Đồ Án Thiết Kế Chống Sét Cho Trạm Biến Áp 220110

N TT NGHIP K THUT IN CAO P

N TT NGHIP K THUT IN CAO P

MC LC4CHNG 1: BO V CHNG ST NH TRC TIP TRM BIN P 220/110KV

41.1.M u

41,2, Cc yu cu i vi h thng chng st nh thng

51,3, Phm vi bo v ca ct thu st v dy chng st

51,3,1, Phm vi bo v ca ct thu st

71,3,2, Phm vi bo v ca dy thu st

81,4, M t i tng bo v

91,5, Tnh ton, la chn cc phng n bo v chng st nh thng cho trm bin p

91.5.1.Phng n 1

191.5.2.Phng n 2

291.6.So snh v la chn phng n

31CHNG 2: TNH TON NI T CHO TRM BIN P 220/110KV

312,1, Yu cu ni t cho trm bin p

332,2, Tnh ton ni t

332,2,1, Ni t an ton

382,2,2, Ni t chng st

442,2,3, Ni t b sung

50CHNG 3: BO V CHNG ST CHO NG DY 110kV

503,1, M u

503,2, Cc ch tiu bo v chng st ca ng dy

503,2,1, Cng hot ng ca st

513,2,2, S ln st nh vo ng dy

523,2,3, S ln phng in do st nh vo ng dy

523,2,4, S ln ct in do st nh vo ng dy

533,2,5, S ln ct in do qu in p cm ng

543,3, Tnh ton ch tiu bo v chng st ca ng dy

543,3,1, Thng s ng dy cn bo v

553,3,2, Tnh vng, treo cao trung bnh, tng tr ca dy chng st v ng dy,

623,3,3, Tnh s ln st nh vo ng dy

633,3,4, Sut ct do st nh vo ng dy

88CHNG 4: BO V CHNG ST TRUYN VO TRM

884,1, M u

894,2, Phng php tnh ton qu in p trn cch in ca thit b khi c sng truyn vo trm

954,3, Tnh ton bo v khi c sng qu in p truyn vo trm

954,3,1, M t trm cn bo v

964,3,2, Lp s thay th tnh ton trng thi sng ca trm

109PH LC

114TI LIU THAM KHO

LI M U m bo tng trng hng nm ca nn kinh t nhu cu nng lng cho s pht trin sn xut, c bit l in nng cn c s tng trng vt trc c v cng sut v cht lng, V vy vic xy dng cc nh my in, h thng truyn ti v phn phi in nng l mt nhim v quan trng,

H thng in l mt h thng dn tri trn mt din tch ln, cc thit b a phn t ngoi tri nn vic bo v n trnh khi cc s c do st l mt nhim v quan trng, c bit vi nc ta c kh hu nhit i gi ma m nn s ngy dng st trong nm ln,

nng cao cht lng in nng cho h thng in th vic bo v chng st cho trm bin p v ng dy ti in l mt vic ht sc cn thit, Nu thc hin tt vic ny n c th gim thiu s ln ct in do st nh lm cho h thng in vn hnh an ton v tin cy hn,

L mt sinh vin ngnh H Thng in - Vin in Trng i hc Bch Khoa H Ni, hon thnh chng trnh o to ti trng em c giao nhim v thit k tt nghip v k thut in cao p, tn ti: Tnh ton bo v chng st v ni t cho trm bin p 110/220kV, Tnh ton ch tiu chng st ng dy 110kV v sng truyn vo trm t pha 110kV,

Do trnh , kin thc hn ch nn bn n khng th trnh khi nhng sai st, Em knh mong s ng gp, ch bo ca cc thy c bn n ca em c hon thin hn,

Em xin chn thnh cm n cc thy c trong b mn H Thng in, c bit l thy Phm Hng Thnh tn tnh hng dn, gip em hon thnh bn n ny,

H Ni, thng 9 nm 2012

Sinh vin

o Mnh cCHNG 1: BO V CHNG ST NH TRC TIP TRM BIN P 220/110KV1.1. M uTrm bin p l mt b phn quan trng trong h thng truyn ti v phn phi in nng, Cc my bin p l thit b ht sc quan trng v c cc c im k thut ring nn cn c cc bin php bo v ring, i vi tram bin ap thi cac thit bi thng c t ngoai tri, nn khi b set anh trc tip c th se gy ra nhng hu qua nng n (hng lp cch in bn trong) nu khng c bo v, S c mt in trm con anh hng n cc ngnh cng nghip v nn kinh t, Do vy tram bin ap co yu cu bao v cao, bao v chng set anh trc tip cho tram bin ap ngi ta dung ct thu li va dy chng st, Tac dung cua h thng nay la tp trung in tich inh hng cho cac phong in set tp trung vao o trnh st nh vo cc thit b bn di tao ra khu vc an toan cho cc thit b nay,H thng thu st phi c cc dy tip a dn dng st t kim thu st vo h thng ni t, nng cao tc dng ca h thng ny th tr s in tr ni t ca b phn thu st phi nh tn dng st mt cch nhanh nht, bo m sao cho khi c dng st i qua th in p trn cc b phn thu st khng ln gy phng in ngc n cc thit b gn , Ngoi ra khi thit k h thng bo v chng st nh trc tip vo trm ta cn phi quan tm n cc ch tiu kinh t sao cho hp l v bo m m quan tng th ca trm,1,2, Cc yu cu i vi h thng chng st nh thng

Yu cu i vi bo v chng st nh trc tip ca trm bin p l tt c cac thit bi cn bao v phai nm tron trong pham vi bao v an toan cua h thng bao v, i vi tram bin ap 220kV ta dung ct thu li, con i vi ng dy 220kV ta dung dy chng set, i vi tram bin ap 220kV co mc cach in cao, do do co th t cac thit bi thu st trn cac kt cu cua tram, Cac kt cu o phai gn vao h thng ni t cua tram theo ng ngn nht sao cho dong in set khuych tan vao h thng ni t theo 3 n 4 thanh ci ni t vi h thng, mt khac phai co ni t b sung ci thin tr s ca in tr ni t, Khu yu nht trong trm phn phi ngoi tri l cun dy my bin p, v vy khi dng ct thu li bo v my bin p th yu cu khong cch gia im ni vo ct thu li v im ni vo h thng ni t ca v my bin p phi ln hn 15m, Tit din cc dy dn dng in st phi ln m bo tnh n nh nhit khi c dng st chy qua, i vi cac dy chng set ta treo doc theo chiu dai cua ng dy bao v va t cao hn cac ng dy c bao v,1,3, Phm vi bo v ca ct thu st v dy chng st

1,3,1, Phm vi bo v ca ct thu st cao ct thu li:

(1,1)

Trong o : hx: cao vt c bao v

ha: cao tac dung cua ct thu li, c xac inh theo tng nhom ct

(ha ( D/8 m, D la ng tron ngoai tip a giac inh la cac chn ct)

-Pham vi bao v cua ct thu li c lp la:

(1,2)

- Nu hx ( 2/3h thi:

(1,3)

- Nu hx > 2/3h thi:

(1,4)

- Pham vi bao v cua nhiu ct ln hn tng ct cng lai, Nhng phi hp bao v gia cac ct thi khoang cach gia hai ct phai thoa man a ( 7h, Khi co 2 ct thu li t gn nhau thi pham vi bao v cao ln nht gia 2 ct l h0 c xac inh theo cng thc:

-Coi h0 l ct thu st gi tng tnh phm vi bo v cho cao hx tng t nh cc cng thc (1,3) v (1,4)

Hinh 1,1, Trng hp 2 ct thu li co chiu cao bng nhau-Trng hp hai ct thu li co cao khac nhau thi vic xac inh pham vi bao v nh sau:

-Khi ct thu li A va B co cao h1 va h2 nh hinh ve di y:

Hnh1,2, Trng hp 2 ct thu li co chiu cao khac nhau -Bng cach gia s vi tri x co t ct thu li C co cao h2, khi o cac khoang cach AB=a, BC=a, Khi o xac inh c khoang cach x va a nh sau:

(1,6)1,3,2, Phm vi bo v ca dy thu stPham vi bao v cua dy chng set c th hin nh hinh ve:

Hinh 1,3, Pham vi bao v cua dy chng set

Chiu rng cua pham vi bao v c tinh theo cng thc sau:

+ Khi hx> 2/3h thi

(1,7)

+ Khi hx ( h thi

(1,8)

Pham vi bao v doc theo chiu dai ng dy nh hinh ve:

Hinh 1,4, Goc bao v cua mt dy chng setCo th tinh toan c goc gii han ( la 30 nhng thc t thng ly khoang (=20 ( 25

1,4, M t i tng bo v -Tram bin ap 220kV/110kV Trng Bch, gm hai may bin ap AT1 va AT2

-Chiu rng tram 139,5m

-Chiu dai tram 266m

-Cc x phia 110kV cao 8m va 11m, cac xa phia 220kV cao 11m v 17m, -S mt bng tram nh hinh ve :

Hnh1,5, Mt bng trm 220/110kV Trng Bch1,5, Tnh ton, la chn cc phng n bo v chng st nh thng cho trm bin p1.5.1. Phng n 11,5,1,1, B tr cc ct thu li

Hnh 1,6, S b tr cc ct thu li ca phng n 1+ Phia 110kV b tri 12 ct: cc ct 1, 2, 3, 4, 5, 6, 7 b tr trn x cao 8m; cc ct 6, 8,9,10,11 v 12 b tr trn cc x cao 11m, + Phia 220kV b tri 21 ct: trong o ct 15 c t trn cac xa cao 17m; cac ct 12,13,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32 v 33 t trn cac ct cao 11m

1,5,1,2, Tnh ton cho phng n 1a) Tinh cao tac dung cua cac ct thu set tinh c cao tac dung cua cac ct thu set ta phai xac inh c ng kinh ng tron ngoai tip a giac i qua cac chn ct D, cao tac dung thoa man iu kin:

+) Phia 110kVng kinh ng tron ngoai tip hinh ch nht: (1; 2; 11; 12) la:

ng kinh ng tron ngoai tip hinh ch nht: (2; 3; 10; 11), (3; 4; 9; 10), (4; 5; 8; 9) v (5; 6; 7; 8) la:

cao tac dung ti thiu cua cac ct ny la:

+) Phia 220kVng kinh ng tron ngoai tip hinh ch nht (25;26; 27; 28) v (24; 25; 28; 29) (23; 24; 29; 30) (22; 23; 30; 31) (21; 22; 31; 32) (20; 21; 32; 33) la:

ng kinh ng tron ngoai tip hinh ch nht (13; 14; 25; 26) (14; 15; 24; 25) (15; 16; 23; 24) (16; 17; 22; 23) (17; 18; 21; 22) (18; 19; 20; 21) la:

cao tac dung ti thiu cua cac ct 13; 14; 15; 16; 17; 18; 19; 20 la:

+)Gia 110 v 220kVXt ng knh ng trn ngoi tip cc tam gic (7; 8; 16), (8; 15; 16), (8; 9 15), (9; 14; 15), (9; 10; 14), (10; 11; 14), (11; 13; 14), (11; 12; 13) ta thy: Vi p l na chu vi; a, b, c l cc cnh; S, R v D ln lt l din tch, bn knh v ng knh ng trn ngoi tip tam gic, p dng cng thc h rng tnh S, ta c:

Suy ra:

Tam gic (7; 16; 17) c:

Tam gic (7; 15; 16) c:

Tam gic (7; 8; 15) c:

Tam gic (8; 14; 15) c:

Tam gic (8; 9; 14) c:

Tam gic (9; 10; 14) c:

Tam gic (10; 13; 14) c:

Tam gic (11; 12; 13) c:

p dng cng thc, ta c bng cao tc dng ti thiu ca cc nhm ct nh sau:Bng 1,1, Bng cc tc dng ti thiu ca cc nhm ct

Nhm ct

ha7; 16; 177; 15; 167; 8; 158; 14; 158; 9; 149; 10; 149; 10; 1411; 10; 13

6,95,55,45,85,75,75,85,4

Nh vy ta co th ly cao tac dung chung cho cac ct la 7m

cao ct thu li 1,2,3,4,5,6,7,11,12 la:

cao ct thu li phia 220kV v 8,9,10 la:

b) Pham vi bao v cua tng ct +) Pham vi bao v cua cac ct phia 110kV (tr cc ct 8,9,10) cao 18mBan kinh bao v cao 8m nn

Ban kinh bao v cao 11m

nn

+) Pham vi bao v cua cac ct phia 220kV cao 24m


nn


nn

c) Pham vi bao v vua cac cp ct bin,* Bn knh bo v ca 2 ct c cao bng nhau:

Xt cp ct (1; 2) c cng cao h = 18m cch nhau mt khong a = 20m:

cao ca ct gi tng gia 2 ct ny l:

