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A separate excited DC motor is running at 1000 rpm when the armature voltage is 600...

A separate excited DC motor is running at 1000 rpm when the armature voltage is 600 V. The motor has a field constant Kphi = 4 V.sec and the armature resistance of the motor is 0.8 Ohms.
i. Calculate the value of the resistance of the dynamic braking at full load. The armature current should be limited to 200 % of the rated value.
ii. If the motor operates in regenerative braking at a speed of 1200 rpm, calculate the armature current.

iii. If the terminal voltage is reversed and reduced to 90 V, calculate the steady-state speed of the motor.

iv. Calculate the terminal voltage required to block (stop) the rotor. v. Sketch the speed-torque characteristics and show all operating conditions.

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