Quy phạm trang bị điện phần II

QTD-2006

Phn II: H thng ng dn in

Chng II.5

NG DY TI IN TRN KHNG

IN P TRN 1KV N 500KV

Phm vi p dng v nh ngha

II.5.1. Chng ny p dng cho ng dy ti in trn khng (DK), in p trn 1kV n 500kV dng dy trn.Chng ny khng p dng cho DK c tnh cht c bit nh li in ng st in kh ha, xe in, t chy in v.v.

on cp ni xen vo DK in p n 220kV phi thc hin cc yu cu nu trong Chng II.3 v iu II.5.67.

II.5.2. DK l cng trnh truyn ti v phn phi in nng, b tr ngoi tri, mc trn vt cch in v ph kin, t trn ct hoc trn kt cu ca cng trnh khc (cu, p v.v.). DK c tnh t im mc dy ca DK ln x ct cng hoc kt cu khc ca trm in.

II.5.3. Trong tnh ton c l:

Ch bnh thng ca DK l ch lm vic khi dy dn hoc dy chng st khng b t.

Ch s c ca DK l ch lm vic khi mt hoc mt s dy dn hoc dy chng st b t.

Ch lp t ca DK l trng thi ca ng dy trong qu trnh dng ct, lp t dy dn hoc dy chng st.

II.5.4. Khu vc ng dn c l nhng thnh ph, th trn, x nghip, bn , cng, nh ga, bn xe t, cng vin, trng hc, ch, bi tm, sn vn ng, khu vc xm lng ng dn v.v.

Khu vc t dn c l nhng ni c nh ca tha tht, mc d thng xuyn c ngi lui ti v cc xe c phng tin c gii qua li, vng ng rung, i trng cy, vn; hoc ni c nh ca, cng trnh kin trc tm thi v.v.

Khu vc kh qua li l nhng ni xe c v phng tin c gii khng th qua li c.

Khu vc kh n l nhng ni m ngi i b rt kh ti c.

Khu vc rt kh n l nhng ni m ngi i b khng th ti c (v d nh mm , vch ni v.v.)

II.5.5. Khong vt ln l khong vt qua cc sng, h, knh, vnh c tu thuyn qua li dng ct vt cao 50m tr ln vi chiu di khong vt t 500m tr ln; hoc chiu di khong vt t 700m tr ln vi ct c chiu cao bt k.

Yu cu chung

II.5.6. Trong khi p dng quy phm ny, nu c nhiu yu cu khc nhau th phi ly yu cu cao nht, iu kin bt li nht tnh ton.

II.5.7. V yu cu c l dy dn ca DK phi tnh theo phng php ng sut cho php, cch in v ph kin mc dy tnh theo phng php ti trng ph hu. Cc ti trng tiu chun xc nh theo quy phm ny.

Ct v mng DK tnh theo phng php trng thi gii hn.

II.5.8. Phi o pha dy dn DK hn ch s khng i xng ca dng in v in p. DK in p 110 - 500kV di trn 100km phi o pha mt chu k trn vn sao cho chiu di ca mi bc trong mt chu k o pha phi gn bng nhau.

S o pha DK hai mch cng in p i chung ct phi ging nhau. Trong li in 110 - 500kV, bao gm nhiu on DK chiu di di 100km th vic o pha c th thc hin trc tip ti cc trm in ( thanh ci, cc khong ct cui ng dy vo ct cng trm v.v.), trong vic o pha phi thc hin sao cho chiu di ca mi bc trong 1 chu k o pha phi gn bng nhau.

Vic o pha cc DK nhm mc ch chng nh hng ca DK i vi ng dy thng tin cn c tnh ton ring.

II.5.9. qun l vn hnh DK cn c trm qun l vn hnh, x l s c v sa cha:

a. t khu vc tp trung nhiu ng dy.

b. Thun tin v giao thng.

c. n gin, gn nh, tn dng cc cng trnh kin trc c sn.

d. C lin h thng tin gia li in khu vc v i sa cha ng dy.

Vic t trm do cc c quan thit k cn c theo yu cu ca c quan qun l in, cn c vo quy m li in v theo qui nh hin hnh.

II.5.10. qun l vn hnh DK in p 110 - 220kV nn c li i b n gn chn ct.

II.5.11. qun l vn hnh DK 500kV phi c ng vi chiu rng nh nht l 2,5m v cch tuyn khng c ln hn 1km, m bo cho xe c gii tip cn i c gn n tuyn DK.

nhng ni xe c gii khng th i c (m ly v rung ly, cc vn cy qu v.v.) phi lm ng i b, cu nh n chn ct. ng i b p rng khng nh hn 0,4m.

Tr nhng ch c bit kh khn, ng phi bo m i c trong ma ma l.

II.5.12. Ct DK nn t cch b sng b xi l mnh cng xa cng tt c xt n s bin i ca lng sng v tc hi ca l lt. Khi b tr ct ti cc tuyn i qua vng ven sng, ven h, qua ni i v vng t bazan, c bit l rng nguyn sinh phi iu tra, nh gi cn thn tnh trng st l, xi mn. Tn sut mc nc l i vi DK 35kV tr xung chn 5% (20 nm lp li mt ln), i vi DK 110kV v 220kV chn 2% (50 nm lp li mt ln) i vi DK 500kV, chn 1% (100 nm lp li mt ln).

Ly mc nc l lch s cao nht nu khng c s liu k trn.

Trng hp phi t ct cc ch trn, phi c bin php bo v ct (mng c bit, p b, lm k, rnh thot nc, dng ct tng cng v.v.).

Phi c bin php bo v khi ct t vo cc ch sau:Vng b ng v ngp nc thng xuyn.

Trn sn i ni, ni c th b nc hoc l xi mn.

II.5.13. Trn ct DK phi c du hiu hoc bin bo c nh sau:

1. S th t trn mi ct, hng v pha ng giao thng, v tr d nhn thy.

2. Trc khi a vo vn hnh, s hiu hoc k hiu ng dy trn mi ct on tuyn c cc DK i song song, trn ct DK hai mch phi c k hiu tng mch.

3. Bin bo nguy him t cch mt t t 2m n 2,5m trn tt c cc ct trong ton tuyn.

II.5.14. Ct kim loi, cc phn kim loi ca ct btng ct thp h ra ngoi v tt c cc chi tit bng kim loi ca ct btng ct thp u phi c m hoc sn chng g theo tiu chun hin hnh.

Cc chn ct kim loi vng thng xuyn ngp lt cn c bin php thch hp chng n mn.

II.5.15. Khi t ct vo mng btng ct thp hoc mng btng c lin khi, bulng neo ct phi c ai c hm, on ren rng bulng phi c chiu di nh ra khi ai c hm 5mm tr ln.II.5.16. Ct DK c chiu cao 80m tr ln phi c sn bo hiu (bo hiu ban ngy) v c n bo (bo hiu ban m) bo m an ton cho my bay v tu thuyn ph hp vi cc quy nh hin hnh. II.5.17. Phi t cc thit b xc nh im s c trn DK 110kV tr ln ti cc trm in

II.5.18. Khi DK i qua nhng khu vc gi mnh, t b st l, m ly, khu vc x v.v. phi tnh n phng n DK i vng, trnh nhng khu vc bt li trn c s so snh kinh t k thut.

iu kin kh hu

II.5.19. Vic xc nh iu kin kh hu tnh ton tnh v la chn kt cu DK phi cn c vo kt qu ca vic x l ti liu quan st nhiu nm v tc gi v nhit khng kh trong vng tuyn DK d kin xy dng.

Khi x l s liu quan st phi xt n c im kh hu cc b nh hng ca p lc gi v cc iu kin thin nhin (a hnh nhp nh, cao so vi mc nc bin, cnh h nc ln, hng gi thi v.v.) cng nh xt n cc cng trnh c hoc ang c thit k xy dng trong vng DK i qua (h cha nc, thp nc v.v.).

II.5.20. p lc gi tiu chun, p lc gi theo tng vng, h s tng p lc gi theo cao, h s gim p lc gi i vi cc DK i trong cc vng khut gi phi ly theo cc tr s v cc quy nh c th nu trong Tiu chun tc ng v ti trng ca TCVN- 2737-1995. i vi DK t 110kV tr ln, p lc gi tiu chun khng c nh hn 60daN/m2.

i vi cc DK, ly thi gian s dng gi nh ca cng trnh l 15 nm i vi DK 35kV tr xung, 20 nm i vi DK 110kV, 30 nm i vi DK 220kV, 40 nm i vi DK 500kV v khong vt ln.

II.5.21. p lc gi tc ng vo dy dn ca DK c xc nh cao ca trng tm quy i ca tt c cc dy.

cao trng tm quy i ca dy dn (hqd) xc nh theo cng thc:

Trong :

htb - cao trung bnh mc dy dn vo cch in, [m]

f - vng dy dn, quy c ly gi tr ln nht (khi nhit cao nht ), [m]

p lc gi tc ng vo dy chng st xc nh theo cao b tr trng tm ca dy chng st.

II.5.22. p lc gi tc ng vo dy dn hoc dy chng st trong khong vt ln phi xc nh theo iu II.5.20, ng thi phi tun theo cc quy nh b sung sau:

i vi khong vt ch c mt khong ct, cao trng tm quy i ca dy dn hoc dy chng st c tnh theo cng thc:

Trong :

h1 v h2: cao im mc dy vo ct vt tnh t mt nc bnh thng ca sng, ngi vnh v.v. [m]

f : vng ln nht ca dy dn, [m]

i vi khong vt bao gm nhiu khong ct, cao trng tm quy i ca dy dn hoc dy chng st phi tnh chung cho c khong vt (gii hn bng 2 ct no hm), theo cng thc:

Trong hqd1 ,hqd2 ... hqdn l cao trng tm quy i ca cc khong ct l1,l2 ln cu thnh khong vt . Nu trong khong vt ln c mt s khong ct k qua cc khu vc khng c nc th h c tnh t mt t.

II.5.23. p lc gi tc ng vo cc kt cu ca ct phi xc nh theo cao ca chng tnh t mt t. Theo chiu cao ct, chia thnh tng di khng ln hn 15m trong mi di p lc gi c ly bng nhau v tnh vi tr s p lc gi cao trung bnh ca di.

II.5.24. Khi tnh tc ng ca gi vo ng dy v dy chng st phi ly hng gc 90o, 45o v 0o vi tuyn ng dy.

Khi tnh ct in phi ly hng gi hp vi tuyn ng dy gc 90o v 45o.

II.5.25. p lc gi tiu chun tc ng vo dy dn hoc dy chng st tnh bng daN, c xc nh theo cng thc:

P= a.Cx.Kl.q.F.sin2 (Trong :

a - H s tnh n s khng bng nhau ca p lc gi trong khong ct, ly bng:

1 khi p lc gi bng 27daN/m2 0,85 khi p lc gi bng 40daN/m2 0,75 khi p lc gi bng 55daN/m2 0,70 khi p lc gi bng 76daN/m2 v ln hn.

