A Single Input Variable FLC for DFIG-Based WPGS in Standalone Mode

This paper proposes a novel single input variable fuzzy logic controller (FLC) strategy for a wind turbine driven doubly fed induction generator (DFIG) with a battery energy storage in autonomous mode. The proposed control scheme has multi-functionalities such as harmonic elimination, compensation of unbalanced load currents, and extraction of maximum power from the wind. The control of rotor side converter and load side converter is based on the field-oriented approach. The proposed single input variable FLC-based control has good dynamic response as compared to conventional control algorithms. The tip speed ratio-based maximum power point tracking technique is used to extract maximum power from the wind. The simulation of DFIG-based wind power generation system is carried out under various conditions, such as constant wind speed, variable wind speeds, and load currents unbalancing, using Simpower Systems toolbox of MATLAB. The DFIG stator voltages and currents are found balanced and sinusoidal by maintaining constant frequency and voltage at PCC. Finally, a prototype of DFIG-based wind energy system is developed in the laboratory to verify the performance of the proposed control scheme at variable wind speeds and linear, nonlinear loads. The total harmonic distortions of the DFIG stator voltages and currents are obtained within the limits of the IEEE 519 standard.