运用功率谱密度PSD理论和时域-频域变换原理,通过考察风电功率波动分量的PSD分布特点,系统地研究并阐述具有不同均值的风电功率波动所具有的频谱特征.构建电网调频仿真模型和以风电功率波动为激励、以电网频率偏差和机组(及储能电源)出力变化量为响应的电网幅频特性,比较研究了仅常规机组调频和储能电源参与调频的电网幅频特性的变化规律.针对单纯的时域指标无法体现调频责任分配的局限性,提出一种基于时、频域指标的储能系统参与调频的效果评价方法.仿真算例表明,所提出的方法能全面有效地评价储能参与调频过程中与常规机组在调频责任分配上的区别,可为评价储能相关控制方式的有效性及分析其在调频过程中所起的作用提供定量参考依据.%Based on the theory of power spectral density(PSD)and the principle of time-frequency domain transforma-tion,the PSD distribution characteristics of wind power fluctuation components are investigated,and the frequency spectrum characteristics of wind power fluctuation with different mean values are systematically studied and described. Grid models are built for simulating frequency regulation,and the amplitude-frequency characteristics of the grid are ob-tained with the wind power fluctuations as incentives,and the grid frequency deviation and the output power increment of the units and energy storage system(ESS)as responses. Considering two cases of frequency regulation for convention-al power units without/with ESS,the amplitude-frequency characteristics are compared. To overcome the limitation that the simple time domain indexes cannot reflect the duty distribution of frequency regulation,a method based on time-fre-quency domain index is proposed to evaluate the effect of ESS on frequency regulation. Simulation examples prove that the proposed method can comprehensively and effectively evaluate the duty difference between ESS and the convention-al units in the frequency regulation process,which can provide quantitative reference for evaluating the effectiveness of ESS related control methods and analyzing their role in the frequency regulation process.
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