Tolydžiųjų asimetrinių reaktyviosios galios kompensatorių kūrimas

The aim of the performed research is development of reactive power compensators for the smooth and asymmetric reactive power compensation in the low voltage utility grid. The cascaded inverter has been modified and adapted for the smooth compensation of reactive power. The topologies of the conventional and cascaded inverter-based reactive power compensators with the individual inverters for the every phase for the asymmetric compensation of reactive power have been proposed. The shunt-connected compensator for the smooth and asymmetric compensation of reactive power in the low voltage utility grid has been developed. The investigation of developed reactive power compensators was performed using simulation and experimentally. The dissertation consists of an introduction, three chapters, general conclusions, references and the list of author's publications on the topic of the dissertation. The research problem, the relevance of the work, the object of research are presented in the introductory chapter. The aim and objectives of the work, the research methodology, scientific novelty of the work, the practical significance of the work results, defended statements are presented as well. At the end of the introduction, the author's publications and conference papers on the topic of the dissertation and the structure of the dissertation are given. The first chapter analyzes the reactive power compensation techniques and compensator types. The inverter-based reactive power compensators and shunt-connected reactive power compensators are analyzed. The conclusions are drawn out and the tasks of the dissertation are formulated. The conventional and cascaded inverter based reactive power compensators are analyzed in the second chapter. The topologies of reactive power compensators with the individual ordinary inverters and cascaded inverters for the every phase for the asymmetric compensation of reactive power are proposed. The Matlab/Simulink models of compensators were created and investigation of compensators using simulation was performed. In the third chapter the developed shunt-connected compensator for smooth asymmetric compensation of reactive power in low voltage utility grid is presented. The investigation of compensator was performed experimentally using developed experimental test bench. The main results of the dissertation have been published in 4 scientific publications – 3 of them have been published in peer-reviewed scientific journals, 1 in conference proceedings. The results were presented at 5 scientific conferences.Doctoral dissertatio