Thesis for a Doctor’s degree in Engineering Science for the specialty 05.09.03 – Electrotechnical complexes and systems (141 – Power engineering, electrical engineering and electromechanics). Kremenchuk Mykhailo Ostrogradskiy National University Ministry of Education and Science of Ukraine, Kremenchuk, 2019.
The start-up processes of powerful electric drives have a significant impact on the technical and economic performance of the enterprise, which is associated with a significant increase in resource costs in startup modes. The complex, multi-vector nature of the influence exerted by the starting processes, led to the lack of theoretical development, dedicated to the control of the starting processes and hardware implementation of starting devices that optimize the starting processes of powerful electric drives.
The dissertation is devoted to the solution of the actual scientific and practical problem of creation of scientific basis for optimization of energy efficiency of processes of start-up of powerful electric drives with the use of operational analysis of a complex of resource costs and the cumulative result of the process of start-up, which will provide an opportunity for structural and parametric optimization of start-up complexes and systems based on start-up efficiency.
It has been established that the most significant components of the resource costs of the start-up process are electricity consumption, technical resource of electromechanical equipment and additional economic risks associated with disruptions due to the local decrease in the quality of the supply voltage.
The efficiency of the start-up process is determined by the ratio of resource costs and the cumulative result obtained, as well as the duration of the start-up process. The necessity of development of existing mathematical models of electromechanical systems to the level of the resource model, which should determine the resource costs and created a useful cumulative result of the starting process, as well as its duration, is substantiated.
For the first time, the criterion for the efficiency of the start-up process is developed, which is determined by the ratio of the square of the expert estimate of kinetic energy, minus the expert estimates of consumed electricity, equipment wear and additional economic risks at the moment of completion of the start-up process, to the product of expert estimates of kinetic energy and the wear of the equipment by the start-up process.
The optimization problem of controlling the start-up of powerful electric drives is formulated as a one-dimensional one-criterion problem with a continuous type of values of control effects and limitation of control influence. The structure of the search engine of the extreme control system of process of start-up of powerful electric drives by the criterion of its efficiency is offered.
The technique of selection of electromechanical equipment of the managed start-up systems based on the comparative analysis of the efficiency index is developed.
In order to increase the speed of the search engine to control the process of start-up by the criterion of its efficiency in the dissertation, a method of dynamic identification of the active resistance of AC motors was developed.
The main theoretical results obtained in the dissertation are tested on mathematical models created and experimentally.
Keywords: controlled start-up, operational approach, the resource model, accelerated wear, additional economic risks, efficiency indicator, identification of the active resistance.
