Research On Lightning Current Characteristics And Frequency Distributions

From the ancient time, the lightning is a natural phenomenon that person is scary. The lightning strike disaster is a nature tragedy that the electric power in thunder-storm cloud is released and shoot object. The lightning can lead to people's death and injury, building damage, the fire of forest. It also results in breaking electric power, damaging communication and computer facilities, bringing about the plane crash affairs, threatening people life and property. Because the occurrence of the lightning has a region characteristic, the lightning is more generation at low latitude than high latitude, the mountain area than the plain, and the plain than the desert. The most parts of Yunnan Province belong to low latitude plateau. The mountainous area accounts for 95% of total area. Yunnan is one of the most serious provinces in the lightning disaster. Therefore, it is important to investigate the circumstance of the lightning strike disaster in Yunnan and analyze the reason of its creation, to master the knowledge of lightning, to make clear on its endanger path. Improving the level of its protective technique has important realistic meaning towards insuring people's life and property, and not to suffer lightning disaster and promoting the safe production of modern item in Yunnan.The research of the lightning current's characteristics and lightning protections is a multi-subject of the combination and a very complex and difficult systematic engineering. The theory and calculation on lightning have not been comprehensive in the world up so far, and there are not very effective protective measures. The rules and regulations of grounding and lightning protection do not perfectly and don't meet the needs of the design and operation in the practice engineering. The most researches of the lightning current's characteristics in our country based on the lightning current's double exponential function model. However, there are some shortages in this model. First, the model's mathematics expression is only described a changing relation of the lightning current to flow time, which can't reflect the changing of the lightning electromagnetism in various point of a system. It also can't reflect a contribution of the lightning electric distributes to the space electromagnetism. Second, to find out this expression type is depended on the electric current waveform tested by the circuit...