A 220V, 3hp, 1800rpm separately excited DC motor is controlled by a one-phase full-wave converter with an AC source of 230V at 60Hz. Assume that full load efficiency of the motor is 88% and enough field inductance is added to ensure continuous current for any torque greater than 25% of rated torque.Ra=1.5?.
1. Determine the firing angle α to obtain the rated torque at 1200rpm.
2. Compute the firing angle for the rated breaking torque at -1800rpm.
3. Find the firing angle corresponding to a torque of 35N·mand speed of 480rpm, assuming continuous conduction