Ôn tập Lưới điện Phần Lý Thuyết docx




 !"#!$$%&"

• 
!
"#$%&'
• ()
!
"
!*(+,-./+0(
#'1+0/+(
!
02+)34+5657
('
%'8!(09:;83<=>?'
@'?A>?#B>?A
C5
/5
#
'
n
n
dt tb
r r a
−
=
D
!
:;0/+(4E7(>??AFG$:;!(09

FH>?A'
'()!*+#,-#,.$
 /6I5#J*K
! /65)J*KLMM
#' N
#
O!J*K0/+
P
%'
P
@
 '
 P$#QQ':R  P$P#&S M T
 ' '
tb
D
d
tb ab bc ca
X x l
x Km
D D D D
+ =
+ = + Ω
+ =
!
P

P$P#UV
P$#QQU': S M T
dt

x Km
r n
= + Ω
%
# #
' ' '
n n
i
B Fe i cuđm i
i i
đm
S
A P t P t
S
= =
 
∆ = ∆ + ∆
 ÷
 
∑ ∑
%
%
# #
' ' ' ' R 
n n
cuđm i
B Fe i i i i
i i
đmB i
P t

A P t m S m m
S m
= =
∆
∆ = ∆ + ≤
∑ ∑
%' N
%
-+(J*K)3;W/W<
/-01& 1.$2$345"67$
581.$29$:.;<
• X=>?5Y+?!<):;=>?5W<:ZY+[<
)$(Y+\()/;=>?3;W-FHY
+!]'
• CY+?!<)4<-W-A[@:W/3Y+'
D40^+9=>?Y+?!<)0(3=>?Y+
$=55W[B'
=>34<:& !.'?8!$3@
/5
X2?W:;2W_%9
• `_%92?W(>Y
• `a_%92?W+0(
• `b_%92?W
A3B CD$EF:& !
#

G9(W<9/(REc./
∆
d


9
∆
d
e
$
∆
d

W
' R 
'
'
i i
tt tt
rđm
Pl
F k
U U
ρ
=
∆
∑

#
'
G!+2Efg5(W<hZ3W<9
/(REc

-A[c


'
#
/
GC2:6./()0/
%
%
# #
' ' ' '
'
n n
cuđm
B Fe i i i
i i
đmB
P
A m P t S t
m S
= =
∆
∆ = ∆ +
∑ ∑
i
i
#
#
'
n
k k
k
S Z

S
Z
∑
=
=
∑
W-4_B
i
k
k
S
Z
Z
∑
,j7B
,j_Y+03)B<>
bR:ZF+
( ) ( )
P P
' ' ' '
i i i i
đm
r P l x Q l
U
U
+
∆ =
∑ ∑
∆
d


k
∆
d

-c

3_ERA0
∆
d

l
∆
d

0A^3)!%Ec

:[#-'
HDI%&
∆
J
$
& $81$"
G 0?(
*
#
E
[ ]
P
P$@& P$Q Mx Km∈ ÷ Ω

*
%

( )
P
' '
i i
x
đm
x Q l
U
U
∆ =
∑
*
@

r cp x
U U U
∆ = ∆ − ∆
*
Q
9>9/(
' R 
'
'
i i
tt tt
rđm
Pl

F k
U U
ρ
=
∆
∑

*
U
!+E>gmA[>9/(R
R 
tc tt
F F≤

P P
$r x
Fc

'
*
&
C2:6./
∆
J
$

∆
d

k

∆
d

-c

3_ERA0
∆
d

l
∆
d

0A^3)!UEc

:[#-'R0A0
3G ?(
*
#
E
[ ]
P
P$@& P$Q Mx Km∈ ÷ Ω
*
%
9
$
xABC xABD
U U∆ ∆
P

# # % %
P
# # @ @
'R 
'R 
xABC
đm
xABD
đm
x
U Q l Q l
U
x
U Q l Q l
U
∆ = +
∆ = +
( )
e $
x xABC xABD
U U U∆ = ∆ ∆
39>YE
xABD
U∆
:;e
*
@

r cp x
U U U

∆ = ∆ − ∆
*
Q
9
# # @ @
R 
'
tt
rđm
Pl Pl
F
U U
ρ
+
=
∆ ∆
./
ex
U∆
*
U
!+E>gmA[>9/(R
R 
tc tt
F F≤

