两种太阳总辐射分钟级预报方法的比较

Comparison on two prediction methods of minutely global solar radiation

利用2010年9月1日至2011年8月31日中国气象局风能太阳能资源中心吐鲁番太阳能试验站水平太阳总辐射逐分钟观测资料,对统计外推法(简称外推法,TRD)和动态神经网络法(简称神经网络法,NNN)两种太阳总辐射分钟级预报方法进行比较。结果表明:从全年平均角度来看,外推法略优于神经网络法。两种预报方法的预报效果都主要依赖于天气形势,晴天预报效果最好,阴雨天气次之,多云和扬沙天气预报效果较差。外推法能较准确地反映起报时刻影响辐射观测的云、气溶胶、沙尘等状况,并将这种影响持续至滚动预报的第一步或第二步;而神经网络法在阴雨、多云等复杂天气形势下预报要素的非趋势性变化规律方面略优;外推法预报日出后3 h和日落前3 h的太阳总辐射变化明显优于神经网络法;而神经网络法预报太阳总辐射突然变化特征时略优于外推法。

Using the minutely global solar radiation data from September 1,2010 to August 31,2011 at the Turpan solar energy station of center for wind and solar energy resources of China Meteorological Administration （CMA） ,two prediction methods of minutely global solar radiation were compared,namely ,a statistical extrapola- tion （TRD） method and a dynamic neural network （NNN） method. The results show that for the annual average, the prediction effect is better by the TRD than by the NNN. The prediction accuracy rates of the two methods is related with weather situation. It is higher in a sunny day than in a rainy day, while it is lower in a cloud day and a sand-storm day. The impact factors of radiation observation such as cloud, aerosol and dust and so on could be ac- curately expressed by the TRD method at the beginning time of prediction, which could be continued to the first or second step of rolling forecasts. The prediction effect is better by the NNN than by the TRD for the non-linear variation of global solar radiation under complex weather such as rainy day and cloud day. The predication accuracy of global solar radiation is higher by the TRD than by the NNN for three hours after sunrise and before sunset. The prediction effect is slightly better by the NNN than by the TRD for a sudden variation of global solar radiation.