风机叶片金属网防护下的雷击损伤特性研究

Study on Lightning Damage Characteristics of Wind Turbine Blades Under Metal Mesh Protection

风机叶片雷击损坏是风电系统实际运行中面临的难题,可采用金属网作为叶片雷电防护补充方法,但叶片敷设金属网后高幅值雷电流接闪过程及损伤机制尚不清晰。为研究风机叶片金属网防雷方法下雷击大电流接闪及叶身复合材料雷击损伤特性,搭建真型风机叶片雷击大电流闪络试验平台,通过先导附着试验,确定风机叶片潜在雷击位置,同步观测雷电引入点的直接损伤效应。试验结果表明,雷击转移电荷量和引下线通流能力是叶片是否产生雷击损伤的重要影响因素,叶尖与叶身之间的压接板有结构撕裂风险,应当优化金属网泄流通道和压接板的型式设计,提高叶片雷击大电流耐受可靠性。研究结果揭示了金属网防雷方法下风机叶片先导附着特性和雷击大电流损伤特征,指导防雷优化设计。

Lightning damage of wind turbine blades is a difficult problem in the actual operation of wind power system.Metal mesh can be used as a supplementary method for lightning protection of blades.However,the lightning process and damage mechanism of high-amplitude lightning current after the blade is laid with metal mesh are not clear.In order to study the lightning protection method of wind turbine blade metal mesh and the lightning damage characteristics of blade composite materials,a test platform for lightning large current flashover of real wind turbine blades is built.Through the leader attachment test,the potential lightning strike position of the wind turbine blade is determined,and the direct damage effect of the lightning introduction point is observed synchronously.The test results show that the amount of lightning transfer charge and the flow capacity of the down lead are important factors for whether the blade is damaged by lightning.The pressure plate between the blade tip and the blade body has the risk of structural tearing.The type design of the discharge channel of metal mesh and the pressure plate should be optimized to improve the reliability of the blade′s lightning high current tolerance.The research results reveal the characteristics of large current damage of wind turbine blades under the lightning protection method of metal mesh,and guide its lightning protection design.