P P
$r x
Fc


'
*
&
C2:6./
∆
J
$

( ) ( )
P P
' ' ' '
i i i i
đm
r P l x Q l
U
U
+
∆ =
∑ ∑
A B
C
D
#
l
%
l
@
l
#
S

→
n
# # # # % % % %
# # # # @ @ @ @
#
'R 
#
'R 
ABC cp
đm
ABD cp
đm
U R Q X P R Q X U
U
U R Q X P R Q X U
U
∆ = + + + ≤ ∆
∆ = + + + ≤ ∆
S
# # # # % % % %
# # # # @ @ @ @
#
'R 
#
'R 
ABC cp
đm
ABD cp
đm
U R Q X P R Q X U

U
U R Q X P R Q X U
U
∆ = + + + > ∆
∆ = + + + ≤ ∆
KDI%&L

& $81$"
G 0?(
*
#
9!W
i i i i i i
S P Q S Cos
ϕ ϕ
= + = ∠ →
*
%
E
[ ]
P
P$@& P$Q Mx Km∈ ÷ Ω
*
@

( )
P
' '
i i
x

đm
x Q l
U
U
∆ =
∑
*
Q

Uo
cpđm
U U
∆ = ×
*
U

r cp x
U U U
∆ = ∆ − ∆
*
&

@' ' R 
r
kđ
i i
U
j
l Cos
ρ ϕ

∆
=
∑
*
V

{ }
 p
tt kt kđ
j j j=
*
q
9>(/6
@
'#P
'
@' '
i
i tt
đm tt
S
F k
U j
−
=
!+E>?./^
r X/6BE:[m
r (/6s:6EA[m'
A0Ec
CA0Ec$?c:

3;f:63
ABC
U∆
*
t
C2:6
∆
d

≤

∆
d

A0
∆
d

l
∆
d

0A0$8>A-:#-'X/69W0
5c:[/69'
3G 6$
*
#
9!W
i i i i i i
S P Q S Cos

ϕ ϕ
= + = ∠ →
*
#
E
[ ]
P
P$@& P$Q Mx Km∈ ÷ Ω
*
%
9
$
xABC xABD
U U∆ ∆
P
# # % %
P
# # @ @
'R 
'R 
xABC
đm
xABD
đm
x
U Q l Q l
U
x
U Q l Q l
U

∆ = +
∆ = +
( )
e $
x xABC xABD
U U U∆ = ∆ ∆
39>YE
xABD
U∆
:;e
*
Q

Uo
cpđm
U U
∆ = ×
*
U

r cp x
U U U
∆ = ∆ − ∆
*
&

# # @ @
@' ' R 
r
kđ

U
j
l Cos l Cos
ρ ϕ ϕ
∆
=
+
∑
9
kđ
j
./(
ex
U∆
*
V

{ }
 p
tt kt kđ
j j j=
*
q
9>(/6
@
'#P
'
@' '
i
i tt

đm tt
S
F k
U j
−
=
!+E>?./^
r X/6BE:[m
r (/6s:6EA[m'
*
t
C2:6./
∆
J
$

n
# # # # % % % %
# # # # @ @ @ @
#
'R 
#
'R 
ABC cp
đm
ABD cp
đm
U R Q X P R Q X U
U
U R Q X P R Q X U

U
∆ = + + + ≤ ∆
∆ = + + + ≤ ∆
( ) ( )
P P
' ' ' '
i i i i
đm
r P l x Q l
U
U
+
∆ =
∑ ∑
A B
C
D
#
l
%
l
@
l
#
S
→
A0Ec
S
# # # # % % % %
# # # # @ @ @ @