Ban kinh bao v ca ct gi tng cao 8m

nn


nn




nn


nn

* Bn knh bo v ca ct cao 24m cao 18m:

nn

Xt cp ct (11; 13) c khong cch gia 2 ct ny l d = 43,2m,Nh vy ta c


Ban kinh bao v ca ct gi tng cao 8m: nn


Xt cp ct (7; 16) c khong cch gia 2 ct ny l d = 35,4m,Nh vy ta c


Ban kinh bao v ca ct gi tng cao 8m:

nn


Xt cp ct (27; 28) (28; 29) (29; 30) (27; 28) (30; 31) (32; 33) (18; 19) (17; 18) (16; 17) c cng cao h = 24m cch nhau mt khong a = 34m:



nn


nn

Xt cp ct (10; 13) c cng cao h = 24m cch nhau mt khong a = 34,7m:



nn

Xt cp ct (8; 16) c cng cao h = 24m cch nhau mt khong a = 51,3m:


Nng chiu cao ct (8,16) ln 24,5m



nn

Tnh ton tng t vi cc ct lin k khc ta c bng sau:Bng 1,2, Kt qu tnh bn knh bo v gia cc ct lin k+ Cc ct pha 110kVCp ct

cao ct

(m)a

(m)h0(m)2/3h0(m)r0x

(m)

hx=8mhx=11m

1-2182015,110,07,653,08

2-3183013,79,15,552,03

3-4183013,79,15,552,03

4-5183013,79,15,552,03

5-6183013,79,15,552,03

6-7183013,79,15,552,03

1-12183013,79,15,552,03

+ Cc ct pha 220kVCp ct

cao ct

(m)a

(m)h0(m)2/3,h0(m)r0x(m)

hx=11mhx=17m

27-28243419,112,88,031,58

28-29243419,112,88,031,58

29-30243419,112,88,031,58

30-31243419,112,88,031,58

31-32243419,112,88,031,58

32-33243419,112,88,031,58

13-26243419,112,88,031,58

19-20243419,112,88,031,58

26-27243319,312,98,331,73

20-33243319,312,98,331,73

10-132434,719,012,71,50

8-1624,551,317,211,40,15

+ Cc ct c cao khc nhau gia pha 110kV v 220kVCp ct

cao ct

(m)a

(m)x

(m)a'

(m)h'0(m)r0x(m)

hx=8mhx=11m

11-1318-2443,24,538,712,53,751,13

7-1618-2435,44,530,913,65,401,95

1,5,1,3, Pham vi bao v cua phng an 1

Hnh 1,7, S phm vi bo v ca phng n 1Nhn xet: Ta thy tt ca cac thit bi trong tram u c bao v,

Tng s ct la 33 ct,Tng chiu dai cac ct la

1.5.2. Phng n 21.5.2.1 , B tr cc ct thu li

Hnh 1,8, S b tr cc ct thu li phng n 2

+ Phia 110kV b tri 10 ct: cc ct 1,2,3,4,5,7,8,9 v 10 b tr trn x cao 11m; ct 6 b tr trn x cao 8m, + Phia 220kV b tri 19 ct: trong o cac ct 19,20,21,23,24,25,26,27,28,29 v 13 c t trn cac xa cao 17m; cac ct 11,12,14,15,16,17,18 v 22 t trn cac ct cao 11m1,5,2,2, Tnh ton cho phng n 2a) Tnh cao tc dng ca cc ct thu st+) Phia 110kV

ng kinh ng tron ngoai tip hinh ch nht: (1; 2; 9; 10), (2; 3; 8; 9 la:

ng kinh ng tron ngoai tip hinh ch nht: (3; 4; 7; 8), (4; 5; 6; 7) la:


+) Phia 220kV

ng kinh ng tron ngoai tip hinh ch nht (21;22; 23; 24) v (18; 19; 27; 28) (17; 18; 28; 29) la:

ng kinh ng tron ngoai tip hinh ch nht (11; 12; 21; 22) (14; 15; 18; 19) (15; 16; 17; 18) la:

ng kinh ng tron ngoai tip cc hnh ch nht (12; 13; 20; 21) v (13; 14; 19; 20) l:

Xt ng knh ng trn ngoi tip cc tam gic (21; 24; 25), (20; 21; 25), (20; 25;26), (19; 20; 26), (19; 26; 27) ta c:

Tam gic (21; 24; 25) c:

Tam gic (20; 21; 25) c:

Tam gic (20; 25; 26) c:

Tam gic (19; 20; 26) c:


+)Gia 110 v 220kVXt ng knh ng trn ngoi tip cc tam gic (6; 13; 14), (6; 7; 13), (7; 12; 13), (7; 8; 12), (8; 11; 12), (8; 9; 11) ta c: Tam gic (6; 13; 14) c:

Tam gic (6; 7; 13) c:

Tam gic (7; 12; 13) c:

Tam gic (7; 8; 12) c:

Tam gic (8; 11; 12) c:

Tam gic (8; 9; 11) c:

p dng cng thc, ta c bng cao tc dng ti thiu ca cc nhm ct nh sau:

Bng 1,3, Bng cc tc dng ti thiu ca cc nhm ct

Nhm ct

ha6; 13; 146; 7; 137; 12; 137; 8; 128; 11; 128; 9; 11

7,15,26,75,76,16,1

Nh vy ta co th ly cao tac dung chung cho cac ct la 8m

cao ct thu li phia 110kV (khng k 7;8;9) la:

cao ct thu li phia 220kVv cc ct 7;8;9 la:

b) Pham vi bao v cua tng ct +) Pham vi bao v cua cac ct phia 110kV cao 19mBan kinh bao v cao 8m nn


nn

+) Pham vi bao v cua cac ct phia 220kV cao 25m


nn


nn

c) Pham vi bao v vua cac cp ct bin,* Bn knh bo v ca 2 ct c cao bng nhau:




nn

Phm vi bo v cha bao hon ton khu vc cn bo v

Nng ct 1;2;3;4;5 ln 21,5m



nn


nn

Xt cp ct (3; 4) c cng cao h = 21,5m cch nhau mt khong a = 30m:



nn


nn




nn


nn

Phm vi bo v cha bao hon ton khu vc cn bo v

Nng ct 23;24;25;26;27;28;29 ln 30m



nn


nn

* Bn knh bo v ca ct cao 21,5m cao 19m:

nn

Xt cp ct (1; 10) c khong cch gia 2 ct ny l a = 22m,Nh vy ta c


Ban kinh bao v ca ct gi tng cao 8m:

nn


Tnh ton tng t vi cc ct lin k khc ta c bng sau:Bng 1,4, Kt qu tnh bn knh bo v gia cc ct lin k


cao ct

(m)a

(m)h0(m)2/3h0(m)r0x

(m)

hx=8mhx=11m

1-221,54015,810,58,703,60

2-321,54015,810,58,703,60

3-421,53017,211,510,804,65

4-521,53017,211,510,804,65


cao ct

(m)a

(m)h0(m)2/3,h0(m)r0x(m)

hx=11mhx=17m

23-24303425,116,817,086,08

24-25303425,116,817,086,08

25-26303425,116,817,086,08

26-27303425,116,817,086,08

27-28303425,116,817,086,08

28-29303425,116,817,086,08

15-16253420,113,49,532,33

11-22251722,615,013,284,20

9-1125352013,39,382,25

7-132540,419,212,81,65

13-14255117,711,85,930,53

+ Cc ct c cao khc nhau Cp ct

cao ct

(m)a

(m)x

(m)a'

(m)h'0

(m)r0x(m)

hx=8mhx=11m

9-1019-25404,535,513,95,852,18

6-1419-2554,34,549,811,92,930,68

Cp ct

cao ct

(m)a

(m)x

(m)a'

(m)h'0

(m)r0x(m)

hx=11mhx=17m

22-2325-30333,829,220,810,582,85

17-2925-30333,829,220,810,582,85

Cp ct

cao ct

(m)a

(m)x

(m)a'

(m)h'0

(m)r0x(m)

hx=8mhx=11m

1-1021,5-19221,920,116,19,153,83

5-621,5-19221,920,116,19,153,83

1,5,2,3, Phm vi bo v ca phng n 2

Hnh 1,9, Phm vi bo v ca phng n 2Nhn xt: Ton b cc thit b trong trm u c bo v, Tng s ct l 24 Tng chiu di ct l:

1.6. So snh v la chn phng nBng 1,5, Bng so snh 2 phng nPhng nPhm vi bo vS ct di thi cng (m)

1Ton b trm33385,0

2Ton b trm29348,5

Ta thy ca 2 phng an u bao v c cac thit bi trong tram, C hai phng n u bo v c ht cc thit b trong trm, nhng do phng n 2 c tng chiu di ct nh hn phng n 1 nn xt c yu cu v tnh kinh t k thut ta la chn phng n 2 l phng n thit k thi cng,CHNG 2: TNH TON NI T CHO TRM BIN P 220/110KV2,1, Yu cu ni t cho trm bin p Nhim v ca ni t l tn dng in xung t m bo cho in p trn vt c ni t c tr s b, H thng ni t l mt b phn quan trng trong vic bo v qu in p, ty theo nhim v v hiu qu m h thng ni t c chia lm 3 loi,Ni t lm vic

Nhim v chnh l m bo s lm vic bnh thng ca cc thit b trng thi qui nh, Loi ny gm c: - Ni t im trung tnh my bin p

- Cc my bin in p, cc thit b chng st

- Ni t cc thit b b ngang trn ng dy ti in i xa Ni t an ton

C nhim v m bo an ton cho ngi khi cch in b h hng, Thc hin ni t an ton bng cch ni t cc b phn kim loi khng mang in nh v my in, thng du my bin p, cc gi kim loi, Khi cch in b h hng th trn cc b phn kim loi s c mt in th nhng do ni t nn in th ny nh khng gy nguy him cho ngi,Ni t chng st

C tc dng lm tn dng in st vo trong t khi c st nh vo ct thu li hay dy chng st, Hn ch s hnh thnh v lan truyn ca sng qu in p do phng in st gy nn, Ni t chng st cn c nhim v hn ch hiu in th gia hai im bt k trn ct in v t, V nguyn tc l phi tch ri cc h thng ni t ni trn nhng trong thc t c th mt h thng ni t chung cho cc nhim v, Song h thng ni t chung phi m bo yu cu ca cc thit b c dng ngn mch ln do vy in tr ni t phi nh, Khi in tr ni t nh th c th tn dng in vi mt ln, tc dng ca ni t an ton hn, Nhng t c in tr ni t nh th rt tn km do vy trong tnh ton ta phi thit k sao cho hp l c hai yu t m bo k thut v kinh t, Mt s yu cu v k thut ca in tr ni t:

Tr s in tr ni t ca ni t an ton c chn sao cho cc tr s in p bc v tip xc trong mi trng hp u khng vt qu gii hn cho php,+ i vi cc thit b in c im trung tnh trc tip ni t yu cu in tr ni t phi tho mn:

+ i vi cc thit b c im trung tnh cch in th: ,+ i vi h thng c im trung tnh cch in vi t v ch c mt h thng ni t dng chung cho c thit b cao p v h p th: ,+ Khi dng ni t t nhin nu in tr ni t t nhin tho mn yu cu ca cc thit b c dng ngn mch b th khng cn ni t nhn to na, Cn nu in tr ni t t nhin khng tho mn i vi cc thit b cao p c dng ngn mch ln th ta phi tin hnh ni t nhn to v yu cu tr s ca in tr ni t nhn to l: ,+ Trong khi thc hin ni t c th tn dng cc hnh thc ni t sn c nh cc ng ng v cc kt cu kim loi ca cng trnh chn trong t,,,Vic tnh ton in tr tn ca cc ng ng chn trong t hon ton ging vi in cc hnh tia,+ V t l mi trng khng ng nht, kh phc tp do in tr sut ca t ph thuc vo nhiu yu t: thnh phn ca t nh cc loi mui, axt ,,, cha trong t, m, nhit v iu kin kh hu, Vit nam kh hu thay i theo tng ma nn m ca t cng thay i theo dn n in tr sut cu t cng bin i trong phm vi rng, Do vy trong tnh ton thit k v ni t th tr s in tr sut ca t da theo kt qu o lng thc a v sau phi hiu chnh theo h s ma, mc ch l tng cng an ton,Cng thc hiu chnh nh sau:

(2,1)

Trong :

(tt: in tr sut tnh ton ca t, (o: in tr sut o c ca t, Km: h s ma ca t,H s Km ph thuc vo dng in cc v chn su ca in cc,2,2, Tnh ton ni t

in tr sut o c ca t: ,in tr ni t ct ng dy ta xt vi gi tr: ,

Dy chng st s dng loi C-70, in tr ca 1km ng dy ny l 2,38/km

Chiu di khong vt ng dy l: pha 220kV pha 110kV in tr tc dng ca dy chng st trong mt khong vt l:

,

S l trong trm:pha 220 kV: n = 7 pha 110 kV: n = 112,2,1, Ni t an tonCho php s dng ni t an ton vi ni t lm vic thnh mt h thng, in tr ni t ca h thng l:

