Doubly fed electric machine

Doubly fed electric machines, also slip-ring generators, are electric motors or electric generators, where both the field magnet windings and armature windings are separately connected to equipment outside the machine.

By feeding adjustable frequency AC power to the field windings, the magnetic field can be made to rotate, allowing variation in motor or generator speed. This is useful, for instance, for generators used in wind turbines.[1] Additionally, DFIG-based wind turbines offer the ability to control active and reactive power.[2][3]

  1. ^ "Generators for wind turbines Standard slip ring generator series for doubly-fed concept from 1.5-3.5 MW" (PDF). ABB. 2014. Retrieved April 24, 2018.
  2. ^ M. J. Harandi, S. G. Liasi and M. T. Bina, "Compensating Stator Transient Flux during Symmetric and Asymmetric Faults using Virtual Flux based on Demagnetizing Current in DFIG Wind Turbines," 2019 International Power System Conference (PSC), Tehran, Iran, 2019, pp. 181-187, doi:10.1109/PSC49016.2019.9081565.
  3. ^ M. Niraula and L. Maharjan, “Variable stator frequency control of stand-alone DFIG with diode rectified output”, 5th International symposium on environment-friendly energies and applications (EFEA), 2018.