The vast majority of wind turbines that are currently being installed use one of the three main types of electromechanical conversion system. The first type is known as the Danish concept. The second type uses a doubly fed induction generator instead of a squirrel cage induction generator. The third type is called the ‘direct-drive wind turbine’ because it does not need a gearbox. In this paper...

-Doubly Fed Induction Generators (DFIGs)find a great deal of application among variable speed wind turbines because of their advantages like operation at variable speed, ability to produce active and reactive power in all the four quadrants, higher efficiency, and extracting maximum electric power at different velocities of wind with the help of speed variation of the rotor and the usage of con...

Wind Energy Conversion Systems (WECS) have become a focal point in the research of renewable energy sources. This paper provides then a comparative study of past and present generator technologies used in WECS. This study is based on an exhaustive review of the state of the art and on an effective comparison of the performances of the four main topologies that are permanent magnet generators, s...

In this paper steady state characteristic of a variable speed Doubly fed induction generator (DFIG) is investigated. Torque and speed is used as design parameters for DFIG. From mathematical model it is found that on increase of rotor injection voltage and resistance, the torque speed response is shifted from over synchronous to sub synchronous range. The stability of DFIG operation is entirely...

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generator...

This chapter presents the theoretical basics of the electric power generation using doublyfed induction drives in wind turbines. This type of drive is the most utilized in wind power plants nowadays. This is mainly due to its fast dynamic response and reduced power electronics on the rotor side. This latter aspect is responsible for less harmonic pollution in the network and reduced acquisition...