,

(2,2)

Trong :

RTN: in tr ni t t nhin,RNT: in tr ni t nhn to ,2,1,1,1, in tr ni t t nhinNi t t nhin ca trm l h thng dy chng st ng dy v ni t ct in 110kV v 220kV ti trm,Ta c cng thc sau:

,

(2,3)Trong :

n: s l dy, Rcs: in tr tc dng ca dy chng st trong mt khong vt, Rc: in tr ni t ca ct in, vi Rc=10()

Pha 220kV

Pha 110kV

Ta c

Ta thy t yu cu v l thuyt, Tuy vy ni t t nhin c nhiu thay i theo ma v vy m bo an ton ta phi ni t nhn to,2,1,1,2, in tr ni t nhn toNi t c cc hnh thc cc di 2-3m bng st trn hay st dt chn thng ng, thanh di chn nm ngang su 0,5-0,8m t theo hnh tia, mch vng hoc t hp ca hai hnh thc trn,- i vi ni t chn nm ngang c th dng cng thc chung sau:

(2,4)Trong :

L: chiu di tng ca in cc, d: ng knh in cc khi in cc dng st trn, Nu dng st dt th tr s d thay bng vi b l chiu rng ca st dt, t: chn su, K: h s hnh dng ph thuc s ni t,- H thng ni t gm nhiu cc b tr dc theo chiu di thanh nm ngang hoc theo chu vi mch vng:

(2,5)Trong :

RC: in tr tn ca mt cc, RT: in tr tn ca thanh hoc ca mch vng, n: s cc, T: h s s dng ca thanh di hoc ca mch vng, C: h s s dng ca cc, i vi trm bin p ny th ta thit k h thng ni t nhn to s dng hnh thc ni t mch vng xung quanh trm bng cc thanh dt, Mch vng cch mng tng bao quanh trm mi chiu 1m,

Hnh 2,1, S quy i mch vng tng ngMch vng bao quanh trm c chiu di l l1=220m, chiu rng l l2 =82,5m v c ng gp khc l3=89m, l4=49m, l5= 177m, l6=41m, l7=46m l8=90,5m chu vi l Lt= 746m,Quy i thnh hnh ch nht tng ng cng din tch v chu vi c cc cnh l l9=269,5m v l10= 103,5m, in tr mch vng ca trm l:

(2,6)Trong :

L: chu vi mch vng, L=746m, t: chn su ca thanh ly t= 0,8m, tt: in tr sut tnh ton ca t i vi thanh lm mch vng chn su t,

Tra bng vi thanh ngang chn su t=0,8m ta c kma=1,6,

d: ng knh thanh lm mch vng, Chn thanh c b rng l b=4cm,

K: h s hnh dng ph thuc hnh dng ca h thng ni t,Gi tr ca c cho bng sau:Bng 2,1, Bng

L9/l1011,5234

K5,535,816,428,1710,4

Ta c th sau:

Hnh 2,2, th

Tra th ta c: Vy in tr mch vng l:

t yu cu do ta khng phi ng thm cc b sung, Ta c in tr ni t ca h thng:

t yu cu,2,2,2, Ni t chng st

y phi cp n c hai qu trnh ng thi xy ra khi c dng in tn trong t:

- Qu trnh qu ca s phn b in p dc theo chiu di in cc,- Qu trnh phng in trong t,Khi chiu di in cc ngn (ni t tp trung) th khng cn xt qu trnh qu m ch cn xt qu trnh phng in trong t, Ngc li khi ni t dng hnh thc phn b di (tia di hoc mch vng) th ng thi phi xt c hai qu trnh c nh hng khc nhau n hiu qu ni t,a. in tr tn xung kch ca ni t tp trungin tr tn xung kch khng ph thuc vo kch thc hnh hc ca in cc m n c quy nh bi bin dng in I, in tr sut v c tnh xung kch ca t,V tr s in tr tn xoay chiu ni t t l vi nn h s xung kch c gi tr :

(2,9) hoc dng tng qut:

(2,10)

b. Tnh ton ni t phn b di khng xt n qu trnh phng in trong tS ng tr ca ni t c th hin nh sau:

Hnh 2,3, S ng tr ca h thng ni t Trong mi trng hp u c th b qua in tr tc dng R v n b so vi tr s in tr tn, ng thi cng khng cn xt ti phn in dung C v ngay c trong trng hp sng xung kch, dng in dung cng rt nh so vi dng in qua in tr tn,

Hnh 2,4, S ng tr rt gn

Trong :

L: in cm ca in cc trn mt n v di,G: in dn ca in cc trn mt n v di,

(2,11)

Vi:

l: chiu di cc, r: bn knh cc phn trc nu cc l thp dt c b rng b(m),

Do

Gi Z(x,t) l in trng xung kch ca ni t ko di, n l hm s ca khng gian v thi gian,

(2,12)

Trong U(x,t); I(x,t) l dng in v in p xc nh t h phng trnh vi phn:

(2,13)

Gii h phng trnh ny ta c in p ti im bt k v ti thi im t trn in cc:

(2,14)

Tng tr xung kch u vo ca ni t:

(2,15)

Vi:

; ;

c. Tnh ton ni t phn b di khi c xt qu trnh phng in trong t Vic gim in p v mt dng in cc phn xa ca in cc lm cho qu trnh phng in trong t cc ni ny c yu hn so vi u vo ca ni t, Do in dn ca ni t (trong s ng tr) khng nhng ch ph thuc vo I, m cn ph thuc vo to , Tuy nhin vic tnh ton tng tr s rt phc tp v vy ta c th b qua trong phm vi n ny,d. Tnh ton cho trm thit k y l trm 220/110kV nn cho php ni t chng st ni chung vo vi ni t an ton, Do ni t chng st l ni t phn b di dng mch vng, Chiu di cc l

in cm ca in cc trn mt n v di l:

C bn knh in cc

Vy

in dn ca in cc trn mt n v di:

(2,16)

Vi (2,17)

kmua,AT =1,6 v kmua,set=1,2

Trong thit k tnh ton ta chn dng sng ca dng in st l dng sng xin gc c bin khng i,Phng trnh sng c dng sau:

(2,18)

Bin dng in st c quy nh l , dc ca dng st l ,Thi gian u sng l

Tng tr xung kch ca h thng ni t nhn to l:

(2,19)

Do coi mch vng l s ghp song song ca hai tia nn:

(2,20)

xc nh c Z(0,ds) ta xt chui s sau:

(2,21)

(2,22)

Trong dy s ny ta ch xt n s hng cha e-4, t s e-5 tr i c gi tr rt nh so vi cc s hng trc nn ta c th b qua, ta tnh n k sao cho:

(2,23)

Ta ly gi tr k t 1-10:Bng 2,2, Bng tnh ton chui s

K12345678910

K2149162536496481100

TK77,6719,428,634,853,112,161,591,2130,9590,777

0,0390,1540,3480,6190,9651,3891,8932,4733,1283, 861

0,9620,8570,7060,5390,3810,2490,1510,0840,0440,021

0,9620,2140,0780,0340,0150,0070,00310,00130,00050,0002

Ta c

Vi

Do my bin p l phn t yu nht nn ta ch cn kim tra vi my bin p, Khi c dng in st i vo ni t m bo an ton phi tho mn iu kin:

(2,24)

ZXK(0,ds): Tng tr xung kch u vo ni t ca dng in st, U50%MBA : in p 50% ca my bin p,Ta c U50%110=460kV; U50%220=900kV, Vy ly U50%MBA=460kV,Kim tra iu kin:

C vy cn phi tin hnh ni t b sung,2,2,3, Ni t b sungTrong ni t b sung ta s dng dng ni t tp trung gm thanh v cc ti chn cc ct thu st, Ta chn hnh thc ni t b sung nh sau:

Chn thanh ni t b sung l loi thp dt c:

Chiu di: lT = 12(m),B rng: bT = 0,04(m),Ni t c tnh ton cho chng st nn ta ly h s kma nh sau:

i vi thanh ngang chn su t = 0,8(m); kma = 1,2,i vi cc di 3m chn su t = 0,8(m); kma = 1,15,a) in tr thanh

Cng thc s dng tnh ton:

(2,25)

Trong :

l: chiu di ca thanh l = 12(m), t: chn su ca thanh lm tia t = 0,8(m)

tt,T: in tr sut tnh ton ca t i vi thanh lm tia chn su t

d: ng knh thanh lm tia, Chn thanh dt c b rng b =0,04(m) nn:

k: h s hnh dng ly do ni t l tia ngang, Vy in tr ca thanh b sung l:

b) in tr cc

(2,26)

Trong : ttC: in tr sut ca t i vi cc chn su t=0,8(m),

d: ng knh ca cc: ,

in tr b sung ca cc l:

c) in tr b sung

Cng thc s dng tnh ton:

(2,27)

Trong : n: s cc

,: h s s dng ca thanh v cc,Vi a/l=1; lcc = 3(m); a=3(m) s cc n=5, Theo [1] ta c: , ,

in tr b sung l:

Tng tr ca h thng khi c ni t b sung

Ta c cng thc tnh tng tr xung kch khi c ni t b sung nh sau:

(2,28)Trong :

Xt chui s

Tng t nh trn ta ch xt n s hng e -4 vi T1 = 77,67s v ds = 3s

Ta tnh n Xk sao cho:

Trong XK l nghim ca phng trnh:

Phng trnh trn khng th gii bng phng php gii tch thng thng, Ta c th gii gn ng bng phng php th:

Hnh 2,5, th biu din cc hm s y= tgX, y= -0,080XCc nghim gn ng X1 = 2,88; X2 = 5,85; X3 = 8,76; X4 =11,75; X5=14,86; X6=17,88; X7= 20,85 ; X8=23,97; X9=27,13; X10=30,21 Bng 2,3, Bng tnh ton chui s

k12345678910

Xk2,885,858,7611,7514,8617,8820,8523,9727,1330,21

cos(Xk)-0,96600,9076-0,78710,6849-0,66150,5657-0,41660,3968-0,41370,3568

1,07171,21391,61432,13202,28523,12525,76326,35045,84427,8539

1,15171,29391,69432,21202,36523,20525,86826,43045,92427,9339

0,96810,87470,74060,58260,42140,28620,18240,10560,05610,0281

BK0,83810,67200,43450,26180,17710,08880,03090,01630,00940,0035

B= 2,53Tng tr xung kch l :

in p khi c dng in i vo ni t ti thi im dng in st t gi tr cc i l

Ta thy tho mn yu cu,CHNG 3: BO V CHNG ST CHO NG DY 110kV

3,1, M u

ng dy l phn t di nht trn h thng in nn thng b st nh gy nn qu in p c th dn ti ct my ct ng dy lm nh hng ti cung cp in, Mt khc khi st nh vo on dy gn trm th s to nn sng truyn vo trm gy s c ph hoi cch in ca cc thit b in trong trm, Do ta phi tin hnh nghin cu chng st cho ng dy ti in ,c bit l nhng on ng dy gn n trm th phi c tnh ton bo v cn thn, V th ng dy cn c bo v chng st vi mc an ton cao,Qu in p kh quyn c th l do st nh thng ln ng dy hoc do st nh xung t gn ng dy to nn qu in p cm ng, Tr s ca qu in p kh quyn l rt ln nn khng th chn mc cch in ca ng dy p ng c hon ton yu cu ca qu in p m ch c th chn theo mc hp l v mt kinh t v k thut, Do yu cu i vi bo v chng st ng dy khng phi l an ton tuyt i m ch cn mc gii hn hp l,Trong phn ny ta s tnh ton cc ch tiu bo v chng st ng dy, trn c s xc nh c cc phng hng v bin php gim s ln ct in ca ng dy cn bo v,3,2, Cc ch tiu bo v chng st ca ng dy

3,2,1, Cng hot ng ca st

S ngy stCng hot ng ca st c biu th bng s ngy c ging st hng nm (nngs), Cc s liu ny c xc nh theo s liu quan trc cc i trm kh tng phn b trn lnh th tng nc, Theo s liu thng k ca nhiu nc ta c :

- S ngy st hng nm vng xch o : 100 150 ngy,- S ngy st hng nm vng nhit i : 75 100 ngy,- S ngy st hng nm vng n i : 30 50 ngy,Mt st

tnh ton s ln c phng in xung t cn bit v s ln c st nh trn din tch 1km2 mt t ng vi mt ngy st, n c tr s khong ms = 0,10,15 ln/km2,ngy st, T s tnh c s ln st nh vo cc cng trnh hoc ln ng dy ti in, Kt qu tnh ton ny cho mt gi tr trung bnh,3,2,2, S ln st nh vo ng dy

Coi mt st l u trn ton b din tch vng c ng dy i qua, c th tnh s ln st nh trc tip vo ng dy trong mt nm l:

(3,1)

