-12);(5-13) khi r le tc ng c 3 pha i mch ct 2.

- Nu r le chy, h hng bo lnh o trm, cng ty bit x

l.

Cun ct b t.

- Kim tra cun ct Y2, Y3 tng pha.

- o thng mch cun ct Y2, Y3 tng pha.

- o in tr 1chiu cun ct. Nu cun dy b t (R= )

hoc cun dy b chp (R=0) th bo lnh o trm v cng ty

bit x l.

b) Khng ct c t kha iu khin Emergency

(i vi mch ct 1)

Cc h hng


My ct

ang v tr

ct


- Nu my ct ang trng thi ng th kim tra tip im trng

thi my ct

S1(1-2, 3-4) 3 pha mch ct 1 b h mch khng.

Kh SF6

khng

- Kim tra ch th p lc kh SF6 trn ng h ti my ct.

- Nu p lc kh SF6 < 7,1 Bar th bo lnh o trm v cng ty

bit x l.

- Nu p lc SF6 ( > 7,1 Bar - p lc SF6 kha mch thao tc)

th kim tra r le K16, K6 ti t QF01 c lm vic khng.

- Nu cc r le trn khng lm vic th kim tra tip im K6(3-

11) t QF01 c b chp khng.

75

p lc du

thy lc

khng

- Kim tra ch th p lc du thy lc trn ng h ti my ct.

- Nu p lc du thy lc < 21,5 Mpa th bo lnh o trm v

cng ty bit x l.

- Nu p lc du thy lc ( > 21,5 Mpa - p lc du thy lc

kha mch ct my ct ) th kim tra r le K5 ti t QF01 c lm

vic khng.

- Nu r le trn khng lm vic th kim tra tip im K5(3-11) t

QF01 c b chp khng.

Kha L/R ti

t my ct

t sai ch

.

- Kim tra v t li kha L/R ch Remote.

- Nu kha L/R t ng ch Remote m vn khng thao

tc c th kim tra tip im kha L/R S10(5-6) b h mch

khng

Kha E/M

ti t iu

khin t sai

ch .

- Kim tra v t li kha E/M ch Emergency.

- Nu kha E/M t ng ch Emergency m vn khng

thao tc c th kim tra tip im kha E/M S6400(5-6) b h

mch khng.

Mt ngun

iu khin

mch ct.

Mch ct 1:


B03.AA2.

- Nu Q805 ng m vn khng c in p trong mch ct th

c th ptmt h hng v phi kim tra in p ngay ti chn

ptmt Q805

- Nu ti chn ptmt c in p th kim tra (+) ngun ti chn

13 ca kha ct ti ch S4. Kim tra (-) ngun ti chn 14 ca

kha ng ti ch S4.

- Nu ti kha S4 khng c in p th kim tra tt c cc chn

76

hng kp ngc v pha ngun Q805.

Lnh ct t

kha iu

khin khng

c tc dng.

- Kim tra li kha iu khin S2301 ti t iu khin c b h

hng khng hoc do tip im nt n S2301(01-1) khng khp

mch trong qu trnh n nt.

H hng r

le ra lnh ct

- Kim tra cun dy ca r le ra lnh ct c b chy khng K4 i

mch ct 1. Nu chy bo lnh o trm, cng ty bit x l.

- Kim tra trng thi tip im ph r le ra lnh ct K4(3-11);(4-

12);(5-13) khi r le tc ng c 3 pha i mch ct 1.

- Nu r le chy, h hng bo lnh o trm, cng ty bit x l.

Cun ct b

t.

- Kim tra cun ct Y2, Y3 tng pha.

- o thng mch cun ct Y2, Y3 tng pha.

- o in tr 1chiu cun ct. Nu cun dy b t (R= ) hoc

cun dy b chp (R=0) th bo lnh o trm v cng ty bit

x l.

c) Khng ct c t my tnh C264-M.

Cc h hng


My ct

ang v tr

ct



thi my ct S1(1-2, 3-4) v S1(9-10, 11-12) 3 pha b h mch

khng.

- Nu vn khng thao tc c th phi kim tra cp dn a tn

hiu trn vo C264-B c b t khng. Nu cp b t th tm si

d phng thay th. Nu cp khng b t th module DI1, DI2-

77

U002-MM-C264M t B03.AA2 b h hng phi bo ngay lnh

o trm v cng ty bit x l.

Kh SF6

khng



bit x l.




11), K6(3-11) t QF01 c b chp khng.




U10*-MP-C264M t B03.AA2 b h hng phi bo ngay lnh


p lc du

thy lc

khng



cng ty bit x l.


kha mch ct my ct ) th kim tra r le K5, K15 ti t QF01 c

lm vic khng.

- Nu r le trn khng lm vic th kim tra tip im K5(3-11),

K15(3-11) t QF01 c b chp khng.



d phng thay th. Nu cp khng b t th phi bo ngay lnh


Kha E/M

ti t iu

- Kim tra v t li kha E/M ch Main.

- Nu kha E/M t ng ch m vn khng thao tc c

78

khin t sai

ch .

th kim tra tip im kha E/M: S6400(7-8) b h mch khng.


hiu trn vo C264-M c b t khng. Nu cp b t th tm si



Kha L/R ti

t my ct

t sai ch

.


- Nu kha L/R t ng ch m vn khng thao tc c

th kim tra tip im kha L/R: S10(5-6) b h mch khng.





Mt ngun

iu khin

mch ct.

