Study of physical processes in laminated magnetic cores of electric machines
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Дата
2021
Науковий керівник
Назва журналу
Номер ISSN
Назва тому
Видавець
КПІ ім. Ігоря Сікорського
Анотація
The aim of the work is to use fast-moving processes to detect defects in the interlayer insulation of
laminated magnetic cores of electric machines. Damages of interlayer insulation causes increased eddy currents
as a result of increased losses and integral local overheating in the magnetic core. The article develops a
mathematical field model of induction distribution in a toroidal toothed magnetic core of a 0.37 kW 4AA63V4U3
asynchronous motor when superimposed on the back of the core of the power winding powered by a high
frequency voltage source in the given range. An experimental study of losses in the magnetic core and the
distribution of eddy current losses and magnetization reversal (hysteresis) were carried out.
When designing an electric machine, its performance, optimum operating conditions, thermal state and
many other factors are calculated using the nominal values of the parameters of steel, windings and all materials
used in the machine. However, these materials do not always have the declared characteristics and quality. For
example, in the manufacture and stamping of electrical steel sheets, it experiences a significant level of influence,
which in a certain way affects its characteristics. In addition, even if one assume that during production all the
stages of manufacturing the material came flawlessly, the state and, as a result, the parameters of the materials
and the electric machine as a whole change during operation as a result of emergencies or even simple aging and
wear.
Therefore, given these facts, it becomes clear that during planned or unplanned repairs it makes sense to
check the condition of materials, insulation, since the allowable loads, temperature conditions, etc. depend on
their condition. In particular, the state of the magnetic core largely determines the temperature around the
conductors in the grooves and, as a result, determines how long the winding will actually last, in contrast to the
specified service life and the rated power at which this electric machine should be used.
The concept of the state of the magnetic core can be divided into the state of electrical steel and the state of
its insulation. The first component changes rather little during operation and is generally caused by the "aging" of
the steel, except for any serious damage as a result of faults, but it can be damaged during manufacture. But it is
the second component that is significantly influenced during operation and significantly determines the quality of
the magnetic core as a whole.
Опис
Ключові слова
electric machine, magnetic cores, eddy current losses, magnetic flux, електрична машина, магнітопровід, втрати на вихрові струми, магнітний потік
Бібліографічний опис
Study of physical processes in laminated magnetic cores of electric machines / V. V. Chumak, М. А. Kovalenko, Y. O. Trotsenko, Y. S. Ihnatiuk, A. S. Stulishenko // Енергетика: економіка, технології, екологія : науковий журнал. – 2021. – № 4. – С. 37-43. – Бібліогр.: 12 назв.