风能计算及其随高度的变化

COMPUTATION OF WIND POWER WITH HEIGHT VARIATION

根据南京164m塔五层风速的资料,用极大似然法估计Weibull模式参数,进而计算平均风能和有效风能密度。用二参数和三参数Weibull模式估计的平均风能密度误差都比较小,有效风能密度的误差,16m高度上三参数模式较小,其余高度上二者几乎无差别。最后给出了用16m高度的有效风能密度、风速变异系数或风速均方差推算不同高度上平均风能和有效风能的经验公式。

Weibull model is used to compute wind power with the wind speed data obtained from a 164m tower in Nanjing. It is found that the relative errors of the mean power densities computed to ones observed (Tab.1) are all less than 3 percent for the threeparameter Weibull model and smaller than 5 percent for the twoparameter model. But the differences in the relative errors between the two models are less than 2 percent. It is also found that the relative errors of the effective power densities for the threeparameter model are less than that of the two-parameter model at the height 16m above the ground, and almost no differences at the heights above 16m. The empirical equations for estimating the variation of wind power with height are proposed.