基于PWMM的三参数Weibull分布参数外推方法的研究

RESEARCH ON PARAMETER EXTRAPOLATION METHOD FOR THREE PARAMETER WEIBULL DISTIRBUTION BASED ON PWMM

为提高低风速区分散式风电项目的风资源评估精度,降低测风成本,在对三参数Weibull分布参数估计和外推的研究基础上,提出基于概率加权矩法(PWMM)的三参数Weibull分布参数垂直外推方法。利用较低高度处风速统计的概率加权矩,经垂直外推得到平坦地形、较高高度处风速Weibull分布的参数,进而得到Weibull分布函数和风功率密度。算例分析表明:基于PWMM的三参数Weibull分布参数垂直外推法在平坦地形不同测风点处有一定的适用性外推较高高度处风速Weibull分布的参数,可有效体现平坦地形低风速区的风速分布特征,提高风功率密度评测精度。

In order to improve the estimation accuracy of wind resource assessment and reduce the cost of wind measurement for distributed wind power projects with low wind speed,based on the study of the estimation and extrapolation of the three-parameter Weibull distribution parameters,a three-parameter Weibull distribution parameter vertical extrapolation method based on Probability Weighted Moments Method(PWMM)is proposed.Using the probability weighted moments of wind speed statistics at the lower height,the wind speed parameters of the Weibull distribution in the flat terrain at a higher height are obtained by vertical extrapolation,then the Weibull distribution function and wind power density are obtained.The analysis of the example shows that the three-parameter Weibull distribution parameter vertical extrapolation method based on PWMM has certain applicability at different wind speed measurement points of flat terrain.It also can effectively reflect the wind speed distribution characteristics of the flat terrain with low wind speed,and improve the accuracy of wind power density evaluation.