A three-phase, fully controlled thyristor bridge converter is used as line commutated inverter to feed 50 kW

A three-phase, fully controlled thyristor bridge converter is used as line commutated inverter to feed 50 kW power 420 V dc to a three-phase, 415 V(line), 50 Hz ac mains. Consider dc link current to be constant. The rms current of the thyristor is 

(A) 119.05 A (B) 79.37 A (C) 68.73 A (D) 39.68 A
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Answer :

A three-phase, fully controlled thyristor bridge converter is used as line commutated inverter to feed 50 kW power 420 V dc to a three-phase, 415 V(line), 50 Hz ac mains. Consider dc link current to be constant. The rms current of the thyristor is 68.73 A

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