All the students of 5 th sem are here with instructed to complete the Examples given below in to file up to the next week for the subject EED. 2150904.
PRACTICAL 1
Design of Field
Regulators.
(a)
For d.c shunt
motor:
(1)
A
250 V, d.c. shunt motor with a normal
speed of 600 rpm takes shunt field current of
2 Amp when running light. If the speed of the motor is to be raised to
1200 rpm in increments of 150 rpm, find the resistance sections of a shunt
field regulator. The O.C.C of the motor at 600 rpm is as under.
|
Field current,
Amp
|
0.5
|
1.0
|
1.5
|
2.0
|
2.5
|
|
EMF, Volt
|
80
|
150
|
210
|
250
|
275
|
(2) A 250 V, d.c. shunt motor with a normal speed
of 600 rpm takes shunt field current of
2 Amp when running light. If the speed of the motor is to be raised to
1200 rpm in increments of 150 rpm, find the resistance sections of a shunt
field regulator. The O.C.C of the motor at 600 rpm is as under.
|
Field
current, Amp
|
0.4
|
0.8
|
1.2
|
1.5
|
2.0
|
2.4
|
|
EMF,
Volt
|
70
|
137.5
|
187.5
|
225
|
250
|
270
|
(b)
For d.c shunt generator:
(1)
Find
the resistance of various sections of a 7 stud field regulator for a D.C. shunt
generator to give an emf variation from 260 V to 200 V in equal steps. The
resistance of the field is 58 Ω. The magnetization curve is given as below.
|
Field
current, Amp
|
1
|
2
|
3
|
4
|
5
|
6
|
|
EMF,
Volt
|
90
|
170
|
220
|
250
|
270
|
284
|
(2)
Find the resistance of various sections
of a 7 stud field regulator for a D.C. shunt generator to give an emf variation
from 260 V to 200 V in equal steps. The resistance of the field is 58 Ω. The
magnetization curve is given as below.
|
Field
current, Amp
|
0.4
|
0.425
|
0.45
|
0.48
|
0.51
|
0.55
|
|
EMF,
Volt
|
250
|
255
|
260
|
265
|
270
|
275
|
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