Leakage fluxes and mechanical forces calculation on the single phase shell-type transformer winding under over currents by 2-D and 3-D finite element methods

Abstract

This paper is focused on the investigation of leakage flux and resulted mechanical forces distribution and magnitude on windings of transformer in the over current conditions. Three dimensional (3-D) and 2-D computer modeling for a real 10MVA 66/11kV single-phase shell-type transformer is employed. The transformer current is supposed to change from normal condition to 25 per unit continuously. 2-D and 3-D finite element methods are used to calculate the magnetic leakage fluxes and electromagnetic forces. Relation between current, magnetic leakage flux and forces are realized and three dimensional descriptions of mentioned parameter is shown. Results indicate 2-D finite element method is not efficient accuracy for calculation of radial component of leakage flux and axial component of forces. Radial component of force related to any conductor is very depended on the radial position of that and axial component of force is very depended on the axial position of conductor on the winding. Results also indicate a linear relation between leakage magnetic flux and current and a nonlinear relation between current and forces.