The Research Of The Impact That Lighting Overvoltage On Secondary Equipment

With the development of electronic industry, electronic systems are becoming more widely used, at the same time they are also becoming more vulnerable to damage by electrical overstresses (e.g. from lightning, electromagnetic pulses from nuclear weapons, and switching of reactive loads), and the progress in developing faster and denser integrated circuits has been accompanied by a general increase in vulnerability. As a very important disturbing source, lightning and its impacts on electronic systems were studied in this dissertation.This dissertation includes five parts, which are the research of new lingtning current waveform, electrical parameters of conducting branches, lightning current distribution in a steel structure, special magnetic field distribution inside the tall building, induced voltage in the metal loop.The new lightning waveform was proposed based on the theory of the gas discharge. Considered the photoionization in the gas discharge, Listed charge density equation, established Matlab mathematical model, Simulation of a lightning discharge charge density changes, Current interpretation of the largest mine-steep for the discharge of a time after a period of time before the peak in the discharge rather than the beginning. Simulate a new lingtning waveform which was more accurate than the traditional double-exponential waveform.During the computation of current distribution in a reinforced concrete structure, the capacitances were calculated by means of the average potential method, while the inductances were evaluated by the Neumann's formula. The current distribution in the steel structure of building is studied using ATP-EMTP.The expressions of magnetic induction intensity in the rooms are derived based on the obtained currents distribution, and induced electromotive force of a metallic circuit is evaluated.