中国典型复杂地形风能资源特性及其形成机制

CHARACTERISTICS AND FORMATION MECHANISM OF WIND ENERGY RESOURCES IN TYPICAL COMPLEX TERRAIN IN CHINA

为提高对复杂地形风资源特性及其形成机制的认识,改进复杂地形风场数值模拟方法,分别选取代表极大起伏山地与宽谷地形的藏南谷地、代表极大起伏山地与深谷地形的横断山区以及代表中、小起伏丘陵山地的山西高原开展风资源特性观测实验,分析不同典型复杂地形条件下天气背景风场、局地大气环流、地形动力强迫、地表摩擦与热力作用对风资源特性形成的贡献,结果表明:山西高原局地大气环流的作用较小;藏南谷地和横断山区的山谷风环流对其风能资源特性的形成起主要作用,尤其是横断山区还存在多尺度的局地大气环流,传统的风电场风资源CFD数值模拟不足以描述如此复杂的风场。因此,在局地大气环流作用明显的复杂地形地区,需要采用中尺度与CFD结合的风电场选址风资源数值模拟方法。

Whether at home or abroad,there is a problem that the actual power generation of wind farms located in complex terrain is lower than that calculated by CFD software.Therefore,it is necessary to improve the understanding of the characteristics and formation mechanism of wind resources in complex terrain and improve the numerical simulation method of wind resource for wind farm siting.For this purpose,wind resource characteristics observation experiments are carried out in southern Tibet,Hengduan Mountains and Shanxi Plateau,which represent the extremely undulating mountains and wide valleys,the extremely undulating mountains and deep valleys,as well as the medium and small undulating hills and mountains.Through analyzing the contribution of the atmospheric background wind field,local atmospheric circulation,terrain dynamic forcing,surface friction and thermal action to the formation of wind resource characteristics under different typical complex terrain conditions,the results are as follows:the role of local atmospheric circulation in Shanxi Plateau is relatively small,the valley wind circulation in the southern Tibetan valley and Hengduan mountain area plays a major role in the formation of their wind energy resource characteristics,especially in Hengduan mountain area,where there are multi-scale local circulations.The traditional CFD numerical simulation of wind resources for wind farms siting is not enough to describe such a complex wind field.Therefore,the numerical simulation method combining mesoscale and CFD is very necessary in the wind resource assessment for wind farm siting in complex terrain.