Discharge characteristics to insulated material

Lightning strikes not only metallic objects such as transmission towers and lightning rods but also insulated material such as blades of wind turbines. The discharge characteristics of insulated material are, however, not clarified till now. In this paper, discharge characterisitics of insulated material have been investigated experimentally using a 12-MV impulse generator. The effects of polarities of the applied voltages and surface conditions of the insulation material are also studied and it is found that pollution on the surface decreases the sparkover voltage drastically. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.