Identification of ground faults according to the analysis of electromagnetic fields of MV lines

Abstract

The methods of assessing the place of the ground fault in compensated MV networks are known. At present realizations, the evaluation of ground faults is usually based on using more methods specialized for the detection of individual types of ground faults. The methods used in the paper follow from the analysis of electromagnetic fields of phase conductors and lines. Ground fault indicators have been installed at points with telecontrolled section switches and reclosers. The development of communication technologies enables new system-wide solutions to be applied in this field. A system-wide solution with telecommunicating indicators and with transmitting not only the result of evaluation but also the development of quantities being measured leads not only to increasing the reliability of determining the section of a MV line affected by the ground fault but, at the same time, it is also possible to assess the type of the ground fault including the prediction of the origination of subsequent ground faults, with the possibility of reducing the number of short-circuits to ground. The used solution enables us to telemeasure the values of phase currents at the point where the indicators have been installed.