Query About Voltage Drop in Impedance

I don't see in your diagram what r, x, and Z represent. If r is your cabling resistance then r≠0 unless your transmission line uses only superconducting materials. It can be r≈0 and with the few significant figures that are shown in your diagram one may make this plausible assumption and therefore no voltage drop will exist.

Thank You, i want to know, suppose we put r=1Ω and x= 5 Ω then the drop in cable or impedance should be = (I∠ø) * (r+jx) but this value is not matched with Etap drop. Please refer attached picture for more clarification.

Your 83.6V or 778V appears to be the arithmetic difference between source and load voltages i.e. the regulation in volts. It is not the vector difference corresponding to the line impedance 2 + j10 you have "forced in" over the libary data for XLPE cable.

I am puzzled that 244? amps go into line & only 146? amps come out! You do not have any line capacitance to cause a difference.

If even Kirchoff's law does not apply, one cannot trust a calculation.

What formula did you use and what calculation does not match? A table showing the results of the manual calculation compared to the automated result would help pinpoint the nature of the discrepancy. The numbers on the SLD look correct.

I don't know why #3 was off-topic since it contains some clues as to where the problem lies. First, the impedance between the busses has changed significantly, resulting in a much larger voltage drop. Second, you still have not provided the manual calculations and the comparison with the Etap results, nor any of your reasoning for the perceived discrepancy.