Transient Analysis for Propagation of Lightning Impulse Creeping Discharge on Low Surface Resistivity Films

摘要

The phenomena that a discharge penetrates an insulator are industrially important. For protection of a wind power generatoragainst lightning damages, blades have a metal part called a receptor in the blade tip. However, if a lightning strikes except thereceptor, lightning may break blades, and power generation opportunities will be lost. In this paper, a relationship between apenetration probability and a surface resistivity was discussed from discharge test results using the uncoated film and the lowsurface resistivity film only coated on the ground electrode side, and a transient analysis based on a distributed constant circuit.As a result, the penetration probability of the uncoated polyethylene terephthalate film was 100% and that of the transparent lowsurface resistivity polyethylene terephthalate film was 0%. Furthermore, in the case of the low surface resistivity film, the sharedvoltage of a surface resistance on the ground electrode side of the film became pulse-like waveform, and was smaller than that inthe case of the uncoated film. From the results, we confirmed that a penetration probability might decrease by reducing timeconstant of potential propagation on the film.