Cc gi tr trung gian ly theo phng php ni suy.

Cx - h s kh ng hc ly bng 1,1 khi ng knh ca dy dn hoc dy chng st t 20mm tr ln v 1,2 khi ng knh ca chng nh hn 20mm.

Kl - h s qui i tnh n nh hng ca chiu di khong vt vo ti trng gi, bng 1,2 khi khong ct ti 50m; bng 1,1 khi 100m; bng 1,05 khi 150m; bng 1 khi 250m v ln hn (cc tr s Kl i vi cc khong vt c chiu di nm gia cc tr s trn th ly theo phng php ni suy).

q - p lc gi tiu chun theo vng quy nh trong tiu chun TCVN 2737-95 ( tnh n cc h s quy nh trong iu II.5.20).

F - tit din cn gi ca dy dn hoc dy chng st, m2( - gc hp thnh gia hng gi thi v trc ca tuyn ng dy.

II.5.26. i vi DK in p n 22kV khi mc dy cao di 12m, tr s p lc gi tiu chun c th ly gim i 15% tr trng hp vn dng h s che chn gim p lc gi trong cc vng khut gi.

i vi on DK thuc vng ni, ch a hnh cao vt ln so vi xung quanh (nh ni, o v.v.) cng nh nhng on giao cho vi thung lng, hm ni gi thi mnh, p lc gi tiu chun ln nht, nu khng c s liu quan st phi ly theo tiu chun hin hnh.

II.5.27. Khi thit k DK phi tnh ton theo iu kin kh hu sau y:

a. Ch bnh thng:

Nhit khng kh cao nht Tmax, p lc gi q = 0

Nhit khng kh thp nht Tmin, p lc gi q = 0

Nhit khng kh trung bnh nm Ttb, p lc gi q = 0

p lc gi ln nht qmax, nhit khng kh T = 25oC

b. Ch s c:

Nhit khng kh thp nht Tmin, p lc gi q = 0

Nhit khng kh trung bnh nm Ttb, p lc gi q = 0

p lc gi ln nht qmax, nhit khng kh T = 25oC

Trong ch s c ca DK, p lc gi tnh ton ln nht qmax cho php ly theo TCVN 2737-1995.II.5.28. Phi tnh kim tra ct ca DK theo ch lp t iu kin nhit khng kh T = 15oC, v p lc gi q = 6,25daN/m2.

II.5.29. Khi tnh ton kim tra khong cch t phn mang in n kt cu ct DK hoc n cng trnh phi ly iu kin kh hu kt hp nh sau:

a. in p lm vic: nhit khng kh T = 25oC, p lc gi q = qmaxb. Khi qu in p kh quyn v ni b, nhit khng kh T = 20oC, p lc gi q = 0,1 qmax nhng khng nh hn 6,25daN/m2.Gc lch ( ca chui cch in treo thng (so vi chiu thng ng) khi c gi tc ng c tnh theo cng thc:

tg( = Trong :

K: h s tnh n ng lc dao ng ca dy dn. Tr s K ly tng ng vi p lc gi theo bng sau:

q (daN/m)K

401

450,95

550,90

650,85

800,80

( 1000,75

Cc tr s trung gian ly theo cch ni suy.

P2 - p lc gi tc ng vo dy dn c xt n hp lc ngang ca lc cng dy trong trng hp gc, daN/m2Gd - Ti trng do trng lng dy dn tc ng vo chui cch in, daN.

Gc - Trng lng ca chui cch in, daN.

Dy dn hoc dy chng st

II.5.30. Cc pha ca DK c th l mt dy hoc nhiu dy phn pha. Vic xc nh ng knh, tit din, s lng dy phn pha, khong cch cc dy phn pha phi thng qua tnh ton.

II.5.31. Theo iu kin bn c hc, DK phi dng dy dn hoc dy chng st nhiu si vi tit din khng c nh hn cc tr s cho trong bng II.5.1.

Khi chn dy DK m bo iu kin tn tht do vng quang gy nn, cao n 1000m so vi mc nc bin, dy dn khng phn pha phi c tit din khng c nh hn:

70mm2 i vi DK 110kV.

240mm2 i vi DK 220kV

Khi chn dy dn DK, ngoi tn tht do vng quang cn phi tnh n nhiu cao tn, nhiu v tuyn in (vi DK 110kV tr ln) v nh hng ca in t trng (vi DK 220 kV tr ln) .

Bng II.5.1: Tit din nh nht cho php ca DK theo bn c hc

c im ca DKTit din dy dn (mm2)

NhmNhm li thp v hp kim nhmThpng

1. Trn cc khong ct thng thng ca DK:35252516

2. Trn cc khong ct ca DK vt qua cc sng, knh c thuyn b qua li:703525

3. Trn cc khong ct ca DK vt cc cng trnh:

- Dy thng tin703525

- ng dn ni v cc ng cp vn chuyn

- ng st

II.5.32. Khi chn tit din dy chng st, ngoi vic tnh bn c hc cn phi kim tra n nh nhit khi xy ra ngn mch mt pha chm t ti ct cui DK (theo Ph lc I.3.2 - Phn I). Trn on DK c mc dy chng st cch in vi t th khng cn phi kim tra n nh nhit. Dy chng st cp quang (OPGW) c chn v bn c hc v kim tra n nh nhit nh vi dy chng st thng.

II.5.33. Khi tnh dy dn hoc dy chng st DK phi cn c vo c tnh c hc ca nh ch to hoc tiu chun hin hnh hoc tham chiu.II.5.34. Phi tnh dy dn hoc dy chng st theo cc iu kin sau y :

a. Ti trng ngoi ln nht

b. Nhit thp nht v khng c ti trng ngoi

c. Nhit trung bnh nm v khng c ti trng ngoi.

ng sut cho php ln nht ca dy dn hoc dy chng st theo cc iu kin trn ghi trong bng II.5.2, tr quy nh theo iu II.5.35.

II.5.35. i vi DK dng dy nhm, hp kim nhm v dy ng c tit din dy dn n 95mm2 trong khu vc ng dn v ti ch giao cho vi cng trnh khc, ng sut cho php ly bng 40% ng sut ko t ca dy dn.

i vi DK dng dy nhm li thp c tit din 120mm2 tr ln ng sut cao nht c php ly n 50% ng sut ko t khi p lc gi tnh ton q (100daN/m2.

II.5.36. ng sut pht sinh im mc dy cao nht trn mi ct ca DK k c khong vt ln khng c vt qu 110% i vi dy nhm li thp, 105% i vi cc loi dy dn khc so vi tr s ghi trong bng II.5.2.

II.5.37. Khi xy dng DK ti nhng vng m kinh nghim vn hnh xc nhn dy nhm li thp b g (b bin, sng h nc mn, x nghip ha cht v.v.) th phi dng loi dy dn chu c n mn (dy nhm li thp c bo v chng g hoc dy ng v.v.).

Trng hp thiu s liu th khong cch an ton chng g phi ly cch b bin 5km v cch x nghip ha cht 1,5km.

Bng II.5.2: ng sut cho php ca dy dn v dy chng st tnh theo % ng sut ko t

Tit din ca dy dn v

dy chng stng sut cho php tnh theo % ng sut ko t ca dy dn v dy chng st

Khi ti trng ngoi ln nht v nhit thp nhtKhi nhit trung bnh nm

Dy nhm, mm2:

16-35

50 v 70

95

( 12035

40

40

4525

Dy hp kim nhm, mm2:

16-95

( 12040

4530

Dy chng st bng thp vi mi tit din, mm25030

Dy nhm li thp v hp kim nhm li thp, mm2:

16-25

35-95

(120 khi A:C = 6,11(6,25

(120 khi A:C = 4,29(4,39

(15035

40

40

45

4525

Dy ng, mm25030

II.5.38. Dy dn hoc dy chng st DK phi c bo v chng rung trong cc trng hp sau:

a. Khong ct di hn 120m, ch nhit trung bnh nm nu ng sut trong dy dn hoc dy chng st ln hn:

4daN/mm2 i vi dy nhm.

6daN/mm2 i vi dy nhm li thp v hp kim nhm tit din n 95mm2. 5daN/mm2 i vi dy nhm li thp v hp kim nhm tit din 120mm2 tr ln.

24daN/mm2 i vi dy chng st bng thp.

b. Vt sng ln, h ln c khong vt trn 500m, khng ph thuc ng sut trong dy dn hoc dy chng st.

i vi nhng on DK khng b gi tc ng theo hng ngang vo dy (ng dy dc thung lng, qua rng cy v.v.) th khng phi chng rung.

i vi DK c phn pha 3 dy tr ln, nu ng sut dy dn nhit trung bnh nm khng vt qu 6,75daN/mm2 v khong cch gia cc khung nh v khng vt qu 60m th cng khng cn bo v chng rung, ngoi tr i vi khong vt ln hn 500m.

II.5.39. Trn DK c phn pha, trong khong ct cng nh ti dy lo trn ct no dy dn phi lp cc khung nh v. Khong cch gia cc khung nh v trong khong ct khng c ln hn 75m.

B tr dy dn, dy chng st

II.5.40. i vi DK, c th dng bt k li b tr dy dn no trn ct.

II.5.41. Khong cch gia cc dy dn DK phi la chn theo iu kin lm vic ca chng trong khong ct, cng nh theo khong cch cch in cho php gia dy dn vi cc b phn ca ct (iu II.5.29 v iu II.5.69).

II.5.42. DK in p 35kV tr ln dng cch in treo, khong cch gia cc dy dn b tr trong mt phng ngang theo iu kin lm vic ca dy trong khong ct khng c nh hn tr s xc nh theo cng thc sau:

Trong :

D: khong cch pha, m

U: in p danh nh, kV

f: vng tnh ton ln nht, m

(: chiu di chui cch in, m

Khi b tr dy dn theo theo mt phng thng ng, th khong cch xc nh theo cng thc:

Khi dy dn b tr khng cng trn mt mt phng:

khi chnh lch cao treo dy h(

v khi chnh lch cao treo dy h(

II.5.43. DK in p 35kV dng cch in ng v in p n 22kV dng loi cch in bt k, khong cch gia cc dy dn theo iu kin lm vic ca dy trong khong ct khng c nh hn tr s xc nh theo cng thc sau:

Trong :

D: khong cch pha, m

U: in p danh nh, kV

f: vng tnh ton ln nht, m

II.5.44. Khong cch gia dy chng st v dy dn theo chiu thng ng c xc nh theo iu kin lm vic ca dy dn hoc dy chng st trong khong ct ph hp vi nhng yu cu nu trong cc iu II.5.63 v II.5.64.II.5.45. i vi mt s khong ct ring bit, c php gi nguyn khong cch gia cc dy dn chn nu vng ln nht khng vt qu 2 ln vng tnh ton.

