A 100 kW, 500 V, 2000 r.p.m separately excited d.c. motor is energized from a 400…

A 100 kW, 500 V, 2000 r.p.m separately excited d.c. motor is
energized from a 400 V, 50 Hz, three phase source through a three
phase full converter. The voltage drop in conducting thyristors is
2 V. The d.c. motor armature resistance is 0.1 Ω, motor constant is
1.6 V-s/rad, rated armature current is 210 A and no-load armature
current is 10% of rated current. Determine the following:
i) Motor terminal voltage at a firing angle of 30
ii) No load motor speed at a firing angle of 30
iii) The firing angle for a speed of 2000 r.p.m at rated
armature current