#
'R 
#
'R 
ABC cp
đm
ABD cp
đm
U R Q X P R Q X U
U
U R Q X P R Q X U
U
∆ = + + + > ∆
∆ = + + + ≤ ∆
M6CD+#,%&< N$281%&O3P"
#' EW<:ZJ*KMM
≥
%5Y+:/6#$%p"#5Y+:/6@'
%' EW/uJ*K./W:mF+
e
S

e
'
'
tt
đmB
S k
S
n k

θ
≥
/5
k
θ
:;W<IG
#
#PP
đm
K
θ
θ θ
−
= +
!E./^(+!4=
e
'
' '
tt
đmB
t
S k
S
n k k
θ
≥
/5C

:;W<^(+:v!4=
C


"#$@rP$@C


e
tb
đ
S
k
S
=
G E./^(+Ww<
'
#$Q'R #
csyc tt
đmB
S k
S
n
≥
−
/5b
W
W+5:vWw<
#$Q/L^(+#$Q:W
Rr##J*K/6'
Q-R<&$5S!$3!$$5PJ
o X(:;#/%W<((-:Z'
o 8/\+d2d]/63/L'
o `(83Z^#63/L4Wx?5^(

$:;A:/\!y'
o `(>63/L4!y3z:;3(
!y:{/5$+,E'
*()Id
r X)I(j`JX
r ,?(J*K
r ,W<=>?'
CA0Ec$?c:
3;f:63
ABC
U∆
T() U 18!&VE$$+#,
'-R<&$3;<$03W3;<$
 X2+,-83;('
 `?/W-)+=>?'
Cc thit b b cspk:
 J(!hB!G
 ;#G[B!G60+
 C
↑
$
↓
>s09_Wx:;J*X*(/\YW0
→
(+
↑
/\
↓
'
! Y

 I59-(
Q →
:;
↑

d
 J<
↓
d+O!Y'
/#;0813;X9
• *h0
↓
A∆ →
9/(0$0|
• *h0|!h2)I($9!O!G
=3!$$:B5SJ
• ,W<=>?MM=>?MM
#đd
tđ
Z
Z
n
=
• hY!hO<=>?
0OY
đm
PR QX
U
U
+

∆ =

b0OY
}
R 
c
đm
PR Q X X
U
U
+ −
∆ =

A-R<&$!*$Y$$B
!*
X2+,-8=>?$+9)+8
→↓
(;8'
(?/(3;'
X?(:;7:-
_G/J*KW<3s>?7%
::;!]'
# # # %
%
% % # #
'U n U n C
U
U n n n
= ⇒ = =
⇒

d
%
~:y
#

#
↑
Rv0
↓

⇒
d
%
↓


#
↓
Rv0
↑

⇒
d
%

↑
z R jX= +
}
Z R jX= +
xc

j−
H672!Z:[:))
• X)Id
• 1+
A∆
→
YOxWx(a::
→
:;+a:
→
+
$U A∆ ∆
K-R<&$3@<:&\-]<C481^3@<>81
<_
r 3@<:&\-]B
•!]$W(?!]/NX
•`W0?!]Wx?-,y/NX3)d3;u'
r `C481
a1<59-,yu3;d
a0(?!]R,yu$?!]aR,yd'
M-R<&1$;<4:bB&
aQW<9/u=>?
P P P P
$ $ $r L g C
•X=>?>;
→
W5+-=)=>?
→
(W<
0(6_=2'

•W<+)_2=>?0,/
P P
$ P'g r =
N[4)W5
@
%
% P P
@
% P % P
'/WR  '#P 'WR 
'/WR  ' '#P 'WR 
x
c
x c
U
I I x j x
Z
U U x jZ I x
α α
α α
−
= +
= +
% %
%
'
đm
P Q
A R t
U

PR QX
U
U
 
+
∆ =
 ÷
 
+
∆ =
•
$
x x
I U
(3;>s63y
9eW/3<=>?'
•
% %
$U I
(3;>s6
<=>?'

c
Z
,jW5=>?
P
P P P
P
$
c

L
Z w L C
C
α
= =
]W<