Surge Modelling of Transformer Using Matlab-Simulink

This paper aims to validate the surge modelling of a transformer using Matlab-Simulink using an electromagnetic model and thereby ascertaining the model accuracy. The studies cover winding responses to both full and chopped standard lightning impulses with time to chop varying over a wide range. Modelling was carried out using the design data of a 3 MVA, 33/11 kV, 3-phase, 50 Hz, Dyn 11 Transformer whose 33 kV mesh connected winding was considered to be subjected to standard full wave (1.2/50 mu s) and chopped impulses chopped at 3 mu s, 8 mu s and 15 mu s. The mathematical model considered takes into account the series and shunt capacitances and inductances of the winding elements, including the effect of their mutual inductances. The Simulation compared with the experimental results shows the validity of the Surge modelling of the transformer.