II.5.46. Trn ct nhiu mch ca DK, khong cch ti ct gia cc dy dn gn nht ca hai mch lin k cng in p khng c nh hn:

2m i vi DK dy trn in p n 22kV vi cch in ng, 1m i vi DK dy bc in p n 22kV vi cch in ng.

2,5m i vi DK in p 35kV vi cch in ng v 3m vi cch in treo.

4m i vi DK in p 110kV

6m i vi DK in p 220kV.

8,5m i vi DK in p 500kV.

II.5.47. i vi DK cn sa cha khi c in, m bo an ton cho ngi tro ln ct, khong cch t dy dn v ph kin mc dy dn n phn c ni t ca DK khi dy dn khng chao lch khng c nh hn:

1,5m i vi DK 35 v 110kV

2,5m i vi DK 220kV

4m i vi DK 500kV

II.5.48. Cc dy dn DK in p khc nhau trn 1kV n 500kV c th b tr trn cng mt ct.

Khong cch ca 2 mch cnh nhau c in p khc nhau ly theo yu cu ca trong iu II.5.46, 47 vi mch c in p ln hn.

Cho php b tr trn cng mt ct cc dy dn ca DK in p n 35kV v cc dy dn ca DK in p n 1kV vi cc iu kin sau:

1. DK in p n 1kV phi thc hin theo cc iu kin tnh ton v c l nh i vi DK in p cao hn.

2. Cc dy dn ca DK in p n 35kV phi b tr pha trn cc dy dn ca DK in p n 1kV, trong khong cch cc dy dn ca 2 DK c in p khc nhau nhit trung bnh nm phi ln hn 2m vi dy trn, 1m i vi dy bc.

3. Dy dn ca DK in p cao mc vo cch in ng phi mc kp (2 cch in ti mi v tr).

Trong li in c trung tnh cch ly hoc khng ni t trc tip in p n 35kV c nhng on dy mc chung trn ct vi DK in p cao hn, th cm ng in t v tnh in ca DK ny khi li in lm vic ch bnh thng khng c lm thay i in p trung tnh qu 15% in p pha ca li c in p thp hn.

Li in c trung tnh ni t trc tip chu nh hng ca DK in p cao hn, khng c yu cu c bit v in p cm ng.

Vt cch in

II.5.49. DK in p 110kV tr ln ch c dng cch in treo, ti cc v tr c bit (o pha, bn cnh chng st, my ct, cu dao v.v.) cho php dng cch in ng ph hp.

Ct c x cch in composit ph hp th khng cn dng vt cch in.

DK in p 35kV tr xung c th dng cch in treo hoc cch in ng.

II.5.50. S bt cch in treo (c chiu di ng r in ca mi bt khng nh hn 250mm) trong mt chui ca DK 6 - 35kV yu cu ly nh sau: n 10kV - 1 bt; 15 v 22kV - 2 bt; 35kV - 3 bt.

S bt cch in treo trong mt chui v loi cch in ng i vi DK in p n 35kV c la chn khng ph thuc vo cao so vi mc nc bin.

Yu cu v cch in ca DK 15kV trong h thng trung tnh ni t trc tip c chn nh i vi DK 10kV h thng trung tnh cch ly.

S bt cch in treo trong mt chui cho DK 110 - 500kV c cao n 1000m so vi mc nc bin c chn theo cng thc:

Trong :

n l s bt cch in trong mt chui

d l tiu chun ng r la chn, ly bng 16mm/kV i vi mi trng bnh thng, 20mm/kV i vi mi trng nhim nh, 25mm/kV i vi mi trng nhim, 31mm/kV i vi mi trng nhim nng hoc gn bin ti 5km.

Umax l in p dy lm vic ln nht ca ng dy, kV.

D l chiu di ng r ca mt bt cch in, ly theo s liu ca nh ch to, mm.

Sau khi tnh c n, qui trn n thnh s nguyn ln hn gn nht.

Khi chn loi bt cch in treo cho mi chui c chiu di ng r in ln hn 2,3 ln chiu di cu to ca chui cch in theo iu kin in p lm vic, phi kim tra li theo iu kin qu in p ng ct. Tr s tnh ton ca qu in p ng ct ly bng 312kVmax i vi ng dy 110kV v 620kVmax i vi ng dy 220kV, 1175kV max vi DK 500kV.

II.5.51. Khi chn s bt cch in trong mt chui cn phi tun theo cc yu cu sau y:

a. S bt (tt c cc loi cch in) trong mt chui no ca DK in p n 110kV phi tng thm mt bt so vi chui . Vi DK in p 220kV, s bt trong mt chui v no ly ging nhau. Ring i vi ng dy 500kV tng thm mt bt trn ton tuyn.

b. Ct vt cao trn 40m, s bt cch in trong mt chui phi tng so vi s bt cc ct khc ca DK .

1 bt khi on vt c t thit b chng st.

1 bt khi ct c mc dy chng st cho mi on ct 10m tng cao thm, k t chiu cao 40m tr ln.

c. DK in p n 110kV i qua khu vc c cao trn 1000 ti 2500m so vi mc nc bin, cng nh DK in p 220kV i qua khu vc c cao trn 1000 ti 2000m so vi mc nc bin, phi tng thm 1 bt trong mt chui cch in so vi mc a v b ca iu ny.

DK i qua nhng vng nhim nng (gn cc x nghip cng nghip, b bin v.v.) phi ty theo iu kin c th m chn s lng v loi cch in cho ph hp.

II.5.52. H s an ton ca cch in l t s gia ti trng ph hu (cch in ng) hoc bn c in (cch in treo) vi ti trng ln nht tc ng ln cch in khi DK lm vic ch bnh thng, khng nh hn 2,7; nhit trung bnh nm, khng c gi th khng nh hn 5,0.

Trong ch s c ca DK, h s an ton ca cch in treo khng c nh hn 1,8 i vi DK 220kV tr xung v khng c nh hn 2 i vi DK 500kV.

Lc tc ng ln cch in kiu treo trong ch s c ca DK xc nh theo iu II.5.83, 84.

Ch DK giao cho vi ng t cp III tr ln, ng t trong th, ng st cng cng, ng thu c thuyn b qua li thng xuyn, phi dng cch in kp.

Ph kin ng dy

II.5.53. Mc dy dn vo cch in treo dng kha hoc kha no.

Mc dy dn vo cch in ng, dng dy buc hoc kp chuyn dng.

II.5.54. Kha c th l kha c nh hoc kha trt, nn dng kha c nh bo m an ton. cc khong vt ln c th treo dy dn hoc dy chng st trn cc rng rc hoc kha c bit.

II.5.55. i vi dy dn ca cc pha khc nhau trn cng mt ct cng nh cc dy dn ca cng mt pha t trn cc ct khc nhau c th dng cc kha kiu khc nhau (kho c nh, kha trt).

II.5.56. Mc dy chng st vo ct phi dng kha kiu c nh; vo ct no dng kha no.

II.5.57. Khng c ni dy dn hoc dy chng st ng dy 110kV tr ln bng kp bulng, m phi bng ng ni chuyn dng. Trong mt khong ct ca DK, mi dy dn hoc dy chng st ch c php c mt mi ni v phi tun theo cc qui nh trong cc iu II.5.101, 106, 117, 141, 145, 151, 162.

II.5.58. H s an ton c hc ca ph kin mc dy l t s gia ti trng c hc ph hy vi ti trng ln nht tc ng ln ph kin, khi DK lm vic ch bnh thng khng nh hn 2,5 v trong ch s c khng nh hn 1,7.

H s an ton ca chn cch in ng khi DK lm vic ch bnh thng khng nh hn 2, trong ch s c khng nh hn 1,3.

Lc tc ng ln ph kin mc dy trong ch s c xc nh theo iu II.5.83, 84.

Bo v qu in p, ni t

II.5.59. DK in p 110kV tr ln phi c bo v khi st nh trc tip bng dy chng st trn sut chiu di ng dy, tr mt s on tuyn c bit khng th b tr c dy chng st. on tuyn ny phi c bin php chng st khc b sung.

II.5.60. DK in p t 22kV tr xung khng yu cu bo v khi st nh bng dy chng st trn sut chiu di. Ct ca DK phi ni t theo iu II.5.71 v II.5.77.

II.5.61. DK in p 35kV khng phi bo v bng dy chng st nhng cc ct phi ni t ng vi yu cu trong iu II.5.71 v II.5.77. v on DK vo trm phi thc hin theo II.5.62

II.5.62. on DK i vo trm bin p phi c bo v trnh qu in p kh quyn ph hp vi yu cu bo v trm.

II.5.63. Khi dng dy chng st bo v DK cn theo cc yu cu sau y:

a. Cc ct kim loi v ct btng ct thp mt tr mc mt dy chng st, gc bo v khng c ln hn 30o.

b. Trn ct kim loi c b tr dy dn nm ngang, mc hai dy chng st, gc bo v i vi dy ngoi cng khng c ln hn 20o.

c. i vi ct btng ct thp hnh cng, cho php tng gc bo v i vi dy ngoi cng n 30o.

d. Khi DK mc hai dy chng st, khong cch gia chng ti u ct khng c vt qu 5 ln khong cch thng ng gia dy chng st v dy dn.

e. Gc bo v yu cu ca tng n thit k ly thp hn hoc bng cc tr s trn, tu theo s ngy st v a hnh ca khu vc ng dy i qua, chiu cao ct v tm quan trng ca DK.

II.5.64. Khong cch thng ng gia dy chng st v dy dn gia khong ct ca DK, khng tnh n s chao lch ca dy do gi tc ng, theo iu kin bo v khi qu in p kh quyn khng nh hn tr s trong bng sau:

Chiu di khong ct

(m)Khong cch

(m)Chiu di khong ct

(m)Khong cch

(m)

1002,070011,5

1503,280013,0

2004,090014,5

3005,5100016,0

4007,0120018,0

5008,5150021,0

60010,0--

Chiu di khong ct gia cc tr s trn y c th ly theo php ni suy. Trn khong ct ca DK c mc dy chng st, vng ca dy chng st khng c ln hn vng ca dy dn. II.5.65. Dy chng st khng c li cp quang trn tt c cc ct ca DK in p 220kV tr ln, phi mc qua cch in song song vi khe h phng in l 40mm. Trong mi khong no di n 10km, dy chng st c ni t ti mt im ct no. Nu chiu di khong no ln hn th s im ni t trong khong no y cn chn sao cho tr s sc in ng dc ln nht sinh ra trong dy chng st khi xy ra ngn mch trn DK khng nh thng khe h phng in.

on vo trm ca DK 220kV c chiu di t 2 n 3km, nu dy chng st khng s dng ly in bng phng php in dung hoc thng tin lin lc th phi ni t tng ct.

on vo trm ca DK 500kV c chiu di di 5km th dy chng st phi c ni t tng ct. Trn DK 500kV dng dy chng st lm phng tin truyn thng tin cao tn th dy chng st phi c cch in t nht bng 2 bt cch in trn sut chiu di DK v phi thc hin o dy (thng qua tnh ton) sao cho sc in ng dc cm ng trn dy chng st khng vt qu tr s cho php xc nh trong thit k trong c ch vn hnh bnh thng v ngn mch trn DK 500kV.

