Giải bài tập Biến đổi năng lượng điện cơ - Chương 6

Chương 6 
6.19 
mnT
jEar
Ia
e 








14330
605.1
)5.17sin(
3
3300
41.23573
5.1741.2357
3
3300
84.2586.5245.1
84.2586.52484.25
33300
33000000

6.20 
a) 
mnT
jmEar
e
m










61.7161
402
)8.18sin(
3
2300
14023
8.18140292.2252
3
2300
,
92.225
32300
3900000
Im
40


b) 
jjQP
laggingPF
Ia
Il
5633821463383321393
3
2300
93.0
216.39392.22545200
45200




6.21a) 
29.1326
60
250000
2.43
685.0
460)
3
550
(3
2.1250000
sin
sin3












eT
Xs
VaEar
Pt
b) 
VArQ
laggingPF
j
Ia
141073)23.3sin(83.262
3
550
998.0
23.383.262
2.1
)3550(2.43460





6.11. 
a) Ta có điên áp mỗi pha là 
)(79.132
3
230
VVa  
)(76.62
379.132
25000
AIa 

 
VjVaIaXsjEar
AIa
7.217.203079.13287.3676.625.1
87.3676.628.0arccos76.62


b) 
A
j
newIa
new
oldEarimfnewEarimf
VnewEar
oldIrnewIr
mà
newIr
oldIr
oldEar
newEar
oldIr
oldEar
newIr
newEar
95.5233.83
5.1
79.132946.1744.244
,
946.17
44.244
)7.21sin(7.203
arcsin
),(),(
44.2442.17.203,
,2.1,
,
,
,
,
,
,
,
,












6.12 
a) 
68.191986.3696.1
3
2300
 jjEar
AIaI
A
Ia
AIa
WP
VVa
l
pha
08.4149.19147.11584.2568.288Im
47.115
32
3400
Im
84.2568.288
68.288
9.07.1154
300000
300000
3
900000
7.1154
3
2000
1











b) 
2122
6010
)45sin(3
45163347.11510
3
2000
,
)(60
60
18002
1800
4
60120
120

















VaEar
T
jmEar
mech
Ns
Nsp
f
e
m
c) 
57.25267516.4778.170107.1154,
46.4778.17008.4149.19181.259Im
81.259
7.1154
300000
1cos




jmEar
IIa
Ia
l

6.14 
a) 
AIl 54.2918.75087.0arccos
87.032300
32600000




b) 
AIa
Ajj
67.652)54.29cos(18.750
)(86.369)54.29sin(18.750Im


c) 
6.15 
68.191986.3696.1
3
2300
 jjEar
a) 
VAjEar
A
5.4947.9887.3613.1566.0
3
208
87.3613.15687.36
8.03208
345000
Im





b) 
)(30
60
9002
900
8
60120
120
mech
Ns
Nsp
f
m 

 







Te max khi Pt max, pt max khi Ear.sin( ) max, tức là imf( Im6.0  j )max, => Im chỉ có phần thực, 
điếu này xảy ra khi PF=1 
3.477
306.0
)96.31sin(3
96.3155.1419.1246.0
3
208
9.124
3208
345000
Im










VaEar
T
jEar
e
6.17 
a) 
3.692
40
87000
2.716
40
300087000
)(40
60
12002
1200
6
60120
120

















ml
e
total
e
m
T
T
mech
Ns
Nsp
f
b) 
92.225
3
2300
3
1090000
sin
90000





Ear
Pttotal
Ear có phần ảo 
PF trễ nên 
87.841.1465
9.1447
92.225)12(10
3
2300
12Im
87.3620
92.225






Ear
B
jBjAjEar
jA
I
jBEar
l
6.18 
a) 
AIl 54.2918.75087.0arccos
87.032300
32600000




b) 
AIa
Ajj
67.652)54.29cos(18.750
)(86.369)54.29sin(18.750Im


c) 
6.19 
mnT
jEar
Ia
e 








14330
605.1
)5.17sin(
3
3300
41.23573
5.1741.2357
3
3300
84.2586.5245.1
84.2586.52484.25
33300
33000000

