In power system, there are a lot of thin conductor configuration, for example, grounding grid, bus-bar, transmission tower. It is necessary to calculate electromagnetic fields produced by this type configuration in order to evaluate the electromagnetic environment and predict the electromagnetic interference in power system. Based on the frequency and time domain techniques, some engineering electromagnetic fields, including spatial field around the tower, grounding potential rise of the grounding grid, transient current and voltage along the bus-bar, have been numerically calculated.