23 hp, dc shunt motor is running at 1000 rpm when the armature voltage is 600...

23 hp, dc shunt motor is running at 1000 rpm when the armature voltage is 600 V. The armature resistance of the motor is 0.8 ohm, and the field resistance is 900 ohm. The efficiency of the motor at full load is 92 %.

a) Calculate the value of the resistance of the dynamic braking at full load. The armature current should be limited to 150% of the rated value.

b) If the motor operated in regenerative braking at a speed of 1100 rpm, calculate the line current.

c) Design a circuit for countercurrent braking (by reversing supply voltage) so that the line current will not exceed 120% of the rated value.

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Expert Solution

Manojponduru answered 6 months ago

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