Chương 6
6.19
3000000 3
25.84 524.86 25.84
3300 3
3300
Ear 1.5 j 524.86 25.84
2357.4117.5
3
3300
3 2357.41
sin(17.5)
3
e
T
14330n m
1.5 60
ng
6.20
a)
.c
om
Ia
co
m 40
900000 3
225.92
2300 3
2300
Ear, m
2 j 225.92 1402 18.8
3
2300
3 1402
sin(18.8)
3
e
T
7161.61n m
2 40
b)
u
I l 200 45
du
o
ng
th
an
Im
cu
Ia 200 45 225.92 393.6 21
PF 0.93lagging
2300
P jQ
39321 3 1463383 563382 j
3
6.21a)
3 Ear Va sin
250000 1.2
sin
0.685
550
Xs
) 460
3 (
3
43.2
250000
Te
1326.29
60
Pt
b)
CuuDuongThanCong.com
/>
46043.2 (550 3 )
262.83 3.23
1.2 j
PF 0.998lagging
Ia
550
262.83 sin(3.23) 3 14107VAr
3
2300
Ear
1.6 j 369.86 j 1919.68 6.11.
3
a) Ta có điên áp mỗi pha là
Q
230
132.79(V )
3
25000
Ia
62.76( A)
132.79 3
Ia 62.76 arccos 0.8 62.76 36.87 A
.c
om
Va
Ear j Xs Ia Va 1.5 j 62.76 36.87 132.790 203.721.7V
co
an
th
ng
Ear, new Ear , old
Ir , new
Ir , old
Ear, old
Ear, new
Ir , new
Ir , old
mà
Ir , new 1.2 Ir , old
Ear, new 203.7 1.2 244.44V
ng
b)
6.12
a)
cu
u
du
o
imf ( Ear, new) imf ( Ear, old )
203.7 sin(21.7)
new arcsin
17.946
244.44
244.4417.946 132.79
Ia, new
83.33 52.95 A
1.5 j
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/>
2000
1154.7V
3
900000
300000W
P1 pha
3
300000
Ia
288.68 A
1154.7 0.9
Ia 288.68 25.84
Va
400 3
115.47 A
23
I l Ia Im 288.68 25.84 115.47 191.49 41.08 A
.c
om
Im
b)
120 60
p Ns
1800
Ns
120
4
2 1800
60 ( mech)
m
60
2000
Ear, m
10 j 115.47 1633 45
3
3 Ear Va sin(45)
2122
Te
10 60
an
co
ng
f
th
c)
du
o
ng
cos 1
300000
Ia
259.81
1154.7
Im Ia I l 259.81 191.49 41.08 170.7847.46
Ear, m 1154.7 10 j 170.7847.16 2675 25.57
2600000 3
arccos 0.87 750.18 29.54 A
2300 3 0.87
cu
Il
u
6.14
a)
b)
Im 750.18 sin(29.54) j 369.86 j ( A)
Ia 750.18 cos(29.54) 652.67 A
c)
Ear
2300
3
1.6 j 369.86 j 1919.68
6.15
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/>
a)
45000 3
36.87 156.13 36.87 A
208 3 0.8
208
0.6 j 156.13 36.87 A 98.47 49.5V
Ear
3
Im
b)
p Ns
120 60
Ns
900
120
8
2 900
m
30 ( mech)
60
Te max khi Pt max, pt max khi Ear.sin( ) max, tức là imf( 0.6 j Im )max, => Im chỉ có phần thực,
.c
om
f
điếu này xảy ra khi PF=1
45000 3
124.9
208 3
208
Ear
0.6 j 124.9 141.55 31.96
3
3 Ear Va sin(31.96)
Te
477.3
0.6 30
th
an
co
ng
Im
ng
6.17
a)
120 60
p Ns
1200
Ns
120
6
2 1200
40 (mech)
m
60
87000 3000
716.2
T e total
40
87000
692.3
T e ml
40
cu
u
du
o
f
b)
Pt total 90000
Ear sin
90000 10
225.92
2300
3
3
Ear có phần ảo
PF trễ nên
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/>
Ear B 225.92 j
I l 20 36.87
Im A 12 j
2300
Ear
10 j ( A 12 j ) B 225.92 j
3
B 1447.9
Ear 1465.41 8.87
Il
2600000 3
arccos 0.87 750.18 29.54 A
2300 3 0.87
b)
ng
Im 750.18 sin(29.54) j 369.86 j ( A)
.c
om
6.18
a)
co
Ia 750.18 cos(29.54) 652.67 A
3
th
2300
1.6 j 369.86 j 1919.68
ng
Ear
an
c)
6.19
cu
u
du
o
3000000 3
25.84 524.86 25.84
3300 3
3300
Ear 1.5 j 524.86 25.84
2357.4117.5
3
3300
3 2357.41
sin(17.5)
3
e
T
14330n m
1.5 60
Ia
6.20
a)
CuuDuongThanCong.com
/>
m 40
900000 3
225.92
2300 3
2300
Ear, m
2 j 225.92 1402 18.8
3
2300
3 1402
sin(18.8)
3
e
T
7161.61n m
