Grounding ZNzn transformers in ETAP 1

[tonyjony]

Hi everyone, I'm sorry if this question is already answered, but I didn't find it.

I have a 132kV system, a 132/13.8kV YNd transformer and a Znzn transformer to provide neutral on 13.2kV system. I need to calculate LG short circuit current, so I'm using ETAP.
I don't know how to simulate the ZNzn transformer. I've tried with a YNyn connected to the 13.2kV, but current still in 0 kA (I don't figure out where to connect the secondary winding).

I've attached a snapshot to clarify.

Any tip?

Thank you very much in advance!

 

[tem1234]

Since the zigzag transformer isn't available in ETAP, you could simulate with a Ygd. Left the secondary not connected. A Ygy will not act as a grounding transformer.

The zero sequence impedance (Z0) of the Ygd transformer must be the same as the zigzag transformer. Since it is in % of the transformer rating, you must convert it in ohms because usually Zigzag grounding transformer have Z0 specify in ohms.

 

[rbulsara]

It took me a whole of 2 seconds to find the following FAQ via Google search. It always pays to search mfr's website, reading their manual or asking their tech support.

http://etap.com/support/faq-pdfs/ETAP-FAQ-modeling-zig-zag-grounding-transformer.pdf

Rafiq Bulsara

http://www.srengineersct.com

 

[tonyjony]

busted! I googled for "Zig-Zag transformers" only thanks a lot!