Global Energy

RAR RUS 7-18 6603036819 Peter the Great St. Petersburg Polytechnic University, Russia Titkov Vassiliy titkovprof@yandex.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Voloshin Kirill Pavel Tukeev TEMPERATURE CALCULATION FOR A GROUP OF UNDERGROUND PARALLEL POWER CABLE LINES Based on the potential theory, an analytical method for calculating the temperatures of a group of power cables laid underground in parallel was developed. The technique is applicable in particular for the case of three-phase high-voltage cable lines laid in ducts. The analytical expressions are presented for effective thermal conductivity coefficients for elements of the duct taking into account conductive heat transfer, convection and radiation. Two algorithms are proposed for calculating the temperatures of cable cores based on the found average temperature of the element building duct. The developed technique provides a relative error of no more than 3% in estimating the temperature of the cable cores in the block when compared with the results of the FEM calculations. The method allows using standard spreadsheet software. 10.18721/JEST.29201 621.315.2 power cable underground power transmission cable line heating of underground cable cable duct analytical calculation of parallel cable group temperature heating mode of cables in tubes convective radiated and conductive heat exchange https://engtech.spbstu.ru/article/2023.124.1/ Titkov%2C-Voloshin%2C-Tukeev.pdf

RAR RUS 19-31 Fedyukhin FEATURES OF LARGE-SCALE COMPRESSED AIR ENERGY STORAGES DEVELOPMENT Transition to low-carbon electric power using high-capacity renewable energy sources is possible only if there are flexible-load units in the energy system structure. This problem can be solved both by traditional power plants using fossil fuels in steam and gas turbine cycles, and by advanced plants based on hydrogen or energy storage systems. As one of the options for covering the peak loads of the energy system, the application of compressed air energy storages (CAES) can be considered. In this article, the author analyzed thermal schemes of various CAES configurations; proposed equipment solutions of high-capacity CAES for the conditions of the unified energy systems of South and Center of the Russian Federation; calculated the operating modes of the CCPP in combination with the CAES; proposed approaches for creating an energy storage system for the unified energy system of the Russian Federation. 10.18721/JEST.29202 620.93 low carbon electric power compressed air energy storages energy storage renewable energy sources cogeneration https://engtech.spbstu.ru/article/2023.124.2/ Fedyuhin.pdf

RAR RUS 32-43 Mannanov E. Stepanov Alexander Kostelov Andrey Andreev Aleksandr DAMAGE ANALYSIS FOR SLOT SEMI-CONDUCTING COATINGS IN TURBOGENERATOR STATOR WINDINGS UNDER OPERATING STRESSES The paper presents studies on the local damage dynamics in various designs of semi-conductive slot coatings of the turbogenerator stator windings under operating conditions. The authors used combined effects of electric voltage, temperature and ozone to imitate the operating conditions of a real air-cooled turbogenerator in a laboratory. They developed a methodology for studying and evaluating the local damage dynamics in semi-conductive enamel and tape slot coatings. Then, the coatings were tested in laboratory conditions on mock-ups for comparison. No significant differences were found in the growth rate of local defects at the selected level of impacts for enamel or tape coatings and their combinations. However, the use of protective dielectric varnishes reduced the degradation rate of coatings. 10.18721/JEST.29203 621.3.048 slot semiconducting coatings stator windings of turbogenerators defect partial discharges insulating system https://engtech.spbstu.ru/article/2023.124.3/ Mannanov%2C-Stepanov%2C-Kostelov%2C-Andreev.pdf

REV RUS 44-102 Ismagilov Z. Matus E.V. Ismagilov I. Hydrogen Production from Coalmine Methane This article has been previously published. Citation link: Z.R. Ismagilov, E.V. Matus, I.Z. Ismagilov Hydrogen Production from Coalmine Methane. 3rd Annual Report of the Global Energy Association. pp. 69–101. The original full text of the report is available at the link: https://globalenergyprize.org/en/wp-content/uploads/2022/06/02545_22_brosh_GlobalEnergy_block_preview-2.pdf . https://engtech.spbstu.ru/article/2023.124.4/ Ismagilov%2C-Matus%2C-Ismagilov.pdf

RAR RUS 102-116 Sakhno Ludmila lsahno2010@yandex.ru Sakhno Olga Olasahno@mail.ru Kobzar Evgenii Paramonov Evgenii METHOD FOR CALCULATING CURRENTS AND LOSSES IN THE SECTIONS OF THE PRIMARY WINDING OF TRANSFORMERS FOR SPOT RESISTANCE WELDING The paper considers multi-winding transformers for resistance spot welding. The primary windings of such transformers have several sections for adjusting the secondary voltage and welding current. The article gives a method for calculating currents and losses in these sections for any series-parallel connection of sections. The method is based on load independence of the ratio of sections currents to the primary current. To analyze the accuracy of the method, a numerical experiment was carried out on a three-winding and six-winding model transformers. The advantage of the developed method is shown in comparison with the use of the equivalent circuit of a multi-winding transformer. An example of calculation of currents and losses in a serial transformer for resistance spot welding using the developed method is given. 10.18721/JEST.29207 621.314.225 resistance spot welding multi-winding transformer primary winding sections equivalent circuit losses in sections https://engtech.spbstu.ru/article/2023.124.5/ Sahno%2C-Sahno%2C-Kobzar%2C-Paramonov.pdf

