The thesis submitted in fulfilment of the Candidate of Engineering Science (PhD) degree in technical sciences on specialty 05.14.02 – «Power stations, networks and systems» (141 Power engineering, electrical engineering and electromechanics). – National Technical University of Ukraine «Igor Sikorsky Kyiv Polytechnic Institute», Kyiv, 2019.
The dissertation is devoted to the solution of the scientific and practical task of information provision efficiency increasing for distributive electrical networks (DEN) 0,4...10 kV control systems (CS) in conditions of SmartGrid technologies introduction by using electric networks for broadband signals with improved characteristics transmission.
In dissertation was analyzes distributive electrical networks of Ukraine as a control object. It is established that the current trends in the development of DEN CS in conditions of increasing the number of RES and other objects of distributed generation, as well as increasing the requirements to the quality of electricity supply to consumers, necessitates the solution of new management tasks that require the appropriate information provision of the CS.
The analysis showed that due to the coincidence of the topology of the DEN with the topology of the DEN CS information flows, as well as on the technical and economic indicators, it is expedient to construct information support systems using of the DEN 0.4...10 kV as a medium for information signals transmission.
On the basis of the analysis of existing methods and means of signals transmission by DEN, it was found that it is expedient to use of spread spectrum (SS) signals as information signals for transmitting by DEN 0.4...10kV, which, in contrast to the existing signals, allows multichannel signal transmission, increase speed and noise immunity. But the limited frequency bandwidth that is suitable for transmitting signals by DEN requires the further development of the approaches to the formation of SS signals to the transmission conditions of the DEN 0.4...10kV.
The analysis of the signals used for the transmission of DEN in the DEN CS information systems, including classical narrowband signals and modern wideband signals, was conducted.
In the spectra of signals for transmission by DEN, obtained by classical methods, 90% of the signal energy lies within the first spectrum tab. The rest of the energy is lost, which leads to distortion of the signal.
In order to reduce the part of the energy that goes beyond the first tab, a new method is proposed, which is to further signal transform using a Wave-wavelet function, which allowed to focus power of the signal in the band of transmission and to increase the efficiency of using frequency band when transmitting SS signals by DEN.
A new method was proposed for the investigation of the phase-frequency characteristics that allows to research phase-frequency characteristics of DEN in the remoteness of transmission and reception points. The developed method is based on the principle of measuring the relative phase shift between signals transmitted at different frequencies, which are phased at the transmission side. It allows to determine the phase shift for discrete values of frequencies between frequencies that differ in two from each other in relation to the selected initial frequency and allows to obtain a relative phase-frequency characteristics of DEN.
An analysis of the approximate methods of DEN calculating as a medium of signal transmission has shown that they are based on the presented HF paths by DEN by two characteristics: the signal damping and the characteristic resistance of the path, which is not enough to evaluate the SS signal propagation process by DEN.
The exact method of calculating DEN as a medium for transmitting signals is a method based on DEN elements representation as lines with distributed parameters, but the use of this method is hindered by DEN elements parameters lack.
To solve the problem of DEN elements parameters determining is proposed to use the numerical solution of Maxwell equations by finite element method for DEN elements spatial models and verify the correctness of obtained results.
