基于短期历史资料的河西地区太阳辐射预报订正研究

Study on correction of solar radiation forecast in Hexi region of Gansu Province based on short-term historical data

基于数值模式的太阳辐射预报往往存在一定的系统性偏差,AVT订正方法能够有效降低预报偏差,本文利用该方法对甘肃河西地区两个光伏电站的太阳辐射预报结果进行订正。结果表明:(1)订正前预报偏差呈现明显的"先增加、后减小"日变化特征,订正后日变化特征不明显,并且订正前预报偏差与观测值线性关系显著,订正后线性关系减弱(相关系数降低、拟合优度降低);(2)太阳辐射存在明显的年变化特征,其预报偏差春季最高,其次为夏季,冬季最小,订正后不同季节的预报偏差均降低,春季和夏季降低较为明显。

There are some systematic biases in prediction of solar radiation based on numerical models, the AVT method has been verified to reduce the prediction bias effectively. The AVT correction method was used to modify the forecasted solar radiation in two photovoltaic power plants in Hexi area of Gansu Province. The results state:(1) Before correction the forecast bias presented obviously diurnal variation with increase first and then decrease, while it wasn’t obvious after correction. There was a strong linear relationship between forecast deviation of solar radiation and observed values before correction, while it got weak after correction(the correlation coefficient and good fitting degree decreased).(2) There was obviously annual change characteristic of solar radiation with the highest forecast bias in spring, followed by summer, autumn and winter. After correction, its forecast bias was reduced in four seasons, especially in spring and summer.