I'm currently working on a project to determine the transmission losses in an LVAC line, as part of an off-grid distributed generation system.

The manufacturer of the cable has given me a DC resistance per km value. I'm looking for more accurate values, so I tried to figure out the AC resistance using skin depth, but the value falls below than the DC resistance specified by the manufacturer.

Is there any correction factor for converting DC to AC resistance of the cable?
In a Quora post, I saw someone mentioning a correction factor of 1.6 but I couldn't find any credible references to back it up.

Some help would be appreciated.

P.S: The DC resistance at 20° Celcius of the 95 X 3+ 70 sq. mm cable given by the manufacturer is 0.320 ohm/km. Based on my calculations I'm getting 0.279 ohm/km.

  • \$\begingroup\$ Pure copper at that size would have a DC resistance of 0.24 ohm/km. I think you're going to have to go with the manufacturer's numbers on this. \$\endgroup\$ – Dave Tweed Jul 22 at 11:28
  • \$\begingroup\$ Perhaps you forgot the filling factor. Not sure if the skin effect is ever taken into account for such low frequencies. \$\endgroup\$ – Marko Buršič Jul 22 at 11:59
  • \$\begingroup\$ Skin depth at 60Hz for pure copper is 8 milliMeters. That is the one-neper depth. \$\endgroup\$ – analogsystemsrf Jul 22 at 15:21
  • \$\begingroup\$ Hi! I'm using an Aluminum Cable. The max length of the transmission line would be 3km. Should I ignore the AC resistance and move on with the calculation? \$\endgroup\$ – Rishikesh Sreehari Jul 23 at 12:44
  • \$\begingroup\$ DC and ac resistances are separate. They add to give an effective resistance. \$\endgroup\$ – StainlessSteelRat Jul 23 at 19:49

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