Design optimization of power transformers. Part 1. Sensitivity analyses for winding insulation and support

To maintain quality, performance and competiveness, finite element analyses are increasingly utilized for the initial design, the design review and the design optimization of power transformers. The detailed geometry of windings, core, tank wall as well as insulation and clamping parts requires 3D numerical calculation methods in order to obtain high accurate values for the material utilization. The paper presents 3D finite element analyses with the intent of an optimization of winding support, core clamping system and tank wall shape. These calculations are carried out for the electric field distribution in the winding support and the sensitivity with regard to various material properties according to production tolerances.