基于加窗FFT的风电场自适应振荡抑制策略

大规模风电送出系统会出现振荡现象，现有抑制策略在振荡频率变化时难以快速、有效地抑制振荡。针对该问题，以直驱风场送出系统为研究对象，提出一种基于加窗快速傅立叶变换(FFT)和附加准比例谐振控制器相结合的振荡自适应抑制方法。首先，基于谐波线性化方法建立直驱风机(permanent magnet synchronous generator, PMSG)阻抗模型，分析PMSG发生振荡的机理以及采用附加准比例谐振控制器抑制振荡的有效性；然后，设计一种基于加窗FFT的振荡频率快速检测和提取方法，并给出相关参数的设计原则。最后，通过PSCAD/EMTDC电磁暂态仿真对比基于加窗FFT和传统FFT的控制器对振荡的抑制效果。结果表明：基于加窗FFT的控制器对振荡的抑制速度和效果具有显著优势，验证了所提振荡抑制策略的有效性。

Adaptive Oscillation Suppression Strategy for Wind Farms Based on Windowed FFT

Regarding the oscillation phenomenon in large-scale wind power transmission systems, the existing suppression strategies can hardly quickly and effectively suppress the oscillation when the oscillation frequency changes. To solve this problem, this paper takes the direct-drive wind farm transmission system as the research object and proposes an adaptive oscillation suppression method combining windowed fast Fourier transform (FFT) with an additional quasi-proportional resonant controller. Specifically, the harmonic linearization method is employed to build an impedance model for direct-drive wind turbines. The oscillation mechanism of the permanent magnet synchronous generator (PMSG) and the effectiveness of the additional quasi-proportional resonant controller in suppressing the oscillation are analyzed. Then, a fast detection and extraction method for oscillation frequency based on windowed FFT is designed, and the design principle of related parameters is presented. Finally, PSCAD/EMTDC electromagnetic transient simulation is conducted to compare the oscillation suppression effect of the controller based on windowed FFT with that of the controller based on traditional FFT. The results show that the controller based on windowed FFT has obvious advantages in oscillation suppression speed and effect, which verifies the effectiveness of the proposed oscillation suppression strategy.