How add a transformer to my model

Im building a model of a synchronous machine connected to a powergrid via a transformer.

The model works fine until i add the transformer. With the transfrormer included in my model i get the following error message:

if true
Initial conditions solve failed to converge.
...Nonlinear solver: Linear Algebra error. Failed to solve using iteration matrix.
......Problems possible for transient initialization, as well as stepsize control for transient solve, due to equations (including nonlinear equations) of one or more components:
    end

I tried to use a fixed step solver and also changed the min and max step size. Didn't solve the Error. Any suggestions why i can't add the transformer?

[Rasmus]

Since there is no answer,i add the Picture of the Model

Answer 1

[Zeno Yuan]

plz try to add a switch before the XFMR.

[Rasmus]

Thanks a lot for the suggestion! Unfotunatelly it didn't work. The error is still the same. I think this might be, because the switch has even when he is open a very small conductance ( 1e-6). So in the moment of initialisation (and all the time) there is a physical connection. On the other hand there has to be a connection or otherwise i would need another solver for the network on the right.

Further suggestions are highly appreciated!

Kind regards