Analysis of two-component mixture Weibull statistics for estimation of wind speed distributions
Analysis of two-component mixture Weibull statistics for estimation of wind speed distributions
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DOI：
10.1016/j.renene.2006.05.005
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发表时间：
2007-03-01
期刊：
影响因子：
8.7
通讯作者：
Ramirez, P.
中科院分区：
文献类型：
--
作者：
Carta, J. A.;Ramirez, P.
典型的双参数威布尔分布是一种灵活的分布，可用于描述许多站点风速的单峰频率分布。一个两个组成部分的混合威布尔分布（WW-probability distribution function（pdf））是更有用的，因为它是额外的能够表示非均匀风制度，其中有双峰或双切线或简单地说，单峰的证据。本文分析了三个最常用的方法在估计的WW-pdf的五个参数和数值方法进行了说明。小时平均风速数据记录在位于大加那利岛（西班牙）的四个气象站被用来分析的估计方法。不需要事先确定混合物的样本成分。分布的适用性是根据风能专业文献中常用的各种拟合检验来判断的。比较了两种方法对实验风功率密度分布的描述能力。一般的结论是，如果样本数据是独立的，那么最大似然（ML）估计应该使用，由于其大的抽样效率。然而，它们需要复杂的计算技术。最小二乘（LS）方法提供了一个强大的和计算效率的替代目前使用的技术。矩量法的缺点是，它并不总是提供一个可行的结果，并缺乏ML和LS估计所需的最优性属性。(c)2006爱思唯尔有限公司保留所有权利。
The typical two-parameter Weibull is a flexible distribution that is useful for describing unimodal frequency distributions of wind speeds at many sites. A two-component mixture Weibull distribution (WW-probability distribution function (pdf)) is even more useful because it is additionally able to represent heterogenous wind regimes in which there is evidence of bimodality or bitangentiality or, simply, unimodality.An analysis is made in this paper of three of the most frequently used methods in the estimation of the five parameters of the WW-pdf and the numerical methods employed are described. Hourly mean wind speed data recorded at four weather stations located in the island of Gran Canaria (Spain) are used to analyse the estimation methods. Prior identification of the sample components of the mixture is not required.The suitability of the distributions is judged from the various tests-of-fit commonly used in the specialised literature on wind energy. A comparison is also made of the ability to describe the experimental wind power density distribution. The general conclusion is that if the sample data are independent then maximum likelihood (ML) estimators should be used due to their large sampling efficiency. However, they require elaborate calculation techniques. The least-square (LS) method provides a robust and computationally efficient alternative to the techniques currently in use. The method of moments has the disadvantage that it does not always supply a feasible result and lacks the desirable optimality properties of ML and LS estimators. (c) 2006 Elsevier Ltd. All rights reserved.