Tnh toan bao ve chong qua dien ap khi quyen cho tram bien ap 220/110kV ppt

 !"!#$
CHƯƠNG 1
TÍNH TOÁN BẢO VỆ CHỐNG SÉT ĐÁNH TRỰC TIẾP
VÀO TRẠM BIẾN ÁP 220/110 kV
1.1. Mở đầu
%&&'()*+),-.
/0,%12()*+345#6)'
778370
9:;1<=4<>7#1
35?.,*@')()4-AB%:7
CD)#E=0FGHIH
E-#0J',8=:,7)8)
*0
95<*KL&)%E
K.,0KMN*,%')51:
3')317K:*#)
*1,0
O)3K.,1*5KPKIQ#)
G095.*KMN*,;1HGN*&
')NB5KI&*G>*#3
KI()*;7&')#EN%:5.,3
=1830R*##
*8()*.S7)#*=%T
6()*U5N*0
1.2. Các yêu cầu đối với hệ thống chống sét đánh thẳng
V7)8):N*%G
18W+*N*0
9: !#$*KL&)%E>I:<K., !#$*KL
K.,0
9: !#$32*>K33541
)7#G)N*0#G)3XGN*

Y<XG*KI#),G
YZ[*G:>4#3GU)5
1N*HG0
\.),)G.<%)&K.,,>;',
#KL&)%E5,;,7)8)#@*5
&)%E5GN*B,%:]0
KK.,KPKIN%:5U1#
3KI,()*0
FR),^$_`O9`#] $9`<9+a\*OR&

 !"!#$
9:K.,*YK+Y-)KN*<K.,4
*<K.,=0
1.3. Phạm vi bảo vệ của cột thu sét và dây chống sét
1.3.1. Phạm vi bảo vệ của cột thu sét
`9&*&)%E

 
  
= +
A0D
3
b
9&*'=

*
9&*KMN*&)%E>=b1YQ3&
A
*
≥J"c>J%<I*S%.&D

`dN*&)%E&%'%
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A D

 

  


= −
+
   A0 D
 `R)
b
≤ "Z;
D
c>!
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
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

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−=
 A0ZD
`R)
b
f "Z;
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`dN*-)&%:Q&&%0R5
@*&;#@**&h*≤g0\3 &)
%E48*);H&*%:G@* &%
!
=b1
YE2
g


 
= −


A0]D

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!
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b

E2A0ZDA0[D
FR),^$_`O9`#] $9`<9+a\*OR&

 !"!#$

0,2h
0
0,75h
a
R


r
x
r
o
x
1,5h
h
x
h
0
h
r
x
Hnh 1.1.
`<=*&)%E3&*#*);b1
*)
`\&)%E_a3&*



;?K:.,
0,2h
2

0,8h
2
0,8h
1
h
1
0,2h
1
h
o
h
2


Z
a'
x
a
0,75h
0,75h
1
1,5h
1
2
1,5h
2
Hnh1.2.
`aWi1b34&)%E3&*

>#3#

_aj*>aj*k0\3b1=#b*k*)

( )
( )



l



0
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e>
0
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e>








−
+
−=−=
−
+

=
A0eD
FR),^$_`O9`#] $9`<9+a\*OR&
Z
 !"!#$
1.3.2. Phạm vi bảo vệ của một nhóm cột thu sét
m&3&?;*=b1H
&-*8:*N*QE&
a
b
c
D
a
b
D
Hnh 1.3. !"
$'3&*
b
W*;H&)?=
)h-)#
J
≤

*
jc0A`
b
D 
A0gD
$:J%<I*;H&)0
Chú ý:

\&*N*&%:Z!;-)#8=)SY
J
≤

*
0jc0A`
b
D0  
A0cD
1.3.3. Phạm vi bảo vệ của dây thu sét
dN*K.,=5;?

h
x
1,2h
0,6h
h
x

h
0,2h
J.,
Hnh 1.4. !"#$%&'(
FR),^$_`O9`#] $9`<9+a\*OR&
[
 !"!#$
-)&N*=YE2*)
`\
b
f;

DAe>!





−=

 
A0nD
`\b≤;
D
c>!
A >





−=
 
A0!D
dK+Y-)K<K.,;?

