Analysis of the Current Difference among Coils Connected Parallel of Single Phase EHV Power Transformer

The current difference among coils connected parallel due to the single phase five legged iron core of EHV transformer 1000 MVA/1000 kV was studied by simulation and experiments. The 3D magnetic field simulation based on the T-method are performed, including the static magnetic field and the time harmonic magnetic field. The current distribution experiments on various operation condition of EHV transformer untanked have been conducted to validate the simulation. The results demonstrated that difference among coils connected parallel of the EHV transformer 1000 MVA/1000 KV is less than 5%, which little influences on the transformer.