A time reversal process for determining a fault location in an electrical power network comprising multi-conductor lines, comprises measuring at an observation point located anywhere along one of the multi-conductor lines, for each of the conductors of the multi-conductor line, respectively a fault-originated electromagnetic transient signal; defining a set of guessed fault locations each having a different determined location in the electrical power network, and each of the guessed fault locations is attributed a same arbitrary fault impedance; defining a network model for the electrical power network, based on its topology and multi-conductor lines electrical parameters capable of reproducing in the network model the electromagnetic traveling waves; and computing for each conductor a time inversion of the measured fault-originated electromagnetic transients signal. The time reversal process method further comprises, as detailed herein, back-injecting a computed time inversion; calculating fault current signal energy; and identifying the fault location.