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Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
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Документ Chornobyl: a History of the Past or a Demonstration. How Science Can Solve the Problems of the Future?!(Serednyak T. K., 2019) Sokol, Y.; Minakova, K.; Petrov, S.; Radohuz, S.; Lazurenko, O.; Zaitsev, R.; Lavrova, I.; Sincheskul, O.; Ilyinskaya, O.; Shestopalov, O. V.The possibilities of a well-known historical event as a starting point for teaching various scientific and technical aspects are shown. In particular, it is indicated how, as an example of the Chornobyl disaster, it is possible to elucidate in detail the principles of the work of the nuclear power engineering and the scientific basis of the processes that took place during and after the accident (based on sections of the school course of physics covering nuclear physics). It is also indicated for scientific discoveries and implementation, as well as engineering and technical solutions that were used during the elimination of the consequences of the accident. Thus, one man-made disaster allows us to disassemble this problem from the history of science and technology, physics, chemistry and ecology. Thus, this approach allows us to introduce the aspects of multidisciplinarity into learning, and to point out the interconnections of different types of sciences, which promotes a better understanding of the need for comprehensive development by students, and motivates the study of natural sciences [1–2].Документ Development of the converter structure that enables power supply to traction induction motors of mine electric locomotives from different levels of voltage(PC Technology Center, 2018) Lazurenko, O.; Shokarov, D. A.; Chorna, V.; Melnyk, O.; Cherkashyna, H. I.; Volynets, V.; Antsyferova, O. O.We have proposed an adjustable structure of the converter of energy of electric drive in the electrotechnical complex of a mine electric locomotive from power sources with different voltage levels ‒ from a contact network and a battery of traction accumulators. A characteristic feature of the converter is the presence of inverter units that can be connected either sequentially or in parallel. When powered by a lowvoltage source, inverter units are connected in parallel over the entire range of change in the output voltage. When powered by a high voltage source, inverter units are connected sequentially in the range of low output voltages and in parallel in the range of high output voltages. Such an approach makes it possible to align the power voltage levels of traction asynchronous motors of a mine electric locomotive at a lower level. The expected alignment of voltage levels is carried out at a lower level compared to a standard circuit of the threephase bridge autonomous inverter and is achieved by controlling the paired bridges in the power circuit of traction induction motors. Given this, the frequency of voltages of widthpulse modulation does not change, which is important for the process of reducing dynamic losses of power in the drive’s elements. It has been confirmed that an increase in the output voltage distortion coefficient in the IGBtransistors of the inverter with the minimal level of energy losses in the electric drive’s elements is achieved by modulating the voltage at a constant switching frequency at different voltage levels. We have proven the fact that the best indicators for the harmonic coefficient were obtained at frequencies about 30 Hz, which are the working ones, so the converter operating mode is most effective at these frequencies. The result of analysis of the classical scheme of the inverter has revealed that increasing the frequency of pulsewidth modulation by three times significantly increases electrical losses in the windings of traction electric motor. In the proposed circuit of the voltage inverter of engine’s power, at leveling the voltage at low level, there is no need to increase the frequency of pulsewidth modulation, which does not lead to a growth in the electrical losses in a traction motor.