Electricity is missing or even unavailable in many localities in our country; while we have many power plants with large capacities (powers).This is partly due to energy losses in the networks. The transformers that are the essential components in the transmission and distribution of electrical energy have an aging population. The degradation of their paper/oil insulation system in the active part is the main cause. The dielectric losses in transformers due to this degradation (aging) are not taken into account in determining the efficiency of transformers. This paper shows that the dielectric losses in oil-impregnated paper-insulated transformers are becoming more and more important and are not to be neglected in the calculation of the efficiency of transformers due to their large number in electrical networks. With the help of DIRANA (Dielectric Analyzer), we made direct measurements of the dissipation factor and the capacity of the paper/oil insulation on real transformers in service in the electrical network in Côte d'Ivoire. In the following we calculated the dielectric power losses.
This paper is about grounding resistances next to the grounding systems of electric pylons and transformation stations in several localities of Ivory Coast. The data of grounding resistances got next to CIE facilitated drawing of curves and their analysis. The low resistances values from 1Ω to 2Ω of ground in some localities show that the electricity network is safe, on the other hand the high values more than 10Ω in other area show that it is necessary to plan appropriate grounding systems to protect the high voltage electricity network. To solve problem, we suggest techniques of reduction of these grounding resistances. The relevance of this paper is to contribute to the improvement of the grounding systems to protect high voltage electricity networks.