Modelling a transformer

[Απόστολος Αρσενόπουλος]

Hii all,
I have trouble modelling a transformer in MATPOWER. Does anyone know how i
can seperate a 20/0.4kV TR from a 20/0.6 one ?? I've been given the r,x
values of my TR. Furthermore my tap ratio is 1.

Any advice would help,
AA