矩函数在风速Weibull分布参数估计中的应用

Application of moment function in Weibull distribution parameter estimation for wind speed

服从Weibull分布的随机变量的各阶矩仍然服从Weibull分布，根据这一统计学性质，采用矩函数法估计WeibuU分布参数。分别基于风速原点矩和风速中心矩对风速的Weibull分布参数k、c进行了估计，并给出了参数估计公式。根据所提方法解出风速概率分布后，可以根据Weibull分布计算风能特征指标。以河西某风电场为算例．分别以所提方法、均值和方差估计法对其进行Weibull分布参数估计和风能特征指标计算．同时给出了直接由风速数据统计出的各项特征指标进行对比，结果表明所提方法计算结果的整体误差较小．精度明显高于均值和方差估计法。

If a random variable obeys the Weibull distribution,its moment of each order still obeys the Weibull distribution,according to which,the moment function is applied to estimate the Weibull distribution parameters. The Weibull distribution parameter k and c of wind speed are estimated respectively based on its origin moment and central moment. The parameter estimation formulas are given and the probability distribution of wind speed is calculated. The characteristic indexes of wind energy are then calculated according to its Weibull distribution. As an example,the Weibull distribution parameters and wind energy characteristic indexes of a wind farm in Hexi are calculated by the proposed method and the mean and variance estimation method. Compared with the characteristic indexes obtained directly from wind speed data,the calculated results by the proposed method have higher precision and less overall error.