Khi s dng dy chng st c li cp quang i song song vi dy chng st khng c li cp quang th tt c cc dy chng st trn u phi ni t cc ct.

II.5.66. Trng hp dng dy chng st bng thp tit din 50mm2 tr xung on DK c dng in ngn mch ln hn 15kA th phi ni t dy chng st bng mt dy ni mc song song vi kha.

II.5.67. Nhng on cp ni vo DK phi bo v qu in p kh quyn bng thit b chng st t u on cp, cc ni t ca chng st phi ni vi v kim loi ca cp bng ng ngn nht.

II.5.68. DK vt sng ln, vt khe ni vi ct cao trn 40m m trn ct khng mc dy chng st, phi t thit b chng st.

II.5.69. DK i qua vng c cao n 1000m so vi mc nc bin, khong cch cch in gia dy dn v ph kin mc dy c mang in vi cc b phn ni t, ct khng c nh hn tr s cho trong bng II.5.3.

Khi DK i qua khu vc cao trn 1000m so vi mc nc bin, khong cch cch in nh nht, theo in p lm vic ln nht phi tng ln so vi tr s trong bng II.5.3 c mi khong 100m tng 1,4%, k t cao 1000m so vi mc nc bin.

II.5.70. Khong cch cch in nh nht gia cc pha ca DK ti ct o pha, ti ch r nhnh v thay i cch b tr dy dn khng c nh hn tr s trong bng II.5.4.

Bng II.5.3: Khong cch cch in nh nht ti ct gia phn mang in v phn c ni t ca ng dy

iu kin tnh ton khi la chn khong cch cch inKhong cch cch in nh nht (cm) ti ct theo in p ca DK (kV)

n 1015(2235110220500

a. Khi qu in p kh quyn:

Cch in ng

Cch in treo

b. Khi qu in p ni b:

c. Khi in p lm vic ln nht:15

20

1025

35

15

735

40

30

10100

80

25180

160

55320

300

115

Bng II.5.4: Khong cch cch in nh nht gia cc pha ti ct ca DK

iu kin tnh tonKhong cch cch in nh nht gia cc pha (cm) theo in p ca DK, kV

n 1015(2235110220500

Khi qu in p kh quyn

Khi qu in p ni b

Khi in p lm vic20

22

-45

33

1550

44

20135

100

45250

200

95400

420

200

II.5.71. DK phi ni t :

a. Ct thp v ct btng ct thp ca:

DK in p 110kV tr ln.

DK in p n 35kV khng c bo v chm t ct nhanh hoc i qua khu vc ng dn c.

DK in p n 35kV c bo v chm t ct nhanh hoc i qua khu vc t dn c th ni t cch ct (2 n 3 khong ct) v ni t ti cc ct giao cho vi ng giao thng.

b. Ct thp v ct btng ct thp vi mi cp in p c mc dy chng st hoc c t thit b bo v st cng nh tt c cc ct trn c t MBA lc hoc o lng, dao cch ly, cu chy hoc thit b in khc. II.5.72. in tr ni t ca ct DK:

a. C dy chng st hoc thit b bo v chng st, v cc thit b khc khng c ln hn tr s trong bng II.5.5.

b. in tr ni t ca DK in p 6 - 22kV vng ng dn c v DK 35kV cng theo bng bng II.5.5.

c. in tr ni t ca DK in p 6 - 22kV vng t dn c:

Khi in tr sut ca t n 100(m, khng qu 30 [(].

Khi in tr sut ca t trn 100(m, khng qu 0,3( [(] .

d. in tr ni t ca ct DK c t cc thit b nh MBA lc, MBA o lng, dao cch ly, cu chy hoc thit b khc th thc hin nh sau:

DK 6 - 35 kV c dng in chm t ln v DK 110kV tr ln phi tun theo bng bng II.5.5.

DK 6 - 35kV c dng in chm t nh, thc hin theo iu I.7.35 v 36 - Phn I.

e. Ti ct DK cao trn 40m c dy chng st th in tr ni t phi nh hn 2 ln tr s nu trong bng II.5.5.

i vi DK c bo v bng dy chng st, in tr ni t trong bng II.5.5 c o khi tho dy chng st ra.

II.5.73. DK i qua vng t c in tr sut ( ( 500(m v khng cha nc c tnh n mn, nn li dng ct thp ca mng btng ct thp lm ni t t nhin hoc kt hp ni t nhn to.

vng t c in tr sut ln hn, khng c tnh n ni t t nhin ca ct thp mng ct, tr s in tr ni t yu cu trong bng II.5.5 phi bo m ch bng ni t nhn to.

Bng II.5.5: in tr ni t ca DK

in tr sut ca t ( ((m)in tr ni t (()

n 100

Trn 100 n 500

Trn 500 n 1000

Trn 1000 n 5000

Trn 5000n 10

15

20

30

6.10-3(

II.5.74. Mng bng btng ct thp khi dng lm ni t t nhin (tr iu II.5.140) phi:Khng qut nha bitum ln mng.

C s ni lin bng kim loi gia bulng no v khung mng, phi o in dn sut ca mng btng ct thp sau khi mng t c hai thng tr ln.

II.5.75. Nn li dng cc thanh thp dc ca ct btng ct thp (c ni bng kim loi vi nhau v ti vt ni t) lm dy ni t.

Dy chng st v cc chi tit lp cch in vo x phi ni bng kim loi vi dy ni t hoc vi ct thp ni t ca ct btng ct thp.

II.5.76. Tit din ca dy ni t trn ct DK khng c nh hn 35mm2, i vi dy mt si ng knh khng c nh hn 10mm, cho php dng dy thp m km mt si ng knh khng nh hn 6mm lm dy ni t trn ct. Trn ct btng ct thp v ct kim loi phi ni dy ni t bng cch hn hoc bt bulng, nhng ti thiu phi c mt ch gn mt t bt bulng.

II.5.77. Kt cu ni t ca DK phi t su t nht 0,5m, vng t cy cy t su t nht 1m, nhng vng t v.v. cho php t cc dy ni t trc tip di lp t vi chiu dy lp ph trn khng c nh hn 0,1m. Khi chiu dy lp ph khng t yu cu trn c th t dy ni t ngay trn mt lp v ph trn bng va xi mng.

Ct

II.5.78. DK c th dng cc loi ct sau y:

Ct , ct no, ct gc, ct o pha, ct hm v ct c bit. Ct c th dng loi mt mch hoc nhiu mch, mt cp in p hoc nhiu cp in p.

Ct c th c kt cu cng hoc kt cu mm, cn ct no v ct hm phi c kt cu cng.

Ct gc c th l hoc no.

Ty thuc vo ch t, tt c cc loi ct c th dng dy no hoc khng c dy no. Nhng ch trn ng i li khng c dng dy no.

Khng dng ct g cho mi DK.

II.5.79. V tr ct no do iu kin lm vic v lp t ca DK xc nh.

Ct no c th t ti gc li ca DK v ch giao cho vi cng trnh khc.

II.5.80. DK c dy dn tit din n 185mm2 mc dy bng kha c nh v kha trt trn cng mt ct th chiu di khong no khng c qu 5km, khi dy dn c tit din ln hn 185mm2 th chiu di khong no khng qu 10km.

Khi mc dy dn vo kha c nh hoc trn cch in ng, chiu di khong no ty thuc vo iu kin tuyn DK.

II.5.81. Ct ca DK c tnh ton vi cc ti trng khi ng dy lm vic trong ch bnh thng v ch s c.

Ct no: phi kim tra s chnh lch v lc cng ca dy dn hoc dy chng st pht sinh do s khc nhau gia hai khong ct i biu v hai pha ca ct.

Ct hai mch: phi kim tra iu kin ch mc dy mt mch trong tt c cc ch . Ct ca DK cn phi kim tra theo cc iu kin lp, dng ct cng nh theo iu kin khi lp dy dn hoc dy chng st.

II.5.82. Trong ch bnh thng ca DK, cc ct tnh ton theo iu kin di y:

Dy dn hoc dy chng st khng b t, p lc gi ln nht (qmax). Ct gc cn phi tnh ton vi iu kin nhit thp nht (Tmin) khi khong ct i biu nh hn khong ct ti hn.

Ct hm tnh ton theo iu kin lc cng ca tt c dy dn hoc dy chng st v mt pha, cn pha trm bin p hoc pha k vi khong vt ln coi nh khng mc dy dn hoc dy chng st.

II.5.83. Trong ch s c ca DK, ct mc cch in treo phi tnh n lc do t dy dn hoc dy chng st gy ra mmen un hoc mmen xon ln nht trn ct theo cc iu kin sau y:

1. t mt hoc cc dy dn ca mt pha (vi bt k s dy trn ct l bao nhiu), dy chng st khng b t.

2. t mt dy chng st, dy dn khng b t.

3. Khi tnh ct, cho php k n tc ng ca nhng dy dn hoc dy chng st khng b t.

4. Lc cng tiu chun ca DK khng phn pha, mc dy bng kha kiu c nh, khi t mt dy dn ly bng cc tr s quy c sau:

a. i vi ct kiu cng (ct kim loi ng t do, ct btng c dy no v cc loi ct cng khc):

Dy dn tit din n 185mm2: 0,5Tmax. Dy dn tit din t 240mm2 tr ln: 0,4Tmaxb. i vi ct btng ct thp ng t do:

Dy dn tit din n 185mm2: 0,3Tmax. Dy dn tit din t 240mm2 tr ln: 0,25Tmax

Trong : Tmax l lc cng ln nht ca mt dy dn trong ch s c.

c. i vi cc loi ct khc (ct bng vt liu mi, ct kim loi kt cu mm), lc cng tiu chun tnh vi h s ph thuc vo un ca ct trong phm vi nu mc a v b.

Trong tnh ton ct DK 220kV tr xung, c phn pha khi t dy, lc cng tiu chun ca dy dn trn kha kiu c nh ca DK c phn pha cng xc nh nh i vi DK khng phn pha nhng nhn vi s dy trong mt pha v nhn thm vi h s:

0,8 khi mt pha phn ra 2 dy



Lc cng tiu chun ca dy chng st ly bng 0,5 Tmax

Trong Tmax l lc cng ln nht ca dy chng st trong ch s c.

i vi ct kiu mm (ct btng ct thp khng c dy no), cho php xc nh lc cng tiu chun khi t dy chng st c xt n un ct.

