Validations of lightning protections for accidents at a wind farm

In Taikoyama wind farm in Kyoto, Japan, wind turbines have often damaged by lightning in winter. In the winter from 2011 to 2012, two typical accidents have been occurred. In one of the accidents, a fire occurred inside the wind turbine close to the lightning protection tower on January 28th, 2012. The accident is caused by lightning to the wind turbine itself or the lightning protection tower; the BTB (Back-To-Back) system had remarkably burned out. Another accident is the breakdowns of the anemometers placed on the lightning protection tower on March 24th, 2012. In this paper, the causes and the protection methodologies for those accidents have been introduced. To confirm reliability of the protection methods, experiments of transient grounding characteristics and a simulation model of the FDTD (Finite Difference Time Domain) method have been made.