风资源评价中风切变指数的研究

Study on the wind shear exponent for wind resource assessment

通过分析现行风资源评价中关于风切变指数的计算和表达方式,提出了几种新的风切变指数计算和表示方法,并从局部和整体对风切变指数进行描述。通过比较不同计算方法的标准差和偏离系数等统计指标,发现分速度段计算的不同高度层的风切变指数精度较高,而采用指数律计算的整体风切变指数具有可信度高和结果稳定的特点。文章进一步地明确了风切变指数的物理含义,详细地描述了风切变年平均结果、日变化和月变化。

This paper proposes some new methods for the calculation of wind shear exponent, through the analysis on the present one for the wind resource assessment. The wind shear exponent is described locally and fully by different methods. By comparing the standard error and departure coefficient of different methods, it is found that the wind shear exponent in different vertical layers calculated in different speed bins has the highest precision. While, the wind shear exponent calcu- lated by the exponent law has the characteristic of high credibility and high stability. Furthermore, the physical meaning of the wind shear exponent is clarified. The annual averaged result, diurnal variation and monthly variation of the wind shear are also described in detail.