Performance Analysis of Adaptive Speed Reference Tracking QFT Robust Controller for Three Phase Grid connected Wind Turbine under Stochastic Wind Speed Conditions

Due to stochastic nature of wind, stator current harmonics arise in PMSG based wind energy conversion system that causes the oscillations in wind turbine shaft. These oscillations shows adverse effect on lifespan of wind turbine. It is desirable to track the speed reference in grid connected variable speed wind system along with the maximum power extraction. In this sense, this paper presents the robust controller design methodology to achieve the reference speed tracking controller with maximum power extraction capability in variable speed PMSG driven wind turbines. Further, A modified fitness function is introduced to design the automated robust controller using Genetic algorithm in quantitative feedback theory framework. MATLAB simulations are performed on 20 kW three phase grid connected wind system to analyse the dynamic performance of proposed robust controller under step variation and stochastic wind speed conditions. It is evident from the simulations that tracking of reference speed is achieved with proposed controller under power injecting to load and power sharing with grid conditions.