Page 288 - Solutions Manual to accompany Electric Machinery Fundamentals
P. 288
(c) Input power
(d) P AG
(e) P conv
(f) P out
(g)
ind
(h) load
(i) Efficiency
SOLUTION The equivalent circuit of the motor is shown below
I 1
R 1 jX 1 j0.5X 2
{ R
+ 1.30 ? j2.01 ? j2.01 ?
0.5Z F j0.5X M 5 . 0 s 2 Forward
j105 ?
{
V = 220?0° V jX 2
j105 ? { j2.01 ?
j0.5X M 5 . 0 R 2 Reverse
0.5Z B 2 s {
-
The impedances Z and Z are:
B
F
R s jX jX
/
Z 2 2 M
F
R 2 / s jX 2 jX M
The slip s 0.05 , so R 2 / s 1.73 / 0.05 20.6
j 20.6 105 2.01 j
Z F 19.12 j 5.654
20.6 j 2.01 j 105
R /2 s 2 jX jX
Z 2 M
B
2 R /2 s jX 2 jX M
The slip s 0.05 , so R 2 / 2 s 1.73 / 2 0.05 0.887
2.01 j 105 j
0.887
Z B 0.854 j 1.979
0.887 j 2.01 j 105
(a) The input stator current is
282