Transient characteristic of an actual wind turbine grounding system

Accidents caused by natural phenomena such as lightning are serious problems for the diffusions of wind power generations. Those problems affect the safety and reliability of wind turbine generator systems. Most of the breakdowns and malfunctions of the electrical and control systems inside or in the vicinity of wind turbines are caused by ground potential rise due to lightning. To solve those problems, the field tests have been carried out at 11 sites so far. In this paper, new measurements of transient grounding characteristics carried out at a wind turbine in the vicinity of the Sea of Japan have been presented.