Trong : ms: mt st vng c ng dy i qua

nng,s: s ngy st trong mt nm, h : chiu cao trung bnh ca cc dy dn (m)

L : chiu di ca ng dy (km),Ly L = 100km ta s c s ln st nh vo 100km dc chiu di ng dy trong mt nm,

(3,2)

Tu theo v tr st nh qu in p xut hin trn cch in ng dy c tr s khc nhau, Ngi ta phn bit s ln st nh trc tip vo ng dy c dy chng st thnh ba kh nng,- St nh vo nh ct :

(3,3) - St nh vng qua dy chng st vo dy dn :

(3,4)

Trong N : tng s ln st nh vo ng dy, : xc sut st nh vng qua dy chng st vo dy dn, n ph thuc vo gc bo v v c xc nh theo cng thc sau:

(3,5)

Trong hc : chiu cao ca ct (m), : gc bo v (),- St nh vo im gia khong vt:

(3,6)

3,2,3, S ln phng in do st nh vo ng dy

Khi b st nh, qu in p tc dng vo cch in ca ng dy (s v khong cch khng kh gia dy dn v dy chng st) c th gy ra phng in, Kh nng phng in c c trng bi xc sut phng in Vp, Nh th ng vi s ln st nh Ni s ln phng in :

(3,7)

Xc sut phng in Vp ph thuc tr s ca qu in p v c tnh cch in (V-s) ca ng dy

(3,8)

3,2,4, S ln ct in do st nh vo ng dy

Khi c phng in trn cch in ca ng dy, my ct c th b ct ra nu c xut hin h quang tn s cng nghip ti ni phng in, Xc sut hnh thnh h quang ph thuc vo in p lm vic trn cch in pha ca ng dy v di cch in ca ng dy, C th xc nh theo bng sau:Bng 3,1, Bng xc sut hnh thnh h quang

50302010

0,60,450,250,1

Vi Ulv : in p pha lm vic (kV), Lcs : chiu di chui s (m),

Hnh 3,2, th

i vi ng dy dng ct g tnh theo cng thc

(3,9)

Etb : l cng trng trung bnh trn tng chiu di cch in ( kV/m),Cui cng c th tnh s ln ct ca ng dy tng ng vi s ln st nh Ni:

(3,10)

S ln ct in tng cng ca ng dy:

(3,11)

3,2,5, S ln ct in do qu in p cm ng

S ln phng in do st nh gn ng dy cm ng gy phng in trn cch in ng dy,

(3,12)

Trong ns : s ngy st trong mt nm, h : treo cao trung bnh ca dy dn, U50% : in p phng in 50% ca chui s,Nh vy s ln ng dy b ct in do qu in p cm ng

(3,13)

ng dy 110kV tr ln do mc cch in cao (U50% ln) nn sut ct do qu in p cm ng c tr s b v trong cch tnh ton c th b qua thnh phn ny,3,3, Tnh ton ch tiu bo v chng st ca ng dy

3,3,1, Thng s ng dy cn bo v

a) Kt cu ct in

Hnh 3,3, S ct n 110kVLoi ct : ct n,Chiu cao ct : 22,8m,Chui s :

+ S lng 8 bt

+ Loi c chiu di 1 bt s l ls = 146mm, cao treo dy dn pha A: 17,83m, cao treo dy dn pha B: 13,83m, cao treo dy dn pha C: 13,83m,b) Dy dn v dy chng st,Dy dn AC-240

Dy chng st C-70

Khong vt lkv=210m

c) Ni t ct in

in tr sut ca t ,in tr ni t ct in vi gi tr ,3,3,2, Tnh vng, treo cao trung bnh, tng tr ca dy chng st v ng dy,3,3,2,1, Dy chng st

Cc thng s ca dy chng st (C-70):

ng sut cho php: ,Modul n hi: ,H s gin n nhit: ,Ti trng do trng lng gy ra ,Ti trng do gi gy ra v tnh vi p lc gi cp 3 ta c ,

Vi

: h s khng u cua ap lc gio,

: h s khi ng hoc cua dy dn, do d lghVy phng trnh trng thi ly ly trng thi ng vi lm trng thi xut pht,

Phng trnh trng thi c dng :

Phng trnh trng thi :

vng ca dy chng st:

treo cao trung bnh ca dy chng st:

Tng tr sng dy chng stDy chng st l dy C 70 c r = 5,75,10-3m nn ta tnh c tng tr sng ca dy chng st nh sau:

Khi khng k n nh hng ca vng quang,

Khi c k n nh hng ca vng quang,

: l h s hiu chnh khi xut hin vng quang c tra t bng vi cp in p 220kV: =1,4

3,3,2,2, Dy dn

a) vng ca dy dn

Cc thng s ca dy AC 240:

ng sut cho php: , Ti trng do trng lng gy ra , Modul n hi: ,H s gin n nhit: ,Ti trng do gi gy ra v tnh vi p lc gi cp 3 ta c tng t nh dy chng st ta c:

Vi

: h s khng u cua ap lc gio,

: h s khi ng hoc cua dy dn, do d>20mm nn

Ti trng tng hp

Nhit ng vi trng thi bo

Nhit ng vi trng thi min

T y ta tnh c lgh:

Lkv = 210m > lgh

Vy phng trnh trng thi ly ly trng thi ng vi lm trng thi xut pht,

Phng trnh trng thi c dng :

Trong :

Phng trnh trng thi :

vng ca dy dn:

b) treo cao trung bnh ca dy dn

treo cao trung bnh ca dy dn pha A l:

treo cao trung bnh ca dy dn pha B,C l:

Gc bo v pha A:

Gc bo v pha B:

Gc bo v pha C:

c) Tng tr sng ca dy dnTng tr sng ca dy dn c tnh theo cng thc:

(3,14)

Trong : r l bn knh dy dn, r=10,8, h: l treo cao trung bnh ca dy dn

+) Pha A:

Khi k n nh hng vng quang:

+) Pha B,C:

Khi k n nh hng vng quang:

d) H s ngu hp

Khi cha c vng quang th h s ngu hp K c tnh nh sau vi dy dn v dy chng st ,

Trong : h2 l treo cao ca dy chng st , r2: bn knh ca dy chng st, d12: khong cch gia dy chng st v dy dn, D12: khong cch gia dy chng st v nh ca dy dn,Khi xt n nh hng ca vng quang in :

Hnh 3,3, S xc nh h s ngu hpH s ngu hp gia dy dn pha A v dy chng stVi pha A ta c:

treo cao trung bnh ca dy dn h1 = 16,34m, treo cao trung bnh ca dy chng st h2 = 21,41m, di ca x lx = 2m

Bn knh dy chng st r2 = 5,75,10-3m

Ta tnh c:

H s ngu hp gia dy dn pha B v dy chng st treo cao trung bnh ca dy dn h1 = 12,34m

treo cao trung bnh ca dy chng st h2 = 21,41m di ca x lx = 2m

H s ngu hp gia dy dn pha C v dy chng st treo cao trung bnh ca dy dn h1 = 12,34m

treo cao trung bnh ca dy chng st h2 = 21,41m di ca x lx = 3m

3,3,3, Tnh s ln st nh vo ng dyTng s ln st nh vo 100km ng dy trong 1 nm l:

(ln/100km,nm)

S ln st nh vo nh ct, khong vt: (ln/100km,nm)

S ln st nh vo dy dn (pha A):

Trong :

=>=1,45,10-3Vy s ln st nh vo dy dn pha A trn 100km/nm l:

(ln/100km,nm)

3,3,4, Sut ct do st nh vo ng dy

a) Sut ct do st nh vng qua dy chng st vo dy dn

S ln ct ca ng dy:

Trong : l xc sut phng in c xc nh nh sau:

;

=>Xc sut phng in

: xc sut hnh thnh h quang xc nh nh sau:

lpd: chiu di phng in, ly bng chiu di chui s

ls: cao mt bt sn: s bt s ca chui s

T th 3,1 ta c

Vy s ln ct ca ng dy trong 1 nm l:

(ln/100km,nm) (1) b) Sut ct do st nh vo khong vtKhi st nh vo khong vt ca dy chng st, n gin cho tnh ton ta gi thit st nh vo chnh gia khong vt, dng in st chia u sang hai bn nh hnh v

Hnh 3,4, St nh vo khong vt dy chng st

Ly vi dng sng xin gc, Lc ny trn dy chng st v mi ct s c dng in l ,Khi tnh ton ta cn tnh vi cc gi tr khc nhau ca dng in st,Khi ng dy ti in b st nh vo khong vt ca dy chng st th s sinh ra cc in p l:

in p tc dng ln cch in khng kh gia dy dn v dy chng st,in p tc dng ln cch in ca chui s,Nu cc in p ny ln th s gy ra phng in st trn cch in lm ct in trn ng dy,+) Sut ct in do qu in p tc dng ln cch in khng kh gia dy dn v dy chng st (ta xt vi pha B(C) v h s ngu hp ca pha ny nh hn ca pha A)

(3,15)

Trong : Kvq: h s ngu hp gia dy dn v dy chng st c k n vng quang, a: dc dng in st, l: khong vt ca ng dy,Trong thit k v thi cng ng dy, thng chn khong cch gia cc dy ln nn kh nng xy ra phng in trong trng hp ny rt t xy ra, V vy sut ct trong trng hp ny c th b qua,+) Sut ct in do qu in p tc dng ln chui s in p tc dng ln chui s khi st nh vo khong vt ca dy chng st l:

(3,16)

Trong : Ulv l in p lm vic

(3,17)

Uc(t): in p ti nh ct,

(3,18)Vi dng sng xin gc xt vi thi gian th:

(3,19)

Rc :in tr ni t ct in , Lc: in cm thn ct

Kvq: h s ngu hp c k n nh hng ca vng quang pha B vi dy chng st

Thay vo cng thc 3,19 ta c:

Theo 3,16 th:

Ta thy Uc(t) = f(a,t), V vy ta cn kim tra vi nhiu gi tr a, t nh sau

a = 10, 20, 30, 30, 40, 50, 60, 70, 80, 90, 100(kA/) t = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20()Ta c bng sau:

Bng 3,2, Gi tr Ucd(a,t) tc dng ln chui s a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,42003434856287719131056119913421484

224944163382510171209140115921784

32985397811022126315041745198622272468

43486389281218150917992089238026702960

539773610761415175520942434277331133452

644683512231612200123892778316735563944

749593313711809224726853123356039984436

8544103115192006249329803467395444414928

9594113016662202273932753811434848845420

10643122818142399298535704156474153275912

15889172025523383421550465878670975418372

2011352212329043675445652276008677975510832

ng thi ta cng c bng c tnh V-S ca chui s nh sau:

Bng 3,3, c tnh phng in ca chui s t((s)12345678910

U(kV)1020960900855830810805800797795

Da vo bng 3,2 v 3,3 ta v th biu din mi quan h ca Uc (t) v c tnh phi tuyn V S ca chui s

Hnh 3,5, th Ucd(a,t)T th ny ta xc nh c cc cp thng s (ti,ai) l giao ca ng cong Uc(t) v c tuyn V-S, Da vo cc cp thng s ny ta xc nh c ng cong nguy him I=f(a) t xc nh c min nguy him v xc sut phng in ,

102030405060708090100

11,196,043,822,531,711,230,750,430,160,01

111,90120,80114,60101,2085,5073,8052,5034,4014,401,00

Hnh 3,6, th I=f(a) xc nh min nguy him

(3,20)

Ta c bng sau:

Bng 3,4, c tnh xc sut phng in

102030405060708090100

11,196,043,822,531,711,230,750,430,160,01

111,90120,80114,60101,2085,5073,8052,5034,4014,401,00

0,01370,00980,01240,02070,03780,05920,13380,26770,57600,9624

0,39950,15960,06380,02550,01020,00410,00160,00060,00030,0001

0,23990,09590,03830,01530,00610,00240,00100,00040,00020,0001

0,00320,00090,00050,00030,00020,00010,00010,00010,00010,0001

Thng qua cc kt qu tnh ton cho bng 3,4 ta c:

Sut ct in ca ng dy khi st nh vo khong vt ca dy chng st, (ln/100km,nm) (2)c) Tnh sut ct do st nh vo nh ct v ln cn nh ct n gin v d tnh ton ta gi thit st ch nh vo nh ct in, khi phn ln dng in st s i vo b phn ni t ca ct in, phn nh cn li s i theo dy chng st vo cc b phn ni t ca cc ct ln cn nh hnh v,

Hnh 3,7, St nh vo nh ct c treo dy chng st

Trong trng hp ny ta phi tnh ton sut ct cho pha c qu in p t ln cch in ln nht Uc(t) max, Do ta phi tin hnh tnh ton in p t ln cch in i vi tng pha,Uc(t) c xc nh theo cng thc sau:

(3,21)

Theo cng thc trn in p xut hin trn cch in khi st nh vo nh ct bao gm,Thnh phn in p ging trn ct,

(3, 22)

