Synchronous Generator In a synchronous generator,rotor-winding current is supplied directly from an outside DC source through a rotating contact. A direct current is applied to the rotor winding,which then produces a rotor magnetic field. The rotor is driven by a prime mover(e.g. a steamturbine)and produces a rotating magnetic field.This rotating magnetic field induces a set of 3-phase voltages in the stator windings