Measurement of transmission line resistance

[simatic7]

Hi everybody
Good morning
Does any body have idea about the variation of transmission line resistance. What is the acceptable range of values of transmission line resistance. How can we measure the transmission line resistance ?
Please suggest me if there is any literature
regards
simatic7

 

[davidbeach]

Resistance is a property of the conductors used. It is what it is. See any of the power system analysis texts referenced in faq238-1287.

 

[waross]

The resistance may be determined by consulting the appropriate tables.
However, the impedance is more important. This depends on configuration, spacing, length, frequency, and the resulting voltage drop also depends on the power factor of the load.
An important factor in allowable impedance is the range of voltage correction available by the On Load Tap Changer at the receiving transformer. One factor is the voltage drop in the line, try to avoid situations where the voltage drop exceeds the capacity of the OLTC to correct it. This limit may be exceeded from time to time for a variety of reasons.

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

 

[simatic7]

Actually I meant transmission line tower footing(grounding) resistance not the transmission line resistance . By mistake I wrote transmission line resistance. Please

 

[7anoter4]

One may test the grounding resistance for all the footing and take an average. The problem is how to combine this result with the static wire impedance grounded through the pole grounding. Our practice, based on IEEE-80/2000, is to appreciate the tower impedances and overhead ground wires or neutrals using Endrenyi method.
But, as stated in IEEE-80, the maximum no.of parallel line which will be taken into consideration is 2. It is not an accurate method but is good enough.
There are a lot of other publication indicate different method. See for instance:

http://ieeexplore.ieee.org/Xplore/l...532102.pdf?arnumber=1532102&authDecision=-203

"Computation of current-division factors and assessment of earth-grid safety at 161/69 kV indoor-type and outdoor-type substations" by Lee, C.-H. Chang, C.-N.
This paper appears in: Generation, Transmission and Distribution, IEE Proceedings-Publication Date: 4 Nov. 2005 Volume: 152, Issue: 6 on page(s): 837- 848

 

[simatic7]

Thanks a lot for your kind response
Simatic7

 

[jghrist]

The main reason for lowering tower footing resistance is to improve lightning performance. The acceptable range depends on the line design and the required lightning performance. See IEEE Std 1243-1997, IEEE guide for improving the lightning performance of transmission lines for the relationship between resistance and performance.

Measurement is usually by the fall-of-potential method. See IEEE Std 81-1983, IEEE guide for measuring earth resistivity, ground impedance, and earth surface potentials of a ground system