EEE 473/591 Electrical Machinery
Solutions to Homework 8
11-9
X'
Rotor powerfactor angle, r tan 1 ' lr
R /s
r
Br
sin r
Bms
2
11-10
In this problem let us use rms values to represent all the phasors.
208 o
0 120 0o
3
At the terminals, the impedance i
Raja Ayyanar
Fall 2011
EEE 473/591 Electrical Machinery
Solutions to Homework 7
Problem 10-5 from book (25 points)
5
2
TL 5 N m I s
10 A and I a I s 6.67 A
3
KT
speed m
5000
2 523.6 rad / s
60
E f K E m 0.5 523.6 261.8V
From Eq.10 22
Assu min g m 0 90
Raja Ayyanar
EEE 473/591 Electrical Machinery
Solutions to Homework 6
Fall 2011
Problem 9-6 from book
is t ia t 0 ib t 120 0 ic t 240 0
N
Fs t s i t s
2
(a)
ia 10 A, ib ic 5 A
is t 100 5120 0 5240 0 = 150 A
N
Fs t s is t 750 0 AT
2
(b)
ia 5 A, ib 10 A, ic
Raja Ayyanar
EEE 473/591 Electrical Machinery
Solutions to Homework 5
Fall 2011
Problem 8.1:
GOL
k
1 s / p
k
1 s / p
GOL
k
k
1
GCL
k
1 GOL 1
k 1 s / p k 1 1 s
1 s / p
(k 1) p
Assuming k>1,
GCL
k
1
k 1
1
1
s
(k 1) p
Therefore, the bandwidth of the cl
Raja Ayyanar
7.1
(a)
Ra 0.35
Va 100 V
Ea
Fall 2011
EEE 473/591 Electrical Machinery
Solutions to Homework 4
no load
La 1.5 mH
kE m m
k E kT 0.5 Trated 4 Nm
no load
Ea 100
200 rad / sec
0.5
kE
at Trated 4 Nm
T
4
8A
0.5
kT
Va k E m Ra I a
Ia
m rated l
EEE 473/591 Electrical Machinery Fall 2011
Solutions to Homework 3
1. Problem 5-9 from book
d
V1 N1
; Let sin t
dt
d
cos t
dt
V1 N1 cos t
V
max
at 60 Hz,
V
2 120
N1
N1 2 60
At 50 Hz, for the same max
2 Vrms,50 Hz
N1 2 50
2 120
N1 2 60
Vrms,50 Hz 120
EEE 473/591 Electrical Machinery Fall 2011
Solutions to Homework 2
Problem 1:
(a)
Vd 400V , back emf , E a 280V , Ra 2, Vtri 1V
For the current Ia to be 10 A, the average pole output voltage, v An should be,
v An E a I a Ra 280 10 2 300V
d
v An
d 0.5
0.