Енергетика: економіка, технології, екологія: науковий журнал, № 4

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https://ela.kpi.ua/handle/123456789/49255

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Перегляд Енергетика: економіка, технології, екологія: науковий журнал, № 4 за Автор "Stulishenko, A. S."

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    Study of physical processes in laminated magnetic cores of electric machines
    (КПІ ім. Ігоря Сікорського, 2021) Chumak, V. V.; Kovalenko, М. А.; Trotsenko, Y. O.; Ihnatiuk, Y. S.; Stulishenko, A. S.
    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.