Bederak Y. Optimization of reactive power flows in power supply systems of industrial enterprises taking into account the quality of electricity

Object of study: operation modes of power supply systems 10 (6) kV, containing nodes with asynchronous loading and compensating devices. Subject of study: calculation methods of the reactive power flows and the operating mode of compensating devices in power supply systems with a voltage of 10 (6) kV. The purpose of the thesis: further development of methods for calculating and optimizing the reactive power flows, calculating the operating mode of compensating devices in power supply systems of industrial enterprises, taking into account the quality of electricity. Methods of research: calculation of alternating current electrical circuits, high voltage techniques, mathematical statistics, iterative method of calculating the operating mode of the electrical network. The reliability of the elaboration is ensured by the correct use of research methods, confirmed by experimental research and industrial implementation. The practical value of the obtained results for the electric power industry is to increase the energy efficiency of reactive power compensation devices and to develop measures to protect against resonance phenomena in power supply systems with compensating devices with 10 (6) kV voltage. The scientific novelty of the obtained results is as follows: for the first time a method for calculating the reactive power flow in power supply systems with a different load, in the absence of the nominal voltage matches at the boundary of the balance inventory and the places of meters installation, has been developed. The method based on the determination of the relative n- minute values of active and reactive power and allows improving the accuracy and validity of the calculations with energy supplying organization for reactive power flows. The method of calculating the operating mode of the network with a capacitor bank, connected in parallel to the active-inductive load in the presence of higher harmonics sources, was further developed. This method is based on determining the impedance and resonance frequency in real time, which allowed improving the protection of the electrical network from resonant phenomena. The method of determining the equivalent inductive resistance of asynchronous electric motors in real time by improving the data processing of automated metering systems has been improved, which makes it possible to use its values for calculation of the steady-state operation of electrical installations. The method of statistical analysis of electrical loads in real time was further developed. The method is based on determining the conditions for obtaining their stationarity intervals, which made possible to reduce the number of stationarity intervals and simplify further calculations. The main results of the research, carried out in the dissertation, were used in PJSC "Azot", Cherkasy, in " Promjelektroproekt Ltd ", Kyiv, in " Tessa Ltd ", Kharkiv, where high technical and economic feasibility of the results has been proved.