Unified Fault Ride‐Through Control of DFIG Wind Turbines via Adaptive Flux Damping and Disturbance‐State Separation

With the increasing penetration of renewable energy, doubly fed induction generator (DFIG) systems are increasingly exposed to low‐high voltage cascading disturbances rather than isolated voltage events. Such disturbances cause stator flux components to be inherited and superimposed across stages, leading to intensified rotor current surges and aggravated DC‐link energy fluctuations. To address this issue, a unified transient model of the DFIG under cascading faults is established to reveal the residual flux inheritance mechanism. Based on this mechanism, a mechanism‐oriented full‐process coordinated control framework is proposed for the rotor‐side converter (RSC) and grid‐side converter (GSC). The RSC integrates active demagnetization with adaptive reactive power regulation to suppress residual‐flux‐induced electromagnetic transients, whereas the GSC employs linear active disturbance rejection control (LADRC) with adaptive fusion of fast and slow linear extended state observers (LESOs) to regulate the DC‐link voltage. A stator‐flux‐error‐based cross‐converter compensation mechanism further couples the transient actions of the RSC and GSC, so that flux damping, reactive power regulation, and DC‐link energy balancing are coordinated throughout the cascading fault process. Simulation results under low‐voltage ride‐through (LVRT), high‐voltage ride‐through (HVRT), and cascading fault conditions show that the proposed method effectively limits rotor current, torque oscillation, and DC‐link voltage deviation to within 0.8, 0.6, and 0.02 p.u., respectively, demonstrating improved overall fault ride‐through performance.