Description
The negative high-voltage switching voltage impulse with long wavefront time was employed to conduct lightning strike discharge simulation testing research on shielding-protection characteristic of lightning rod. In order to simulate the leader attachment and the protection process of lightning rod, the rod to rod discharge electrode arrangement was applied, the upper rod electrode was used to simulate the natural lightning downward leader while the lower one simulated the scaled tested lightning rod; meanwhile, a scaled conductive bar was placed around the tested lightning rod to simulate protected object. By conducting repeatedly the lightning discharge simulation test at different height and different distance of the protected object (conductive bar) for the tested lightning rod, the attachment probability and the protection range of the tested lightning rod can be statistically figured out. According to the method described above and contraposing the 30 meters protection radius, using 1:7.5, 1:10, 1:12.5 scaled-down models, the shielding-protection characteristic of a 12 meters height lightning rod was investigated by employing the lightning strike simulation test. Based on the discharge attachment probability of lightning rod to be greater than the value of 90%, the protection curves (areas) of the tested lightning rod were obtained for each scaled model, and compared with the rolling sphere method with radius of 30 meters. The results showed that the influence of the scaled ratio is small for the protection curve testing and all the tested curves are well consistent with the rolling sphere method, when employing an about 2.5 meters long bar to bar discharge gap arrangement and negative switching voltage impulse with wave front time of 125 ± 20 microseconds. The consistency seems indicating that it would be reasonable to use the negative switching impulse voltage with long wavefront time to conduct the lightning strike discharge simulation test, and this would be instructive for experimental testing of the lightning protection performance of new-type lightning protection devices.
Authors
Prof.
Zemin Duan
(Aviation Key Laboratory of Science and Technology on High Intensity Electrophysics Environment Protection)
Dr
Zhibao Li
(Aviation Key Laboratory of Science and Technology on High Intensity Electrophysics Environment Protection)
