Thespeed of a 20-hp, 300-V, 1800-rpm separately excited DC motor iscontrolled by a three-phase full converter drive. The field currentis also controlled by a three-phase full converter and is set tomaximum possible value. The AC input is a three-phase, Y-connected,208-V., 60 Hz supply. The armature resistance is 0.25 Ω, thefield resistance is 245 Ω, and the motor voltage constantKv is 1.2 V/A rad/s. The armature and field currents canbe assumed to be continuous and ripple free. The viscous frictionis negligible. Determine:
The delay angle of the armature converter if the motor supplies therated power at the rated speed.
The no-load speed if the delay angles are the same as in (a) andthe armature current at no load is 10% of the rated value.
The speed regulation.