Ac and Dc in synchronous generators

Discussion in 'General Electronics Chat' started by rakankhair, Apr 19, 2017.

  1. rakankhair

    Thread Starter New Member

    Apr 1, 2017
    in synchronous generators we use a DC on the rotor then rotate it but what if we use AC while rotating the rotor won't we need less mechanical power for the rotation because of the rotational Magnetic field ?
  2. crutschow


    Mar 14, 2008
    The mechanical power a generator requires is basically equal to the output power, since large generators are near 100% efficient.
    That efficiency has little to do with how the rotating field is generated (which is what converts the mechanical power to electrical).
    In other words, there's no free lunch. :rolleyes:
    rakankhair likes this.