Кафедра "Електричні апарати"

Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/43

Офіційний сайт кафедри http://web.kpi.kharkov.ua/ea

Кафедра "Електричні апарати" була створена в 1931 році при Харківському електротехнічному інституті. Засновником, організатором і першим завідувачем кафедри був видатний фахівець в галузі електротехніки професор Вашура Борис Федорович.

Кафедра входить до складу Навчально-наукового інституту енергетики, електроніки та електромеханіки Національного технічного університету "Харківський політехнічний інститут", веде підготовку фахівців що мають глибокі знання з електромеханіки та різнобічні знання в області комп’ютерної техніки й інформаційних технологій.

У складі науково-педагогічного колективу кафедри працюють: 2 доктора технічних наук, 6 кандидатів технічних наук, 1 кандидат фізико-математичних наук; 5 співробітників мають звання доцента, 1 – старшого наукового співробітника.

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Influence of cuts in the housing and armature of the forced electromagnet of the fuel injection system on its speed
(VSB-Technical University of Ostrava, 2023) Bajda, Yevgen I.; Pantelyat, Michael G.; Vyrovets, S. V.
Electromagnetic mechanisms are widely used in various systems due to the simplicity of their design and reliability in operation. One such system is the fuel injection system for an internal combustion engine. The electromagnets installed in such systems should have a number of special properties: they should have small dimensions, high speed, which is ensured by forcing, a small mass of moving elements, an increased residual air gap, a small armature stroke and minimal eddy currents in the magnetic core. The reduction of eddy currents is carried out by the use of steels with increased resistivity and special cuts in the housing and armature, which significantly complicates the design of the electromagnet, but is an effective approach for re ducing losses in DC electromagnetic systems. To assess the influence of the design of an electromagnet on its speed, the article present a comparative analysis of the solution of the problem of dynamics in a 3D formulation for a forced armored DC electromagnet and an improved electromagnet with reduced eddy current losses due to special structural cuts in the housing and armature.
A refined mathematical model of physical processes in a conductor at a high-current pulse discharge
(Харківський національний університет міського господарства імені О. М. Бекетова, 2021) Bajda, Yevgen I.; Pantelyat, Michael G.
A novel mathematical model describing physical processes during the flow of an aperiodic pulse current with amplitude of 100 kA along a conductor with a circular cross-section is proposed and investigated. It is shown how a short-term electric discharge of an aperiodic shape affects the distribution of the current density in the cross-section of the conductor, causing its nonuniform heating and the appearance of significant thermal forces as well as mechanical stresses and strains. Based on the developed mathematical model, the relationship between electromagnetic, thermal and mechanical phenomena is shown, allowing a deeper understanding of the multiphysics processes taking place. The maximum values of the current density are calculated, which on the surface of the conductor reach values of 47 kA/mm2, while the temperature rise of a copper conductor with a diameter of 2.44 mm is no more than 80ºC at high temperature gradients, which causes the appearance of thermal stresses that have value (40–50)% of the value of the short-term strength limit of electrical copper. Utilization of this model allows to more accurately determine the required conductor cross-section based on the characteristics of electromagnetic, thermal and mechanical processes. It is shown that the simplified model (the condition for the uniform distribution of the current over the cross-section) gives significantly underestimated values of temperatures and does not take into account temperature deformations.
To the problem of protection of medium voltage instrument transformers with fuses: analytical research
(Харківський національний університет міського господарства імені О. М. Бекетова, 2021) Bajda, Yevgen I.; Grechko, Oleksandr; Buhaichuk, Viktor; Knápek, Robert
In the medium voltage power grid of 6–35 kV, there is a problem of protecting voltage instrument transformers. This is due to the insufficiently effective level of their protection with fuses. Recently, there have been more and more reports of accidents associated with the failure of voltage instrument transformers not only in Ukraine, but also abroad. The issue of conducting an analytical study of the problem of protection of medium voltage instrument transformers by fuses is relevant. Goal. Investigation of designs and characteristics of fuses for medium voltage instrument transformers to improve the efficiency of their protection. Results. The article shows that protection of medium voltage instrument transformers with epoxy insulation is often provided by fuses, in which the nominal current of the fuse-link is significantly higher than the maximum permissible long-term current of the primary winding of the instrument transformer. A comparative analysis of the current values of the primary winding of medium voltage instrument transformers with the values of the rated currents of the fuse-links of fuses of various manufacturers presented on the Ukrainian market is carried out. The design features and technical characteristics of fuses for medium voltage instrument transformers have been investigated in order to increase the efficiency of their protection. The advantages and disadvantages of the designs of fuses from various manufacturers have beeninvestigated and it has been established that the design of fuses requires further improvement in order to increase the efficiency of protection of medium voltage instrument transformers. Discussion and prospects for further development. Since in Ukraine, the need for fuses to protect medium voltage instrument transformers is provided mainly by supplies abroad, a promising direction for further development in this direction is the creation of a domestic competitive design of a fuse and its introduction into production.
Peculiarities of Calculating Forced Electromagnets Shunt Windings Heating in Transient Modes
(Technischen Universität Graz, Austria, 2018) Bajda, Yevgen I.; Klymenko, Borys; Pantelyat, Michael G.; Korol, Olena G.; Yelanskyi, Yurii
An analytical expression is obtained that makes it possible to calculate the volumetric density of sources of transient heating of shunt windings, in which as they are heated up, the volumetric density of sources integrally decreases, but at the same time, at points with higher temperature, the source density is higher then at points with lower temperature. Using the example of temperature calculations of miniature gas distributors, it is shown that at forced heating of the electromagnets in shunt windings significant temperature drops, reaching 35% of the maximum temperature, as well as a slight effect on the heating of surrounding objects, in particular, steel of the magnetic core, are observed.
Lumped Parameter and Circuit Models of Electromechanical Switching Device Electromagnet
(Technischen Universität Graz, Austria, 2020) Bajda, Yevgen I.; Clemens, Markus; Pantelyat, Michael G.; Korol, Olena G.
Forced DC electromagnets are widely used in modern electromechanical switching devices. In cases, where the total costs of simulation of high-fidelity electromagnetic field's 3D and even 2D models are unacceptably high, alternative techniques based on lumped parameters and magnetic circuit models of switching device electromagnets can be used. The paper presents a technique for calculating the dynamics of forced DC electromagnets using the Maple code as an example of simulation of the magnetic circuit of an electromagnet used in vacuum contactors.