Analysis Of Lightning Current Distribution On High Buildings

With the development of semi-conductor elements and integrated circuits inconstruction of electrical, computers are becoming more widely used, at the same time theyare also becoming more and more high to the requirement of working environment. Theseweak current equipments widely have weaknesses such as: low level of dielectric strength,poor over current and overvoltage tolerance ability, high sensitivity to electromagneticinterference and so on. Once a substation building is struck by lightning, the stronglightning current suddenly flows from the lightning strike point into all the distributedbranches of the building’s structural reinforcing steel and finally scatters from thegrounding body into earth. However newly produced devices without uses of protectiveelements or systems，characterize diminished resistive to natural source of electromagneticdisturbances. Which may easily make electronic and micro-electronic devices temporarilyineffective or even permanently damaged.We apply Matlab and ATPDRAW to research and computation of magnetite fieldduring a tall building struck by lightning. In this dissertation there are four parts. They arethe computation of the capacitance and inductance parameters in a reinforced concretestructure, lightning current distribution in a steels structure.During the computation of the parameters in a reinforced concrete structure，based onthe calculation of electrical parameters of building reinforcing steel bar structure, theelectric parameters o f conducting branches were represented in capacitance and impedancemo de, the capacitance parameters were calculated by means of average potential method,while the impedance parameters were evaluated by Neumann’s formula.Based on electric parameters, the conducting system was converted to an equivalentnetwork constituted for a series of coupled Π type circuits. The network was analyzed byMatlab orATPDRAW and the surge current distribution was presented.