ABSTRACT
The DFIG-based wind turbine has been used widely when connecting to the AC grid. As a variable-speed wind generator, the DFIG has a number of advantages compared to fixed-speed generators, including that the machine can operate in subsynchronous mode, synchronous mode, as well as super-synchronous mode, decoupled control of active and reactive power, better energy capture, mechanical stress reduction, and low cost with the development of the power electronics converters [50]. The conventional topology, the bi-directional buck-boost DC-DC converter, is connected between the fixed DC Link voltage. The RSC is connected to the rotor controlling the active and reactive power of the DFIG stator. The GSC regulates the DC Link voltage with the AC side to the converter connected to the grid [61, 65].
