rated current of overhead line

[HeinzS]

Hi All,

i am working on a very basic simulation of the transmission network in spain and the impacts of a rising share of wind energy. In Spain, they operate with 220 and 400kV overhead transmission lines.

I couldn't get information on the current capacities, but i do need the rated current to proceed with my simulation done with DIgSilent/Power Factory. They vary from line to line, but an estimation that covers the average would realy help.

I am thankfull for every link and reference.

Have a nice weekend,

heinz

 

[Overvoltage]

It really depends on the construction of the line and the rating methodology. The capacity could be anywhere from 200A to 2000A, depending on the size of the conductor, the amount of "sag" allowed in the conductor, and other variables.

You really need to get in contact with the owner/operator of those lines to get the right information, although I suppose you could look at it at the extremes (above may be a decent starting point), and check those. If it ends up ok at both ends, it probably would be ok in the middle...at least for a first look WITHOUT all of the necessary data to do it right.

 

[jghrist]

http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet16

has ampacities of ACSR conductor (North American sizes) at 75°C conductor, 25°C ambient.

As indicated by Overvoltage, there are many factors that go into determining the rating. The thermal rating in the link is one, but the temperature limit may be different. The line may be limited by stability criteria as well as thermally.

 

[itsmoked]

BTW:

Welcome to Eng-Tips HeinzS.

And a belated welcome to Overvoltage.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[lansford]

At those voltage levels and depending on the lengths, the ampacity limit is more determined by the surge impedance loading rather than the thermal rating.
JIM

 

[waross]

Reactance becomes more of a factor than resistance. As a rough rule of thumb, utilities may decide on the maximum voltage drop that they can adjust for on the receiving end. (This would often depend on the normal working range of the tap changer on the receiving transformer.) The limiting factor becomes the line impedance. The farther the line is extended, the less MVA can be transmitted without exceeding the allowable voltage drop.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ELEP]

This is base data from one of the Utility, which we used for design of transmission lines. This is max. power assumed at each voltage level. I don't have any reference but this data is based upon Utility experience & design practices. Refer if you found helpfull.

765 KV line having 4 X 686 sq. mm
conductor -2250 MW per circuit.

765 KV line having 4 X 686 sq. mm conductor
operating at 400 kV -614 MW per circuit.

400 KV line having 2 X 520 sq. mm conductor
with shunt reactor - 410 MW per circuit.

400 KV line having 2 X 520 sq. mm conductor
without shunt reactor - 533 MW per circuit.

400 KV line having 2 X 520 sq. mm conductor
operating at 220 kV - 155 MW per circuit.

220 kV line - 132 MW per circuit.
132 kV Line - 50 MW per circuit.

 

[HeinzS]

Thanks for all your answers and Keith for the warm welcome.

Your posts give me a fist hint, but i guess that the net operator is the only one who could give me a satisfactory figure.
If anybody of you know anybody working with or at the spanisch net operator REE (Red Electrica Espana

http://www.ree.es),

i would realy appreciate to get in touch with a contact person over there. Because right now, i didn't receive any answer writing at redelectrica@ree.es.

Best

Heinz