Problem with short circuit level in 13.2 kV in etap

[ingenieria12345]

The short circuit calculation in 13.2kv is around 0.6KA, where it should be at least 16 kA, do any of you have any idea what may be happening?
The trasnformes ir Delta/Delta

This is the system:

Bus 1 - Bus 2 (Transmision line 33 kV) 1/0 ALUMINIUM 274 meters
Bus 3 - Bus 4 (underground network 33 kV) 1/0 ALUMINIUM 42 meters
Bus 4 - Bus 6 (Transmision line 33 kV) 1/0 ALUMINIUM 196 meters
-------------------------------------------------------------------------------------------------->
Bus 6 - Bus 7 ( 1MVA - 33/13.2 kV - Delta/Delta)
Bus 7 - Bus 8 (underground network 13.2 kV) 4/0 CU 400 meters
LOAD = 1.5 MVA

in Attachments there are the archives jpg and .rar of etap.

thanks.

[himmelstern]

check it by hand calculations, on the source, check the kA level for 3Phase and 1phase SC currents.

take that current and apply by hand the transformer ratio and get the SC fault level in the secondary, and check where your error could be. also check the fabriaction standar at transformer, IEC or ansi

[ingenieria12345]

Thanks, I will do what you suggest

[hafidabdelhalim]

verify the data of transformer and specially the short circuit impedance Ucc

[ingenieria12345]

When in the transformer, I put Ucc = 0.001%, I increase the short circuit currents in 13.2 kV to 12 KA, but it is not logical that value, the typical value for that transformer is 6%

[link Point to another website Only the registered members can access]

[albedo]

Transformer is too small for that voltage level
Maximum Let Through = Isc = (Transformer kVA) × 100 / ((√3)×(Secondary kV)×(%Z transformer))
= 1000 x 100 / ((√3)×(13.2)×(6) = 0.729 kA.

[hafidabdelhalim]

the best verification is to calculate the Icc by classical method (Hand), and after verify all DATA of the network also the base of ( power and voltage) used in the software to calculate.

[user82]

You have 1.5 MVA load and a 1 MVA transformer

A 1 MVA transformer full load current at 13.2 kV = 43 Amps

A 1 MVA transformer @ Z = 7.1% will give you around 600A short circuit current

Solution:
Increase MVA size of transformer or lower Z%