The effects of impulse voltages on transformer windings

The effects of the application of impulse voltages of varied wave-shapes to transformers are analysed theoretically and experimentally. Single and multiple transients have been considered, and oscillographic tests have been made on model transformers of different winding characteristics, and on both single-phase and 3-phase transformers. The constants of the transformers important for determining the voltage distribution within the windings due to Ihe impact of a surge have been calculated and measured, and the effect of altering these constants has been examined. In general, good agreement has been obtained between theory and experiment. The transference of surges from one winding to another has been briefly considered, and the testing of transformers with impulse voltages has been discussed in the light of the foregoing analytical study.