The solar power is delivered into a LVAC grid, which is connected by a Yd11 transformer to a MVAC grid.
The power is split between the LVAC and MVAC grid and there is no other way to control the power flow than to adjust phase and voltage level of the LVAC and MCAC grid.
In the simulation there is a power flow from the MVAC to the LVAC grid when the solar power is zero.
The phase angle of the MVAC grid is 30 degrees behind the phase of hte LVAC grid, because of the transformed Yd11 construction, which has a phase delay of 30 degrees.
