Voltage problems of Eza(BGA) to the medium voltage grid

In the protection relay is an HV cables angle of 9 ° at a time of 0, set 2 sec. At least according to the documentation. Check I can the set values on the Thursday, then am local.
However, I forgot to mention that the last reason of the protection tripping U > was.

Would the vector jump relay not only in RUS-side short interruptions come to fruition? The public mains network seems to be stable?

> How can have influence on the sync of the EVU? <

> That was my question! <

And also my question? I don't know that the EVU there has influence.