风资源评估中WindSim水平分辨率的敏感性试验

Sensitivity Test of Horizontal Resolution of WindSim in Wind Resource Assessment

利用基于计算流体力学(CFD)的风能资源评估系统软件WindSim,在不同水平网格分辨率条件下对我国黄土高原地区陕西靖边县境内某风电场2010年7月～2011年6月的风资源情况进行了模拟,并将模拟结果与测风塔观测结果进行了对比分析。结果表明,在低水平网格分辨率下,WindSim对风能资源的空间分布模拟主要以海拔高度为基础,对局地地形的影响并不能很好地反映,模拟风速误差较大;提高分辨率后,对风能资源空间分布的模拟能力明显提高,模拟风速的误差也显著减小。但不同分辨率下的风速频率和风向频率分布并无显著差别,不能很好地体现出风能特性。通过估算发电量发现,输入不同测风塔资料得到的发电量差异较大,说明在地形较为复杂的风电场,应多布设测风塔,以期得到较为准确的发电量结果。

Using the wind energy resources evaluation system software （WindSim） based on the computational fluid dynamics （CFD） method, we simulate the wind energy from July 2010 to June 2011 of a wind power station in Jingbian City of Shaanxi Province in the loess plateaus region under the different horizontal resolutions. The simulated data are compared with the wind power observation data. The results show that in the low horizontal mesh resolution, spatial distribution of wind energy is simulated based on the sea level elevation; the influence of local terrain can not he reflected clearly, which caused large error in simulated wind speed; while in the high resolution, the simulation ability is obviously improved and the simulation error was remarkably reduced; but in the different resolutions, the wind speed frequency and wind direction frequency distribution have no significant difference, and the simulation results do not well reflect the wind energy characteristics; the estimation of generated energy domenstrates the different wind tower observation data resulted in significantly different generated energy. Therefore, in order to obtain relatively accurate generated energy, as many data of wind tower as possible should be used when the wind farm is located in complex terrain.