C
B
A
α

2

α

1

Hnh 1.5.) !"#$%&'(
35=3:α%Z!
!
<%G,#
αj !
!
÷ ]
!
1.4. Mô tả đối tượng bảo vệ
` !#$"!#$>o*,__
`-)& !
`-)K !
`b*!#$*c>b* !#$*g0
`Fo4W;?
FR),^$_`O9`#] $9`<9+a\*OR&
]
!"!#$
210
120
5
5
8x17=1366
5
5
15x10=150

4
4.5
5
13
14
8.5
6.5
5
5
21
AT1 AT2
27
13
7
25.5
33.5
7
16
4
4
912
Hình 1.6. Mặt bằng trạm biến áp 220/110 kV
17m
17m 17m 17m 17m17m
17m
17m
17m 17m17m
17m 17m 17m
11m 11m
11m

11m
11m 11m 11m 11m 11m
11m 11m 17m 11m 11m
Bể n ớc
Trạm bơm
cứu hỏa
Nhà
điều khiển
Nhà QLVH
TN2
TN1
Bể dầu sự cố
AT1 AT2
8m
FR),^$_`O9`#] $9`<9+a\*OR&
e
!"!#$
1.5. Tớnh toỏn, la chn cỏc phng ỏn bo v chng sột ỏnh thng
cho trm bin ỏp
1.5.1. Phng ỏn 1
Hình 1.7: Sơ đồ bố trí các cột thu lôi của ph ơng án 1
4
4.5
AT1 AT2
4
4
11m
17m 17m 17m 17m17m
17m
11m

17m
11m
17m
11m 11m 11m
11m 11m
11m
11m
11m 11m 11m 11m 11m
11m 11m 11m 11m 11m
Bể n ớc
Trạm bơm
cứu hỏa
Nhà
điều khiển
Nhà QLVH
TN2
TN1
Bể dầu sự cố
AT1 AT2
8m
1 2 3 4 5
6
7
8
9
10
11
12
13
14

15
16 17 18 19 20 21
22 23 24 25 26 27
8m 8m 8m 8m 8m
FR),^$_`O9`#] $9`<9+a\*OR&
g
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`d*!#$ &
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d* !#$
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
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-)#
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3
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≥
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AZp[pnpcD>A[p]p!pnD%

Z[ g Zc>!A D3 
= + =
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Z[ Z[ [c>!cA D3 
= + =
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Zc>!
[>g]A D
c c
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3
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Bảng 1.1.7#2"'(

FR),^$_`O9`#] $9`<9+a\*OR&
c
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40.**56
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ZD>Acpnp ]p [D>Anp !p ep ]D>A !p p gp eD%

Z! Z!>] [ >gcA D3 
= + =
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[ >gc
]>Z]A D
c c

3
 
= = =
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Bảng 1.2.7#2"'(
qDr@*! !#$
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= − − −
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
8
9
=
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A D


3 
8
=
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n
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[Z>n]A D

  
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+ + + +
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[Z>n]0A[Z>n] Z!DA[Z>n] ZZ>eDA[Z>n] [>ZD Z]Z> A D8 
= − − − =
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= + = + =
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a#H&*c


c 0g>] >eg

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= < = =
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c
c
>]0g>]0A D > ]A D
!>c0g>]
 
= − =
a#H&*
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Z Z

 
= < = =
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!>c0g>]
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Phạm vi bảo vệ ở độ cao 8m
Phạm vi bảo vệ ở độ cao 17m
Phạm vi bảo vệ ở độ cao 11m
r=14,625m
r=4,875m
r=5,625m
r=11,25m
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cứu hỏa
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1 2 3 4 5
6
7
8
9
10
11
12
13 14
15
16 17 18 19 20 21
22 23 24 25 26 27
Hình 1.8: Sơ đồ phạm vi bảo vệ của ph ơng án 1
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#<I*()*.&J
9&*KMh-)#
c
3


≥

40.56
9<#<I;@'Ap p]peD>A pZpepgD>
AZp[pgpcD%


] Z[>] e>]gA D3 
= + =
9&*KM5)N*&,%
e>]g
g>gA D
c c

3
 
= = =
9<#<I;@'A]pepnp!D>Aepgp!pD>
Agpcpp D%


] g ]Z>geA D3 
= + =

9&*KM5)N*&,%
]Z>ge
e>g A D
c c

3
 
= = =

*3#()%)*)
Bảng 1.7. 7#2"'(
FR),^$_`O9`#] $9`<9+a\*OR&
]
 !"!#$
40.**56
9<#<I;@'AZp[pcpnD%

