Analytic frequency domain corrections to winding single line model

Frequency domain analysis of the very fast transient over-voltages (VFTO) in transformer windings gained importance with the spread og Gas Insulated Switchgear (GIS). The frequency domain solutions and the solutionsin the time domain with the method of characteristics lead to the linear algebraic systems of the equal complexity. Algebraically small scale multi-line corrections, found with time domain analysis are translated into multi-line corrections of a single line approximation in the frequency domain. It has been established that multy-line corrections unfavorably affect resonance characteristics at much lower frequencies then expected