Secondary Tapped Transformer
Secondary Tapped Transformer
(OP)
Good day,
We're performing electrical short circuit and arc flash studies for a customer who has wind turbine generators that supply to a 2-Winding transformer.
Now the problem is, this 2 winding transformer has a tapped secondary which supplies an external load of 400V.
Therefore, the transformer acts as a three winding transformer. Primary is rated 34.5 kV, secondary is 1000V and the tapped secondary (that acts as a tertiary) is 400V.
I have to provide both positive and zero sequence PS, PT and ST impedances for SKM. All I have from manufacturer are the attached files.
I have been using load losses to calculate for R value (using PLoss = 3xI^2xR) at secondary and tertiary, and use them for Zs and Zt (not Zps or Zpt).
I then use Zps = Zp+Zs, Zst=Zs+Zt and Zpt = Zp+Zt.
Using the test certificate from Siemens, I have measurement of load losses at secondary and so called tertiary, however I'm stuck at how to determine the R value for Zp.
Hope i've been clear explaining my problem, any help is much appreciated. Remember again, this not a typical 3 winding transformer but a 2-winding transformer with a tapped secondary supplying external loads.
Thank you.
Regards
We're performing electrical short circuit and arc flash studies for a customer who has wind turbine generators that supply to a 2-Winding transformer.
Now the problem is, this 2 winding transformer has a tapped secondary which supplies an external load of 400V.
Therefore, the transformer acts as a three winding transformer. Primary is rated 34.5 kV, secondary is 1000V and the tapped secondary (that acts as a tertiary) is 400V.
I have to provide both positive and zero sequence PS, PT and ST impedances for SKM. All I have from manufacturer are the attached files.
I have been using load losses to calculate for R value (using PLoss = 3xI^2xR) at secondary and tertiary, and use them for Zs and Zt (not Zps or Zpt).
I then use Zps = Zp+Zs, Zst=Zs+Zt and Zpt = Zp+Zt.
Using the test certificate from Siemens, I have measurement of load losses at secondary and so called tertiary, however I'm stuck at how to determine the R value for Zp.
Hope i've been clear explaining my problem, any help is much appreciated. Remember again, this not a typical 3 winding transformer but a 2-winding transformer with a tapped secondary supplying external loads.
Thank you.
Regards