Thnh phn in p cm ng t xut hin do h cm ca dy dn v knh st gy ra,

(3,23)

(3,24)

Vi: hdd : cao ca dy dn

: h s vn tc ca dng in st c ly = 0,3

, vi c l vn tc truyn sng, c = 300m/

Khi tnh ton vi dng sng xin gc is= a,t ta c th tnh theo cng thc sau:

(3,25)

Thnh phn in p cm ng do cm ng tnh in gia dy dn v in tch ca dng in st:

(3,26)

Trong : a : dc u sng ca sng xin gc, K: h s ngu hp c k n nh hng ca vng quang,Thnh phn in p do dng in st i trn dy chng st gy ra:

(3,27)

Vi: (3,28)

Thnh phn in p lm vic,

(3,29)

Ta ln lt i tnh cc thnh phn i vi cc pha, tnh c cc thnh phn in p ta cn phi tnh c dng in i vo ct ic(t) v thnh phn bin thin dng in theo thi gian , Khi tnh ton dng in ny ta c th da vo s tng ng ca mch dn dng in st trong hai trng hp nh sau:

+ Khi cha c sng phn x t ct bn cnh v

Hnh 3,9, S tng ng mch dn dng in st khi cha c sng phn xTrong :

l in cm ca ct:

Rc : in tr ni t ct in, Zcs: tng tr sng dy chng st c k n nh hng ca vng quang,T s ta tnh c:

(3,30)

(3,31)

(3,32)

+ Khi c sng phn x t ct bn cnh v

Hnh 3,10, S tng ng mch dn dng in st khi c sng phn xVi: Lcs l in cm ca mt khong vt ca dy chng st

(3,33)

Ta c:

(3,34)

(3,35)

(3,36)

in p t ln cch in pha A so snh Uc(a,t) ta s tin hnh so snh vi 1 gi tr c th nh sau:

a= 10kA/; t = 3

Ta c cc thng s i vi pha A nh sau:

T cc thng s trn ta tnh c cc gi tr ca cc thnh phn in p nh sau:

thi gian ny c sng phn x t ct ln cn v do in p t ln cch in c tnh theo s hnh 3,10

Thnh phn in p ging trn ct:

Thnh phn in p cm ng do h cm gia dy dn v knh st:

Thnh phn in p cm ng do cm ng tnh in gia dy dn v in tch dng in st:

Thnh phn in p do dng in st i trong dy chng st gy ra:

Thnh phn in p lm vic:

in p tc dng ln cch in pha A

in p tc dng ln cch in pha B(C):Ta c cc thng s i vi pha B(C) nh sau:

Ta c,

Thnh phn in p ging trn ct:



Thnh phn in p do dng in st i trong dy chng st gy ra:


in p tc dng ln cch in pha B:

Kt lun: Vy pha A c Uc(t) ln hn nn ta s tip tc tnh ton in p t ln cch in chui s trong trng hp tng qut l vi pha A,Tnh ton qu in p t ln chui s Uc(a,t)

tnh c Ucd(a,t) ta cn phi tnh cc thnh phn in p nh sau:



Kt qu tnh ton vi cc a,t khc nhau cho bng sau:Bng 3,9, Gi tr

Khi cha c sng phn x a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

0-19,99-39,98-59,98-79,97-99,96-119,95-139,95-159,94-179,93-199,92

0,579,60159,21238,81318,41398,02477,62557,22636,82716,43796,03

1119,27238,55357,82477,09596,37715,64834,91954,181073,461192,73

1,4140,59281,17421,76562,34702,93843,51984,101124,681265,271405,85

Khi c sng phn x t ct ln cn v

a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,4140,59281,17421,76562,34702,93843,51984,101124,681265,271405,85

2164,31328,61492,92657,22821,53985,831150,141314,441478,751643,05

3192,37384,74577,10769,47961,841154,211346,581538,941731,311923,68

4212,82425,64638,46851,281064,101276,921489,741702,571915,392128,21

5228,93457,85686,78915,701144,631373,551602,481831,402060,332289,25

6242,21484,42726,63968,841211,061453,271695,481937,692179,902422,11

7253,52507,04760,561014,081267,601521,121774,642028,162281,682535,20

8263,37526,73790,101053,461316,831580,191843,562106,922370,292633,65

9272,08544,16816,251088,331360,411632,491904,572176,662448,742720,82

10279,90559,81839,711119,611399,521679,421959,322239,232519,132799,03

15310,17620,35930,521240,691550,871861,042171,212481,392791,563101,73

20331,78663,56995,341327,121658,901990,672322,452654,232986,013317,79


Bng 3,10, Gi tr Khi cha c sng phn x a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

015,9231,8447,7763,6979,6195,53111,46127,38143,30159,22

0,542,4884,95127,43169,91212,38254,86297,34339,82382,29424,77

157,52115,03172,55230,07287,58345,10402,61460,13517,65575,16

1,466,18132,37198,55264,73330,92397,10463,28529,47595,65661,83


a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,474,70149,39224,09298,78373,48448,17522,87597,56672,26746,95

276,18152,36228,53304,71380,89457,07533,25609,43685,60761,78

388,36176,72265,08353,44441,80530,15618,51706,87795,23883,59

497,42194,84292,25389,67487,09584,51681,92779,34876,76974,18

5104,63209,27313,90418,53523,16627,80732,43837,06941,691046,33

6110,63221,26331,89442,52553,14663,77774,40885,03995,661106,29

7115,76231,52347,28463,04578,80694,55810,31926,071041,831157,59

8120,24240,48360,73480,97601,21721,45841,70961,941082,181202,42

9124,22248,45372,67496,89621,12745,34869,57993,791118,011242,24

10127,80255,61383,41511,22639,02766,83894,631022,431150,241278,04

15141,72283,45425,17566,89708,61850,34992,061133,781275,511417,23

20151,70303,41455,11606,81758,52910,221061,921213,631365,331517,04

Thnh phn in p ging trn ct: tnh c phn ny ta cn tnh ic(a,t), trong hai trng hp+ Khi cha c sng phn x v

+ Khi c sng phn x v

Kt qu tnh ton cho bng Bng 3,11, Gi tr

Khi cha c sng phn x

a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

0-1,13-2,26-3,39-4,52-5,65-6,78-7,91-9,04-10,17-11,30

0,53,456,9110,3613,8217,2720,7324,1827,6431,0934,55

18,1016,2024,3032,4040,4948,5956,6964,7972,8980,99

1,411,8323,6635,5047,3359,1670,9982,8394,66106,49118,32

Khi c sng phn x t ct ln cn va(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,411,3422,6834,0345,3756,7168,0579,3990,73102,08113,42

215,8331,6547,4863,3079,1394,95110,78126,61142,43158,26

322,9045,8068,7091,60114,50137,39160,29183,19206,09228,99

429,5259,0588,57118,09147,62177,14206,66236,19265,71295,23

535,7471,48107,22142,96178,70214,44250,18285,92321,66357,40

641,5883,16124,74166,32207,90249,48291,07332,65374,23415,81

747,0794,15141,22188,30235,37282,44329,52376,59423,66470,74

852,24104,48156,73208,97261,21313,45365,70417,94470,18522,42

957,11114,22171,32228,43285,54342,65399,75456,86513,97571,08

1061,69123,38185,07246,76308,45370,14431,83493,51555,20616,89

1580,91161,82242,73323,64404,55485,46566,37647,29728,20809,11

2095,20190,40285,60380,80476,00571,20666,40761,60856,80952,00

Bng 3,12, Gi tr Khi cha c sng phn x

a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

09,519,028,538,047,557,066,576,085,595,0

0,59,519,028,538,047,557,066,576,085,595,0

19,519,028,538,047,557,066,576,085,595,0

1,49,519,028,538,047,557,066,576,085,595,0


a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,47,7815,5623,3431,1238,9046,6854,4662,2470,0277,80

27,4714,9422,4129,8837,3544,8252,2959,7667,2374,71

37,0014,0121,0128,0135,0142,0249,0256,0263,0370,03

46,5813,1619,7426,3132,8939,4746,0552,6359,2165,78

56,1912,3818,5624,7530,9437,1343,3149,5055,6961,88

65,8311,6517,4823,3029,1334,9540,7846,6052,4358,25

75,4910,9716,4621,9527,4432,9238,4143,9049,3854,87

85,1710,3415,5120,6825,8631,0336,2041,3746,5451,71

94,889,7514,6319,5024,3829,2534,1339,0043,8848,75

104,609,1913,7918,3922,9927,5832,1836,7841,3845,97

153,446,8810,3213,7517,1920,6324,0727,5130,9534,39

202,585,167,7410,3212,9015,4818,0620,6323,2125,79

Gi tr Uc c tnh bng cng thc:

Bng 3,13, Gi tr Uc(a,t)Khi cha c sng phn x

a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

0155,5311,1466,6622,1777,7933,21088,71244,31399,81555,3

0,5210,6421,1631,7842,21052,81263,31473,91684,51895,02105,6

1266,3532,6798,91065,11331,41597,71864,02130,32396,62662,9

1,4311,1622,2933,31244,41555,41866,52177,62488,72799,83110,9

Khi c sng phn x t ct ln cn v a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,4274,6549,2823,81098,31372,91647,51922,12196,72471,32745,9

2322,9645,8968,71291,51614,41937,32260,22583,12906,03228,8

3399,4798,91198,31597,81997,22396,62796,13195,53595,03994,4

4471,4942,81414,11885,52356,92828,33299,63771,04242,44713,8

5539,01078,01617,12156,12695,13234,13773,14312,14851,25390,2

6602,71205,31808,02410,63013,33615,94218,64821,35423,96026,6

7662,61325,11987,72650,23312,83975,34637,95300,55963,06625,6

8719,01437,92156,92875,83594,84313,75032,75751,66470,67189,6

9772,11544,12316,23088,33860,44632,45404,56176,66948,67720,7

10822,11644,22466,33288,44110,54932,65754,76576,87399,08221,1

151032,12064,33096,44128,55160,76192,87225,08257,19289,210321,4

201188,32376,63564,94753,25941,57129,88318,29506,510694,811883,1

Thnh phn in p do dng in st i trong dy chng st gy ra,C 2 trng hp: + Khi

+ Khi

Ta cng tnh c ic(a,t), nh thnh phn in p ging trn thn ct:

Bng 3,14, Gi tr

a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

0-66-133-199-265-332-398-464-531-597-663

0,5-91-181-272-362-453-544-634-725-815-906

1-111-223-334-446-557-668-780-891-1003-1114

1,4-127-254-381-508-635-762-889-1016-1143-1270


a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,4-114-229-343-457-572-686-800-915-1029-1143

2-131-262-393-524-655-786-917-1048-1179-1310

3-156-312-468-624-780-936-1092-1248-1405-1561

4-179-358-537-715-894-1073-1252-1431-1610-1788

5-200-400-599-799-999-1199-1399-1599-1798-1998

6-219-439-658-877-1096-1316-1535-1754-1973-2193

7-237-475-712-950-1187-1424-1662-1899-2137-2374

8-254-509-763-1017-1272-1526-1781-2035-2289-2544

9-270-541-811-1081-1351-1622-1892-2162-2432-2703

10-285-570-856-1141-1426-1711-1996-2281-2567-2852

15-347-695-1042-1389-1737-2084-2432-2779-3126-3474

20-393-787-1180-1574-1967-2361-2754-3148-3541-3935

T cc thnh phn in p ta tnh c Ucd(a,t):

Bng 3,15, Gi tr

Khi cha c sng phn x a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

0142,3227,4312,6397,7482,8567,9653,0738,1823,3908,4

0,5299,2541,3783,31025,41267,41509,51751,51993,52235,62477,6

1388,9720,61052,21383,91715,62047,32379,02710,73042,33374,0

1,4448,1839,01229,91620,72011,62402,52793,43184,33575,23966,1


a(kA/(s) t((s)10

20

30

40

50

60

70

80

90

100

1,4424,2791,21158,21525,31892,32259,32626,32993,33360,33727,3

2489,6922,01354,41786,82219,32651,73084,13516,53948,94381,3

3581,31105,41629,52153,62677,73201,83725,94250,14774,25298,3

4660,01262,71865,52468,33071,13673,84276,64879,45482,26084,9

5730,01402,72075,52748,23421,04093,84766,55439,36112,16784,8

6793,41529,62265,93002,13738,34474,55210,85947,06683,27419,4

7851,61646,02440,53234,94029,34823,75618,16412,67207,08001,4

8905,41753,62601,83450,04298,15146,35994,56842,77690,98539,1

9955,31853,42751,53649,74547,85445,96344,07242,18140,29038,3

101001,81946,52891,13835,84780,45725,06669,77614,38559,09503,6

151193,92330,53467,24603,85740,56877,28013,89150,510287,111423,8

201335,52613,83892,15170,46448,77727,09005,210283,511561,812840,1

th biu din mi quan h ca Uc(t) v c tnh phi tuyn VS ca chui s

Hnh 3,9, th Ucd(a,t)T th ny ta xc nh c cc cp thng s (ti,ai) l giao ca ng cong Uc(a,t) v c tuyn V - S, Da vo cc cp thng s ny ta xc nh c ng cong nguy him I = f(a) t xc nh c min nguy him v xc sut phng in Vp

