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For cables to operate under normal conditions in a distribution system, two aspects must be analyzed: firstly, the parameters of different types of cables under normal operation, which include impedance matrix, power loss, and voltage drop; and secondly, the best configuration of cables in a ductbank based on the total ampacity value. A case study for 3-phase single circuit overhead transmission line with two ground wires has been given here. Two bundle conductors used in the configuration are considered. The line length is 100 km, level 100 kV voltage and lines are perfectly transposed. 100 MVA base is used for calculation purposes. 3.1 Table and 3.2 gives.
Underground Cable Impedance-in Duct
Underground Cable Impedance-in Duct
I know how to calculate underground cable impedances if they are direct buried.
What factors needs to be considered if they are run inside a Duct or RPVC conduit?
The first factor will be P( Soil resistivity) which cable is not in contact with it anymore.
The second factor that I can think of is the affect of barrier(duct or conduit) in mutual impedance calculation as the GMR is different now.
I appreciate any feedback on this subject.
Regards,
What factors needs to be considered if they are run inside a Duct or RPVC conduit?
The first factor will be P( Soil resistivity) which cable is not in contact with it anymore.
The second factor that I can think of is the affect of barrier(duct or conduit) in mutual impedance calculation as the GMR is different now.
I appreciate any feedback on this subject.
Regards,
Zero sequence mutual impedance for underground cables
Zero sequence mutual impedance for underground cables
![Calculation Calculation](https://i1.rgstatic.net/publication/229015950_Estimation_of_the_Zero-Sequence_Impedance_of_Undergrounds_Cables_for_Single-Phase_Fault_Location_in_Distribution_Systems/links/0deec5187a796513cf000000/largepreview.png)
Hi to everyone. I have been searching for the zero sequence mutual impedance equation for underground cables for a while. I am aware that this equation exists for overhead cables but does it so also for the underground cables? If not, how can I reach a rational result from existing formulas?
For instances;
There is a system consists of 2 circuits which have 3-phase cables separately.
- Can I use the self impedance formula for each cable separately and then mutual impedance formula for 1 circuit and in the end mutual impedance formula for 2 circuits?
- Should I consider the images of the cables above the ground?
- I actually need three values;
. B/w cable - cable
. B/w cable - earth
. B/w conductor - sheath
Thanks in advance for you helps.
For instances;
There is a system consists of 2 circuits which have 3-phase cables separately.
- Can I use the self impedance formula for each cable separately and then mutual impedance formula for 1 circuit and in the end mutual impedance formula for 2 circuits?
- Should I consider the images of the cables above the ground?
- I actually need three values;
. B/w cable - cable
. B/w cable - earth
. B/w conductor - sheath
Thanks in advance for you helps.