presentation1_2495

8/13/2019 presentation1_2495

1/34

Thc hin: Phan Hp Thng


2/34

Mt s khi nim

H thng ni t:

Cc tip a

H thng ni t t nhin H thng ni t nhn to

H thng ni t lm vic

H thng ni t bo v

.


3/34

cimcaqu trnh phn tn

dng introng t.

Phn bdng chmt.

d

dd

X

IU

..2

.

d

dd

X

IU

..2

.

d

dd

XIU

..2.

Xd: Bn knh bnccId: dng int.


4/34

Vai tr ca bo v ni t.

To mch c in dnln

Gim phn lng dngin qua ngi

Rd

Rdn

Rng

Rph

Id

Rtd

Rdn

Rph

Id

dng

dd

ng

tddng

RR

RI

R

RII

..

S thay th .


5/34

Cu trc bo v ni t.

Hnh.Cc loi h thng ni t

a) Ni t ngoi bin;

b) Ni t bao quanh.

a)

b)

.in p tip xcUtx1- h thng ni t ngoi bin;

Utx2- h thng ni t bao quanh.

Cctipa Thanh ni

Utx2

Utx1


6/34

Tnh ton ni t.

Tnh ton nittheo intrnityu cu(Ryc)

1.Trnh ttnh ton ivitngnht:

a)Xc nhintryu cucahthngnit

()

Trong

Iddng inngnmchchytrong t, A;

UL - inp tnh ton c gi trULUcp;

Ucp- gi trcp tipxc cho php

d

Lyc

I

UR


7/34

Tnh ton ni t.1.Trnh t tnh ton i vi t ng nht:

b)Xc nh in tr ni t nhn to

()

Trong :

Rn.tao- in tr ca h thng ni t nhn to;

Rtn- in tr ca h thng ni t t nhin.

yctn

yctn

taonRR

RRR

..


8/34


c)Chn in cc tip a v xc nh in tr

(Xem bng ph lc)

d)Xc nh s lng in cc cn thit khi cha tnhn thanh ni ngang

taon

dc

R

Rn

.

1
http://localhost/var/www/apps/conversion/tmp/scratch_1/sc/Bangphuluc1.doc


9/34


e) Xc nh in tr ni t nhn to(c thanh ngang)

Rnga- in tr ca thanh ni ngang c tnh n h s sdng.

:in tr thanh ni ngang.

: h s s dng (la/l v n)

taonnga

taonngataon

RRRRR

.

..

'.''

nga

nganga

RR

'

ngaR

nga


10/34


S b tr cc

la lal


11/34


f) Xc nh s lng in cc chnh thc:

Vi dc- h s s dng ca cc in cc

g) Kim tra k n nh ca h thng:

k n nh:

FminFnga

taondc

dc

R

Rn

.'.

C

tIF k

dmin


12/34

Tnh ton ni t.2) Tnh ton ni t trong trng hp c hai lp

t khc nhau.

in tr cc c tnh:

kkdn- h s khng ng nht

n: s thanh ngang.

))1(2

2ln.

.4.(ln

)1.2

.(1

1

..2 1

1

nhl

hnlk

d

l

l

hk

k

lR

n

n

kdn

kdn

kdndc

12

12

kdnk


13/34

Tnh ton ni t.2) Tnh ton ni t trong trng hp c hai lp

t khc nhau.

Cng thc gn ng

sai s di 3% nu t l l/h >6, sai s c th t n 15% nu t l l/h =1,5

d

l

lhlh

lRdc

.4ln

)).(

.(.221


14/34

Tnh ton ni t.2) Tnh ton ni t trong trng hp c hai lp t

khc nhau.

Biu xc nh su cc

2/R= 5

3

2

10,1

0,01

30

25

20

15

10

2

/1

= 0,75

0,5

0,3

0,2

0,1

0,01

0,00160

50

40

30

20

10

h,m 5,0 4,0 3,0 2,0 1,0 0 1,0 2,0 3,0 4,0 5,0 hs,m

A


15/34

Tnh ton ni t.

3)Tnh ton ni t theo in p tip xc v in pbc cho php:

Bc 1: xc nh tng chiu di ca cc in cc. L=2.n.D

Bc 2: dng s c chm mass (coi Z1= Z2)

- Xc nh tit din thanh dn: F= F0.Ik

ng knh thanh dn:

021

.3

ZZZ

U

I

ph

k

012

.3

ZZ

U

Fd

4


16/34

Tnh ton ni t.3)Tnh ton ni t theo in p tip xc v in

p bc cho php:

Biu xc nh

kch thc thanh dn

F0

0,1 0,2 0,3 0,5 1,0 2,0 3,0 5,0 10 20

20

25

30

40

50

50

40

30

20

100

200

400

600

800

1000

10

5

2,5

1,0

100

80

6040

20

10

5

4

3

2

1

A/mm2 mm2/kA Kch thc thanhdn ngang mils/A

NO.304 steel

30%CCS

97% Cu (2500C)

97% Cu (.thau)40%CCS

tk, sec

97% Cu & 100% Cu (thau)


17/34


p bc cho php:

Bc 3 Gi tr cho php ca in p bc:

Gi tr cho php ca in p tip xc:

k

BSSbSng

cpbt

kCbRU

)..( ..

k

BSStxSng

cptxt

kCbRU

)..( ..

