The dc armature winding resistance between terminals of a 750 kVA, 4400 volt, three-phase alternator is 0.9 ohm. Calculate the copper loss in the winding at full-load.
Answer (1)
The answer is 26,164 W or 26.16 kW.Given - 750 kVA, 4400 V, three-phase alternator, resistance = 0.9 ohm.Step 1 - Full-load current (I) = Power / (Voltage × √3) = 750,000 / (4400 × 1.732) = 98.43 A per phase.Step 2 - Copper loss = I² × R × 3 (for three phases) = (98.43)² × 0.9 × 3= 26,164 W or 26.16 kW.
