1. A method for fault location in electric power lines, in which division of the transmission or distribution system line into sections is used and a hypothetical location of the fault is assumed in at least one of these sections, characterised in that: current for fault condition and pre-fault condition is measured in all terminal stations of the system, the line phase voltage for fault and pre-fault conditions is measured in one terminal station of the system, symmetrical components of the measured current and voltage signals and the total fault current in the fault point are calculated, the first hypothetical fault point located in line section between the beginning of the line and the first tap point, the second hypothetical fault point located in line section between the end of the line and the last tap point of the branch, and a consecutive hypothetical fault point which is located in the branch are assumed, while for multi-terminal lines consecutive hypothetical fault points located in the line sections between two consecutive tap points are additionally assumed, the distance from the beginning of the line to the fault point, the distance from the end of the line to the fault point, the distance from the end of the tapped line to the fault point located in this branch are calculated, while for multi-terminal lines the distance from the tap point to the fault point located in the line section between two tap points is additionally calculated, and then for all hypothetical fault points in each section fault resistance is calculated, the actual fault point location is selected first by comparing the numerical values concerning the previously determined distances and rejecting the results whose numerical values are negative or bigger than 1 in relative units and then by analysing the values of the calculated fault resistances for fault points and rejecting those results of the calculations for which the value of fault resistance is negative, and if it is found that only one numerical value concerning the distance is contained in the numerical interval between zero and one in relative units and the value of calculated fault resistance for this distance to the fault point is positive or equal to zero, then these results are final and they indicate the actual distance to the fault point and the value of fault resistance in the fault point, if, after the selection of the actual fault point it turns out that at least two numerical values concerning the previously calculated distances are contained within the numerical interval from zero to one in relative units and the values of the calculated fault resistances for these fault points are positive or equal to zero, then impedance modules or impedances of equivalent source systems for the negative sequence component for phase-to-ground faults, phase-to-phase faults, and double phase-to-ground faults or for the incremental positive sequence component for three-phase faults are determined and assuming that the fault occurred in a definite section, and during the impedance determination it is additionally checked whether the calculated values of the impedance of equivalent source systems are contained in the first quadrant of the Cartesian co-ordinate system for the complex plain and these distances to fault points are rejected for which impedance values are not contained in this quadrant of the system, and if it turns out that only one value of the impedance of the equivalent source system concerning distance is contained in the first quadrant of the system, then the result of the calculation of the distance to the fault point, for this impedance, is considered to be final, whereas if it turns out that at least two values of the impedance of equivalent source systems concerning distance are contained in the first quadrant of the system, then the modules of these impedances are determined, the values of the modules of impedance of equivalent source systems are compared with realistic values which really define the system load or supply, and the distance for which the value of the module of the equivalent source impedance is nearest to the realistic values really determining the system load or supply is considered to be the final result.