lightning constitutes the greatest threat to wind power industry. The characteristics of the distributed electric field prior to lightning strike plays an important role in determining lightning discharge attachment point as well as the efficiency of wind turbine protection systems. It was assumed that electric field due to upward initiated lightning might be the same as that of downward initiated lightning. However, more lightning damages which are upward initiated are now highly recorded. In this paper, the blades of a modern sized wind turbine (Vestas V100 with 2 MW rated power, 100 m rotor diameter, and 49 m long blade) are rotated from 0 to 360 degrees and used to investigate the characteristics of the distributed electric field around an operational wind turbine. The model of the extended vertical tri-pole cloud charge distribution model developed with finite element analysis is used to study the variations in maximum electric field strength required for the initiation of upward leader. By comparing the electric field strength as the blade is rotated, the field behavior is evaluated. In addition, experimental evaluations are carried out to support the findings. Result showed that the field around the blade surface and the receptor for an upward initiated lightning is more complex than was assumed and different from downward initiated lightning. This will consequently affect the proficiency of the protection device.

Wind Turbine

finite element analysis

protection

lightning