engineering recuitment HPCL Engineer Mock Test 2024 Power Electronics and Drives Phase Controlled Rectifiers Three Phase Thyristor Converter Circuits
A three-phase full controlled converter (with 6 SCRS only) is feeding the armature of a separately excited DC motor. The motor has to also operate in quadrant-III. Which of the following methods is suitable?
1
By connecting a freewheeling diode across the armature in addition to adjusting the triggering angle α
2
By adjusting the triggering angle α only
3
By adjusting the triggering angle α followed by armature connection reversal
4
By operating with triggering angle α > π/2 rad