Chương 6
6.19
m n T
j
Ear
Ia
e
14330 60
5 1
) 5 17 sin(
3
3300 41
2357
3
5 17 41 2357 3
3300 84
25 86 524
5
1
84 25 86 524 84 25 3
3300
3 3000000
6.20
a)
m n T
j m
Ear
e
m
61 7161 40
2
) 8 18 sin(
3
2300 1402
3
8 18 1402 92
225 2
3
2300
,
92 225 3
2300
3 900000
Im
40
b)
j jQ
P
lagging
PF
Ia
I l
563382 1463383
3 21 393 3
2300
93
0
21 6 393 92 225 45 200
45
200
6.21a)
29 1326 60
250000
2
43
685 0 460 ) 3
550 ( 3
2 1 250000 sin
sin 3
e
T
Xs
Va Ear
Pt
b)
Trang 2VAr Q
lagging PF
j Ia
14107 3
) 23 3 sin(
83 262
3
550
998
0
23 3 83 262 2
1
) 3 550 ( 2
43
460
6.11
a) Ta có điên áp mỗi pha là
) ( 79 132
3
230
V
) ( 76 62 3
79
132
25000
A
V j
Va Ia Xs
j
Ear
A Ia
7 21 7 203 0 79 132 87 36 76 62 5
1
87 36 76 62 8 0 arccos 76
62
b)
A j
new
Ia
new
old Ear imf new
Ear
imf
V new
Ear
old Ir new
Ir
mà
new Ir old Ir
old Ear new
Ear
old Ir
old Ear
new
Ir
new
Ear
95 52 33 83 5
1
79 132 946 17 44 244
,
946 17 44
244
) 7 21 sin(
7 203 arcsin
) , ( )
,
(
44 244 2 1 7 203 ,
, 2
1
,
, ,
, ,
,
, ,
,
6.12
a)
68 1919 86
369 6
1 3
2300
Ear
Trang 3A Ia
I
A Ia
A Ia
W P
V Va
l
pha
08 41 49 191 47 115 84 25 68 288 Im
47 115 3
2
3
400
Im
84 25 68
288
68 288 9 0 7
1154
300000
300000 3
900000
7 1154
3
2000
1
b)
2122 60
10
) 45 sin(
3
45 1633 47
115 10 3
2000
,
) ( 60 60
1800
2
1800 4
60 120 120
Va Ear
T
j m
Ear
mech
Ns Ns
p
f
e
m
c)
57 25 2675 16
47 78 170 10 7 1154
,
46 47 78 170 08 41 49 191 81 259 Im
81 259 7
1154
300000
1
cos
j m
Ear
I
Ia
Ia
l
6.14
a)
A
I l arccos0.87 750.18 29.54
87 0 3
2300
3 2600000
b)
A Ia
A j j
67 652 ) 54 29 cos(
18
750
) ( 86 369 )
54 29 sin(
18
750
Im
c)
6.15
68 1919 86
369 6
1 3
2300
Ear
Trang 4a)
V A
j Ear
A
5 49 47 98 87 36 13 156 6 0
3
208
87 36 13 156 87 36 8 0 3
208
3 45000
Im
b)
) ( 30 60
900
2
900 8
60 120 120
mech
Ns Ns
p
f
Te max khi Pt max, pt max khi Ear.sin() max, tức là imf( 0.6 jIm )max, =>Im chỉ có phần thực, điếu này xảy ra khi PF=1
3 477 30
6 0
) 96 31 sin(
3
96 31 55 141 9 124 6 0 3
208
9 124 3
208
3 45000
Im
Va Ear T
j Ear
e
6.17
a)
3 692 40
87000
2 716 40
3000 87000
) ( 40 60
1200 2
1200 6
60 120 120
ml
e
total
e
m
T
T
mech
Ns Ns
p
f
b)
92 225 3
2300 3
10 90000 sin
90000
Ear
Pt total
Ear có phần ảo
PF trễ nên
Trang 587 8 41 1465
9
1447
92 225 )
12 ( 10 3
2300
12
Im
87 36
20
92 225
Ear
B
j B
j A j Ear
j A
I
j B
Ear
l
6.18
a)
A
I l arccos0.87 750.18 29.54
87 0 3
2300
3 2600000
b)
A Ia
A j j
67 652 ) 54 29 cos(
18
750
) ( 86 369 )
54 29 sin(
18
750
Im
c)
6.19
m n T
