为了准确分析风速与系统负荷之间的相关性,提出一种计及风速一负荷相关性含风电机组(Wind Turbine Generator,WTG)的配电网可靠性评估方法。利用多元统计方法建立风速与负荷的正态分布模型,计算二者的相关系数,得到风速一负荷联合二元正态分布函数。采用该方法对改进RBTS系统进行计算,根据联合分布函数用MonteCarlo法对风速一负荷序列进行抽样,结合WTG出力模型,得到其对孤岛的供电能力范围,分别计算每种抽样结果的可靠性指标,最后得到系统可靠性指标,并分析多种因素对可靠性指标的影响。该方法能准确反映时序风速和负荷的相关性,从而提高可靠性计算的精确性。
In order to analyze correlations between wind speed and load accurately, an algorithm considering the correlation between the time series of wind speeds and loads for evaluating the reliability of distribution systems containing wind turbine generator (WTG) is presented. This method based on multivariate statistical analysis technique is used to evaluate the normal distribution functions of wind speeds and loads and calculate the correlation coefficient between them, then the wind-load bivariate normal distribution is established. Taking improved RBTS system as an example, the wind-load sequence is produced using the Monte Carlo method based on bivariate normal distribution, and then the probability and supplied area of WPGs for a sampling state can be determined using WPG output model. The load point reliability indices can be evaluated, then the feeders and system reliability indices can be obtained. The results of the RBTS system show that the proposed algorithm can correctly describe the correlation between the time series of wind speeds and loads and is suitable for evaluating the reliability of distribution systems containing WTG.