L
Hi,
I am doing a plant modeling on easypower for shortcircuit calculations and i ran into problems modeling a 3-winding transformer (xfo). I work from a single line diagram (SLD). i will try to be as explicit as possible.
The problem in short is i have only two impedances on the SLD, and Easypower asks for 3. I suppose the info i have is for primary to secondary (ps) and primary to tertiary (pt)and EasyPower needs secondary to tertiary (st). maybe i'm wrong.
Here's what i have:
the xfo is Delta-Wye with a neutral resistance on both secondary and tertiary
10.0/14.94 MVA
25/13.8kV
z=8.1% @ 10MVA
Rn=100A const. 2500A, 10s
6.5/9.7 MVA
25/2.4/1.385kV
z=6.9% @ 6.5MVA
Rn= 500A, 10s
Now the problem i have is EasyPower needs this table to be filled (hope it shows ok):
R1 X1 R0 X0 MVA base
Zps
Zpt
Zst
Now im thinking Zps = 8.1% and Zpt = 6.9%. How do i get R1 X1 R0 X0 from the Z= X% and how do i get info for the Zst ?
All help welcomed,
Lespoils
I am doing a plant modeling on easypower for shortcircuit calculations and i ran into problems modeling a 3-winding transformer (xfo). I work from a single line diagram (SLD). i will try to be as explicit as possible.
The problem in short is i have only two impedances on the SLD, and Easypower asks for 3. I suppose the info i have is for primary to secondary (ps) and primary to tertiary (pt)and EasyPower needs secondary to tertiary (st). maybe i'm wrong.
Here's what i have:
the xfo is Delta-Wye with a neutral resistance on both secondary and tertiary
10.0/14.94 MVA
25/13.8kV
z=8.1% @ 10MVA
Rn=100A const. 2500A, 10s
6.5/9.7 MVA
25/2.4/1.385kV
z=6.9% @ 6.5MVA
Rn= 500A, 10s
Now the problem i have is EasyPower needs this table to be filled (hope it shows ok):
R1 X1 R0 X0 MVA base
Zps
Zpt
Zst
Now im thinking Zps = 8.1% and Zpt = 6.9%. How do i get R1 X1 R0 X0 from the Z= X% and how do i get info for the Zst ?
All help welcomed,
Lespoils