Enhancing Low-Voltage-Ride-Through in Grid-Connected DFIG-based WECSs Using an Adaptive Backstepping Control Approach

To accommodate the widespread use of grid-connected wind energy systems (GCWES), grid operators frequently update grid codes to ensure improved grid stability. Wind energy conversion systems (WECS) employ low-voltage-ride-through (LVRT) as a crucial feature for sustained grid connection during transient voltage disruptions. Despite control mechanisms in place, challenges such as imbalanced phase voltage, parameter uncertainty, and insufficient reactive power assistance have been observed. Hence, this paper proposes an adaptive backstepping controller (ABC) for doubly fed induction generators (DFIGs)-based GCWES to enhance the LVRT. The controller aims to provide adequate active and reactive power to the grid for enhancing LVRT capacity, specifically addressing issues related to rotor-side converters and DC-link voltage dynamics. The proposed controller utilizes adaptation principles and it is developed iteratively through the Lyapunov control theory. Control Lyapunov Functions (CLFs) are employed to ensure convergence of physical features of DFIGs-based GCWES. Finally, MATLAB/Simulink validates the proposed approach, simulating severe faults at the wind farm's point of common coupling and comparing results with existing controllers.