Analysis of the operating modes of a fragment of the 110 kV electrical network of PJSC "Lvivoblenergo" and design of the substation "Bilyavtsi"
Students Name: Raptsevych Ivan Fedorovych
Qualification Level: magister
Speciality: Electric Systems and Networks
Institute: Institute of Power Engineering and Control Systems
Mode of Study: part
Academic Year: 2020-2021 н.р.
Language of Defence: ukrainian
Abstract: There are changes in the world’s approaches to energy policy: the transition from an outdated model of the energy sector, dominated by large producers, fossil fuels, inefficient networks, imperfect competition in the markets of natural gas, electricity, coal - to a new model in which a more competitive environment is created, opportunities for development are equalized and the dominance of one of the types of energy production or sources and / or ways of fuel supply is minimized. At the same time, preference is given to improving energy efficiency and the use of energy from renewable and alternative sources. Implementing measures to prevent and adapt to climate change is also one of the priorities of global energy development. This poses new economic and technological challenges to Ukraine, but at the same time opens up new opportunities for finding and implementing innovative developments in mining, fossil fuel processing, production, transformation, supply and consumption of energy, which necessitates the formation of a new energy policy. The load of electrical networks is constantly increasing, due to the increase in users and their increasing load. This leads to equipment overload. In this regard, there is a need to build new substations, renovate existing ones, or switch networks to a higher voltage class to provide users with electricity. Such development of power grids should be carried out both on a permanent basis and in sufficient volumes in accordance with long-term plans, which are formed on the basis of analysis of technical condition, technological violations and importance of substations or transmission lines to ensure power system reliability. In our case, a new 110 kV Rozdilnoe substation is being built, which should provide electricity to the area. It will be put into operation on the site of the old 35 kV substation. Object of study In the master’s work the analysis of modes of development of an electric network of Brody REM of PJSC "Lvivoblenergo" is carried out and the project of substation "Bilyavtsi" is developed. Subject of study Development of a fragment of the 110 kV power grid scheme. It consists in the commissioning of the Bilyavtsi substation and the construction of two new overhead lines with a nominal voltage of 110 kV (Brody - Bilyavtsi and Bilyavtsi - Yaseniv). Two transformers with rated voltages 110/35/10 will be installed at this substation. The aim of the study Analysis of electrical network modes, calculation of short-circuit currents and equipment selection. To select devices (protective, switching, measuring, etc.) I determine the short-circuit currents on the high, medium and low voltage busbars of the substation. The calculation was performed using the software package "Dakar" [3]. During the operation of the coordinates, the modes of the electrical network are constantly changing, because there are constant changes in the load, and the network scheme itself may also change as a result of emergency or operational shutdown of individual elements. On the digital model of the network development scheme with the Bilyavtsi substation, which was formed in the DAKAR software package, normal and post-emergency steady-state regimes were investigated. From the calculations we can draw the following conclusions: In all operating modes, the currents in the lines and transformers are within normal limits, but the voltages in the maximum and post-emergency modes require additional correction due to regulation. Keywords: mode analysis, substation design, reliability, quality, equipment selection. List of used literature sources 1. Energy Strategy of Ukraine until 2035: "Security, Energy Efficiency, Competitiveness" Approved by the order of the Cabinet of Ministers of August 18, 2017 № 605-r. - Access mode: http://mpe.kmu.gov.ua/minugol/doccatalog/ document? Id = 245213112. 2. 2. Dakar software package