Comparison of Controlling Techniques for Active and Reactive Power in Wind Energy Conversion System

Abstract

Wind energy has emerged as one of the sustainable power sources in recent years. One of the major challenges in wind energy is to extract maximum power from the generation of wind farms as wind power generation strongly depends on wind speed variation. The purpose of this thesis is to get the best control mechanism for maximum power extraction in Doubly Fed Induction Generator (DFIG) based wind turbine. The proposed techniques allow the generator to track the optimal operation points under a variable-speed wind energy conversion system. The proposed system contains the model of DFIG, wind turbines, generator side convertor, grid side convertor, and model of the controller. Then establish simulation model for DFIG-based wind turbine with controlling techniques based on MATLAB/Simulink platform with Proportional-Integral Controller (PI), Fuzzy Logic Controller (FLC), and Super Twisted sliding Mode Controller (STSMC). The most extensively used and applicable controller in the wind sector is the conventional PI controller, which requires modification for every change in reference pattern and also has a high overshoot and a prolonged settling time. Hence, to ensure robustness against external disturbances, FLC and SMC are applied to the converters, but the conventional SMC has a chattering problem. To improve this phenomenon, the STSMC technique is implemented on this thesis. The result shows an improved performance in terms of settling time, overshoot and rise time for active power. The response shows that the PI has a settling time of 1.0351 sec and an overshoot of 3.9 %. Whereas FLC has a settling time of 0.8021 sec and an overshoot of 2.8 %. The last STSMC has a settling time of 0.3314 sec and an overshoot of 2.2 %. This leads to the conclusion that the STSMC controller has better-controlling performance.