A 230 V, 1000 rpm, 30 A separately excited motor has armature resistance and inductance of...
A 230 V, 1000 rpm, 30 A separately excited motor has
armature resistance and
inductance of 0.7 Ω and 50 mH respectively. Motor is controlled in
regenerative braking
by a chopper operating at 800 Hz from a dc source of 230 V.
Assuming continuous
conduction
a) Calculate duty ratio of chopper for rated torque and the speed
of 800 rpm.
b) What will be the motor speed for duty ratio of 0.6 and rated
motor torque?
c) What will be the maximum allowable speed of motor, if chopper
has a maximum
duty ratio of 0.9 and maximum allowable motor current is twice the
rated current?
d) Calculate power fed to the source for operating conditions in
(c).
e) Motor field is also controlled along with armature voltage.
Rated field current is 0.5
A. Calculate field current for the duty ratio of 0.9 and motor
speed of 1500 rpm and
armature current of 30 A.
Homework Answers
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A 230 V, 1000 rpm, 30 A separately excited motor has
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