Supervisors:

ii To my family iv By introduction of modern electronics into railway system, new challenges in under-standing the electric and electromagnetic behavior of these systems arise. In this thesis, electromagnetic modeling of electrical networks above dielectric and perfect electrically conducting surfaces are studied. The approach is based on the Partial Element Equivalent Circuit (PEEC) method for solving Maxwell’s equations. The most challenging problem within electromagnetic modeling of large systems is computational speed and for railway systems, modeling of the ground becomes the major bottleneck. The purpose of the thesis is to develop maintenance program for the railway system in the Northern Sweden to deal with the failures created by electromagnetic disturbances using mathematical modeling of the electromagnetic phenomena. First, a grid PEEC approach was used to improve the computation time of the original program