Palachov S. Harmonic currents and voltages in low-voltage electricity supply networks of Ukraine

The object of research: three-phase low voltage network with non-linear power consumers and the reducing harmonics appliances. The purpose of research: the development of methods of analysis, the creation of models and methodologies for calculating and reducing voltage harmonics in low voltage electrical networks in consideration of the requirements of international standards for harmonic current emissions. Methods of research: at the decision of tasks of dissertation the methods of mathematical and imitation design; theory of electric chains; methods of harmonic analysis were used. Theoretical and practical results and innovations the scientific value of the work is in developing methods for the analysis of low voltage electrical networks with nonlinear load and the technical means of harmonics reducing. This can define the non-sinusoidal parameters of voltage supply, as well as for the consumption current. For the first time the method for determining the EMC allowable nonlinear active power load for low-voltage networks with different parameters has been proposed. The practical significance of the work is to determine the optimal ways of solving the problem of reducing harmonics in low voltage electrical networks, in particular the recommendations on the use of individual and group technology to reduce harmonics and calculation of parameters of this appliances. The obtained results were used for the improvement of the national regulatory framework in the area of EMC and power quality by harmonizing it with the European one. A subject degree of introduction: the main results have been used during the creation of 10 existing Ukrainian standards for power quality and EMC by "Ukrenergo" (Kyiv) and Technical Committee № 22 for Standardization (Kharkov), in the Test Center "Omega" (Sevastopol), as well as in the teaching of subjects “Power supply systems” and “Special Issues of power supply” at the Institute for energy Saving and Energy NTU "KPI" (Kyiv). Effectiveness of implantation: further use of the obtained results may be by implementing of the method of determining the permissible active power of non-linear consumers in the Ukrainian regulations to ensure the EMC and power quality in power networks. Sphere of use: low voltage power networks, which include equivalent nonlinear load and technical equipment for harmonic reducing.