- Kim tra aptomat cp ngun cho mch ct 1 l Q805 t

B03.AA2.


c th aptomat h hng v phi kim tra in p ngay ti chn

aptomat Q805.

- Nu ti chn ptmt c in p th phi kim tra tt c chn cc

hng kp trong mch ct t C264-M.

Lnh ct t

C264 khng

c tc dng.

- Kim tra my tnh C264 c lm vic tt khng.

- Kim tra ch lm vic ca C264. Nu ang ch Remote

th phi chuyn v ch Local.

- Kim tra cc tn hiu trn C264 gii tr ht cha.

Cun ct b

t.

- Kim tra cun ct Y2 tng pha.

- o thng mch cun ct Y2 tng pha.



79

x l.

d) Khng ct c t my tnh C264-B

Cc h hng


My ct ang

v tr ct



thi my ct S1(1-2, 3-4) v S1(9-10, 11-12) 3 pha b h mch

khng.




U002-MM-C264M t B03.AA2 b h hng phi bo ngay lnh


Kh SF6

khng



bit x l.




11), K6(3-11) t QF01 c b chp khng.




U10*-MP-C264M t B03.AA2 b h hng phi bo ngay lnh


p lc du

thy lc



80

khng

cng ty bit x l.


kha mch ct my ct ) th kim tra r le K5, K15 ti t QF01

c lm vic khng.







Kha E/M ti

t iu khin

t sai ch

.


- Nu kha E/M t ng ch m vn khng thao tc c

th kim tra tip im kha E/M: S6400(7-8) b h mch khng





Kha L/R ti

t my ct t

sai ch .








Kha L/R ti

t my ct t



81

sai ch .






Mt ngun

iu khin

mch ct.

- Kim tra aptomat cp ngun cho mch ct 1 l Q805 t

B03.AA2.


c th aptomat h hng v phi kim tra in p ngay ti chn

aptomat Q805.

- Nu ti chn aptomat c in p th phi kim tra tt c chn

cc hng kp trong mch ct t C264-M.

Lnh ct t

C264 khng

c tc dng.


- Kim tra ch lm vic ca C264. Nu ang ch Remote

th phi chuyn v ch Local.

- Kim tra cc tn hiu trn C264 gii tr ht cha.

Cun ct b

t.





x l.

e) Khng ct c t my tnh HMI

Cc h

hng


My ct - Kim tra trng thi my ct.

82

ang v

tr ct

- Nu my ct ang trng thi ng th kim tra tip im

trng thi my ct S1(1-2, 3-4) v S1(9-10, 11-12) 3 pha b

h mch khng.

- Nu vn khng thao tc c th phi kim tra cp dn a

tn hiu trn vo C264-M c b t khng. Nu cp b t th

tm si d phng thay th. Nu cp khng b t th module

DI1, DI2-U002-BM-C264B t B03.AA2 b h hng phi bo

ngay lnh o trm v cng ty bit x l.

Kh SF6

khng



bit x l.

- Nu p lc SF6 ( > 7,1 Bar - p lc SF6 kha mch thao

tc) th kim tra r le K16, K6 ti t QF01 c lm vic khng.

- Nu cc r le trn khng lm vic th kim tra tip im

K16(3-11), K6(3-11 thao tc c th phi kim tra cp dn

a tn hiu trn vo C264-M c b t khng. Nu cp b t

th tm si d phng thay th. Nu cp khng b t th module

DI1, DI2-U10*-MP-C264M t B03.AA2 b h hng phi b) t

QF01 c b chp khng.

- Nu vn khng o ngay lnh o trm v cng ty bit x

l.

p lc du

thy lc

khng



cng ty bit x l.


kha mch ct my ct ) th kim tra r le K5, K15 ti t QF01

c lm vic khng.


83



hiu trn vo C264-M c b t khng. Nu cp b t th tm

si d phng thay th. Nu cp khng b t th phi bo ngay

lnh o trm v cng ty bit x l.

Kha L/R

ti t my

ct t sai

ch .


- Nu kha L/R t ng ch m vn khng thao tc

c th kim tra tip im kha L/R: S10(5-6) b h mch

khng.



tm si d phng thay th. Nu cp khng b t th phi bo


Kha E/M

ti t iu

khin t

sai ch


- Nu kha E/M t ng ch m vn khng thao tc

c th kim tra tip im kha E/M: S6400(7-8) b h mch

khng.



tm si d phng thay th. Nu cp khng b t th phi bo


Mt ngun

iu khin

mch ct.


B03.AA2.



chn ptmt Q805.

- Nu ti chn ptmt c in p th phi kim tra tt c chn

cc hng kp trong mch ct t C264-M.

84

Lnh ct t

my tnh

HMI khng

c tc dng

- Kim tra my tnh HMI nhp Password cha.

- Kim tra my tnh HMI c lm vic tt khng.

- Kim tra ch lm vic ca HMI. Nu ang ch

Dispatching th phi chuyn v ch Substation.

- Kim tra cc tn hiu trn my tinh HMI v C264 gii tr

ht cha.


- Kim tra ch lm vic ca C264. Nu ang ch Local

th phi chuyn v ch Remote.

Cun ct b

t.



- o in tr 1chiu cun ct. Nu cun dy b t (R= )

hoc cun dy b chp (R=0) th bo lnh o trm v cng ty

bit x l.

3.2.5.2. Kim tra mch iu khin my ct trong vn hnh:

Khi nhn ca v trong thi gian i ca cc nhn v

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