Rudenko S. Monitoring and Diagnostics Methods Improvement for Grounding Grids in Active High-Voltage Power Facilities in Ukraine

The thesis is devoted to the improvement of existing methods of determination of normalized parameters at each of the stages of electromagnetic diagnostics, as well as the creation of a qualitatively new approach to the issuance of recommendations for reconstruction a grounding grids to improve the safety of personnels on energy objects of Ukraine. The statistic of soil electrical properties to evaluate the optimal technical requirements for equipment for vertical electrical soil sounding when performing diagnostics of grounding systems is used. The model of the grounding device was based on the solution of the problem about the electrical field potential of the point current source, located in a three-layer soil. This model allows to determine the field potential at any point in case of the location of the grounding device in any of the layers of soil. Mathematical model and computer program for analyzing and interpreting results of the soil sounding by Wenner configuration was created on the base of the analytical solution for field of current point source located in four-, three- or two-layer structure. The method of equivalenting with bringing the multilayer soil to the form of the calculated models was improved. The adequacy of developed mathematical models for experimental measurements on more than 70 existing high-voltage power facility’s of Ukraine with voltage classes 35-150 kV has been checked. It was proved that the reconstruction of grounding system for requirements of touch voltage both in terms of electrical safety and in terms of material and labor costs is more effectiveness. The parametric model that allows predicting the probable material and technical costs for the reconstruction was created. Keywords: grounding grids, high-voltage power facility, normalized parameters, vertical electrical sounding, soil electrical properties, mathematical model, equivalenting technique, electrical safety.