Lightning strike is a natural phenomenon, which amazes us again and again when displayed in front of our eyes. We can admire it, but when it comes too close. we can be powerless. That's why I choose this topic, because lightning strike is a frequent event and it is supposed to be well studied. The first lightning strike researches started with Benjamin Franklin in 1752, who also set the physical background behind this admirable phenomenon. He also quickly after his research invented the first device for protection against lightning and it is still the base for the modern lightning protection devices.
Thesis is assembled from four parts. The first one contains theoretical basis for understanding of the lightning discharge, so the reader is enabled for easier understanding of the research part of this thesis. In the second part it was importand to connect the theory about lightning discharge to physical properties of the lightning current, which is the main quantity when lightning discharge occurs on objects. Of course lightning current is only a consequence of the high potential difference between clouds and earth surface, but the power of the lightning current is the one causing damage to us, facilities or devices. In the third part of this thesis I used different examples of the calculations made for the purposes of the standardization IEEE, for describing how potential spreads on the surface in the moment when lightning strikes a tree or a lightning protection system. The obtained data contributed a lot to the understanding of lightning protection. In the last part I combined all the information I gained during the writing the thesis and made a conclusion about what I think is the best possible way to ground a fence and what we should pay attention to when we are designing a lightning protection system.
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