关键词: 双馈异步风电机组, 功率解耦, 滑模变结构

Abstract: In traditional vector control of double-fed induction generators (DFIGs), voltage cross-coupling compensation caused by counter- electromotive force of the rotor side makes the active and reactive power of the system cannot be decoupled completely. Moreover, traditional vector control relies on parameters of DFIGs heavily, which makes its control performances sensitive to the parameter variations and external disturbances. So, the exact linearization theory of decoupling control method is applied, which can reflect the time-variation strong-coupling characteristics of the high-order nonlinear system more accurately. In addition, taking account of the operation environment of the uncontrolled and strongly random wind speed, which makes the adjustment process of the traditional PI controller excessively lag behind and affect the dynamic-response performances, the sliding mode variable structure control theory is applied to design the controller with good dynamic-response and robustness against outside interferences and parameter uncertainties. The simulation results show that the proposed decoupling control method can make the controller achieve complete-decoupling and robust control of the active and reactive power with good dynamic-performance.

Key words: doubly-fed induction generator, power decoupling, slide-mode and variable structure control