An alternator has an armature of 12 poles, having a flux of 0.0988 Wb and 72 slots. Calculate: (a) The speed of rotation, if the frequency of the generated e.m.f. is 50Hz. (b) The terminal e.m.f. when star-connected full-pitch, 3-phase windings with 8 conductors per slot. (c) The terminal e.m.f. when star-connected if the coil span is reduced to 2/3 of the pole pitch. Assume distribution (breadth) factor = 0.966.
Synchronous Generator
In comparison to an asynchronous generator, it is a machine where the rotor speed is equal to the rotating magnetic field produced by the stator, i.e., mechanical speed is equal to the electrical speed, thus called synchronous, and not asynchronous.
Salient Pole Rotor
Salient pole rotor includes a large number of exposed poles mounted on a magnetic wheel. The construction of a bright pole is as shown in the image on the left. The proposed poles are made of metal laminations. The rotor winding is provided on these poles and is supported by pole shoes.
An alternator has an armature of 12 poles, having a flux of 0.0988 Wb and 72 slots. Calculate:
(a) The speed of rotation, if the frequency of the generated e.m.f. is 50Hz.
(b) The terminal e.m.f. when star-connected full-pitch, 3-phase windings with 8 conductors per slot.
(c) The terminal e.m.f. when star-connected if the coil span is reduced to 2/3 of the pole pitch.
Assume distribution (breadth) factor = 0.966.
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