¿How does the phasorial OLTC transformer model works?

Hello everybody!!

I have a model of a wind farm connected to the grid. The WTGs are modeled as current sources with a PI section impedances between it. The grid is modeled as a voltage source with a SRC (that is with a short circuit power and impedance).

To connect the high voltage (grid) with the medium voltage (wind farm) I have used a OLTC transformer. The simulation is a phasorial one. If I use the three phase OLTC model, the simulation works fine, but with the phasorial model (with the same configuration) I have a NaN problem in the winding currents.

So the primary winding of the transformer is high voltage (voltage source model) and the secondary is the medium voltage (current source model). Does the phasorial OLTC model work good with this configuration? There is a known problem with this block?

Thanks in advance.

Best regards.