Browsing by Author "Nikolenko, Anatolii V."
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Item Identification of the Thermal Process in an Induction Motor(Dnipro University of Technology, Dnipro, Ukraine, 2022) Kuznetsov, Vitalii V.; Tryputen, M.; Nikolenko, Anatolii V.; Tsyplenkov, D.; Kuvaiev, Victor; Savvin, Oleksandr V.ENG: Purpose: synthesis of a mathematical model of an asynchronous motor, taking into account the impact of changes in the quality of electricity on the processes of heating and heat exchange for an economically justified choice of means of protection. Methodology: Theoretical substantiation of the expediency of using a one-mass thermal model of an asynchronous motor, for the conditions of operation of the latter in conditions of low-quality electricity, in order to determine losses in it. Results: Experimental studies of the operation of an asynchronous motor at nominal load were carried out. The obtained results of the measurements made it possible to determine the parameters of the single-mass thermal model, the heat transfer coefficient of the engine, and the coefficient of its heat capacity. A single-mass thermal model of an induction motor is a mathematical model used to describe the thermal processes occurring in an induction motor. This model is based on the assumption that all motor elements can be combined into one mass that heats up during engine operation. The model assumes that the thermal capacity of the motor is a constant, and the heat flow that is released during the operation of the motor is proportional to the square of the current passing through the motor windings. In addition, the model assumes the presence of thermal conductivity between the mass of the motor and the external environment, which affects the rate of heat dissipation. Scientific novelty: A methodology for determining losses in an asynchronous motor using a synthesized mathematical model is proposed, taking into account the influence of changes in the quality of electricity on the processes of heating and heat exchange in it. Practical significance: The obtained results indicate the adequacy of the proposed thermal model of an asynchronous motor operating in a network with low-quality electricity. Taking into account the fact that for many types of engines in the reference literature, there are no necessary data on the coefficients of heat transfer and heat capacity, and only the thermal time constants for certain types of engines are given, the value of the specified parameters of the model can be obtained on the basis of the methodology presented in the work. A single-mass thermal model can be useful for analyzing the thermal processes occurring in an induction motor and for improving the efficiency of the motor. In particular, it can help determine the optimal operating temperature of the motor, as well as calculate the necessary cooling system to ensure stable operation of the motor under conditions of variable load and temperature conditions.Item Improvement of the Process of Conducting Arc-Free Ferronickel Melting in a Six-Electrode Furnace(Elsevier/SSRN, 2021) Bezugliy, Anatolii V.; Nikolenko, Anatolii V.; Shevchenko, D. V.; Ovcharuk, Anatolii N.; Kuvaev, Viktor Iu.; Bezugliy, V. A.; Zamkovoy, O. V.ENG: Purpose. The aim of the authors is to find a technical solution to effectively control the appearance of an arc discharge in the subelectrode space of each of the six electrodes in submerged-arc furnaces from operational point of view. Methodology. A scheme was drawn up for modeling of the furnace circuit of a six-electrode furnace, which made it possible to obtain the zero point offset voltage and control its third harmonic and other components. For this purpose, two three-phase systems were created in the electrical circuit of the six-electrode furnace, consisting of half-phases of odd and even electrodes. For each of these systems, an artificial symmetric "star" was created separately. The neutral offset voltage for each of the systems was measured between the star zero point and the conductive hearth. Findings. Analysis of the harmonic composition of the shape of the neutral offset voltage curve, created by using an artificial symmetric star, made it possible to obtain a number of information (dependencies) that can be used in control algorithms. The proposed measuring scheme was tested on operation industrial six-electrode furnace of the Pobuzhsky Ferronickel Plant. During the melting, arcs were artificially created under the electrodes. Wherein: 1) the presence of an arc discharge was confirmed by the appearance of the third harmonic of the zero point offset voltage; 2) phase shifts of the first harmonic unambiguously indicated to the electrode with an arc discharge. Practical value The proposed method for monitoring the presence of electric arcs under the electrodes can be used to control ore-thermal furnaces both independently and as an addition to the already used systems for monitoring and controlling the electric mode of six-electrode furnaces.Item Preventing the Development of Emergency Modes of Interlocked Electric Drives of a Rolling Mill under the Impact Loads(Polish Society of Technical Diagnostics (Polskie Towarzystwo Diagnostyki Technicznej - PTDT), 2023) Druzhinin, Valeriy; Sivyakova, Galina; Kalinin, Alexey; Tytiuk, Valerii; Nikolenko, Anatolii V.; Kuznetsov, Vitaliy V.; Kuzmenko, MykhailoENG: In recent years, due to the tightening of competition in the global market of steel producers, the requirements for the quality of hot-rolled steel have increased. The finishing group of the rolling mill is characterized by a complex structure of mechanical and electrical parts. The operation of electric drive systems of such units is characterized by the interrelation of electromagnetic processes, mechanical phenomena and technological factors. As experimental studies have shown, the quality of the supply voltage is inextricably linked with the impact nature of the loads in the rolling stands of the roughing and finishing groups of the hot rolling mill. A decrease in the supply voltage may be accompanied by the development of emergency modes of synchronous electric drives, leading to a decrease in the quality of the finished product.The paper developed a mathematical model of the power supply system of the rolling mill JSC "ArcelorMittal Temirtau". It is shown that this can lead to loss of synchronism of the synchronous motor. Such a voltage drop has a significant impact on the operation of DC electric drives of the finishing group. Various strategies are proposed to counter the development of emergency situations.