太阳辐照测量对光伏系统发电性能评估的影响

Influence of Solar Irradiation Measurement on the Performance Evaluation of Photovoltaic System

以国内某光伏电站为研究对象,利用两种不同精度的太阳辐照计对电站现场的太阳辐照情况进行测量比对,基于得到的辐照数据与发电数据对系统发电性能进行分析。通过为期一个月的现场采集数据对比分析,发现该电站原有辐照计A测量数据比参考辐照计B测量数据平均低约22.23%。对二者进行相关性分析,得到了对辐照计A测量数据的修正计算公式,利用该修正计算公式可得到与电站现场实际情况较为一致的太阳辐照数据。此外,以参考辐照数据B计算出的电站11月日均PR为73.27%;经修正前后的辐照数据A计算出的PR分别为94.53%、71.07%。修正前的辐照数据A与参考辐照数据B计算出的PR相对差异为28.92%;修正后的PR相对差异为-2.39%。研究结果表明,太阳辐照的精准测量对光伏发电系统性能的准确评估至关重要。建议在电站现场配备精度高、运行稳定的太阳辐照监测设备。

Two kinds of pyranometers with different precision are used to measure and compare the solar irradiation of a photovoltaic(PV)power station in China,and the performance of the power station is analyzed based on the obtained data of irradiation and power generation.Through the comparison of the field data for a period of one month,we found that the irradiation data measured from original pyranometer A are about 22.23%lower than the reference pyranometer B in average.By analyzing the correlation between the data of A&B,a modified formula for calculating the corrected irradiation data of A is obtained and the irradiation data which are consistent with the actual situation of the power station can be obtained by using this modified formula.In addition,the system's average daily PR calculated by reference irradiation B is 73.27%,and calculated by irradiation A before a nd a fter correction is 94.53%a nd 71.07%,respectively.T he relative difference of PR calculated between original irradiation A and reference irradiation B is 28.92%,and the relative difference of PR calculated between corrected irradiation A and reference irradiation B is-2.39%.The results of this paper show that the sophisticated measurement of solar irradiation is very important for the accurate evaluation of PV systems'performance.Therefore,it is suggested that the solar irradiation monitoring equipment with high precision and stable operation should be equipped in the PV power station.