6.20 
a) 
68.191986.3696.1
3
2300
 jjEar
mnT
jmEar
e
m










61.7161
402
)8.18sin(
3
2300
14023
8.18140292.2252
3
2300
,
92.225
32300
3900000
Im
40


b) 
jjQP
laggingPF
Ia
Il
5633821463383321393
3
2300
93.0
216.39392.22545200
45200




6.21a) 
29.1326
60
250000
2.43
685.0
460)
3
550
(3
2.1250000
sin
sin3












eT
Xs
VaEar
Pt
b) 
VArQ
laggingPF
j
Ia
141073)23.3sin(83.262
3
550
998.0
23.383.262
2.1
)3550(2.43460





6.1/ 
Máy điện đồng bộ 
 
3
0
0
*
0
120
1800
2
60
60
3 sin
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
PT W
P
T Nm
b
E
E V
I A
j
lagging
V I
j kV

 





 
 
 
 

 
 

  
    
   
 
14107
A
Q kVA 
6.2/ 
a/ 
 
0
*
3 0
0 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
P V I j
I A
I I I
 
  
    
     
 
b/ 
PF of the motor : 
0 , cos 0,9626 leading    
c/ 
 1327 .2.384 11,3 1396,9 32,6
ar a s aE V jX I
j V
 
    
6.3/ 
a/ 
 3
0
0
0
*
0
120
3 sin
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
3z
s
a ar
T
s
as a
a
s
T a a
T a a
f
N
p
V E
P W
x
b
E X
I
jX j
P V I
S V I

 
 

 
   
  

 
 
  
  
6.4/ 
 
 
 
 
 
0
*
0
0
3 5
0
5
120
1500
2
60 /
60
1905,255 0
3 1000
175
175 36,87
. 2015 40
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
N rmp
p
N
rad s
V V
V I kVA
I A
I A
E jX I V V
P
V E
P
T Nm

 



 
 
 
 

 
  
   
 
  
 
  
6.5/ 
 
 
 
 
 
 
 
0
3
0
120
360
2
12 /
60
cos 1, 1327
201
1386,5 16,85
800.10
21220
12
6.6 /
/
3810
120
720
2
24 /
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
N rmp
p
N
rad s
V V
I A
E V jX I V
P
T Nm
a
V V
f
N rmp
p
N
rad s
Ia A
E V jX I j

 

 

 
 
 
 

   
  

 
 
 
    
  
 3
0
802, 27 13,73
3 sin
3 .0,6 868,68.10
sin 0,2374
3 .
13,74
11524
a ar
T
s
T a a
T
ar
e T
m
A
V E
P
X
P V I W
P
V E
P
T Nm







 
    
  
 
b/ 
Công suất phảng kháng từ nguồn là: 
3651,6.10 AR
0,8
TPQ V 
c/ 
6.7/ 
a/ 
 
 
 
0 0 0
33
3 sin
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
P kW
V E
X
E motor
I E
I
jX j
PF of motor leading
b
I I A
leading




  
  
   

      

6.8/ 
a/ 
 
 
 
 
 
 
0
0
0
120
300
2
10 /
60
1963
1360,5
. 2388,4 34,7
254648
/
2388,4 34,7
sin 0,5688
3
34,66
s
s
m
a
a
ar a s a
e T
m
as
s T
a ar
f
N rmp
p
N
rad s
V V
I A
E V jX I V
P
T N m
b
E
X P
V E

 



 
 


   
  
 
 
 
   
 
 
 
 
 
 
0
0
/
1,2
1,2
sin
sin 0,474
1, 2
28,29
1678 13,55
r new r old
ar new old
r new r old
arar new
new
aar new
a
s
c
I I
E E
I I
E E
E V
I
jX





 
  
 

  
6.9/ 
a/ 
 
 
120
1200
2
40
60
s
s
m
f
N rmp
p
N
rmp

 
 
  
:
87
692,3
40
:
40
90
716, 2
40
e
T
m
e T
T machanical load
P kW
N m
P losses
T rlectrical origin
kW
N m
 


  

  
6.10/ 
a/ 
 
 
 
0
0
*
0
3 sin
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
E V
I
jX
lagging
S V I j kVA
c
I A
E V I jX





 


  

  
 
 
 