Abstract
We conducted feasibility study of detection system for unexpected lightning damage for wind
turbine blade. In this study, puncture of blade skin and disconnection of down conductor are considered as
the lightning damage. Aimed at detect these damages, three systems are examined. The first system
consists of two down conductors and current measuring devices that installed at root part of the
conductors. The first system is appropriate to detection of puncture of blade skin caused by lightning
strike of wintertime thunderbolt. The second system consists of two down conductors and optical fiber
current sensors which are installed at tip and root of each conductors. The second system has the merits of
enable to simple judgement system for lightning damage and periodic inspection (to confirm the
soundness of the down conductors). The third system is based on acceleration measurement by sensors
that installed at the blade skin. The acceleration sensors measure the elastic wave caused by lightning
strike (puncture of the blade skin). Feasibility of the third system was confirmed by model experiment.
The third system can be retrofit to an existing wind turbine blade.
