The Identification of Single Phase to Earth Faults in Overhead Lines of Electrical Power Distribution Systems

Service continuity is one of the aspects of greater importance in the definition of the quality of electrical energy. After the electrical energy market liberalization, distributors have moved towards new investments in research, first of all in the field of faults diagnostic. The Authors have already studied the problem of the service continuity and this paper represents the development of the research carried out in the field. The paper presents the extension, to overhead distribution lines, of the new diagnostic approach to identify, locate and characterize the faulty events, made up by the Authors. The proposed methodology must be integrated in an electrical distribution networks management system. Indeed its implementation requires the installation of a data processing and control infrastructure which is already available for transmission systems. The technique is based on the use of the theory of the symmetrical components and the quadripolar models to represent each line of the network, both under faulty and normal conditions. The generalized model for single phase to earth faults in overhead distribution lines is presented and some interesting applications are reported.