Quote Originally Posted by vlady34 View Post
It's nameplate transformer, according to IEEE 242-2001 Z0 is 0.85 times the Z1 for a delta-wye connection. But according to IEC 60076 for star-star connection with grounded low voltage side of the Z0 is equal or greater than 60%. My question is how to simulate this type of connection DigSilent if in reality the single-phase fault current is much higher than that obtained from PowerFactory.
Ahh.. so you're saying that an actual fault occurred in your system and you want to simulate that fault? And it so happened that you cannot obtained the actual value of the fault based on DigSilent simulation? This is what I think.

a) First, if you say it is a nameplate value, use that nameplate value. Don't override it with the standard.

b) Second, verify if your Yny0 transformer doesn't have any buried delta within. Sometimes, Yny0 transformers have buried delta to stabilize ampere-turns of the transformer.

c) Check if you have the updated fault-level or short circuit level at the source.

d) If you cannot get the value and you think that the transformer has something wrong, have that transformer checked its impedance, it that way you can know the z1, and z0 actual impedance.