An analysis on the characteristics of induced overvoltage caused on the AWS signal line by artificially triggered lightning

The artificially triggered lightning test was conducted and a 4-element AWS (Automatic Weather Station) was simulated near the lightning channel. This paper analyzes and studies the induced effects caused by the near lightning on the signal line and the key lightning protection techniques for AWSs. It analyzes the induced overvoltage characteristics as caused by the lightning with multiple return strokes on the signal cable of wind speed and direction, as well as their relationship with the changing rate of the triggered lightning current. The results indicate that the induced voltage peak of the signal line is in a V structure, with the crest value up to thousands of volts, and lasts only a few microseconds; and that a continuous voltage, which attenuates slowly, appears after the peak voltage, with the crest value up to hundreds of volts. The wind speed signal line has a higher induced voltage than the wind direction signal line does. The negative peak of the induced overvoltage on the signal line is well correlated with the gradient of the triggered lightning current, with the correlation coefficient being 0.70.