叶片转动对风机引雷能力影响的模拟试验研究

Experimental Study of the Influence of the Blade Rotation on Triggered Lightning Ability of Wind Turbine's Blades

风力发电机组与其它地面雷击目标物相比,最显著的特征是其叶片在遭受雷击时一般处于转动状态。为了研究叶片转动对风机引雷能力的影响机理,该文设计选取了适用于研究风机接闪试验的圆弧形高压电极,施加负极性250/2500μs标准操作波,对典型2MW风机的1:30微缩模型进行了叶片静止和旋转等不同状态下的接闪放电比对试验。采用升降法获取50%放电电压,并进行放电过程观测,结果表明:在1和1.3m间隙条件下,击穿电压随着叶片转速的提升而提升,先导连接位置随着转速的提升更加接近叶尖,叶片转动导致风机的引雷能力降低。分析认为叶片的旋转改变了叶尖区域的电荷分布,使叶尖上行先导发展不充分,从而影响了放电发展过程。所得结果可为风电机组的防雷保护提供参考借鉴。

Compared with other lightning targets on ground, the most notable feature of wind turbine is that its blades are generally in rotating state during lightning strike. In order to study the specialty and mechanism of the influence of blade rotation on triggered lightning ability, the paper conducted some lightning discharge comparison tests under different status （stationary and rotating blades） on typical 2MW wind turbines＇ 1：30 miniature. In these tests, a negative polarity 250/2500ps standard operating wave on the high voltage electrode was applied and the up-and-down method was adopted for 50% discharge voltage. The discharge process was observed, and the experimental results show that under the condition of lm and 1.3m gaps, the breakdown voltage would get higher and the location of the leader connection point would get closer to blade tips with increasing speed, which means that blade rotation reduces triggering lightning ability. Through the analysis of lightning discharge process, it is found that the rotation of the blades changes the charge distribution on blade tip region, thus weakening the upward leader development on the blade tip, which affects the discharge development process. This result provides a reference for lightning protection of wind turbines.