Editing Electric power transmission (section)

===Lossless line===
The lossless line approximation is the least accurate; it is typically used on short lines where the inductance is much greater than the resistance. For this approximation, the voltage and current are identical at the sending and receiving ends.
[[File:Losslessline.jpg|thumb|Voltage on sending and receiving ends for lossless line]]
The characteristic impedance is pure real, which means resistive for that impedance, and it is often called surge impedance. When a lossless line is terminated by surge impedance, the voltage does not drop. Though the phase angles of voltage and current are rotated, the magnitudes of voltage and current remain constant along the line. For load&nbsp;>&nbsp;SIL, the voltage drops from sending end and the line ''consumes'' VARs. For load&nbsp;<&nbsp;SIL, the voltage increases from the sending end, and the line ''generates'' VARs.