对光伏系统发电量的准确预测有利于实现电站效益的最大化,掌握动态环境因素对光伏系统发电量的影响规律是实现准确预测的基础。为探究其影响规律,文章以常州市637 k W光伏阵列为案例,采集2015年第一季度日发电量的记录数据,基于多因子综合回归分析方法研究各环境因素对光伏系统发电量的综合影响,具体分析了日类型、环境温度、风力、辐照量、空气质量等因素对发电量的直接影响和间接交叉作用。研究发现,空气质量对该地区光伏系统发电量影响不大,而其它因素均有不同程度的影响,其中辐射量对光伏系统发电量的影响最为显著。工程实例验证表明,在光伏系统发电量的预测中,充分考虑环境因素的单一和交叉影响,可以进一步提升光伏系统发电量的预测精度。
Smooth switchover of micro-grid from parallel operation mode to island operation mode is a signif icant method to guarantee the continuous power supply to important loads.This paper puts forward an online work mode on the basis of analyzing the features of parallel operation mode and island operation mode.According to the features of online work mode,the paper gives a f ixed and unf ixed DC bus voltage control strategy and builds the simulation model of unf ixed DC bus voltage control strategy based on Matlab/Simulink.The simulation results show that online work mode based on the unf ixed DC bus voltage control strategy can avoid the unstable problem caused by handoff process between parallel mode and island mode,ensure uninterrupted power supply for important loads,and achieve maximum power tracking of photovoltaic power generation,in addition to reducing the complexity and cost of the system.
