Transmission Line Impedance
Transmission Line Impedance
(OP)
I am in the process of trying to calculated a transmission line impedance for the purpose of distance protection. I do not have any software to model the line and was wondering if there was a more straight forward(real world) method of calculating the impedance without having to use the complicated mathmatics used in college. The transmission line is 69kv, 8 miles long, 795mcm acsr.






RE: Transmission Line Impedance
Gunnar Englund
www.gke.org
RE: Transmission Line Impedance
R= Value from table (see link below)
X= 0.0754.Ln(GMD/GMR) Ohm/km to neutral @ 60 Hz
GMD= (Dab.Dac.Dbc)^1/3
GMR from ACSR cable table (see link below)
http://www
PS: For zero sequence and accurate values, probably you need to go for approach that is more complex and provide additional data.
RE: Transmission Line Impedance
RE: Transmission Line Impedance
Take a look at the Areva website, the PRAG handbook can now be downloaded free gratis
RE: Transmission Line Impedance
"..The transmission line is 69kv, 8 miles long, 795mcm acsr."
As cuky2000 pointed out, you can also find this standard values of ohm/ft, etc thru conductor tables (usually named after the family birds) like; Power System by Stevenson in the appendices, G.E Handbook, etc.
To ease computations' hassles, you must be able to familiarize the terminology relating to transmission line, GMR, GMD, cable type, and other parameters then used computer software simulation.