双馈风电系统中电流控制与直流电容动态交互的跨时间尺度研究

The Doubly-Fed Induction Generator (DFIG) based wind turbine (WT) contains control loops and energy storage components operating across multiple timescales, leading to potential cross-timescale influence dynamics in DFIG-WT-dominated power systems. Previous analyses have primarily focused on single timescale dynamics or the interactions between control loops at different timescales, with limited attention given to the cross-timescale influences between control loops and energy storage components. This paper aims to reveal the cross-timescale influence mechanism of current control at the AC-current-control timescale on the dynamics of the DC capacitor at the DC-voltage-control timescale. Modal analysis is a mature method used to uncover the cross-timescale influence phenomena and laws of current control on the dynamics of the DC capacitor. Subsequently, an equivalent circuit model is established to analyze the mechanism by which current control affects the dynamics of the DC capacitor. Finally, the conclusions are validated through simulations based on a four-machine two-area power system and the power grid of Northwest China.