Transient based method for identifying faults in a high / medium voltage electric power transmission system

An apparatus comprising

• a fault-identification module for identifying faults in an electrical power transmission and/or distribution system having a current transmission line (L12, L13, L23) the fault-identification module being configured for:
• memorization of a physical model of the electrical power transmission and/or distribution system with said current transmission line, the physical model describing fault parameters and behavior of travelling waves due to a fault in the electrical power transmission and/or distribution system and, in case of a fault, fault parameters comprising a fault-location parameter on said current transmission line (L12, L13, L23) and a fault-impedance parameter,
• measurement of voltage and/or current evolution at a specific location in said power system,
• iterative simulation of the voltage and/or current evolution by the physical model at the measurement point with a set of fault parameters, wherein, at each iteration of said iterative simulation, simulated and measured voltage and/or current evolutions are compared and the set of fault parameters is adapted according to a convergence criterion,
• identification of a fault and fault parameters thereof when convergence of the measured voltage and/or current evolutions and simulated voltage and/or current evolutions has been reached,
• wherein the physical model is based on a telegraph equation for describing the fault parameters and the behavior of travelling waves due to the fault in said electrical power transmission and/or distribution system, and
• wherein the only traveling waves are taken into account when iteratively simulating the voltage and/or current evolution are those that can reach the measurement point before a predetermined maximum time tmax between one and ten milliseconds.