T-line Impedance 1

[james001]

Does anyone know where I can get info on the T-line impedance. I have 795ACSR line with normal tangent structure and wondering how to obtain/calculate the impedance per mile (ohms/mile)

thanks

james001

 

[dpc]

You will need to compute this using standard reference text such as Westinghouse (ABB) Transmission & Distribution, "Elements of Power Systems Analysis" by Stevenson, or "Analysis of Faulted Power Systems" by Anderson. Any basic text on power systems should have the information you need.

The calculation has to take into account the self-inductance of each conductor as well as the mutual inductance between phases. This depends on conductor geometry as well as spacing and configuration. Zero-sequence calculations require information (or assumptions) on earth resitivity and height above ground.

It's a little involved, but not really that difficult if you have a good reference.

 

[SidiropoulosM]

The calculation of transmission line impedance is straightforward once you have a good understanding of all the necessary parameters on conductor geometry. I agree with dpc's suggestions. Here are some more:

1. EPRI's "Transmission Line Reference Book". It has extensive tables and you may be able to find your line without doing the calculations yourself.

2. B.M.Weedy, "Electric Power Systems". This book has the necessary formulas (pages 71-75) and some tables. The explanation of the formulas is given in an easily understandable way.

I don't want to give you the formulas here, because you need to understand how they are affected by the conductor geometry, which you can only get by reading the textbook. Michael Sidiropoulos

 

[jbartos]

Suggestion: In addition to the above postings, visit

http://ceaspub.eas.asu.edu/PowerZone/SparseVisual/Lecture slides/Lecture 16/Branch Modeling.ppt

http://xnet.rrc.mb.ca/janaj/E602 Power Systems/transmission lines characteristics.doc

etc. for more info

 

[SidiropoulosM]

jbartos you get a star for these two excellent references. Michael Sidiropoulos

 

[ergon]

http://www.ece.utexas.edu/~grady/TOWERABC.html

There is a free program at the above site.