Question

A 3- phase, 2 pole Y-connected synchronous machines has a line-line voltage of 6,000V in 60Hz power line, has an armature reactance of 2ohms/ phase and negligible armature resistance. Compute the following

A) In case of generating action if the line current is 385 A at a leading power factor of 0.8, the armature voltage per phase is 3464V, Compute the voltage per phase and power angle.

B) Draw the phasor diagram.

C) If the losses in the machine is 1000W Calculate the efficiency and the voltage regulation for the above case

D) compute the torque applied to generate the rated voltage

E) In case of the motoring action if the line current is 385A at a lagging power factor of 0.8, calculate the voltage per phase if armature voltage =3464V and power angle.

F) Draw the phasor diagram

G) If the losses in the machine is 1500W compute the output torque generated for the rated voltage.

H) Calculate the efficiency of the machine and speed regulation

Answer 1