II.5.84. Trong ch s c ca DK, cc ct no v hm phi tnh n lc khi t dy dn v chng st gy ra mmen un hoc mmen xon ln nht ln ct theo cc iu kin sau y:

a. t dy dn ca mt pha trong mt khong ct khi s mch trn ct bt k, dy chng st khng b t.

b. t mt dy chng st trong mt khong ct, dy dn khng b t.

II.5.85. Trong tnh ton ch s c ct DK 500kV c phn pha, khi dy b t, ti trng tiu chun quy c tnh ti im treo dy ca mt pha c quy nh bng 0,15 Tmax nhng khng nh hn 1800 daN.

II.5.86. Ct no phi kim tra theo iu kin lp t nh sau:

a. Mt trong cc khong ct vi s dy dn trn ct bt k ch lp dy dn ca mt mch, khng mc dy chng st.

b. Mt trong cc khong ct c mc dy chng st, khng lp dy dn.

Khi kim tra ly iu kin kh hu theo iu II.5.31.Trong iu kin lp t (dng ct, mc dy dn hoc dy chng st v.v.) khi cn thit c th tng vng chc (tm thi) ca tng b phn ct v t dy no tm.

II.5.87. Trong ch s c ca ct khong vt ln vi dy dn khng phn pha mc dy bng cc kha c nh, lc tc ng tnh ton khi dy dn b t ly bng lc cn d ton phn ca dy dn tnh trong iu kin kh hu nu trong iu II.5.28.

Khi treo dy dn hoc dy chng st trn cc rng rc, trong ch s c lc tc ng theo chiu dc tuyn DK ly bng 2.000daN khi pha c mt dy dn, 3.500daN khi mt pha c 2 dy dn v 5.000daN khi mt pha c 3 dy dn.

Ct mt mch tnh vi trng hp t dy dn ca mt pha v ct 2 mch tnh vi trng hp t dy dn ca 2 pha, dy chng st khng b t.

Lc tiu chun ca dy chng st mc bng kha c nh, khi b t tc ng vo cc ct vt ly bng lc cng ti a ton phn ca dy chng st, dy dn khng b t.

Cc ct no hm mt mch ca khong vt ln trong ch s c phi tnh vi iu kin t dy ca mt pha, cn ct no nhiu mch tnh vi t dy dn ca 2 pha, dy chng st khng b t.

Lc tiu chun ca dy chng st khi b t tc ng vo ct no vt trong ch s c ly bng lc cng ti a ton phn ca dy chng st, dy dn khng b t.

II.5.88. Ct no DK 500kV phi c kim tra theo cc iu kin lp t sau:

a. mt khong ct lp tt c dy dn hoc dy chng st, cn khong ct khc dy dn hoc dy chng st cha lp.

Lc cng ca dy dn hoc dy chng st lp quy nh tnh bng 2/3 tr s ln nht, iu kin kh hu ly theo nhit khng kh T = 15oC v p lc gi Q= 7daN/m2. Trong trng hp ct v ton b cc chi tit bt cht xung mng cn phi c bn ng theo tiu chun khi khng dng dy no tm.

b. Trong mt khong ct vi s lng dy dn trn ct bt k, cc dy dn ca mt mch c lp theo th t v theo trnh t bt k, cc dy chng st cha lp.

c. Trong mt khong ct vi s lng dy chng st trn ct bt k, cc dy chng st c lp theo th t v trnh t bt k, cc dy chng st cha lp.

Trong iu kin lp t (dng ct, mc dy dn hoc dy chng st v.v.) khi cn thit c th tng cng vng chc tm thi ca tng b phn ct v t dy no tm.

II.5.89. X v gi dy dn, dy chng st ca tt c cc ct phi c kim tra vi ti trng tng ng theo phng php lp t ghi trong thit k, c tnh n thnh phn lc cng ca dy no, trng lng ca dy dn, dy chng st v cch in cng nh trng lng ca ph kin lp t v cng nhn lp t c mang dng c. Nhng ti trng ny t vo ch lp cch in.

Ti trng tiu chun ca ph kin lp t v th lp t c mang dng c ly nh sau:

100daN: ct dng cch in ng.

150daN: ct , dng cch in treo n 220kV.

200daN: ct no dng cch in treo n 220kV.

250daN: ct 500kV.

II.5.90. i vi DK in p 110kV tr ln, nu l ngun cung cp in duy nht, kt cu ct phi tha mn iu II.5.47 c th tin hnh sa cha khng cn ct in.

II.5.91. ng sut trong dy no khi t dy dn hoc dy chng st khng c ln hn 70% lc ko t ca vt liu lm dy no.

II.5.92. Kt cu ct kim loi, ct btng ct thp ca DK phi m bo cho cng nhn c th tro ln ct.

Trn ct kim loi, gc nghing ca thanh ging i vi mt phng ngang nn nh hn 30o, trng hp gc nghing ln hn phi lm bc tro, ct btng ly tm phi c l gn chn tro.

Cc b phn ging ca ct, tr cc thanh nm ngang u ni gia hai on ct, phi tnh vi trng lng ngi l 70kg.

Ct c im mc dy trn cng c cao trn 70m phi c thang ln xung v sn ngh c bo v xung quanh bng chn song. Thang hoc mc ln xung ca ct phi t cch mt t 3m tr ln.

II.5.93. Trn thn ct thp v btng ct thp phi c m hiu loi ct ca nh my hoc ni ch to trong c ghi r nm sn xut.DK i qua khu vc t dn c

II.5.94. DK i qua khu vc t dn c, tit din nh nht ca dy dn phi theo iu II.5.31, ni dy theo iu II.5.57.

II.5.95. Khong cch thng ng t im thp nht ca dy dn n mt t t nhin, trong ch lm vic bnh thng khng c nh hn:

5,5m i vi DK in p n 35kV

6m i vi DK in p n 110kV


khu vc kh n, khong cch trn cho php gim i 1m, ch rt kh n (nh mm , vch ni v.v.) cho php gim i 3m.

i vi DK 500kV quy nh nh sau:

Vng t dn c: 10m

Vng kh qua li: 8m

Nhng ni ngi i b kh n (nh mm , dc ni v.v.): 6m

Khong cch thng ng xc nh theo vng ca dy dn khi nhit khng kh cao nht, khng c gi v khng tnh n s pht nng do dng in.

II.5.96. Khong cch ngang t mt phng thng ng ca dy dn ngoi cng ca DK trng thi tnh n b phn nh ra gn nht ca nh ca hoc cng trnh (hnh lang bo v) khng nh hn:






i vi cp bc n 35kV khong cch trn c gim i 1/2.

II.5.97. Cm ti nc bng thit b phun ma ti vng t canh tc trong hnh lang bo v ca DK 500kV.

II.5.98. DK i trong rng hoc ni trng cy phi bo m khong cch ti thiu theo qui nh hin hnh v bo v an ton li in cao p.

DK i qua khu vc c nc

II.5.99. Khi DK i qua khu vc c nc (sng, knh, h, vnh, bn cng v.v.) gc giao cho khng quy nh.

II.5.100. Ct vt sng, knh, h c tu thuyn qua li v.v. phi dng ct no.

i vi DK c dy dn tit din 120mm2 tr ln mc bng kha kiu c nh v kha c bit, c php dng ct vt nhng ct k phi l ct no.

i vi khong vt ln phi dng ct no hm vt. Nu DK c dy dn tit din 120mm2 tr ln mc bng kha kiu c nh v kha c bit th cng c php dng ct vt nhng ct k phi l ct no hm.

Trng hp dng ct trong khong vt dy dn hoc dy chng st ca DK phi mc kha kiu c nh hoc kha c bit.

II.5.101. Tit din dy dn hoc dy chng st trong khong ct giao cho, theo iu kin bn c hc khng c nh hn 35mm2 i vi dy nhm li thp, dy hp kim nhm v dy thp, 70mm2 i vi dy nhm khi vt qua sng v knh c tu thuyn qua li.

Trong khong ct giao cho, dy dn hoc dy chng st khng c c mi ni, tr DK c dy dn tit din t 240mm2 tr ln c php c mt mi ni trn mi dy dn trong mt khong ct.

II.5.102. Khong cch t dy dn di cng ca DK n mt nc ni c tu thuyn i li khng c nh hn tr s ghi trong bng II.5.6a.

Khong cch t dy dn ca DK n mt nc ni khng c tu thuyn qua li c qui nh ti bng II.5.6b.

Khi khong vt gn st cu khng quay (hoc khng nhc nhp ln tu i qua c), c th cn c vo cao ca cu gim khong cch trong bng trn nhng phi c s tha thun vi c quan vn ti ng thy.

II.5.103. Ch DK giao cho qua sng, knh v.v. c tu thuyn qua li, phi t tn hiu v du hiu theo quy nh ca Nh nc.

Bng II.5.6a: Khong cch nh nht t dy dn ca DK n mt nc ca ng thu ni a ti khong giao cho

Cp k thut ca ng thu ni aKch thc lung lch (m)Khong cch an ton thng ng t im thp nht ca dy dn n mt nc cao nht trung bnh nm (m)

Sng thin nhinKnh oBn knh congn 35kV110 kV220 kV500 kV

Chiu su ncChiu rng yChiu su ncChiu rng y

I( 3,0( 90( 4,0( 50( 70013,5141516

II2-370-903-440-50500-70012,5131415

III1,5-250-702,5-330-40300-50010,5111213

IV1,2-1,530-502-2,520-30300-5009,5101112

V1-1,220-301,2-210-20100-200

VI(110-20(1,21060-150

Bng II.5.6b: Khong cch nh nht t dy dn ca DK n mt nc khn g c tu thuyn qua lic im ch giao choKhong cch nh nht (m) theo in p ca DK (kV)

n 35110220500

n bi sng hoc ni b ngp nc hng nm5,5678

n mc nc cao nht ca sng, knh khi nhit khng kh cao nht2,5345

DK i qua khu vc ng dn c

II.5.104. DK i qua khu vc ng dn c, gc giao cho vi ng ph khng quy nh.

Khi DK i dc ng ph cho php b tr dy dn trn phn ng i li. Cm dng ct c dy no trn ng ph.

II.5.105. Ct t nhng ch giao cho v ch ngot ca ng ph, phi c bo v xe c khi m vo.

II.5.106. Tit din ca dy dn hoc dy chng st dng cho DK theo iu kin bn c hc khng c nh hn:

50mm2 vi dy nhm

35mm2 vi dy nhm li thp hoc hp kim nhm

Dy dn trn t trn cch in ng phi mc kp, dy dn trn cch in treo bng kha kiu c nh. Cho php dng kha trt i vi dy dn c tit din t 300mm2 tr ln.

Trong khong ct DK vt ng ph, dy dn hoc dy chng st khng c c mi ni, trng hp dy dn c tit din t 240mm2 tr ln cho php mi dy dn c mt mi ni trong mt khong ct.

