低风速条件下变速变桨风力机叶片的优化设计

Optimization Design of Variable-speed Variable-pitch Wind Turbine Blade in Low Wind Speed Condition

目前全国可利用低风速资源丰富,若对其加以利用,可有效降低输电成本,提升电力供给。但将现有叶片直接应用于低风速风场会存在匹配性问题,有必要对其进行优化设计。本文考虑变速变桨风力机的特性,以年发电量最大和叶片面积所代表的材料成本最小为优化目标,建立了低风速条件下风力机叶片的优化设计模型。在此基础上,将具有高空气动力学性能的CQU-A系列翼型族用于某850 KW叶片,在平均风速为7m/s的低风速下对叶片的气动外形和最佳桨距角进行了优化设计。与原叶片相比,优化后的叶片在年发电量增加3.6%的同时叶片面积减小了34.6%。

Currently,the available low wind speed resources is rich in nationwide,we can effectively reduce power transmission cost and improve power supply if taking advantage of them.However,when existing blade is used in low wind sites,their aerodynamic performance will change,so it is necessary to redesign the blade.In this paper, considering the characteristics of variable-speed variable-pitch wind turbine,wind turbine blade optimization model with the objective of maximum annuaI energy production and minimum the blade area are established.Then,CQU-A airfoil family which characterized as high lift-drag coefficient and high lift coefficient at low Reynolds number are applied to an 850 KW blade,the aerodynamic shape and optimal pitch angle of the blade is optimized in low wind speed （average wind speed is 7m/s）.As a result,annual energy production of the optimized blade is increased bv 3.6%,while blade area is reduced bv 34.6%.