Bng 3,16, c tnh xc sut phng in

102030405060708090100

5,522,010,930,560,350, 250,200,170,140,10

55,240,227,922,417,5151413,612,610

0,12060,21430,34340,42390,51150,56290,58490,59390,61710,6817

0,39950,15960,06380,02550,01020,00410,00160,00060,00030,0001

0,23990,09590,03830,01530,00610,00240,00100,00040,00020,0001

0,02890,02060,01320,00650,00310,001458,10-524,10-512,10-56,7,10-5

Vy

Sut ct in ca ng dy khi st nh vo nh ct

(ln/100km,nm) (3) T (1) (2) v (3) ta c:Sut ct in do st nh vo ng dy

(ln/100km,nm)

Ch tiu chng st ca ng dy ti in (nm/1ln ct in), Ch tiu chng st ca ng dy truyn ti 110 kV theo quy nh ca truyn ti in quc gia:

- i vi s c vnh cu: 0,838 nm/1ln ct in,- i vi s c thong qua: 3,351 nm/1ln ct in,Nhn xt: Vi ch tiu chng st ca ng dy l 0,26 nm/1 ln ct in, ta thy ch tiu ny rt thp so vi quy nh ca truyn ti in quc gia,V vy cn phi c bin phap giam sut ct ng dy nh: Gim in tr ct

Gim gc bo v Tng mc cch in

Lp t thm chng st vanCHNG 4: BO V CHNG ST TRUYN VO TRM

4,1, M u

Khi st nh thng vo ng dy hoc nh xung mt t gn ng dy gy nn qu in p kh quyn tc dng ln cch in h thng, Nhng sng xut hin bi st nh vo ng dy hoc gn ng dy khng gy ra phng in m truyn vo trm s gy ra nguy him i vi cc thit b, n c th chc thng lp in mi gy phng in trn cch in dn n s c trong h thng in, Bi vy khi nghin cu bin php bo v chng st cho h thng in cn phi da trn c s ca s tnh ton phn tch cc qu trnh truyn sng trn ng dy,Cc my bin p l nhng thit b rt quan trng, gi thnh cao, cch in ca cc thit b ny li rt yu, V vy bo v qu in p do st nh t ng dy truyn vo trm c yu cu rt cao, bo v chng sng truyn vo trm ngi ta dng chng st ng, chng st van tng cng bo v cho on ng dy gn trm hoc s dng ng dy cp, t in, khng in,,,Bo v chng sng truyn t ng dy vo trm nhm m bo cc ch tiu an ton ca cch in vi sng qu in p, Vi cc trm n gin th vic tnh ton cc ch tiu c th thc hin mt cch tng i d dng, cn i vi cc trm phc tp th khi lng tnh ton tng i ln v vic tnh ton cng rt kh khn, Do khi tnh ton sng truyn vo trm ngi ta a ra mt s gi thit n gin ho, m bo iu kin lm vic bnh thng ca chng st van ta cn hn ch dng qua chng st van khng qu 510kA, dng in st qu ln s gy nn in p d tng cao, nh hng ti cch in trong ni b trm v c th lm hng chng st van,Trn c s cu trc trm xc nh cc ch tiu bo v chng sng truyn vo trm, y l nhng s liu quan trng, n cho php nh gi mc an ton vi sng qu in p ca trm, Do tham s ca sng t ng dy truyn vo trm rt khc nhau (ph thuc vo tham s ca dng in st, vo kt cu ca ng dy, v tr st nh ,,,) do vic tnh ton qu in p trong trm khng phi vi mt hay mt vi sng nht nh m phi tnh vi nhiu tham s khc nhau, Da vo tm ra tham s ti hn nguy him ca sng st truyn vo trm, vt qu tr s ny s xy ra phng in t nht mt thit b no trong trm,Do trm c bo v vi mc an ton cao nn khi xt bn cch in ca cc thit b khng k n hiu ng tch lu v c tnh cch in c ly vi in p xung kch,Thng sng qu in p xut hin trn cch in c di sng ln: bin bng in p d trn chng st vn xp chng vi mt in p nhy vt hoc dao ng, V th phi ly in p th nghim phng in xung kch vi sng ct v ton sng so snh vi ton b ng cong sng qu in p,4,2, Phng php tnh ton qu in p trn cch in ca thit b khi c sng truyn vo trm

Vic tnh ton qu in p do sng truyn vo trm c th c thc hin trn cc m hnh hoc tnh ton trc tip, Dng phng php m hnh th c th cho php xc nh ng cong tnh ton nguy him cho bt k mt trm c kt cu phc tp, N cho php gii quyt vn mt cch chnh xc v nhanh chng, Phng php tnh ton trc tip phc tp hn v ch dng cho trm c kt cu n gin, C s ca phng php tnh ton trc tip l lp s thay th v da trn quy tc sng ng tr v phng php lp bng ca cc sng ti ln lt tnh ton tr s in p ti cc nt chnh,Ta bit rng qua trnh truyn sng s hon ton xc nh c nu ta xc nh c s bin dng ca sng khi truyn trn ng dy, xc nh c sng phn x v khc x khi truyn ti cc nt,Do sng truyn trong trm trn nhng khong cch khng ln gia cc nt nn ta c th coi qu trnh truyn sng l khng bin dng, Sng c truyn i vi tc khng i v trn ng dy nn nu c mt sng t nt m no ti nt x, ti nt m sng c dng , th khi ti x sng s c dng vi ,

Hnh 4,1, Qu trnh truyn sng gia hai ntT thy rng, nu dng phng php lp bng, cc gi tr ca sng phn x ti nt m c ghi trong mt ct th ct gi tr sng ti nt x ging nh ct sng phn hi ti nt m v ch li mt khong thi gian,Vic xc nh sng phn x v khc x ti mt nt d dng gii c nh quy tc sng Petersen v nguyn l sng ng tr,Theo quy tc Petersen, mt sng truyn trn ng dy c tng tr sng Z n mt tng tr tp trung Zx cui ng dy th sng phn x v khc x cui ng dy c th tnh c nh s tng ng vi thng s tp trung nh sau:

Hnh 4,2, S tng ng ca quy tc PetersenVi s ny, sng khc x Ux c tnh nh in p trn phn t Zx cn sng phn x c tnh theo cng thc

(4,1)Ut: l sng ti nt x,+ Nu Z v Zx l cc thng s tuyn tnh, Ut l hm thi gian c nh phc hoc ton t th c th tm Ux bng phng php ton t,+ Nu Zx l in dung tp trung v Ut c dng ng cong bt k th Ux c xc nh bng mt trong nhng phng php gii gn ng, v d nh phng php tip tuyn,+ Nu Zx l phi tuyn (chng hn nh tng tr ca chng st van) th phi xc nh Ux bng phng php th,Trng hp nt x c nhiu ng dy i ti th c th lp s Petersen bng cch p dng quy tc sng ng tr, Trong trng hp ny s tng ng vn ging nh khi c mt ng dy ch khc tr s ngun phi ly l 2Ut v tng tr sng phi ly l Zt vi 2Ut v Zt xc nh theo cc cng thc sau:

(4,2)Trong :

: sng ti x t nt m ( y phi tnh tr s ca sng khi ti x ),

: l h s khc x,

(4,3)

: tng tr sng ca ng dy ni nt m v nt x,

(4,4)

Sng khc x Ux cng c tnh bng cc phng php nh i vi trng hp c mt ng dy tu theo tnh cht ca Zx,

Hnh 4,3, S nguyn l sng ng tr Xc nh in p ti im nt bng phng php thNu nh im nt c ghp in cm, in dung hoc phn t phi tuyn v sng ti c dng bt k th vic xc nh in p im nt bng phng php ton hc thng rt phc tp, Trong cc trng hp ny ngi ta dng phng php th,a) Tc dng ca sng bt k ln in tr phi tuyn t cui ng dyGi thit sng ti Ut(t) truyn theo ng dy c tng tr sng Z tc dng ln in tr phi tuyn c c tnh V A: UR = f(iR) nh hnh sau:

Hnh 4,4, c tnh in tr phi tuyn

Hnh 4,5, S thay th theo quy tc PetersenTa c phng trnh:

( 4,5 )

xc nh in p ta dng phng php th c biu din nh hnh sau SHAPE \* MERGEFORMAT

Hnh 4,6, Phng php cng thPhn bn phi v ng c tnh V A ca in tr phi tuyn v in p ging trn tng tr sng Z c gi tr bng iR,Z, sau xy dng ng cong UR + iR,Z,Phn bn tri v quan h 2Ut(t), ng vi mt gi tr bt k ca sng ti s xc nh c im a trn ng cong 2Ut(t) v im b trn ng UR + iR,Z, T b dng thng xung gp ng c tnh V A s c im c cho cp nghim (UR,iR), Quan h ca UR(t) theo thi gian c v bng cch t im c ko ng thng ngang cho gp ng thng ng v t im a chng giao nhau im d, l mt im ca ng cong UR(t), chnh lch gia hai ng cong Ut(t) v UR(t) cho ta sng phn x t pha in tr phi tuyn tr v ng dy, Quan h i(t) c v bng cch t im c xc nh c iR, Vi tr s iR ny xc nh sang trc to mi nh hnh v, T UR(t) im d xc nh trn ta xc nh c im e l mt im ca iR(t) bng cch t d k ng thng vi Oi n ct ng thng qua I song song vi Ot e, Lm tng t vi cc im khc ta s xc nh c ng cong iR(t),b) Sng bt k tc dng ln chng st van t cui ng dyChng st van l thit b cu to bi cc in tr phi tuyn (M n ), Ph bin l loi in tr phi tuyn trn c s xit km ZnO, Di tc dng ca in p danh nh li in, dng in r qua n l rt b (nh hn 10mA), Nhng khi c in p ln t vo th in tr s gim mnh, iu ny c th hin rt r trong c tnh V-A ca chng st van ZnO,

Hnh 4,7, c tnh V A ca chng st van ZnO

Vi trm ta chn chng st van c c tnh V A nh sau:

Cch xc nh in tr trn chng st van cng l cch xc nh in p trn in tr phi tuyn,c) Sng bt k tc dng ln in dung t cui ng dy (phng php tip tuyn)Thc cht phng php ny l gii th bng phng trnh vi phn dng:

(4,6)Xt vi in dung cui ng dy v gi thit in dung c np sn ti in p Uco, Ta c s Petersen nh hnh sau:

Hnh 4,8, S PetersenT s Petersen ta c:

(4,7)

t

(4,8)

(4,9)Thng chn cc khong u nhau nhng c chnh xc cn thit lm sao cho cc khong phn chia trng vi cc im c bit,4,3, Tnh ton bo v khi c sng qu in p truyn vo trm4,3,1, M t trm cn bo v

Hnh 4,9, S vn hnh Cc thit b chnh cn c bo v+ My bin p,+ Thanh gp+ Chng st van,+ My bin in p4,3,2, Lp s thay th tnh ton trng thi sng ca trmS xut pht thng rt phc tp do qu trnh tnh ton c gim bt ta ch tnh mt s nt cn quan trng, Da vo s y ta phn tch tm ra trng thi nguy him nht, Thng l trng thi vn hnh m thit b cn bo v (my bin p, my ct ,,,) xa chng st van,ch c mt ng dy v mt my bin p ang lm vic, Vi s trm cho ta c s nh hnh sau,

Hnh 4,9a, S trng thi sng nguy him

Hnh 4,9b, S trng thi sng nguy him nht (sp xp li),S thay th c lp nh sau: Da vo trng thi sng nguy him lp s thay th trng thi sng nguy him, Trong s ny ng dy thanh gp c thay th bng mch gm nhiu chui phn t hnh in dung c ly theo tng tr sng v tc truyn sng ca chng, Trong tnh ton thng ly gn ng tng tr sng Z = 400 cho c ng dy v thanh gp, Tc truyn sng ly v = 300m/s, Cc thit b khc c thay bng cc in dung tp trung tng ng ca n, Cc gi tr in dung ny c th tra trong cc bng, (khong cch c ly t s tht ca trm)Ta c s thay th nh hnh sau:

Hnh 4,10, S thay th trng thi sng nguy himTrong s hnh 4,10 in dung c cc gi tr nh sau,My bin p:

Dao cch ly:

Thanh gp :

: chiu di thanh gp,

My ct :

My bin in p :

S trng thi sng rt gn,T s thay th trng thi sng nguy him ta rt gn s v 4 im nh sau:

+ im 1: im t my bin in p BU, + im 2: im t ti thanh gp, + im 3: im t ti chng st van, + im 4: im t ti my bin p,T s ta c khong cch gia cc im nh sau:

