The paper presents an analytical method to compute the leakage magnetic field inside a transformer’s window generated by the magnetizing magneto motive force supposing the magnetic permeability of the core to be infinite. The same magnetic field is computed using a 2D finite element method taking into account the non-linear magnetizing characteristic of the transformer’s core. A comparison between the results of the two methods is also presented.

Keywords: 2D finite element method, Leakage magnetic field, Electric power transformer, Magnetizing magneto motive force.