System voltage and frequency control using DFIG based Wind Energy Conversion System

The penetration of wind power in electrical power systems has been increasing at an unprecedented rate. Hence, the wind generators can be expected to behave more like the conventional generators. A doubly fed induction generator (DFIG) has two converters connected to the rotor winding which can be useful in supplying additional active and reactive power to the system during system frequency and voltage sag respectively. This paper proposes to use two separate current control loops on the Machine Side Converter to supply additional active power during system frequency distortions and to reduce the transients in stator voltage after clearing the system voltage dips. In so far we have proposed the design of a current controller on the Grid Side Converter (GSC) to bring the system voltage level to the desired level during the system voltage sag condition. The result and concepts has been validated using MATLAB/SIMULINK environment.