+ Khong cch gia im 1 v im 2 : L12= 34m + Khong cch gia im 2 v im 3 : L23 = 60m + Khong cch gia im 3 v im 4 : L34 = 6m

Ta c s thay th trng thi sng nguy him sau khi c rt gn nh sau:

Hnh 4,11, S thay th rt gn ca trng thi sng nguy himTa qui i in dung v cc im cn xt theo qui tc phn b lc:

CA = C0 ;CB = C0

Trong s hnh 4,11 in dung nhn cc gi tr c th nh sau:

Thit lp phng php tnh in p vi tt c cc nt trn s rt gnThi gian truyn sng gia cc ntThi gian truyn sng gia nt 1 v nt 2:

Thi gian truyn sng gia nt 2 v nt 3:

Thi gian truyn sng gia nt 3 v nt 4:

Ta chn , thun tin cho vic tnh ton in p ti cc nt ta ly thi im sng ti nt 1 lm gc thi gian, V vy theo con ng truyn sng, gc thi gian ca cc nt sau chm hn nt trc n mt khong thi gian bng thi gian truyn t nt trc

Tnh ton in p ti cc ntNt 1

L nt c hai ng dy i ti vi tng tr sng Z = 400, Tng tr tp trung l in dung C1 , T y ta c s Petersen nh sau

Hnh 4,12, S Petersen ti nt 1

Khi (gc thi gian nt 1) th U21= 0 nn:

Khi (gc thi gian nt 1) th U21 0 nn:

tnh c 2Ut thi gian ny ta phi quan tm ti nt 2,Ta tm dng tnh nt 1 v i tnh nt 2, Sau khi tnh c in p ti nt 2 ta quay tr li tnh in p ti nt 1:

Do tng tr tp trung ti nt 1 l in dung C1 = 610pF, Nn theo phng php tip tuyn ta c:

Vi U1(0) = 0 (gc thi gian i vi nt 2)Nt 2

Hnh 4,13, S Petersen ti nt 2

Ging vi nt 1 ta c:

Khi (gc thi gian nt 2),

(gc thi gian nt 1) th U32= 0 nn:

Khi (gc thi gian nt 2),

(gc thi gian nt 1) th U32 0 nn:

tnh c 2Ut thi gian ny ta phi quan tm ti nt 3, Ta tm dng tnh nt 2 v i tnh nt 3, Sau khi tnh c in p ti nt 3 ta quay tr li tnh in p ti nt 2

in dung C2 = 2006,2pF,

Vi U2(0) = 0 (gc thi gian i vi nt 3)Nt 3

Trong trng hp ny ta c th b qua gi tr in dung C3 v c s Petersen nh hnh v:

Hnh 4,14, S Petersen ti nt 3Ging vi nt 1 ta c:

Khi (gc thi gian i vi nt 3)

(gc thi gian i vi nt 1) th U43= 0 :

Khi (gc thi gian i vi nt 3)

(gc thi gian i vi nt 1) th U43 0 :

tnh c 2Ut thi gian ny ta phi quan tm ti nt 4, Ta tm dng tnh nt 3 v i tnh nt 4, Sau khi tnh c in p ti nt 4 ta quay tr li tnh in p ti nt 3:

Do tng tr tp trung ti nt 3 l phn t phi tuyn nn ta s dng phng php th, T 2Ut ta tm c U3,Nt 4

L nt c mt ng dy i ti vi tng tr sng Z = 400, Tng tr tp trung l in dung C, T y ta c s Petersen nh hnh v:

Hnh 4,15, S Petersen ti nt 4Ta c:

Do tng tr tp trung ti nt 4 l in dung C4 = 1500pF, Nn theo phng php tip tuyn ta c:

Vi U4(0) = 0 (gc thi gian ti nt 4),Cc c tnh cch in ti cc nt cn bo vc tnh chu ng ca my bin p 220kV

Tra trong gio trnh k thut in cao p ta c c tnh cch in ca my bin p theo in p chu ng cc i Bng 4,1, in p chu ng ca my bin p theo thi giant(s)01,8246810

UMBA(KV)3101010970870760710710

c tnh V A ca chng st van

Hnh 4,16, c tnh V A ca chng st vanc tnh cch in ca thanh gpc tnh cch in ca thanh gp chnh l c tnh phng in ca chui s

Bng 4,2, c tnh V-S ca thanh gpt(s)12345678910

U(kV)1020960900855830810805800797795

Dng sng qu in p truyn vo trmVi trm cn bo v ta tin hnh tnh ton vi dng sng xin gc c bin bng in p U50% cch in ng dy, Ta c phng trnh dng sng nh sau,

a: dc u sng (kV/) U50%: in p phng in U50% ca ng dy, Vi ng dy 110kV ta c U50%=660kV,Ta tnh ton vi sng c dc a = 280(kV/s)

Kt qu gi tr tnh ton in p ti cc nt c cho trong bng phn ph lc in p ti cc nt c dng nh th sau:

Hnh 4,17, in p ti cc nt khi c sng c dc a=280kV/s truyn vo trmDa vo kt qu tnh ton trong phn ph lc ta c th dng in qua chng st van nh sau:

Hnh 4,18, Dng in qua CSV khi sng qu in p c dc a= 280kV/ s truyn vo trm

Nhn xt: Khi c sng qu in p vi dc a=280/s truyn vo trm th:in p ti thanh gp lun nm di c tnh V-S ca thanh gp

in p trn my bin p nh hn ng cong chu ng ca my bin pDng trn chng st van nh hn 10kA

Vy trm c bo v an ton,PH LCt(s)U'01(kV)U1(kV)U2(kV)Icsv(kA)U3(kV)U4(kV)

0,000,000,000,000,0000,000,00

0,025,601,010,000,0000,000,00

0,0411,202,840,000,0000,000,00

0,0616,805,350,000,0000,000,00

0,0822,408,420,000,0000,000,00

0,1028,0011,950,000,0000,000,00

0,1233,6015,840,050,0000,000,00

0,1439,2020,050,190,0000,000,00

0,1644,8024,500,450,0000,000,00

0,1850,4029,170,850,0000,000,00

0,2056,0034,001,400,0000,000,00

0,2261,6038,792,120,0000,000,00

0,2467,2043,433,020,0000,000,00

0,2672,8047,834,090,0000,000,00

0,2878,4051,975,350,0000,000,00

0,3084,0055,846,780,0000,000,00

0,3289,6059,458,430,0000,050,00

0,3495,2062,8210,310,0000,140,01

0,36100,8065,9812,430,0000,270,02

0,38106,4068,9714,790,0000,420,05

0,40112,0071,8217,370,0000,610,14

0,42117,6074,4220,160,0000,860,21

0,44123,2076,7623,140,0001,110,31

0,46128,8078,8726,300,0001,390,45

0,48134,4080,8129,630,0001,700,62

0,50140,0082,6433,100,0002,050,84

0,52145,6084,4336,730,0002,491,11

0,54151,2086,2540,520,0002,991,44

0,56156,8088,1344,440,0003,561,84

0,58162,4090,1348,480,0004,202,31

0,60168,0092,2852,600,0004,892,86

0,62173,6094,5056,780,0005,653,50

0,64179,2096,7860,990,0006,494,23

0,66184,8099,1765,210,0007,395,05

0,68190,40101,7269,440,0008,375,97

0,70196,00104,4673,640,0009,447,00

0,72201,60107,4277,830,00010,638,13

0,74207,20110,6382,020,00011,969,37

0,76212,80114,0886,170,00013,4210,73

0,78218,40117,7690,270,00015,0012,21

0,80224,00121,6694,310,00016,7013,81

0,82229,60125,6798,270,00018,4615,55

0,84235,20129,77102,160,00020,4217,43

0,86240,80133,96105,960,00022,4519,44

0,88246,40138,26109,680,00024,6021,59

0,90252,00142,68113,320,00026,8823,89

0,92257,60147,20116,920,00029,3026,33

0,94263,20151,80120,470,00031,8928,92

0,96268,80156,46123,970,00034,6231,66

0,98274,40161,14127,420,00037,4934,55

1,00280,00165,81130,810,00040,4837,60

1,02285,60170,37134,140,00043,5940,79

1,04291,20174,83137,420,00046,8344,14

1,06296,80179,19140,650,00050,2047,63

1,08302,40183,48143,850,00053,6951,28

1,10308,00187,70147,020,00057,3255,06

1,12313,60191,84150,180,00061,1058,99

1,14319,20195,90153,350,00065,0463,05

1,16324,80199,86156,510,00069,1567,26

1,18330,40203,69159,650,00073,4071,60

1,20336,00207,40162,800,00077,7876,08

1,22341,60210,93165,930,00082,2980,69

1,24347,20214,29169,070,00086,8785,43

1,26352,80217,55172,220,00091,6690,31

1,28358,40220,73175,400,00096,5295,31

1,30364,00223,84178,600,000101,49100,44

1,32369,60226,89181,850,000106,59105,69

1,34375,20229,89185,150,000111,82111,06

1,36380,80232,83188,490,000117,19116,55

1,38386,40235,72191,870,000122,66122,15

1,40392,00238,56195,280,001125,08127,76

1,42397,60241,32198,730,002132,67133,44

1,44403,20244,06202,220,004140,72139,26

1,46408,80246,80205,750,006145,65145,21

1,48414,40249,60209,340,009150,76151,25

1,50420,00252,45212,970,014156,53157,36

1,52425,60255,37216,670,020161,35163,50

1,54431,20258,34220,430,030167,01169,66

1,56436,80261,37224,230,043172,20175,80

1,58442,40264,45228,090,062177,64181,90

1,60448,00267,59231,830,085182,47187,91

1,62453,60270,77235,730,115187,22193,80

1,64459,20274,03239,810,151191,60199,51

1,66464,80277,40243,910,194195,72205,00

1,68470,40280,89248,040,246199,72210,21

1,70476,00284,48252,240,304203,34215,11

1,72481,60288,18256,460,370206,77219,63

1,74487,20291,99260,740,442209,91223,75

1,76492,80295,90265,060,519212,80227,42

1,78498,40299,89269,430,601215,47230,63

1,80504,00303,97273,810,700218,28233,36

1,82509,60308,10278,210,778220,25235,60

1,84515,20312,33282,610,855222,02237,34

1,86520,80316,67287,010,947223,96238,60

1,88526,40321,11291,401,036225,68239,39

1,90532,00325,62295,761,117227,13239,76

1,92537,60330,20300,121,198228,48239,73

1,94543,20334,84304,431,269229,60239,36

1,96548,80339,51308,711,335230,59238,70

1,98554,40344,20312,931,393231,43237,81

2,00560,00348,91316,981,445232,15236,73

2,02565,60353,60321,071,489232,74235,54

2,04571,20358,29325,211,526233,23234,29

2,06576,80363,00329,271,555233,60233,04

2,08582,40367,71333,241,578233,90231,84

2,10588,00372,36337,171,594234,10230,73

2,12593,60376,96341,001,605234,23229,77

2,14599,20381,53344,781,612234,32228,97

2,16604,80386,04348,471,614234,34228,37

2,18610,40390,46352,081,615234,36227,99

2,20616,00394,81355,611,625234,48227,83

2,22621,60399,05359,041,615234,36227,89

2,24627,20403,21362,361,605234,23228,18

2,26632,80407,30365,561,610234,29228,66

2,28638,40411,30368,651,617234,38229,33

2,30644,00415,17371,611,624234,47230,16

2,32649,60418,92374,451,638234,64231,14

2,34655,20422,56377,161,653234,82232,22

2,36660,80426,08379,731,675235,08233,38

2,38666,40429,45382,181,700235,38234,58

2,40660,00430,52384,381,732235,75235,81

2,42660,00430,82386,561,768236,17237,03

2,44660,00430,47388,711,810236,64238,21

2,46660,00429,59390,701,855237,13239,34

2,48660,00428,23392,561,904237,66240,39

2,50660,00426,38394,211,957238,21241,35

2,52660,00424,16395,602,012238,78242,21

2,54660,00421,64396,732,068239,33242,95

2,56660,00418,80397,592,126239,90243,58

2,58660,00415,69398,182,184240,45244,09

2,60660,00412,71398,492,253241,08244,49

2,62660,00409,87398,502,301241,52244,78

2,64660,00407,22398,222,349241,94244,97

2,66660,00404,76397,642,407242,44245,07

2,68660,00402,46396,772,461242,90245,09

2,70660,00400,24395,522,511243,32245,06

2,72660,00398,10393,922,560243,72244,98

2,74660,00396,05391,952,603244,06244,87

2,76660,00394,01389,652,644244,39244,74

2,78660,00391,96387,032,681244,67244,62

2,80660,00390,15384,012,717244,95244,50

2,82660,00388,50380,812,750245,20244,42

2,84660,00386,95377,452,781245,44244,37

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2,92660,00380,06361,502,883246,19244,66

