The Investigation of Newly Designed Transformer Windings with Reduced Thickness of Oil-Impregnated Paper Insulation

For determining the insulation dimensions, Smit Transformers uses a so called “design curve”. As the oil-impregnated paper insulation of the windings has been improved, a new design curve has to be established. A number of different types of transformer winding samples were subject to lightning impulse tests. The breakdown voltages measured from step-up tests with full and chopped impulse waves were recorded. Although no safety factors were applied, the new design curves present significant increase of breakdown voltage at the same thickness, when they are compared with the old design curve.Electrical Power EngineeringHigh Voltage Technology and ManagementElectrical Engineering, Mathematics and Computer Scienc