j
Ear
Ia
e
14330 60
5 1
) 5 17 sin(
3
3300 41
2357
3
5 17 41 2357 3
3300 84
25 86 524
5
1
84 25 86 524 84 25 3
3300
3 3000000
6.20
a)
68 1919 86
369 6
1 3
2300
Ear
Trang 6m n T
j m
Ear
e
m
61 7161 40
2
) 8 18 sin(
3
2300 1402
3
8 18 1402 92
225 2
3
2300
,
92 225 3
2300
3 900000
Im
40
b)
j jQ
P
lagging
PF
Ia
I l
563382 1463383
3 21 393 3
2300
93
0
21 6 393 92 225 45 200
45
200
6.21a)
29 1326 60
250000
2
43
685 0 460 ) 3
550 ( 3
2 1 250000 sin
sin 3
e
T
Xs
Va Ear
Pt
b)
VAr Q
lagging PF
j Ia
14107 3
) 23 3 sin(
83 262
3
550
998
0
23 3 83 262 2
1
) 3 550 ( 2
43
460
6.1/
Máy điện đồng bộ
Trang 7
3
0
0
*
0
120
1800
2
60 60
250.10 ( )
1, 2 sin 0, 6846
43, 2
1326
/
460 43, 2
262,83 3, 23
1, 2
3, 23 0 cos 0, 998
3.550
3 0 262,83 3, 23
3
249982 14107
s
s
m
a a
e T
m
ar
ar a
a
T a a
f
N
p
N
E V
P
b
E
j
lagging
V I
14107
A
6.2/
a/
0
*
0
1327 0
3 1500 300
0,384 11, 3.10 384 11, 3
384 11, 3 250 45
244, 27 15, 7
a
T a a
a
am a L
V
b/
PF of the motor :
0 , cos 0,9626 leading
c/
1327 2.384 11, 3 1396, 9 32, 6
ar a s a
6.3/
a/
Trang 8
3
0
0
0
*
0
120
250.10
sin 0,846 43, 025
/
550
460 43, 025 0
3
1, 2 314,58 3, 42
3 cos cos 0,834
550
3 3 .314,88 3, 42
3
z
s
a ar T
s
as a
a
s
T a a
T a a
f
N
p
V E
x
b
I
6.4/
0
*
0
0
0 5
120
1500
2
60
1905, 255 0
175
175 36,87
1000.10 0,8 8.10
3 sin
sin 0, 06946 1
3, 98 8.10
4244 60
s
s
m
a
a a
a
a
ar s a a
T
a ar
e T
m
f
p
N
rad s
P
V E
P
6.5/
Trang 9
0 3
0
120
360
2
60
cos 1, 1327
201
1386, 5 16,85 800.10
21220 12
6.6 /
/
3810
120
720
2
60
95 36,87
3810 15.95 36,87 4
s
s
m
a
a
ar a s a
e T
a
s
s
m
ar a s a
f
p
N
rad s
P
a
f
p
N
rad s
3
0
802, 27 13, 73
3 0, 6 868, 68.10
3
13, 74
11524
a ar
T
s
T a a
T ar
e T
m
A
V E
P
X
P
V E
P
b/
Công suất phảng kháng từ nguồn là:
3
651, 6.10 AR
0,8
T
P
Trang 106.7/
a/
33
220 30
127 220 30
100 30
1, 27 0,866 /
50 45 100 30 122,83 6,84 cos 6,84 0.993,
T
a ar
s
ar
a ar
a
s
a L
V E
X
I
b
leading
6.8/
a/
0
0
0
120
300
2
60
1963
1360, 5
2388, 4 34, 7 254648
/
2388, 4 34, 7
3
34, 66
s
s
m
a
a
ar a s a
e T
m
as
s T
a ar
f
p
N
rad s
P
b
E
X P
V E
Trang 11
0
0
/
1, 2
1, 2
sin
1, 2
28, 29
1678 13, 55
r new r old
ar new old
r new r old
ar
ar new
new
a
ar new
a
s
c
I
jX
6.9/
a/
120
1200
2
40 60
s
s
m
f
p
N
rmp
: 87
692,3 40
: 40 90
716, 2
40
e
T
m
T rlectrical origin
kW
6.10/
a/
Trang 12
0
0
*
0
sin 0, 6846
43, 2
/
263 3, 23 cos 0, 998
3 250 14,116
/
263 36,87
566, 3 26, 477
a ar
T
s
ar a
a
s
T a a
anew
ar a a s
V E
P
X
b
I
jX
lagging
c