Robust Control Design for DFIG based Wind Turbine under Voltage Sags

Recently, grid stability and power generation are key issues. Due to the high penetration of wind power, grid faults recovery behaviors of a wind turbine have significant effect on power system stability. Grid voltage faults cause voltage fluctuations and harmonic current in DC-linked capacitor of Doubly Fed Induction Generator (DFIG) based Wind Turbines (WTs), which degrade the performance and reliability of capacitor in voltage source converters. However, robust controller is required to provide stable DC-linked voltage. In this paper Adaptive Proportional Integral (API) algorithm is proposed for Grid Side Converter (GSC) of DFIG based WTs which mitigate voltage fluctuations and harmonic current in DC-linked capacitor. Furthermore, it also enhances active and reactive power quality injected to the grid. For validation of the proposed control algorithm, MATLAB/Simulink simulation of 2MW DFIG model has been considered and results are compared with conventional used Proportional Integral (PI) controller. Total Harmonic Distortion (THD) further validate and analyze the effectiveness of proposed controller by comparing it with the conventional PI controller.