Experimental determination of enlarged primary parameters of a three-wire power transmission line

A three-wire power transmission line (PTL) and its accessories can be replaced with a single passive octupole with an L-shaped equivalent circuit. The parameters of such an equivalent circuit are referred to as enlarged parameters. The enlarged primary parameters include larger active resistance and conductivity values, as well as the larger inductance and capacitance of the entire three-wire PTL. Before these parameters can be calculated, the corresponding voltages, currents, and their respective initial phases must be measured directly. The paper presents the entire experimental procedure. Indirect measurement of the enlarged longitudinal parameters of a three-wire PTL requires a short-circuit experiment as well as an idling experiment. Indirect measurement of the enlarged transverse parameters requires three experiments. The paper provides the necessary guidelines. It also presents formulas to calculate the enlarged parameters of a three-wire power transmission line.