Numerical analysis and optimization of lobe-type magnetic shielding in a 334 MVA single-phase auto-transformer

In this paper, the influences of the lobe-type magnetic shielding in a transformer in terms of its leakage fields, stray losses in structural parts, shielding losses, and short-circuit impedance are examined using 3-D non-linear frequency-domain finite element method. An ODFS-334 MVA/500 kV single-phase auto-transformer is used as the prototype model under study. The magnetic shielding geometry of the transformer is optimized with its stray losses minimized based on 3-D non-linear finite element analysis. To validate the feasibility of the proposed model and method, experimental data and simulation results are compared and reported.