Trong :

Cs : hssuygimhs: dy lpvn


18/34


p bc cho php:

: h s khng ng nht

Hoc Cs c x theo CT:

n s lng thanh ngang song song

b bn knh tng ng ca bn chn

0 0,04 0,08 0,12 0,16 0,20 0,24

1,0

0,8

0,6

0,4

0,2

kkdn=-0,1

-0,2

-0,3

-0,4

-0,5

-0,6

-0,7

-0,8

-0,9

kkdn=0

hS, m0

CS

kdnk

12

12

kdnk

1

]2)/.2(1

21[96,0

1

n S

nB

Sbhn

kC


19/34


p bc cho php:

Bc 4:Xc nh in tr ca h thng ni t

Bc 5 : dng th t:

Edng= Id. Rluoi

Nu Edng< Utx.cpth bi ton kt thc,nu ngc lith tip tc lm bc 6

)]/20.1

11(

.20

11[

ndnd

luoiFhFL

R


20/34

Tnh ton ni t.3)Tnh ton ni t theo in p tip xc v

in p bc cho php:

Bc 6: Xc nh in th li:

H s hnh hc ca h thng ni t

h s hiu chnh theo su:

Nu Eluoi> Utx.cp, th cn phi b sung thm in cc

L

kkIE imdluoi

...

]

)1.2(

8ln)

4.8

)2(

..16

[ln(

2

1 22

nk

k

d

h

dD

hD

dh

Dk

h

ii

m

0

1h

hk

h

Trong : intrsutcatL: tngchiudi ccnithtkm:Hshnh hccaht nitki: hshiuchnhk

i=0,656+0,172n

n - l sthanh dnni//khhshiuchnhtheo suh0- chiusu tlinitnmtt


21/34


p bc cho php:

Bc 7:Xc nh in p li

LTtng chiu di ca cc cc tip a: LT =Lng+ 1,1.Lc Lngtng chiu di cc in cc nm ngang

Lc- tng chiu di cc cc tip a thng ng.

NuEli< Utx.cp th bi ton kt thc, cn trong

trng hp ngc li th lp li php tnh

T

imdluoi

L

kkIE

...


22/34


p bc cho php:

Bc 8

Xc nh in p bc tnh ton:

kSl h s hnh hc ca li ni t:

Nu Ub.tt< Ub.cpth coi nh h thng ni t t yucu, trong trng hp ngc li, cn b sung cc cctip a v lp li php tnh

T

iSdttb

L

kkIU

....

])5,01(11

2

1[

1 2

n

S DhDhk


23/34

o in tr ni t1) Phng php o in tr sut ca t

a) thc hin theo phng php 4 cc(phng php Wenner)

in tr sut ca t c xc nh:=2.a.R, .m

Trong

+ - in tr sut ca t, .m ;

+ a - khong cch gia cc cc thm d, m;

+ R in tr hin th trn thit b o,


24/34


a) phng php 4 cc:

S u dy:

S o in tr sut ca t theo phng php 4 cc


25/34

o in tr ni t 1) Phngphp ointrsutcat

b) Phngphp 3 cc

S o in tr

Vng nhhng

Vng nhhng

Vng nh hng

Vng nh

hng

Vng nhhng

HE

S

S

o ln 2

o ln 1

Vng nh hng

Vng nh hng

Vng nhhngVng nh hng

Vng nh hng

Vng nh hng


26/34


c)Phng php hai cc

Trong trng hp khng

th, hoc rt kh mc cc

cc tip a. Cc thit b

o HANDY GEO, SATURN

GEO, UNILAP GEO chophp thc hin php o

hai cc ca in tr hoc

mch vng S mch o


27/34


c) Phng php khng dng in cc

S o in tr ni t


28/34


Phng php khng dng in cc Khong cch t in cc

S o in tr ni t

bng Amper km

ng cho

ca HTN

kiuli

Khong cch

caccthmd

inp P2/S

Khong cchca cc nit ph C2/H

20 30 50

25 50 80

30 70 100

50 100 170

70 130 200


29/34

o in tr ni t 2) o in tr ni t ca cc thit b ang hotng

a)o in tr ni t mch vng

S o in tr n mch vng


30/34


b)o in tr ni t ca ct in cao th

S o in tr ni t ct cao th.


31/34


b)o in tr ni t ca ct in cao th

S o in tr ni t ln lt tng chn ca ct cao th.


32/34


c)o in tr ni t ca trm bin p

o in tr ni t ca trm bin p


33/34

Cc binphp gimintrca

hthngnit S dng cc in cc tip a tng cng

S dng cc dung dch ha cht


34/34

Mt s hnh nh v ni t

Documents

presentation1_2495