II.5.107. Khong cch thng ng t im thp nht ca dy dn n mt t t nhin, trong ch lm vic bnh thng khng c nh hn:

7m i vi DK in p n 110kV.



Trng hp buc phi xy dng DK qua khu vc c cc cng trnh c tm quan trng v chnh tr, kinh t, vn ho, an ninh quc phng, thng tin lin lc, nhng ni thng xuyn tp trung ng ngi trong khu ng dn c, cc khu di tch lch s - vn ho, danh lam thng cnh c Nh nc xp hng th phi m bo cc iu kin sau:

a. on ng dy dn in trn khng vt qua cng trnh v cc a im trn phi c tng cng cc bin php an ton v in v xy dng.

b. Khong cch t im thp nht ca dy dn in n mt t t nhin khng c nh hn:




Khong cch trn quy nh trong ch lm vic bnh thng, vng tnh vi nhit khng kh cao nht, khng c gi v khng tnh n nh hng pht nng do dng in.

II.5.108. DK vt qua ng ph, nu tit din dy dn nh hn 185mm2 th khong cch t dy dn n mt t t nhin phi kim tra theo iu kin t mt dy dn khong ct k, vi nhit khng kh trung bnh nm v khng tnh n s pht nng do dng in. Khong cch ny khng c nh hn:

4,5m i vi DK in p n 110kV.


II.5.109. Khong cch ngang t mp ngoi cng ca mng ct n mp ng t (c tnh n qui hoch m rng) khng c nh hn 1,5m. Trng hp c bit vi DK n 35kV khong cch trn c gim n 0,5m.

II.5.110. Cm DK i trn nh ca v cng trnh, tr nhng cng trnh Nh nc cho php theo qui nh hin hnh. II.5.111. Khong cch ngang t mt phng thng ng ca dy dn ngoi cng ca DK trng thi tnh n b phn nh ra gn nht ca nh ca v cng trnh (hnh lang bo v) theo iu II.5.96.II.5.112. Khong cch t phn ni t ca ct DK ti cp lc t trong t phi thc hin theo cc iu quy nh trong Chng II.3.

II.5.113. Trong hnh lang bo v DK 500kV, cm xy dng nh v cc cng trnh. Nh v cc cng trnh c t trc phi di chuyn. Trong ch lm vic bnh thng ca DK phi m bo cng in trng nh hn 5kV/m i vi cc nh gn st hnh lang tuyn.

Trong hnh lang bo v ca DK 220kV tr xung, ch cho php tn ti nh hoc cng trnh c trc khi xy dng ng dy nu m bo cc iu kin theo quy nh hin hnh ca Nh nc.

DK giao cho hoc i gn nhau

II.5.114. Gc giao cho ca DK in p trn 1kV vi nhau v vi DK in p n 1kV khng quy nh.

Ch giao cho DK n 220kV phi la chn gn vi ct ca ng dy pha trn, nhng khong cch ngang t ct ny n dy dn ca ng dy pha di khi dy lch nhiu nht khng c nh hn 6m, cn t nh ct ca ng dy pha di n dy dn ca ng dy pha trn khng c nh hn 5m.

i vi ct no ca DK 500kV th khong cch t v tr giao cho n ct no khng c nh hn 10m.

II.5.115. Ti ch DK giao cho nhau c th dng ct no hoc ct .

II.5.116. Dy dn ca DK in p cao hn thng phi t trn DK in p thp hn. Trng hp c bit cho php t DK in p 110kV tr ln c tit din dy dn ln hn 120mm2 i trn dy dn ca DK c in p 220kV nhng phi dng cch in kp.

II.5.117. Tit din dy dn ca DK giao cho nhau khng c nh hn quy nh trong iu II.5.106.

Trong khong ct giao cho, dy dn hoc dy chng st ca DK pha trn khng c c mi ni, nhng dy dn c tit din ln hn 240mm2 th cho php mi dy dn c mt mi ni trong mt khong ct.

II.5.118. Trong khong ct giao cho, DK pha trn dng ct th dy dn phi mc bng kha kiu c nh. Khi tit din dy dn l 300mm2 tr ln c php dng kha trt.

Khi dng cch in ng DK pha trn, cch in trong khong ct giao cho phi mc kp.

II.5.119. Khong cch thng ng gia cc dy dn hoc gia dy dn hoc dy chng st gn nht ca DK giao cho nhau nhit khng kh xung quanh 20oC, khng c gi, khng c nh hn nhng tr s trong bng II.5.7.

Trong bng II.5.7, cc tr s trung gian ca chiu di khong ct xc nh bng phng php ni suy.

Khi xc nh khong cch gia cc dy dn ca DK giao cho nhau, nn tnh kh nng st nh vo c hai ng dy v ly khong cch i vi trng hp bt li hn. Nu DK pha trn c bo v bng dy chng st, tnh kh nng st nh vo DK pha di.

Cho php gi li ct ca DK in p n 110kV di dy dn ca DK vt pha trn, nu khong cch thng ng t dy dn ca DK ny n nh ct ca DK pha di ly theo tr s khong cch tng ng cho trong bng II.5.7 cng thm 2m.

Ti ch giao cho nu DK pha trn c dy chng st, khong cch ghi trong bng trn tnh cho DK pha di.

Bng II.5.7. Khong cch thng ng nh nht gia cc dy dn hoc gia dy dn v dy chng st ca nhng DK giao cho nhau

Chiu di khong ct (m)Vi khong cch nh nht t ch giao cho n ct gn nht ca DK (m)

305070100120150

Khi DK 500kV giao cho vi nhau v giao cho vi DK in p thp hn

200

300

4505

5

55

5

5,55

5,5

65,5

6

7-

6,5

7,5-

7

8

Khi DK 220kV giao cho vi nhau v giao cho vi DK in p thp hn

n 200

300

4504

4

44

4

44

5

44

4,5

4-

5

6,5-

5,5

7

Khi DK 110-22kV giao cho vi nhau v giao cho vi DK in p thp hn

n 200

3003

33

33

44

4,5-

5,0-

-

Khi DK 6-10kV giao cho vi nhau v giao cho vi DK in p thp hn

n 100

1502

22

2,5-

2,5-

--

--

-

II.5.120. Khi DK i gn nhau v song song, khong cch gia dy dn ngoi cng ca DK khi dy dn trng thi tnh, khng c nh hn khong cch ngang ca hnh lang bo v ca DK c in p cao hn.DK giao cho hoc i gn ng thng tin (TT)

hoc ng tn hiu (TH)

II.5.121. Gc giao cho DK vi TT hoc TH thuc mi cp khng quy nh.

Dy dn ca DK phi b tr pha trn dy dn ca TT hoc TH.

Ch giao cho phi chn gn vi ct DK.

Khong cch ngang t ct DK n 220kV n dy dn ca TT hoc TH khng c nh hn 6m, t ct TT v ct TH n dy dn ca DK n 220kV khng nh hn 7m.

Cho php gi li ct ca TT hoc TH di DK n 220kV giao cho nu khong cch t nh ct TT hoc TH n dy dn ca DK khng nh hn:

- 6m i vi DK 110kV

- 7m i vi DK 220kV

Trong khong ct giao cho gia DK in p 35kV n 220kV vi TT, nu DK c dng lm ng thng tin cao tn v iu khin t xa c t thit b thng tin c cng sut ra ca mi mch ln hn 10W v TT c di tn s trng vi tn s ca mch thng tin cao tn th TT phi i bng cp chn trong t.

II.5.122. Khng cho php b tr ct TT, TH di dy dn ca DK 500kV.

Khong cch t nh ct u cp ca TT, TH n dy dn thp nht ca DK 500KV khng nh hn 20m.

Khong cch t ct ca TT, TH dng dy trn n mt phng thng ng ca dy dn ngoi cng ca DK 500kV ly theo tr s tnh ton nh hng nhiu ca DK.II.5.123. Ct DK gii hn khong giao cho vi TT cp I(*), ng dy t ng hoc bn t ng ca ng st, TT hoc TH ca trm iu trung tm phi l ct no. i vi DK in p 35kV tr ln vi tit din dy dn 120mm2 tr ln khi giao cho vi TT th c dng ct .Ghi ch (*): Cn c vo tnh cht quan trng v chnh tr, kinh t, quc phng v thng tin quc t, ng dy trn thng tin ng di chia lm 3 cp:

ng dy cp I: gm nhng ng dy lin lc gia trung ng vi cc thnh ph, th x, khu t tr, khu cng nghip, hi cng quan trng, nhng ng dy lin lc quc t v nhng ng dy quc phng quan trng.

ng dy cp II: gm nhng ng dy lin tnh, lin lc gia cc thnh ph, th x, khu t tr, khu cng nghip vi nhau.

ng dy cp III: gm nhng ng dy ni tnh, lin lc gia tnh vi huyn, gia huyn vi huyn vi th x hoc ng dy lin lc gia cc x nghip vi nhau, gia c quan x nghip n c quan bu in.

II.5.124. Tit din dy dn ca DK trong khong ct giao cho vi TT thuc mi cp v vi TH khng c nh hn:

35mm2 i vi dy nhm li thp hoc hp kim nhm.

70mm2 i vi dy nhm.

Trong khong ct giao cho, dy dn DK hoc dy chng st khng c c mi ni. Dy dn DK c tit din t 240mm2 tr ln c php c mt mi ni trn mi dy dn trong mt khong ct.

II.5.125. Cc ct DK gii hn khong giao cho vi TT hoc TH hoc cc ct k bn chng nm l ng cn c bo v xe c khi va chm.

I.5.126. Trn ct ca TT hoc TH, khong giao cho cng phi t khe h bo v. in tr ni t khng qu 25(.

II.5.127. Trong khong ct giao cho vi TT hoc TH, dy dn ca DK khi dng cch in treo phi mc kha kiu c nh, khi dng cch in ng phi mc kp.

II.5.128. Khong cch thng ng t dy dn ca DK vi dy dn ca TT hoc TH ti ch giao cho trong ch lm vic bnh thng ca DK v khi t dy dn khong ct k khng c nh hn tr s trong bng II.5.8. i vi DK dng dy dn tit din t 185mm2 tr ln, khng cn kim tra theo ch t dy dn khong ct k.

Khong cch thng ng trong ch bnh thng c xc nh theo vng ca dy nhit khng kh cao nht, khng tnh n pht nng do dng in; cn ch s c tnh theo nhit khng kh trung bnh nm, khng c gi.

Bng II.5.8: Khong cch nh nht theo chiu thng ng t dy dn ca DK n dy dn ca TT hoc TH

Ch tnh tonKhong cch (m) theo

in p ca DK (kV)

102235110220

Ch bnh thng23334

Khi t dy khong ct k ca DK dng cch in treo11112

II.5.129. DK in p ti 35kV giao cho vi ng trc truyn thanh th trong khong giao cho, dy truyn thanh nn i bng cp ngm.

