Improved fluctuation behavior of SCIG based wind energy system using hybrid pitch angle controller

The variation in wind speed causes the variation in the real/reactive power transfer of Squirrel Cage Induction Generators (SCIGs) based wind energy system (WES) connected to the grid resulting in fluctuations in the grid voltage and frequency. The SCIG based wind energy systems have to rely upon the mechanical pitch angle control of their wind turbines to smoothen out power fluctuations. This paper, therefore, presents a hybrid (conventional PI plus fuzzy logic) controller for pitch control of SCIG based WES to smoothen power output fluctuations. PI controller is designed using pole placement technique to contribute effective damping to the system under different operating conditions. The PI controller is tuned and adapted using the fuzzy logic controller (FLC). It is observed that the proposed hybrid pitch angle controller is capable of smoothing power fluctuations compared to PI controller.