include the coupling between coils of the same
winding. Although lumped-parameter models are
still used for representing transformers and reactors,
it is also possible to consider the application
of a distributed-parameter model for transformer
windings by considering models based on a singlephase
transmission line (STL) and combining
both MTL and STL to obtain detailed information
about the internal voltage distribution. This section
introduces MTL based-models for machines
and transformers and describes the steps to be
made for obtaining lumped-parameter models
and, in case of transformers, STL based-models