- 7 A 3 Phase Synchronous Motor Connected To 6 600 V Mains Has A Star Connected Armature With An Impedance Of 2 5 J15 O 1 (17.43 KiB) Viewed 72 times
7. A 3-phase synchronous motor connected to 6,600-V mains has a star-connected armature with an impedance of (2.5+j15) ohm per phase. The excitation of machine gives 7000 V. The iron, friction and excitation losses are 12 kW. Find the maximum output of the motor. [153.68 kW] 8. A 3300-V, 3-phase, 50-Hz, star-connected synchronous motor has a synchronous impedance of (2+j15) ohm. Operating with an excitation corresponding to an e.m.f. of 2.500 V between lines, it just falls out of step at full-load. To what open-circuit e.m.f. will it have to be excited to stand a 50% [4 kV] excess torque. AFETIV