Three-phase doubly fed induction generators: an overview

Adjustable speed induction generators, especially the doubly fed induction generators (DFIG), are becoming increasingly popular due to their various advantages over fixed speed generator systems. A DFIG in a wind turbine has the ability to generate maximum power with varying rotational speed, ability to control active and reactive power by the integration of electronic power converters such as the back-to-back converter, low rotor power rating resulting in low cost converter components, and so on. This study presents an extensive literature survey over past 25 years on the different aspects of DFIG.