ENERGY KIDS

Main wind turbine concepts


Concept 1 - fixed speed (Danish Concepts)

Wind turbine concepts 1 In that concepts the configuration denotes the fixed speed controled wind turbine with SCIG (Squirrel Cage Induction Generator) that is directly connected to the grid through a transformer.
Since SCIG always draws reactive power from the grid, this concept uses a capacitor bank for reactive power compensation.
Smoother grid connection occurs by incorporating a soft-starter.


Concepts 2 - variable speed wind turbine with variable rotor resistance

Wind turbine - concepts 2 Here in the turbine is used Controlled CRRIG (Rotor Resistance Induction Generator) and pitch control.
The rotor winding of the generator is connected in series with a controlled resistance, whose size defines the range of the variable speed.
Since the losses are proportional to the slip, a limited slip range is used.
As in the Danish wind turbine concepts (consepts 1), the reactive power compensation and a soft starter are required for this concepts.


Concepts 3 - variable speed wind turbine concepts with partial-scale frequency converter (DFIC)

Wind turbine - concepts 3 The concepts denotes the variable speed controlled wind turbine with a DFIG (Double Fed Induction Generator) and pitch control.
The stator is directly connected to the grid, while the rotor is connected through a partial-scale frequency converter, typically with a capacity of only 25-30% of a full-scale converter.




Concepts 4 - variable speed concepts with full-scale frequency converter

Wind turbine - concepts 4 The concepts corresponds to the full variable speed, pitch controlled wind turbine, with the generator connected to the grid through a full scale frequency converter.
The frequency converter provides the reactive power compensation and a smooth grid connection for the entire speed range.



Source: ISES