SYNCHRONOUS MACHINES Generation of electrical energy by utility companies is done almost exclusively with synchronous machines. Assuming a constant frequency source, the speed of a synchronous motor does not vary with load. The stator windings of a synchronous machine are basically the same as those of an induction machine.
Potential for Power-Factor Correction The synchronous motor can act as a source of reactive power. Proper use of synchronous motors can lower energy costs of an industrial plant by increasing the power factor.
Auxiliary Windings Two windings that are 90° apart physically and carrying currents 90° apart in phase produce a rotating magnetic field. Single-phase induction motors contain an auxiliary winding displaced by 90 electrical degrees from the main winding.