Analysis of electromagnetic fields generated by lightning in different configurations of protection structures

Abstract

This paper presents results of the electromagnetic field generated by different configurations of protection structures, when lightning strikes such structures. The transitory nature of the current in the structure, and the return current is taken into account in the calculation of the field. This paper also presents an elegant expression for calculating the resultant electromagnetic field produced by the current transients in cables or transmission lines. By taking into consideration a line disposed arbitrarily in the Cartesian coordinate system, using the Maxwell equations and applying the magnetic potential vector, we come to the generalized expressions for the electric and magnetic fields as a function of current and position in the time domain. This expression is a generalization of the expression proposed by Christopoulos. The method has been shown to be very useful in applications where lines are disposed in arbitrary manners and especially in systems in which various lines are interconnected such as lightning protection systems (LPS) or a grounding system. The results obtained with such expressions are compared to other numerical methods. The results are obtained applying TLM (transmission ine modeling) method to obtain the current transient.