Ouput power smoothening of variable-speed wind turbine systems by pitch angle control

This paper proposes a new strategy of the output power smoothening for the variable speed wind turbine systems, which is based on the pitch angle control using the fuzzy logic controller. In this method, the turbine power and its reference are used as control input variables for the fuzzy logic controller (FLC), in which the turbine power reference is determined depending on the double exponential smoothening (DES) method. This method is effective to smoothen the generator output power without any need of the power compensation by the energy storage system. The effectiveness of the proposed method is verified by simulation results for a 2-MW PMSG wind turbine system.