Lykhovyd Y. Overvoltages in asymmetric modes of main electrical networks

The оbject of research: there are modes in the main electrical networks in which overvoltages occur. The purpose of research: are methods and models of overvoltage analysis in asymmetric modes of operation of main electric networks. Methods of research the solution of the tasks set in the work is based on the laws of electrical engineering, the theory of linear and nonlinear circuits, methods of mathematical modeling. In deriving the equations of normal and abnormal regimes, classical methods of analysis of multiphase electric circuits were used. Verification of the results obtained with the help of mathematical models was performed according to the data of start-up and adjustable tests of NVN transmission lines in UES of Ukraine. Theoretical and practical results and innovations: mode of operation in incomplete phase and vice versa, which in practice allow to eliminate the consequences of incomplete compensation of the line phase by shunt reactors (SHR) and reduce the overvoltage levels of this phase. Also, the results of research on the impact of lightning protection cables on the level of overvoltages, which made it possible to reduce the level of technical requirements for special hardware protection, found practical use in the design of grounding in new and reconstructed transmission lines. A subject degree of introduction the results of work in the form of methodical materials are implemented in the design organization of LLC "ENCOR PLUS" (Berezan) and recommended for use in NEC "Ukrenergo" (Kyiv) during the operation of main electrical networks of high voltage.. Effectiveness of implantation: a significant technical and economic effect is obtained, which consists in increasing the efficiency of overvoltage protection and reducing operating costs by developing new methods of using a four-beam reactor circuit. Sphere of use: main electric networks.