MV collection feeder: loss and voltage rise at two voltages

One radial feeder, equal stations, one tapered aluminium cable set. Screening tool for the SolarSoftwares MV/LV design page.

Cable data: Southwire SPEC 46715, AL Compact 35kV TRXLPE 133% IL, revision 1.000.006 (updated 4 June 2025): AC resistance at 90 °C, inductive reactance at 60 Hz and duct ampacity at 90 °C as printed. Not the standard text, not a protection or thermal study. Cable size is picked by ampacity only. Below 35 kV the 35 kV-class cable is a simplification; duct ampacity is a screen, not a direct-burial rating.

Maths: station current = MVA / (√3 × kV). Each segment carries the stations beyond it. Loss = 3 I² R L. Voltage change = √3 I (R cosφ ± X sinφ) L, summed along the feeder and shown for generation, so it is a rise at the stations. Resistance is the 90 °C value, so full-load loss is an upper figure. One station per feeder tap, equal loads, nominal voltage assumed at every station.