Problem 4:
A \( 1,200-\mathrm{V} \), three-phase, Y-connected synchronous motor takes \( 110 \mathrm{~kW} \) (exclusive of field winding loss) when operated under a certain load at \( 1,200 \mathrm{r} / \mathrm{min} \). The back emf of the motor is \( 2,000 \mathrm{~V} \). The synchronous reactance is \( 10 \Omega \) per phase, with negligible winding resistance. Find the line current and the torque developed by the motor.
Solution:
