Surge Voltage Distribution in a Transformer Winding Model for Fast Rising Double Exponential Switching Surges

Abstract

In power systems, ‘Power Transformer is one of the very important components in the power system. Any
failure of the power-transformer results in widespread and serious disturbances. Also at higher voltage levels, it is not
practical to have stand-by units of large and very expensive transformers. Thus transformer failures cause a long
duration power outage as well as large financial losses.
In view of the above, transformer failures have been widely investigated but there are still many unexplained failures.
Therefore in this paper an attempt is made to understand the behaviour of transformer for lightning and fast rising
representative switching surges of double exponential nature waveforms. Different surges of 1kV magnitude are
generated in the laboratory and are applied to a custom built transformer winding model having 160 turns which is
partly interleaved. Studies are carried out for lightning impulses and fast rising switching impulsesmentioned above.