Limiting the current from 3 phase source

What I am trying to do is to model a simple grid. I have a 3-phase source(1 MVrms) connected to a 3 phase transformer (1 MV/250 k) which in turn is connected to 10 purely resistive loads. It seems that the source will supply as much current as the loads needs even if the current gets to 1 billion amps!

Is there a way to limit the current from the source?