Development of an arc-extinguishing lightning protection gap for 35 kV overhead power lines

摘要

Given that currently available lightning protection measures cannot effectively protect overhead lines from lightning strikes, this study develops an active and fast arc-extinguishing lightning protection gap to address this issue. When a power frequency arc is formed within the protection gap due to a lightning strike, the lightning current immediately ignites the device, while strong airflow is synchronously produced. In this manner, the follow-up power frequency arc can be extinguished within an arc duration that is considerably shorter than the action time of relay protection; thus, relay protection can be avoided, and the lightning trip-out of overhead lines can be effectively prevented. A test of insulation coordination for impulse flashover and a test of power frequency arc extinction are performed to validate the effectiveness of the device. The arc-extinguishing test proves that the strong airflow can extinguish the arc within 0.4 ms. The devices have been widely applied in China and have been extremely successful.