Analysis of Active Power Dynamic Response Characteristics and an Improved Strategies for Grid-Forming DFIG

Compared with the phase-locked loop-based grid-forming control (GFL), the power-synchronized grid-forming double-fed induction generator (GFM-DFIG) has better stability under weak grid conditions. However, for GFM-DFIG with the closed-loop control strategy using power outer loop and stator voltage & rotor current inner loop, the multi-loop structure may lead to insufficient damping in the system. In this paper, a modeling and analysis of GFM-DFIG is conducted to quantify the influence of power loop and voltage loop parameters on the active power response characteristics. A strategy combining lead-lag control strategy (LLCS) and proportional feedforward of active power rotor current control strategy (PFA-PRC) is proposed to improve the active power response characteristics of GFM-DFIG. Finally, the effectiveness of the proposed strategy is verified through simulation.