A 230 V, 500 rpm, 100 A separately- excited dc motor has an armature resistance of...

A 230 V, 500 rpm, 100 A separately- excited dc motor has an armature resistance of 0.1 ohms. The motor is driving, under rated conditions, a load whose torque is constant and independent of speed. The speeds below the rated speed are obtained with armature voltage control (with full field) and the speeds above the rated speed are obtained by field control (with rated armature voltage).

What motor terminal voltage is needed to run it at 400 rpm?
By what amount should flux be reduced to get a motor speed of 800 rpm?

Neglect the motor’s rotational losses.

3.The separately- excited motor of the previous problem is now coupled to an overhauling load with a torque of 800 N-m. Determine the speed at which the motor can hold the loadby regenerative braking. Source voltage is 230 V. Neglect the motor’s rotational losses.

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Manojponduru answered 1 year ago

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