II.5.130. Khi DK giao cho ng cp TT hoc TH chn ngm trong t thc hin cc yu cu sau:

a. Khi s dng DK lm ng thng tin cao tn c gii hn tn s t 30 n 150kHz vi thit b thng tin c cng sut ra ca mi mch thng tin ln hn 10W th TT hoc TH phi i bng on cp ngm ni xen vo. Chiu di on cp ni xen c xc nh thng qua tnh ton nh hng ca DK n TT ng thi khong cch ngang t ct u cp TT hoc TH n hnh chiu ln mt t ca dy dn DK gn nht phi khng c nh hn 100m.

b. Khong cch t ng cp TT hoc TH ngm n vt ni t gn nht ca ct DK (nu ct khng ni t th n b phn gn nht ca ct) khng c nh hn tr s trong bng II.5.9.

Trng hp ng cp TT hoc TH ngm t trong ng thp bo v, to mn chn hoc bn ngoi c p st ch U bng chiu di bng khong cch gia hai dy dn ngoi cng ca DK cng thm 10m mi pha, th cho php khong cch bng trn ly bng 5m. Trng hp ly nh hn 5m th phi c tnh ton kim tra.

Khi chn tuyn DK, khong cch t tuyn ti cp TT hoc TH ti ct DK ty iu kin nn ly cng xa cng tt.

Bng II.5.9: Khong cch nh nht t cp TT hoc TH ngm n vt ni t hoc b phn gn nht ca mng ct DK

in tr sut (() ca t ((m)Khong cch nh nht (m)

theo in p ca DK (kV)

Ti 35T 110 tr ln

n 1000,83

10

Trn 100 n 5001025

Trn 500 n 10001135

Trn 10000,35

50

II.5.131. Khi DK i song song vi TT hoc TH, khong cch ngang gia cc dy dn ngoi cng gn nht ca cc ng dy ny cn c vo tnh ton nh hng ca DK n TT hoc TH, nhng khng c nh hn chiu rng hnh lang bo v ca DK (xem iu II.5.96).

Khi ct TT hoc TH phi c ct chng hoc ct kp phng trng hp TT hoc TH b , dy dn ca chng khng th chm vo dy dn ca DK.

Khng quy nh bc o pha dy dn ca DK theo iu kin nh hng khi cc ng dy gn nhau.

II.5.132. Ti ct gc ca DK mc cch in ng i gn vi TT hoc TH, khong cch gia cc ng dy ny phi m bo an ton theo iu II.5.96 khi dy dn ct gc ca DK b t vng ti dy dn ca TT gn nht.

Nu khng c kh nng thc hin cc yu cu trn, cch in ca DK t v pha ngoi phi mc kp.

II.5.133. Khng cho php mc chung ng dy thng tin, tn hiu (tr ng cp quang) trn ct DK in p trn 1kV.

II.5.134. Khi DK i gn vi ng cp TT hoc TH chn trong t phi thc hin cc yu cu trong iu II.5.130.

II.5.135. DK i gn trm pht sng v tuyn in, khong cch nh nht n ct ngten ly theo bng II.5.10.

Bng II.5.10: Khong cch nh nht t DK n ct ngten ca trm pht tn hiu

ng ten phtKhong cch nh nht (m) theo in p ca DK (kV)

n 110220 v 500

Pht sng trung v di100

Pht sng ngn theo hng bc x chnh200300

Pht sng ngn theo cc hng cn li50

Pht sng ngn nh hng yu v v hng150200

Bng II.5.11: Khong cch nh nht t DK n trung tm thu nhn v tuyn in

Trung tm thu Khong cch nh nht (m)


6-35110-220500

Trung tm thu chnh, min v khu vc50010002000

Trung tm thu tch bit4007001000

Trm thu a phng200300400

II.5.136. DK i gn trung tm thu nhn v tuyn in c chia lm nhiu trm v trm thu a phng, khong cch ca DK n gii hn trung tm ly bng tr s trong bng II.5.11.

Cho php DK i gn n c ly 50m vi iu kin mc nhiu lon t trng khng vt qu tr s quy nh ca B Bu chnh Vin thng.

Trng hp thit k tuyn DK qua khu vc c nhng trung tm thu c bit quan trng, cn theo ng quy nh ca c quan hu quan trong qu trnh thit k DK.

Trng hp c bit nu khng thc hin c cc tiu chun i gn, cho php gim bt khong cch t DK n trung tm thu thanh vi iu kin p dng cc bin php nhm bo m gim thp mc nhiu lon n mc cho php.

DK giao cho hoc i gn ng st

II.5.137. Gc giao cho gia DK v ng st khng quy nh, i vi ng st in kh ho (SK) gc giao cho khng c nh hn 40o. Trong mi trng hp, nu c th, th nn chn gc giao cho gn 90o.

II.5.138. Khi DK giao cho hoc i gn ng st, khong cch t chn ct DK n bin hnh lang ca ng st khng in kh ha hoc tm ct ca mng in tip xc ca ng st in kh ho khng c nh hn chiu cao ct cng thm 3m.

Trn nhng on tuyn hp cho php ly khong cch khng nh hn:

3m vi DK in p n 22kV.

6m vi DK in p 35 v 110kV.

8m vi DK in p n 220kV.

10m vi DK in p 500kV.

Ti on tuyn ny, khng c php t ct c dy no.

Cho php gi li ct ca mng tip xc SK di DK nu khong cch t dy dn ca DK n nh ct ca mng tip xc khng nh hn:

7m i vi in p n 110kV.

8m i vi in p n 220kV.

9m i vi 500kV.

Trng hp c bit, trn on tuyn hp cho php mc dy dn ca DK v dy dn ca mng in tip xc trn ct chung. iu kin k thut thc hin vic mc chung phi tha thun vi c quan ng st.

II.5.139. Khi DK giao cho hoc i gn ng st, khong cch t dy dn n mt ray hoc bin hnh lang ca ng st khng c nh hn tr s trong bng II.5.12.

vng ln nht ca dy dn nhng ch giao cho vi ng st cng cng v SK c xc nh trong ch bnh thng khi nhit khng kh cao nht cng vi nh hng ca s pht nng dy dn do dng in. Trng hp khng c s liu v ph ti ca DK th nhit dy dn ly bng 70oC.

Trong ch s c, khong cch trn c kim tra nhit trung bnh nm, khng c gi.

Khi DK giao cho hoc i gn ng st, dc theo ng st c TT hoc TH th ngoi bng II.5.12 cn phi theo cc yu cu trong iu II.5.120 n II.5.131.

Bng II.5.12: Khong cch nh nht khi DK giao cho hoc i gn ng st.

Cc trng hp giao cho hoc i gnKhong cch nh nht (m)


n 2235-110220500

1. Khi giao cho, tnh t dy dn n mt ray trong ch bnh thng ca DK7,57,58,512

2. Khi i gn, tnh t dy dn ca DK n kh gii hn xy dng ca ng st khi dy dn b gi lm chao lch nhiu nht1,52,52,54,5

3. Khi giao cho vi SK v mng tip xc trong ch bnh thng ca DKNh cc DK giao cho vi nhau, xem bng II.5.7

4. Nh mc 3, vi trng hp t mt dy khong ct k1123,5

II.5.140. Khi DK giao cho vi ng st cng cng v SK, ct phi l kiu no, cch in phi mc kp.

Khi DK giao cho vi nhiu ng st thng xuyn khng c tu khch qua li th trong khong giao cho gii hn bng ct no c php t thm ct . Dy dn nhng ct ny phi mc bng kha kiu c nh.

Trng hp giao cho vi ng st chuyn dng cho php dng ct , dy dn mc bng kha kiu c nh.

Cm s dng ct thp ca ct v ca mng btng ct thp ti ch vt lm vt ni t.

II.5.141. Tit din ca dy dn khi giao cho vi ng st khng nh hn:

35mm2 i vi dy nhm li thp v hp kim nhm.

70mm2 i vi dy nhm.

Dy dn hoc dy chng st khng c c mi ni trong khong ct giao cho.

II.5.142. Khi DK giao cho vi ng st c trng cy bo v dc hai bn ng th phi thc hin cc yu cu trong iu II.5.98.

DK giao cho hoc i gn ng t

II.5.143. Gc giao cho DK vi ng t khng quy nh.

II.5.144. Khi DK giao cho vi ng t cp I, cc ct gii hn khong giao cho phi l ct no, cch in phi mc kp; khi giao cho vi ng t t cp II n cp V (*) c th dng ct mc dy bng kha kiu c nh, nu dng cch in ng th phi mc kp.

Ghi ch (*): Cn c vo Tiu chun thit k ng t theo TCVN 4054-1985, cc cp k thut ng t, tuyn ng t c phn nh thnh cc cp k thut vi ch tiu ch yu quy nh theo bng II.5.13.

II.5.145. Tit din dy dn ca DK khi giao cho ng t cp I, II theo iu kin bn c hc khng c nh hn 35mm2 i vi dy nhm li thp v hp kim nhm, 70mm2 i vi dy nhm.

Dy dn hoc dy chng st khng c c mi ni trong khong DK giao cho ng t cp I, II.

i vi dy dn tit din t 240mm2 tr ln c php c mt mi ni cho mi dy.

Bng II.5.13: Cp k thut ng t

Cc ch tiu ch yuCp k thut ng t

a hnhIIIIIIIVVVI

Tc tnh ton, km/hng bng12010080604025

Min ni-8060402515

S ln xeng bng2-42-42211

Min ni-22211

B rng mt ng, mng bng15,07,57,06,03,53,5

Min ni-7,06,05,53,53,5

B rng nn ng, mng bng26,013,512,09,06,56,0

Min ni-13,09,07,56,56,0

II.5.146. Khong cch khi DK n 220kV giao cho hoc i gn ng t khng c nh hn cc tr s trong bng II.5.14.

vng ln nht ca dy dn xc nh trong ch bnh thng ca DK khi nhit khng kh cao nht v khng tnh n s pht nng do dng in.

Trong ch s c, khong cch trn kim tra nhit trung bnh nm, khng c gi.

II.5.147. Ct DK st ng t phi c bo v xe c khi va vo.

II.5.148. Khong cch DK 500kV giao cho hoc i gn ng t (k c on cong ca ng t) khng c nh hn cc tr s sau:

a. Khong cch theo chiu thng ng:

T dy dn n mt ng: 10m

T dy dn n phng tin vn ti: 5,5m

b. Khong cch theo chiu ngang t bt c b phn no ca ct n mp nn ng khi giao cho v song song: 10mBng II.5.14: Khong cch nh nht khi DK n 220kV giao cho hoc i gn ng t

Cc trng hp giao cho hoc i gnKhong cch nh nht (m)theo in p ca DK (kV)

n 2235-110220

1. Khong cch thng ng t dy dn n mt ng:

a. Trong ch bnh thng:778

b. Khi t mt dy dn khong ct k (i vi dy nh hn 185mm2):555,5

2. Khong cch ngang t b phn bt k ca ct ti l ng:

a. Khi giao cho ng t cp I v II:555

b. Khi giao cho ng t cp khc:1,52,52,5

c. Khi DK i song song vi ng t, khong cch t dy dn ngoi cng n l ng lc dy dn trng thi tnh:246

DK giao cho hoc i gn ng xe in hoc t in

II.5.149. Gc giao cho gia DK vi ng xe in hoc t in khng quy nh.

