Modelling grounding reactor as transformer
I have done this before.



Make the 132kV winding of the 3W transformer be un-earthed wye.

Insert a "node bus" at 132kV.

At the node bus, model a shunt impedance (if PSS/E will let you do such a thing - maybe it's called a 'constant admittance'.)

Make the shunt impedance have infinite positive sequence impedance, and 30 ohm zero sequence resistance, such that the phase to ground fault current is 2,540 amps. Note 2,540 A = 132kV / sqrt(3) / 30 ohms. (If you get a funny number, try using Z0 = 1/3rd of 30 ohms, or 3 times 30 ohms - funny things happen with 3 × I0.)



I have to run now, please comment if anything requires further explanation.