The first step in modelling a real grid in the frequency range 2-500 kHz is discussed in this paper. The distributed parameters of the equivalent transmission line (TL) model are determined combining the benefits of three techniques: Four-terminal (4T) sensing is used to evaluate resistances, time-domain reflectometry (TDR) to determine lengths of cables, and impedance (Z) measurements to estimate inductances and capacitances. Finally, a measurement of the network impedance is performed in order to have a more complete view of the behaviour of the network.