Analysis of transient voltage distributions in transformer windings at different voltage stimuli

Transformers operating in power grid or in industrial environment are nowadays subjected to different overvoltages. Traditionally, in the case of power transformers the stresses are related to lightning and switching phenomena. In industrial networks distribution transformers are exposed to many switching operations often generating overvoltages. Transformer windings subjected to such effects are stressed due to the voltage distribution along the winding and potential resonance phenomena. External transients occurring in power systems might trigger out internal overvoltages of high maximum value in transformer windings. The paper presents results of voltage distribution measurements performed on disk and layer winding subjected to different voltage stimuli. The presented results might be used both for design and optimization of transformers windings.