Analysis of High Frequency Electromagnetic Transients in Transformer Windings through White Box Modelling and Experimental Measurements

Power transformers are subjected to high-frequency electromagnetic transients originating from lightning and switching operations, which may cause excessive overvoltages and non-uniform voltage distributions along the windings, leading to insulation stress. The increasing frequency of switching events in modern power systems highlights the need for an improved understanding of transformer behavior under such conditions. This paper presents a comparative investigation of the transient response of continuous disc and interleaved disc winding configurations. An analytical (white-box) model based on constructive and geometrical parameters is developed to represent winding resistance, capacitance, and inductance through equivalent electrical networks, enabling detailed transient simulations.