Mid span standing voltage - solid bonded cables 1

[Power0020]

Cable sheathes boned at both sides (solid bonded) have circulating currents while showing zero voltages to ground at both extremities, a voltage peak is experienced at the mid span.

I couldn't locate a formula to calculate that voltage peak.

I bet this is a bit similar to voltage peak occurring on barbed wire running parallel to a TL,with voltage adding up with distance, earthing points may be placed too far that the mid span peak voltage is hazardous? though I think the circulating current will be the same, independent of length.

Any clue?

 

[WHiPCPL]

The best I could find was a standard IEEE-575. (Although only valid for 5kV to 500kV cables). Researchgate has an article that wrote down some of the equations in the standard.
Link

That's about all I can help you with. If you need something more specific, let me know, although I'm probably limited in how much I can help you from this point on.

 

[Marmite]

There isn't any voltage that is sensible to calculate or measure. It is shunted by the sheath to earth bonds. The issue becomes one of circulating current rather than of voltage.If you really wanted to calculate the voltage between two arbitrary points, calculate the circulating current and the use the resistance per unit length of the screen wires to work out the voltage between your two points.
Regards
Marmite

 

[Power0020]

Well, thanks for that.

what will be the criteria for maximum spacing of fence earthing running along a transmission line?

 

[magoo2]

Even though your last question is a new topic, there is an old IEEE paper, Safety Hazards Beneath High Voltage Lines, by Gross and Hesse addresses that much of what you need to consider with a fence paralleling a transmission line.