Z! Z!>] [ >gcA D3 
= + =
9&*KM5)N*&,%
[ >gc
]>Z]A D
c c

3
 
= = =
9<#<I;@'A]pep p !D>Aepgp p
D

>] [! []>cnA D3 
= + =
9&*KM5)N*&,%
[]>cn
]>g[A D
c c

3
 

= = =
s<#<I*A[p]pnD>A]pnp !D*
G,
$:%i*)p*>>%pF>tJ%8%=%K>#
<#<I*0
uKME2EF>*3

A DA DA D8       
= − − −

[

8
9
=
F),*
A D


3 
8
=
s*A[p]pnD3
Z!>] []>cn [!>c
]c>eA D

  
 
+ + + +
= = =

]c>e0A]c>e Z!>]DA]c>e []>cnDA]c>e [!>cD e!>!gA D8 
= − − − =
Z!>]0[]>cn0[!>c
[e>cA D
0e!>!g

3 
8
= = =
9&*KM5)N*&,%
FR),^$_`O9`#] $9`<9+a\*OR&
e
 !"!#$
[e>c
]>c]A D
c c

3
 
= = =
*3#()%)*)
Bảng 1.8. 7#2"'(
40)>**5A56
s<#<I*Ap pgD>ApgpeD>
Ap!peD>A]pep!D>A]p!pnD>A]p[pnD*G,
$:%i*)p*>>%pF>tJ%8%=%K>#
<#<I*0
uKME2EF>*3


A DA DA D8       
= − − −

[

8
9
=
F),*
A D


3 
8
=
s*Apgp D3
]!>g Z[ Z
]c>Z]A D

  
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+ + + +
= = =

]c>Z]0A]c>Z] ]!>gDA]c>Z] Z[DA]c>Z] Z D ]Z]>g8 
= − − − =
]!>g0Z[0Z
]>][A D
0]Z]>g


3 
8
= = =
9&*KM5)N*&,%

]>][
e>[[A D
c c

3
 
= = =
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Bảng 1.9. 7#2"'(
FR),^$_`O9`#] $9`<9+a\*OR&
g
 !"!#$
R',*35%G,&*KM)&%c
9&*&)%E*!#$%
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 
   
= + = + =
9&*&)%E* !#$%
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= + = + =
0 !":;
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a#H&*
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Z Z

 
= < = =
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l
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= − =
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

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
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l
g
g
!>g]0 ]0A D e>!!A D
]

 
= − =
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a#H&*c


c 0n  >eg
Z Z

 
= < = =
7
c
c
>]0n0A D Z>]!A D
!>c0n
 
= − =
a#H&*


 0n  >eg
Z Z

 
= < = =
7


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!>c0n
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!
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g g
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c 0[>g n>c
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]
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l
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= − = − =
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l
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[e>[
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Z Z
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
!

 0 >Zg c> ]
Z Z
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!>g]0 >Zg0A D >!ZA D
 >Zg

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= − =
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- &%-#-*!#$
Bảng 1.10+-. !"1.**56
FR),^$_`O9`#] $9`<9+a\*OR&
n
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`&* !#$
Bảng 1.11+-. !"1.56
`&3&*#*)@**!#$ !#$
Bảng 1.12+-. !>1
*+,++? !"/
R'b*G,G1-)=0
U&% &0
U  -)  K    &  %
!0A ] gD 0A ] D c0An D 0An cD n[A D@ 
= − + − + − + − =
1.6. So sánh và lựa chọn phương án
 *G, -)=10*
-)=1>K3U-)
FR),^$_`O9`#] $9`<9+a\*OR&
!
 !"!#$
K&%: 7b,7)8)-##6)'*%*+
 %#E0
FR),^$_`O9`#] $9`<9+a\*OR&

!"!#$
r=13,5m

r=7,88m
12
r=16,88m
r=6m
AT1 AT2
Bể n ớc
Trạm bơm
cứu hỏa
Nhà
điều khiển
Nhà QLVH
TN2
TN1
Bể dầu sự cố
AT1 AT2
1 2 3 4
5
6
7
8
9
10
11
13 14
18 19 20
15
21 22
16 17
Phạm vi bảo vệ ở độ cao 8m
Phạm vi bảo vệ ở độ cao 17m

Phạm vi bảo vệ ở độ cao 11m
Hình 1.10. Sơ đồ phạm vi bảo vệ của ph ơng án 2
FR),^$_`O9`#] $9`<9+a\*OR&

 G !"!#$
CHƯƠNG 2
TÍNH TOÁN NỐI ĐẤT CHO TRẠM BIẾN ÁP 220/110kV
2.1. Yêu cầu nối đất cho trạm biến áp
RMN*G%KIb)G57'
=G310OG%&&'()*+
()>L,YM)()G=*%Z
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