Abstract: 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.

Key words: wind turbine blades, large lightning current, metal mesh, down conductor, damage characteristics