2,94660,00377,91356,982,904246,34244,87

2,96660,00375,50352,312,924246,49245,13

2,98660,00372,82347,542,943246,62245,44

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3,08660,00357,02322,783,034247,26247,40

3,10660,00352,98317,703,052247,38247,80

3,12660,00348,63312,613,073247,53248,20

3,14660,00344,01307,543,090247,64248,56

3,16660,00339,12302,503,107247,76248,90

3,18660,00333,98297,533,124247,88249,19

3,20660,00328,80292,553,142248,00249,44

3,22660,00323,51287,733,159248,11249,63

3,24660,00318,09283,083,176248,22249,78

3,26660,00312,52278,483,192248,33249,87

3,28660,00306,80273,963,206248,42249,92

3,30660,00300,92269,493,220248,51249,91

3,32660,00294,98265,093,231248,59249,86

3,34660,00289,05260,813,241248,65249,77

3,36660,00283,14256,643,249248,70249,65

3,38660,00277,27252,613,254248,74249,49

3,40660,00271,63248,713,267248,82249,32

3,42660,00266,11244,913,261248,78249,13

3,44660,00260,71241,213,253248,73248,93

3,46660,00255,41237,613,255248,74248,73

3,48660,00250,22234,113,254248,74248,53

3,50660,00245,12230,673,248248,70248,34

3,52660,00240,21227,323,243248,66248,16

3,54660,00235,54224,093,233248,60248,00

3,56660,00231,06220,983,222248,53247,87

3,58660,00226,79217,993,210248,45247,75

3,60660,00222,86215,043,199248,38247,66

3,62660,00219,15212,273,186248,29247,59

3,64660,00215,61209,693,174248,21247,54

3,66660,00212,23207,183,161248,12247,52

3,68660,00209,01204,763,148248,04247,51

3,70660,00205,91202,433,135247,95247,51

3,72660,00203,03200,213,121247,85247,53

3,74660,00200,39198,133,107247,76247,56

3,76660,00197,95196,193,093247,67247,59

3,78660,00195,68194,403,079247,57247,62

3,80660,00193,67192,763,073247,53247,64

3,82660,00191,80191,233,052247,38247,66

3,84660,00190,04189,823,032247,25247,66

3,86660,00188,37188,523,023247,18247,64

3,88660,00186,82187,353,012247,11247,61

3,90660,00185,35186,282,999247,02247,56

3,92660,00184,05185,362,988246,94247,48

3,94660,00182,92184,582,973246,83247,39

3,96660,00181,92183,952,959246,73247,28

3,98660,00181,04183,462,944246,63247,14

4,00660,00180,34183,032,931246,54246,99

4,02660,00179,70182,802,917246,43246,82

4,04660,00179,14182,762,904246,34246,64

4,06660,00178,64182,812,890246,24246,45

4,08660,00178,23182,952,876246,14246,25

4,10660,00177,89183,212,861246,03246,04

4,12660,00177,71183,582,845245,91245,84

4,14660,00177,69184,092,829245,79245,63

4,16660,00177,80184,722,812245,67245,44

4,18660,00178,00185,482,796245,55245,25

4,20660,00178,36186,342,787245,48245,07

4,22660,00178,78187,282,763245,30244,90

4,24660,00179,27188,292,740245,13244,74

4,26660,00179,84189,382,727245,03244,59

4,28660,00180,53190,542,714244,93244,46

4,30660,00181,29191,762,697244,80244,34

4,32660,00182,22193,072,683244,69244,24

4,34660,00183,30194,452,667244,57244,15

4,36660,00184,48195,902,652244,45244,07

4,38660,00185,74197,412,637244,33244,00

4,40660,00187,12198,902,624244,23243,94

4,42660,00188,53200,502,612244,13243,89

4,44660,00190,00202,192,601244,04243,84

4,46660,00191,53203,882,591243,96243,80

4,48660,00193,15205,582,581243,88243,76

4,50660,00194,81207,312,571243,80243,72

4,52660,00196,60209,062,562243,73243,69

4,54660,00198,49210,862,553243,66243,65

4,56660,00200,42212,682,545243,59243,62

4,58660,00202,38214,522,537243,53243,58

4,60660,00204,40216,372,538243,54243,54

4,62660,00206,40218,202,524243,42243,49

4,64660,00208,41220,022,513243,33243,45

4,66660,00210,43221,832,511243,32243,39

4,68660,00212,49223,632,509243,30243,34

4,70660,00214,56225,432,504243,26243,28

4,72660,00216,67227,222,501243,23243,23

4,74660,00218,83229,012,496243,19243,17

4,76660,00220,95230,792,492243,16243,11

4,78660,00223,04232,552,488243,13243,06

4,80660,00225,13234,222,486243,11243,01

4,82660,00227,15235,922,484243,09242,96

4,84660,00229,13237,652,483243,08242,91

4,86660,00231,09239,332,482243,08242,88

4,88660,00233,04240,952,481243,07242,85

4,90660,00234,94242,552,479243,05242,82

4,92660,00236,86244,112,478243,04242,81

4,94660,00238,77245,662,478243,04242,80

4,96660,00240,61247,162,477243,03242,80

4,98660,00242,38248,642,477243,03242,81

5,00660,00244,12250,062,484243,09242,83

5,02660,00245,78251,422,478243,04242,85

5,04660,00247,38252,732,474243,01242,88

5,06660,00248,95253,992,480243,06242,92

5,08660,00250,49255,202,484243,09242,96

5,10660,00251,98256,362,486243,11243,01

5,12660,00253,44257,482,490243,14243,05

5,14660,00254,88258,552,492243,16243,11

5,16660,00256,23259,562,496243,19243,16

5,18660,00257,50260,522,499243,22243,21

5,20660,00258,72261,372,505243,27243,27

5,22660,00259,85262,222,510243,31243,33

5,24660,00260,93263,072,515243,35243,38

5,26660,00261,97263,832,521243,40243,44

5,28660,00262,98264,532,527243,45243,49

5,30660,00263,90265,172,533243,50243,54

5,32660,00264,81265,762,539243,54243,60

5,34660,00265,67266,302,545243,59243,65

5,36660,00266,45266,782,551243,64243,70

5,38660,00267,14267,222,557243,69243,75

5,40660,00267,79267,602,569243,79243,80

5,42660,00268,35267,912,568243,78243,85

5,44660,00268,87268,162,570243,80243,89

5,46660,00269,34268,362,580243,88243,94

5,48660,00269,79268,512,588243,94243,98

5,50660,00270,15268,612,594243,99244,03

5,52660,00270,49268,672,602244,05244,07

5,54660,00270,78268,682,607244,09244,11

5,56660,00270,98268,642,613244,14244,16

5,58660,00271,11268,562,618244,18244,20

5,60660,00271,19268,382,625244,24244,24

5,62660,00271,19268,212,632244,29244,29

5,64660,00271,16268,062,639244,35244,34

5,66660,00271,10267,842,645244,39244,38

5,68660,00271,01267,562,651244,44244,43

5,70660,00270,83267,262,657244,49244,48

5,72660,00270,64266,912,662244,53244,53

5,74660,00270,41266,542,668244,57244,58

5,76660,00270,11266,132,673244,61244,63

5,78660,00269,76265,702,678244,65244,68

5,80660,00269,37265,232,689244,74244,74

5,82660,00268,94264,732,688244,73244,79

5,84660,00268,48264,202,689244,74244,83

5,86660,00268,01263,642,697244,80244,88

5,88660,00267,51263,072,704244,85244,92

5,90660,00266,96262,462,708244,88244,97

5,92660,00266,40261,852,714244,93245,01

5,94660,00265,82261,222,718244,96245,04

5,96660,00265,18260,572,722244,99245,08

5,98660,00264,51259,912,725245,01245,11

6,00660,00263,83259,192,730245,05245,14

6,02660,00263,11258,512,735245,09245,17

6,04660,00262,40257,882,739245,12245,19

6,06660,00261,68257,202,743245,15245,22

6,08660,00260,96256,512,746245,17245,24

6,10660,00260,18255,812,749245,20245,26

6,12660,00259,42255,102,752245,22245,28

6,14660,00258,67254,392,754245,23245,29

6,16660,00257,88253,682,757245,26245,31

6,18660,00257,08252,982,759245,27245,32

6,20660,00256,29252,282,765245,32245,33

6,22660,00255,49251,572,761245,29245,34

6,24660,00254,71250,872,759245,27245,35

6,26660,00253,94250,162,763245,30245,36

6,28660,00253,17249,472,767245,33245,36

6,30660,00252,38248,772,767245,33245,37

6,32660,00251,61248,102,769245,35245,37

6,34660,00250,86247,432,769245,35245,37

6,36660,00250,09246,772,769245,35245,38

6,38660,00249,32246,132,769245,35245,38

6,40660,00248,58245,462,770245,35245,38

6,42660,00247,83244,862,771245,36245,38

6,44660,00247,12244,312,771245,36245,37

6,46660,00246,42243,752,771245,36245,37

6,48660,00245,74243,192,771245,36245,37

6,50660,00245,04242,652,770245,35245,37

6,52660,00244,38242,112,769245,35245,36

6,54660,00243,75241,612,768245,34245,36

6,56660,00243,12241,112,767245,33245,36

6,58660,00242,50240,652,766245,32245,35

6,60660,00241,92240,202,769245,35245,34

6,62660,00241,34239,772,762245,29245,34

6,64660,00240,80239,352,757245,26245,33

6,66660,00240,29238,942,759245,27245,31

6,68660,00239,80238,562,759245,27245,30

6,70660,00239,29238,202,757245,26245,29

6,72660,00238,84237,862,756245,25245,27

6,74660,00238,41237,542,753245,23245,25

6,76660,00237,99237,252,751245,21245,24

6,78660,00237,59236,982,749245,20245,22

6,80660,00237,22236,692,748245,19245,20

6,82660,00236,86236,482,746245,17245,18

6,84660,00236,54236,332,744245,16245,16

6,86660,00236,25236,162,742245,14245,14

6,88660,00235,98236,002,740245,13245,12

6,90660,00235,69235,872,738245,11245,10

6,92660,00235,46235,742,735245,09245,08

6,94660,00235,27235,642,732245,07245,05

6,96660,00235,08235,562,729245,04245,03

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7,00660,00234,79235,472,728245,04245,00

7,02660,00234,67235,452,720244,97244,98

7,04660,00234,58235,432,714244,93244,95

7,06660,00234,51235,432,715244,94244,93

7,08660,00234,47235,452,715244,94244,91

7,10660,00234,42235,492,712244,91244,89

7,12660,00234,41235,542,710244,90244,87

7,14660,00234,44235,612,707244,87244,85

7,16660,00234,47235,702,704244,85244,83

7,18660,00234,51235,812,701244,83244,82

7,20660,00234,58235,902,700244,82244,80

7,22660,00234,65236,052,698244,81244,78

7,24660,00234,75236,242,696244,79244,76

7,26660,00234,87236,422,694244,77244,75

7,28660,00235,00236,592,692244,76244,73

7,30660,00235,12236,782,690244,74244,71

7,32660,00235,28236,972,687244,72244,70

7,34660,00235,48237,172,685244,70244,69

7,36660,00235,67237,392,683244,69244,67

7,38660,00235,87237,622,681244,67244,66

7,40660,00236,09237,852,683244,69244,65

7,42660,00236,31238,082,676244,64244,63

7,44660,00236,55238,322,671244,60244,62

7,46660,00236,80238,562,672244,60244,61

7,48660,00237,05238,802,673244,61244,59

7,50660,00237,29239,052,671244,60244,58

7,52660,00237,57239,312,670244,59244,57

7,54660,00237,86239,572,668244,57244,56

7,56660,00238,15239,842,667244,57244,54

7,58660,00238,43240,122,665244,55244,53

7,60660,00238,72240,362,665244,55244,52

7,62660,00239,00240,662,664244,54244,51

7,64660,00239,30240,982,663244,53244,50

7,66660,00239,60241,272,662244,53244,50

7,68660,00239,91241,542,661244,52244,49

7,70660,00240,19241,822,660244,51244,48

7,72660,00240,50242,092,659244,50244,48

7,74660,00240,82242,372,658244,49244,47

7,76660,00241,14242,642,658244,49244,47

7,78660,00241,44242,912,657244,49244,47

7,80660,00241,75243,182,660244,51244,46

7,82660,00242,04243,442,654244,46244,46

7,84660,00242,35243,682,651244,44244,46

7,86660,00242,65243,922,654244,46244,46

7,88660,00242,94244,162,656244,48244,46

7,90660,00243,21244,402,655244,47244,46

7,92660,00243,51244,632,656244,48244,46

7,94660,00243,81244,862,655244,47244,46

7,96660,00244,09245,092,655244,47244,46

7,98660,00244,35245,312,655244,47244,46

8,00660

Đồ Án Thiết Kế Chống Sét Cho Trạm Biến Áp 220110

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