II.5.150. Khi DK giao cho vi ng xe in hoc t in, trong khong ct giao cho phi dng ct no. Vi DK c tit din dy dn 120mm2 tr ln cho php dng ct .

II.5.151. Tit din ca dy dn DK giao cho vi ng xe in hoc t in khng c nh hn:

25mm2 i vi dy nhm li thp, hp kim nhm.

35mm2 i vi dy nhm.

Dy dn hoc dy chng st khng c c mi ni trong khong giao cho, tr dy dn c tit din 240mm2 tr ln c php c mt mi ni cho mi dy.

II.5.152. Trong khong ct giao cho vi ng xe in hoc t in, nu trn ct ca DK dng cch in treo mc dy dn n th ch c dng kha c nh, khi DK c phn pha t 3 dy tr ln c php dng kha trt, khi dng cch in ng phi mc kp.

Bng II.5.15: Khong cch nh nht t DK khi giao cho hoc i gn ng xe in hoc t in

Trng hp giao cho hoc i gnKhonh cch nh nht (m)theo in p ca DK (kV)

n 110220500

1. Khong cch thng ng t dy dn

ca DK:

a. Khi giao cho vi ng xe in (trong ch bnh thng):

+ n mt ng ray:10,511,515

+ n dy dn ca mng tip xc:345

b. Khi t mt dy dn ca DK trong khong ct k, n dy dn ca mng tip:12-

c. Khi giao cho ng t in (trong ch bnh thng):

+ n im cao nht ca phn ng i li111213

+ n dy dn ca mng tip xc345

2. Khong cch ngang t dy dn khi b gi lm lch nhiu nht n ct ca mng tip xc:345

II.5.153. Khong cch khi DK giao cho hoc i gn ng xe in hoc t in khi dy dn c vng ln nht khng c nh hn tr s trong bng II.5.15.

vng ln nht ca dy dn xc nh trong ch bnh thng theo nhit khng kh cao nht v khng tnh n s pht nng do dng in.

Trong ch s c, kim tra khong cch nhit trung bnh nm khng c gi.

II.5.154. Cho php gi li ct ca mng in tip xc i di dy dn ca DK khi khong cch thng ng t dy dn ca DK n nh ct ca mng in tip xc khng nh hn:




DK i qua cu

II.5.155. on DK i qua cu hoc i qua phn quay ca cu phi l ct no hoc l kt cu kiu no. Tt c cc phn khc trn cu c th l kt cu trung gian mc dy bng kha kiu c nh, cch in phi mc kp.II.5.156. Trn cu kim loi cho ng st, c ng i di, nu sut chiu di u c b phn ging trn, cho php t dy dn ca DK trc tip vo nhp cu pha trn hoc ngoi gii hn ca khung cu.

Khng c php b tr dy dn trong hnh lang c b tr li in tip xc ca ng st in kh ha.

Trn cu trong thnh ph hoc cu ng t, c php t dy dn ca DK pha ngoi cc kt cu ca cu cng nh trong phm vi chiu rng ca phn ng i b v xe c.

II.5.157. Khong cch nh nht t dy dn ca DK n b phn ca cu phi ly theo s tha thun vi c quan giao thng vn ti, vng xc nh nhit khng kh cao nht.

DK i qua p hoc

II.5.158. Khi DK i qua p hoc , khong cch t dy dn khi vng ln nht v b lch nhiu nht n b phn ca hoc p khng c nh hn tr s trong bng II.5.16.

Khi DK i qua p dng lm phng tin giao thng th cn phi theo cc yu cu nh khi DK giao cho hoc i gn cc cng trnh tng ng.

vng ln nht ca dy dn xc nh nhit khng kh cao nht.

Khong cch ngang ti thiu t mng ct n chn thc hin theo Php lnh bo v iu hin hnh.

Bng II.5.16: Khong cch nh nht t DK n cc b phn ca , p

Tn gi b phn ca , pKhong cch nh nht (m)


n 110220500

n mt hoc ch nh cao ca

n b dc ca

n mt nc trn qua p6

5

47

6

510

8

7

II.5.159. Khi t ct DK trong hnh lang bo v ca p phi c s tha thun gia c quan qun l , p v c quan in lc nhm bo m an ton cho p v ph hp vi cc iu kin kinh t k thut ca DK.

DK giao cho hoc i gn ng dn trn mt t hoc

ng cp vn chuyn trn khng

II.5.160. Gc giao cho gia DK vi ng dn trn mt t hoc ng cp vn chuyn trn khng khng quy nh.

II.5.161. Khi DK giao cho vi ng ng dn trn mt t hoc ng cp vn chuyn trn khng, ct DK trong khong giao cho phi dng ct no. i vi DK in p tit din dy dn 120mm2 tr ln cho php dng ct .

Cm treo li bo v vo ct DK.

II.5.162. Dy dn ca DK phi vt bn trn ng ng dn hoc ng cp vn chuyn trn khng. Trng hp c bit cho php DK ti 110kV i di ng cp vn chuyn trn khng nhng phi c cu hoc li bo v cho dy dn ca DK.

Tit din dy dn ti ch giao cho khng c nh hn:

35mm2 i vi dy nhm li thp v hp kim nhm.

70mm2 i vi dy nhm.

Trong khong ct giao cho, dy dn DK khng c c mi ni. Dy dn DK c tit din t 240mm2 tr ln c php c mt mi ni trn mi dy dn trong mt khong ct.

II.5.163. Trn ct DK, trong khong giao cho phi dng cch in treo, kha phi dng kiu c nh, khi dng cch in ng phi mc kp.

II.5.164. Trong ch bnh thng, khong cch ngang t dy dn khi lch nhiu nht v khong cch thng ng khi vng dy dn ln nht n b phn bt k ca ng dn hoc ca ng cp vn chuyn trn khng khng c nh hn:


4m i vi DK in p n 35 - 110kV.


II.5.165. nhng ni DK 500kV giao cho vi ng ng dn kh ni, t trn mt t hoc ng cp vn chuyn trn khng (tr nhng ng ng chn trong t) cn c bo v bng hng ro. Hng ro cn phi nh ra vi khong cch l 6,5m theo hai hng tnh t hnh chiu ca dy dn ngoi cng ca DK 500kV khi lch dy dn ln nht.

II.5.166. Khong cch khi giao cho hoc i gn hoc song song gia DK 500kV vi ng ng ni, khng c nh hn cc tr s sau:1. Khong cch theo chiu thng ng t dy dn ca DK 500kV n bt c phn no ca ng ng ch bnh thng: 6,5m2. Khong cch theo chiu ngang:

a. Khi i song song vi nhau:

T dy dn ngoi cng n bt c phn no ca ng ng (tr ng ng chnh dn du v sn phm du) ch bnh thng: khng nh hn chiu cao ca ct.

T dy dn ngoi cng n bt c phn no ca ng ng chnh dn kh ch bnh thng: khng nh hn hai ln chiu cao ca ct.

T dy dn ngoi cng n bt c phn no ca ng ng chnh dn du, sn phm du ch bnh thng: 50m nhng khng nh hn chiu cao ct iu kin cht hp t dy dn ngoi cng n bt c phn no ca ng ng khi lch dy dn ln nht: 6,5m.

b. Khi giao cho:

T ct DK 500kV n bt c phn no ca ng ng ch bnh thng: khng nh hn chiu cao ca ct.

iu kin cht hp, t ct ca DK 500kV n bt c phn no ca ng ng: 6,5m.

II.5.167. Trong khong giao cho vi DK, ng ng dn kim loi, cu, li, hng ro kim loi v ng cp vn chuyn trn khng phi ni t bng h ni t nhn to ph hp vi quy phm ni t. in tr ni t khng c ln hn 10(.

DK giao cho hoc i gn ng dn chn trong t

II.5.168. Gc giao cho gia DK cp in p ti 35kV vi ng dn chn trong t khng quy nh; gia DK 110kV tr ln vi ng ng chnh dn kh, du v sn phm du khng c nh hn 60o.

II.5.169. Cc ng dn hi trc chnh c p sut trn 1,2MPa v ng dn du chnh (hoc sn phm du) phi t ngoi hnh lang bo v ca DK.

Trong iu kin cht hp, khi cc tuyn DK i song song, cng nh nhng ch DK giao cho vi cc ng dn trn, khong cch cho php t mp mng hoc b phn ni t gn nht ca DK n mp ng dn nh sau:


10m i vi DK in p 110 - 220kV.


II.5.170. Khi DK giao cho, i gn cc ng hi c p sut 1,2MPa tr xung, ng dn du v sn phm du hoc cc ng dn khc, khong cch t mp mng hoc b phn ni t gn nht ca DK n mp cc ng dn k trn khng nh hn:


10m i vi DK in p 110kV tr ln.

on ng dn i trong hnh lang bo v ca DK, phi kim tra tt c cc mi hn ca ng dn chnh p sut 1,2MPa tr xung bng phng php vt l.

II.5.171. DK 500kV phi xy dng cch xa vi kh x t 300m tr ln.

II.5.172. Khi DK 500kV giao cho hoc i gn ng ng nc, h thng thi nc (c p lc t chy), x nc th khong cch chiu thng t b phn ni t gn nht v phn mng ct DK gn nht v phn mng ct DK 500kV ti ng ng khng c nh hn 3m.DK i gn cng trnh cha cht chy n

II.5.173. DK i gn nh v cng trnh c cha cht chy n, phi thc hin ng cc tiu chun k thut, quy phm v an ton phng n, phng chy cha chy hin hnh.

i vi nhng cng trnh khng ni trong quy phm hin hnh, khong cch ni trn khng c nh hn 60m.DK i gn ngn la t du v kh

II.5.174. Khi i gn ngn la t du v kh th khong cch nh nht t DK n ngn la l 60m.

DK i gn sn bay

II.5.175. Xy dng DK i gn sn bay phi c s tha thun vi c quan hng khng khi:

Khong cch t DK ti gii hn ca sn bay n 10km vi ct cao bt k.

Khong cch t DK ti gii hn ca sn bay t 10 n 30km v cao tuyt i ca nh ct DK cao hn cao tuyt i ca sn bay t 50m tr ln.

Khong cch t DK ti gii hn ca sn bay trn 30 n 75km v DK c ct cao t 100m tr ln.

Quy phm trang b in

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