中文摘要：

平滑效应是大规模风电群聚所共有的特性之一,其显著程度直接影响总出力的波动性,掌握其基本规律可为大规模风电的预测及评估提供可靠依据。本文采用数理统计的分析方法,研究了多时空尺度下风机集群的平滑效应,建立了平滑效应、出力相关性、风机台数三者之间的函数关系,分析了同一风电场内风机集群的平滑效应极限值。基于风电场的实测数据,对比分析了不同时间尺度、风机间距、风速大小下的出力相关性,进而给出了平滑效应的时空变化特性。研究结果表明：在分钟级时间尺度下,风电集结的空间规模效应较显著,平滑系数随风机台数（N）的递增呈现近似N-1/2的下降趋势;在给定的时空尺度下,平滑效应随风速的增大而增强。

英文摘要：

Smoothing effect is one of the common features of large-scale wind power aggregations and its significative degree directly impacts the fluctuation of the aggregated power output, thus mastering its basic law can offer reliable foundations for the prediction and evaluation of large-scale wind farms. Utilizing the analysis methods of mathematical statistics, the smoothing effect of wind turbine clusters in multiple spatial and temporal scales is studied and the functional relation among the smoothing effect, the output correlations and the number of wind turbines （N） is established, and the limiting value of smoothing effect of wind turbine clusters in the same wind farm is analyzed. Based on the measured data of a wind farm, the output correlations under different temporal scales, turbine spacings and wind speeds are compared and analyzed, and further the temporal-spatial characteristics of smoothing effect are given. The results show that the spatial effect of aggregating wind turbines is significant under the time scale of minutes and the smoothing coefficient decreases by an approximate factor of N^-1/2 with the increase of N. Moreover, the smoothing effect enhances with the increase of wind speed under given temporal and spatial scales.