青海共和盆地固定支架式光伏阵列对阵内风场的影响

Influence of fixed-stand photovoltaic array on wind field in Gonghe Basin,Qinghai,China

青海省共和盆地是中国最大的新能源基地之一,大规模光伏设施的建设对区域生态环境必然产生较大的影响。通过在光伏阵列内外建立风况观测断面,架设5套5梯度的自动气象站,实施同步监测,对不同风向条件下光伏阵列对阵内风场的影响进行观测研究。结果表明:(1)光伏阵列具有导向作用,使风向以顺光伏组串长轴方向的偏西风和偏东风为主。当旷野风向与光伏组串长轴方向夹角β≥45°时,光伏阵列内出现围绕光伏串的横向绕流,阵列内存在明显的双风向,且β越大,双风向特征越明显。(2)光伏阵列整体具有减速作用,且减速率随高度呈指数递增关系,但20 cm高度风速减弱作用具有很大的不确定性,甚至出现增强风速的作用。减速率随风向的变化呈三峰三谷的区间分布特征,三峰三谷区间的极大值出现在β=45°或β=67.5°处,极小值多出现在β=22.5°处。(3)受光伏组串北高南低的结构和光伏阵列内风程长度的影响,光伏阵列内风向和风速变化存在非对称性特征。光伏阵列对阵内风场的影响,一方面有利于光伏面板除尘,另一方面会增加阵内地表就地起尘的潜在风险。光伏场建设应更加注重光伏阵列内生态保护和修复,提高地表植被覆盖度,减少起尘量,提高发电效率。

Gonghe Basin in Qinghai is one of the largest new energy bases in China. The large-scale construction of new energy facilities will have a great impact on the regional environments. In this paper,the influence of photovoltaic arrays(PVA)on the wind field is studied by establishing the wind observation sections inside and outside the arrays,setting up 5 sets of 5-gradient mobile automatic anemometer stations,and carrying out the synchronous monitoring. The results show that:(1)The PVA can change the wind direction in the array,and the wind direction is mainly westerly and easterly. When the angle β ≥45° between the wind direction of the open field and the long axis of the PVA,there is a transverse flow around the PVA.(2)The whole PVA has the effect of weakening wind,and the rate of weakening wind increases exponentially with the height,but the weakening effect of wind speed at 20cm in height has uncertainty,even increasing the wind speed. The rate of weakening wind have a three-peak and three-valley pattern with the wind direction variation. The maximum rate appears atβ=45° or β=67.5°,and the minima rate mostly appears at β=22.5°.(3)The wind direction and wind speed in the PVA are asymmetric due to the structure of the PVA with north-high and south-low and the wind path length. The dual-wind-direction characteristic of PVA and the wind-guiding effect of the lower part of the PVA are beneficial to the dust removal of PVA,but increase the potential risk of dust emission on the ground surface in the PVA.More attention should be paid to ecological protection and restoration in PVA to improve the coverage of vegetation,reduce dust emission and improve the efficiency of power generation.