Control Strategy of Voltage-Controlled Doubly-Fed Induction Generator Based on Model Predictive Control

The conventional current-controlled doubly-fed induction generator utilizes phase-locked loop synchronization, depending on grid-connected point information. It exhibits characteristics of low inertia and damping, making it unsuitable for highly penetrated grid systems. The voltage-controlled doubly-fed induction generator (VC-DFIG), self-synchronized with the grid, offers voltage and frequency support, particularly suitable for weak grid operation. To enhance VC-DFIG's dynamic performance, this study proposes a model predictive control strategy. Modeling DFIG on a two-phase stationary coordinate system, employing virtual synchronous control, the structure integrates stator voltage outer loop and rotor current predictive control to establish rotor current prediction equations. Model predictive control replaces the traditional PI-controlled rotor current loop, improving system dynamic response and robustness while avoiding complex coordinate transformations and PI parameter rectifications. Theoretical analysis and an 11KW DFIG simulation platform validate the control strategy's effectiveness.