Study on leakage magnetic field and magnetic field shielding for transformers

Accurate calculation of magnetic field and reduction of eddy current loss to eliminate local overheating of tank are the focus of traction transformer research. In this paper, a large-capacity traction transformer is established, and the leakage magnetic field and eddy current loss of the transformer tank are calculated by the layered subdivision method and the surface impedance method. To reduce eddy current loss, the plate-shaped magnetic shielding and electromagnetic shielding are arranged in the tank wall. And the simulation results show that plate-shaped magnetic shielding has better shielding effectiveness compared with electromagnetic shielding. Based on the plate-shaped magnetic shield a tile-shaped magnetic shield is proposed to further reduce the leakage magnetic field and loss of the tank. By analyzing the shielding effect of tile-shaped shielding at different heights and widths, the tile shielding structure with the best shielding effect is obtained.