Maximum insulation stresses under transient voltages in the HV barrel-type winding of distribution and power transformers

Analytical as well as experimental results are presented for voltages developed in HV (high-voltage) windings of dry-tyre power and distribution transformers when subjected to surge transients. Although the existence of this phenomenon has been known for years, it has not always been taken into consideration in the calculation of insulation stresses. The possibility of accurate prediction of the developed voltages is demonstrated