One of the challenges facing electric power systems is the failure of overhead and cable transmission lines. Short circuits pose a particular danger. This fact requires increasingly faster information acquisition and processing for estimating a system state and making preventive measures to ensure sustainable power supply with minimum loss of time. This paper is devoted to the problem of on-line determination of the coordinates of a short circuit point in the transmission line. The suggested methods are based on the assumption that the short circuit current at the transmission line beginning depends on the distance to the short circuit point.