SKM PowerTools Three-winding Transformer - short circuit
SKM PowerTools Three-winding Transformer - short circuit
(OP)
I am a student of electrical engineering from Germany and begin to work with PowerTools during my internship. (By the way, this is no Homework and I haven’t anything to calculate and so on :) ) I have to find new software for simulation. I compare some software to find the most user-friendly and practical software.
I have to deal amongst other with two- and three-windings transformers. At this moment I use the calculator 4 (Rated Short Circuit Voltage %, kW Loss at Rated Current) of the 2-windings transformer to calculate the impedance values in % for the 3-windings transformer
The problem I have is that my results of the short circuit simulation with PowerTools can’t be right. The secondary and tertiary winding have exact the same properties – and therefore they have to get the same short circuit. But the SKM PowerTools results are different (Ik’’sec = 17.2kA; Ik’’ter = 18kA). I calculate this setup per hand also and agree with 17.2kA. Other simulation software also has the value for Ik’’ = 17.2kA.
My questions are: “Why are there different values for Ik’’ by simulating with PowerTools? And why are there the diffences?”
Data of the transformer:
155kV/31.5kV/31.5kV
240MVA/120MVA/120MVA
Uk12=12.9% Pk12=307.6kW Sn12=120MVA
Uk13=12.9% Pk13=307.6kW Sn13=120MVA
Uk23=23.76% Pk23=549.9kW Sn23=120MVA
Best regards
Tobias
I have to deal amongst other with two- and three-windings transformers. At this moment I use the calculator 4 (Rated Short Circuit Voltage %, kW Loss at Rated Current) of the 2-windings transformer to calculate the impedance values in % for the 3-windings transformer
The problem I have is that my results of the short circuit simulation with PowerTools can’t be right. The secondary and tertiary winding have exact the same properties – and therefore they have to get the same short circuit. But the SKM PowerTools results are different (Ik’’sec = 17.2kA; Ik’’ter = 18kA). I calculate this setup per hand also and agree with 17.2kA. Other simulation software also has the value for Ik’’ = 17.2kA.
My questions are: “Why are there different values for Ik’’ by simulating with PowerTools? And why are there the diffences?”
Data of the transformer:
155kV/31.5kV/31.5kV
240MVA/120MVA/120MVA
Uk12=12.9% Pk12=307.6kW Sn12=120MVA
Uk13=12.9% Pk13=307.6kW Sn13=120MVA
Uk23=23.76% Pk23=549.9kW Sn23=120MVA
Best regards
Tobias






RE: SKM PowerTools Three-winding Transformer - short circuit
If your source is infinite, using IEC60909-0 with c factor of 1.0, I get following :
I"k3 sec = 17.048kA
I"k3 ter = 17.048kA
Probieren geht über studieren.