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Determining the starting time of car movement to stabilize the internal pressure and the temperature in the tires
(Харківський національний автомобільно-дорожній університет, 2021) Karpenko, V. O.; Kaps’kyy, D. V.; Rudenko, N. V.; Neskreba, E. Ye.; Карпенко, В. О.; Капський, Д. В.; Руденко, Н. В.; Нескреба, Е. Є.
Problem. The problem of road safety does not lose its relevance in our time. The condition and performance of tires has a significant impact on the safety of road transport. Unfortunately, the tire pressure monitoring requirements of the developers are not always met. Naturally, now some modern cars are equipped with various systems for monitoring and even adjusting the internal tire pressure. However, there are relatively short periods of time during which the pressure and temperature in the tire change dramatically, and hence its other performance and properties. First of all, we are talking about dramatically changing weather conditions and the starting movement of the car. And then additional monitoring of tire pressure is needed. Goal. On the basis of the experimental studies carried out, to obtain the dependence of the tempera-ture and pressure changes inside the tire on the time of car movement. To determine the initial period of time of car movement until the pressure and temperature in the tested tires stabilize. Methodology. The work used the technique of both bench tests of tires in the laboratory and road tests under real weather conditions by car. Based on the numerical processing of the ex-perimental results, dependencies were obtained, using which it is possible to determine the in-crease in temperature and pressure in tires in the mode of starting movement of the car. Results. The analysis of scientific publications on this topic is performed. The time from the beginning of the car to the stabilization of temperature and internal pressure in the tires is determined, as well as the increase in temperature and pressure inside the tire during this period. The method of determining the starting time of the car to stabilize the internal pressure and temperature is proposed. Originality. In this work, for the first time, a method is proposed for assessing the temperature and internal pressure in tires in the mode of starting movement of the car, which makes it possible to obtain dependencies without resorting to further experimental studies. Prac-tical value. Using the obtained dependencies for certain tires and under different weather condi-tions, it is possible to predict the change in tire pressure at the starting mode of the car's movement, and therefore make adjustments to this value, if necessary, which will have a positive effect on the safety of moving vehicles.
Electrical power unit of the transformer oil centrifugal cleaning unit
(Харківський національний автомобільно-дорожній університет, 2021) Hnatov, A. V.; Arhun, Shch.; Bagach, R. V.; Nechaus, A. O.; Tarasova, V. V.; Ruchka, O. O.; Don, A. V.; Patlins, A.; Гнатов, А. В.; Аргун, Щ. В.; Багач, Р. В.; Нечаус, А. О.; Тарасова, В. В.; Ручка, О. О.; Дон, А. В.; Патлінс, A.
Problem. Cleaning transformer oil is one of the important engineering tasks, whose solution is associated with significant material and energy expenditure. Due to the increase in electricity consumption at modern automobile companies (firms, organizations, service stations, etc.), the load on transformer substations increases and the requirements for reliability of electrical and electronic devices become more complicated. This, in turn, leads to the problem of cleaning and recycling of transformer oil. Goal. The goal is the research and development of an efficient unit for centrifugal cleaning of transformer oil with a drive control system that provides automation of the start and braking mode of the drive. Methodology. Analytical methods of research, methods of the theory of electric machines and electric drives are used, as well as the methods of calculating electric circuits. Also, methods of analysis of circuits and control of power electronics devices, principles of operation and methods of control of static converters are used. Results. The structural scheme of the unit for cleaning transformer oil is developed. The calculations of the main elements of the power block of the transformer oil cleaning unit are performed. The block diagram of the voltage converter with frequency f = 50 Hz to alternating voltage with frequency f = 400 Hz is developed. Control circuits of the electric drive of the centrifugal separator are chosen. The analysis of operation of electric drive control circuits is carried out and the principles of their work concerning two components are considered: the regulated rectifier and the inverter. Originality. The scheme of the converter of alternating three-phase current with voltage of 220 V and frequency of 50 Hz, into alternating three-phase current with voltage of 220 V and frequency of 400 Hz is developed. This frequency, in addition to providing the necessary characteristics of the oil separator, allows you to develop a converter device of a relatively small weight and volume, and also provides its high reliability. Practical value. Utilizing the used transformer oil in this way will solve several problems at once. It is possible to reduce the initial production of transformer oil. The issue of waste oil disposal is being resolved leading to the solution of the environmental aspect of this problem. All this will reduce the cost of oil poured into transformers and the operating cost of transformer substations.

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