2 40
Im
.c
om
b)
I l 200 45
P jQ
2300
3
39321 3 1463383 563382 j
co
6.21a)
ng
Ia 200 45 225.92 393.6 21
PF 0.93lagging
3 Ear Va sin
250000 1.2
sin
0.685
550
Xs
) 460
3 (
3
43.2
250000
Te
1326.29
60
ng
th
an
Pt
du
o
b)
46043.2 (550 3 )
262.83 3.23
1.2 j
PF 0.998lagging
550
262.83 sin(3.23) 3 14107VAr
Q
3
cu
u
Ia
6.1/
Máy điện đồng bộ
CuuDuongThanCong.com
/>
120 f
1800
p
2 N s
m
60
60
Ns
3EaVa sin
1, 2
PT 250.103 (W )
sin 0,6846
43, 20
P
T e T 1326 Nm
.c
om
m
b/
Ear 46043, 2 0
Ear Va
262,83 3, 23 A
j1, 2
3, 23 0 cos 0,998 lagging
co
3.550 0
0 .262,833, 23
3
249982 j14107 kVA
Q 14107kVA
ng
Ia
*
th
an
T 3Va . I a
ng
6.2/
a/
Va 132700
du
o
*
PT 3Va . I a 1500 j300
I a 0,384 11,3.103 384 11,30 A
u
I am I a I L 384 11,30 250 450
cu
244, 2715, 7 0
b/
PF of the motor :
0 , cos 0,9626 leading
c/
Ear Va jX s I a
1327 j.2.384 11,3 1396,9 32,6 V
6.3/
a/
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/>
120 f
p
Ns
PT 250.103 W
3Va Ear sin
xs
sin 0,846 43,0250
b/
550 0
46043,025
0
Eas X a
3
Ia
jX s
j1, 2
*
STz 3Va . I a 3.
.c
om
314,58 3, 420
PT 3Va .I a cos cos 0,834
550
.314,883, 420
3
ng
6.4/
120 f
1500 rmp
p
2 N s
m
60 rad / s
60
Va 1905, 25500 V
th
an
co
Ns
*
I a 175 A
du
o
I a 175 36,870 A
ng
3Va I a 1000 kVA
Ear jX s .I a Va 2015400 V
Te
3.Va Ear sin
sin 0, 06946
1
3,980
cu
u
PT 1000.103.0,8 8.105
PT
m
8.105
4244 Nm
60
6.5/
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/>
120 f
360rmp
p
2 N s
m
12 rad / s
60
cos 1, Va 1327 V
Ns
I a 201 A
Ear Va jX s I a 1386,5 16,850 V
800.103
21220 Nm
T
12
6.6 /
a/
.c
om
PT
e
Va 3810 V
120 f
720rmp
p
2 N s
24 rad / s
m
60
Ia 9536,870 A
th
Ear Va jX s I a 3810 j15.9536,87
an
co
ng
Ns
4802, 27 13, 73 A
3Va Ear sin
Xs
ng
PT
PT
0, 2374
3V .Ear
u
sin
du
o
PT 3Va I a .0, 6 868, 68.103 W
m
cu
13, 740
P
T e T 11524 Nm
b/
Công suất phảng kháng từ nguồn là:
Q
PT
651, 6.103 VAR
0,8
c/
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/>
6.7/
a/
PT 33kW
3Va Ear sin
Xs
motor
Ear 220 30
Ia
I a Ear 127 220 30
10030
jX s
j1, 27
.c
om
PF of motor 0,866 leading
b/
I a I L 50 450 100300 122,836,840 A
cos 6,84 0.993, leading
ng
6.8/
a/
120 f
300 rmp
p
2 N s
10 rad / s
m
60
Va 1963 V
an
th
ng
I a 1360,5 A
co
Ns
Te
PT
m
du
o
Ear Va jX s .I a 2388, 434,7 0 V
254648 N m
u
b/
sin
cu
Eas 2388, 434,7 0
X s PT
0,5688
3Va Ear
34, 660
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/>
c/
I r new 1, 2 I r old
Ear new
I r new
E old
I r old
Ear new 1, 2 Ear
sin new
sin
0, 474
1, 2
Ia
Ear new Va
jX s
.c
om
28, 290
1678 13,550
6.9/
a/
120 f
1200 rmp
p
2 N s
40 rmp
m
60
an
co
ng
Ns
T e machanical load :
87kW
692,3 N m
40
6.10/
a/
u
90kW
716, 2 N m
40
cu
PT losses
40
du
o
T e rlectrical origin :
th
m
ng
PT
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/>
PT
3Va Ear sin
Xs
sin 0,6846
43, 20
b/
Ia
Ear Va
263 3, 230
jX s
cos 0,998 lagging
kVA
.c
om
*
ST 3Va . I a 250 j14,116
c/
I anew 263 36,870 A
Ear Va I a . jX s
cu
u
du
o
ng
th
an
co
ng
566,326, 477
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