<scp>Model‐assisted</scp> active disturbance rejection controller for maximum efficiency schemes of <scp>DFIG</scp> ‐based wind turbines
Ahmed Sobhy, Dong Lei
Abstract
This article deals with the improvement of maximum efficiency schemes of doubly fed induction generator–based wind turbines (DFIG-WTs) through controlling their rotor current. The nonlinearity characteristics, parameters uncertainty, and grid disturbances in the DFIG-WTs may affect the tracking performance and the energy conversion efficiency. The magnetizing inductance has the highest value, compared to the other DFIG parameters. Also, its value varies during grid disturbances due to main flux saturation. Therefore, improper setting of its value in the controller can result in significant performance distortion. Active disturbance rejection controller (ADRC) is a simple and robust control technique that can deal with the system's internal and external disturbances. Besides, ADRC does not strongly depend on the accurate mathematical model of the system. For further improvement of the response speed of the traditional ADRC, a novel control strategy based on a model-assisted ADRC (MA-ADRC), considering the variation of the magnetizing inductance, is proposed to regulate the rotor current. Furthermore, a new tuning approach is suggested to evaluate the parameters of the MA-ADRC. Response of the presented strategy is assessed on a 1.5 MW DFIG-WTs using MATLAB/Simulink package. The proposed MA-ADRC is compared with the traditional proportional-integral (PI) controller and existing ADRCs strategies under various scenarios. The simulation results validate the precise tracking performance of the suggested strategy and its robustness against grid disturbances and wind speed variations.