遮挡现象对大型并网光伏电站输出性能的影响

摘要

西北地区地域开阔、太阳资源丰富，有广泛分布的戈壁、沙漠、滩涂，是建设光伏电站的的良好场所。光伏电站在实际的长期户外使用中往往会碰到许多复杂的环境因素，其中，遮挡现象是影响电站发电特性的重要因素。该文首先阐述了光伏组件受到遮挡时的数学模型；同时，根据对某大型光伏电站的现场考察结果，总结了大型并网光伏电站的遮挡共性，分别是前后排阵列、配电装置、植被以及鸟粪遮挡，并在电站现场就不同类型的遮蔽物遮挡进行实验；结合光伏组件/串I-V特性测试仪的测试结果，验证了数学模型计算出来函数断点与实测的数据有一定的一致性；最后得出各种遮挡现象导致的电站发电量损失，并提出有效的防范措施，日后电站建设有一定的参考意义。%The northwest area provides ideal situation for installing PV power systems with its rich solar resource and open area,such as Gobi desert.A prototype of a shaded photovoltaic module is presented. And then,the typical shading types are concluded,which is classified as front row shading,vegetation, wire poles and distribution rooms and birds dropping after longtime surveys and observation.The shading effects caused by some particular obstacles are measured and analyzed according to the field test on a 20-MW PV system.Reduction of the I-V and P-V characteristic has been observed and compared with the theoretical value.In the end,some suggestions on dealing with these shading problems in the installation and operation of the PV system are proposed.