Calculation of protection setting for two phase PT for railway

[DiMiTKo]

Hello! I have to calculate a overcurrent protection of one two phase power transformer. For three phase calculation is not problem, but may be in two phase there is something specific. Is there someone who knows how to do the calculation. I found one document of Areva but there is a calculation example only for overhead lines for rail.

 

[PHovnanian]

Sounds like an interesting problem. Can you supply some more information? Like aa link to the Areva paper, some specifications of your two phase transformer (winding configuration, phase relationships, etc).

Not everyone here is familiar with railway systems. But we might be able to contribute some insights into the special case of symmetrical components or other math involved.

 

[waross]

Is this two independent phases, two phases connected at a corner, two phases connected phase end to center tap, two phases connected center tap to center tap or some other connection, possibly some variation of the Scott connection?
It may make a difference.
How about grounding?

Bill
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"Why not the best?"
Jimmy Carter

 

[Skogsgurra]

This kind of transmission lines are often used as a backbone for long distance railway systems. The configuration is center tap grounded transformer and two phases with 180 degrees shift.

Using grounded center tap, you can build the line for e.g. 65 kV to ground and still have the transmission capability of a 130 kV line.

Settings are the same as for a singe phase line.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[DiMiTKo]

Some additional information for power transformer is in the attached file. In fact the transformer is single phase and supply instead phase-ground is phase-phase (phB-phC).

 

[lz5pl]

DiMiTKo, is it for Voluyak s/s ?

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[DiMiTKo]

Yes. Do you know this s/s? It is almost ready.