RAR RUS 117-128 Ivanov Ivan Glivenko Dmitrii Pechnikov Alexey Hojamov Ahmet ARAMETRIC AND CATASTROPHIC FAILURE OF METALLIZED FILM CAPACITORS IN ULTIMATE LOAD OPERATION CONDITIONS n this paper the automated ramp voltage test method for metallized film capacitors was suggested. This method was used to investigate the causes of capacitors failure under high electric load. For this purpose, experimental setup and software for experimental data processing were developed. The experimental investigation method was based on high voltage testing of different metallized film capacitor types. It was found that in the case of high electric load, capacitors failure is related to dielectric resistance decreasing due to multiple breakdown events. The conditions of parametric and catastrophic failures of the tested capacitors were revealed. The suggested test method also allows “soft” treatment of metallized film capacitors. 10.18721/JEST.29208 621.319.4 metallized film capacitor self-healing ultimate load conditions parametric and catastrophic failure “soft” treatment https://engtech.spbstu.ru/article/2023.124.6/ Ivanov%2C-Glivenko%2C-Pechnikov%2C-Hodzhamov.pdf

RAR RUS 129-149 Belko Viktor Pechnikov Alexey Plotnikov Andrey andreyplotnikow@gmail.com Feklistov Efrem Hojamov Ahmet OPTIMUM PARAMETERS OF METAL-FILM CAPACITORS ELECTRODES FOR POWER ELECTRONICS The aim of the study is to reveal the influence of the electrode configuration of metal-film capacitors on their characteristics in order to further develop approaches to the optimal choice of electrode parameters. We showed the influence of the capacitor electrodes on its performance under the conditions typical for power electronics conditions and experimentally studied the effect of the sprayed electrode thickness on the breakdown strength. The effects from the fracture of sprayed electrodes caused by electrical discharges occurring during self-healing of metal-film capacitors are demonstrated. Authors propose a new type of electrode for metal-film capacitors called hybrid. Comparative calculations of the surface resistance and active area of segmented and hybrid electrodes showed the advantage of the latter. We experimentally established that at comparable process durations the deposited energy for the fracture of hybrid electrodes was less than for segmented ones. 10.18721/JEST.29209 621.319.42 film capacitor self-healing metallization numerical simulation https://engtech.spbstu.ru/article/2023.124.7/ Belko%2C-Pechnikov%2C-Plotnikov.pdf

RAR RUS 150-161 Blinov Lev lnblinov@ftim.spbstu.ru Krylov Nikolay Polyakova Vera INVESTIGATION OF SOME ELECTROPHYSICAL PROPERTIES OF SEMICONDUCTOR VIDEO INFORMATION STORAGE BASED ON SELENIUM AND LEAD OXIDE The results of a study of the physicochemical characteristics of glassy and crystalline semiconductors and semiconductor materials based on PbO-Se are presented. It is shown that for the efficient operation of vacuumless photovoltaic converters (PVCs) with memory, information storage devices are required, consisting of a highly sensitive recording layer and a high-resistance storage layer. According to the data of theoretical scientific and applied research, effective operation of this type of PVC with memory requires creating multilayer inorganic video information storage devices with a continuous structure. In our case, the lead (II) oxide – selenium system was chosen. The conducted studies allowed the authors to find out a number of regularities that reveal the influence of storage technology, in particular, substrate temperature, deposition mode, residual vapor pressure in the system, sublayer parameters and quality of the source material on the electrophysical parameters of photovoltaic converters. 10.18721/JEST.29210 546 thin layers of PbO-Se; production technology; current-voltage characteristics; illumination; currents limited by space charges (CLSC); single-layer and double-layer storage media; electrophysical parameters; video signals https://engtech.spbstu.ru/article/2023.124.8/ Blinov%2C-Krilov%2C-Polyakova.pdf

RAR RUS 162-174 Dobosh Ludmila dobosh87@mail.ru Golod Valery cheshire@front.ru MESOSCALE ANALYSIS OF STRUCTURAL HETEROGENEITY DURING SOLIDIFICATION OF MULTICOMPONENT CAST ALLOYS OF EUTECTIC TYPE The nature of the cast microstructure and its heterogeneity affect the fluidity of the alloys, the formation of shrinkage voids, the kinetics of linear shrinkage, and the occurrence of hot cracks. The paper investigates the inhomogeneity of the dendritic and eutectic structural components formed in the multicomponent aluminum alloy AK12 at different cooling rates (from 0.02 to 11 K/s). The kinetics of change and morphology of the local dendritic and/or dendritic-eutectic structure are described in this work using computer analysis of the nonequilibrium crystallization of the alloy in combination with a statistical study of a significant array of experimental data on the microstructure of the AK12 alloy. Using the methods of mathematical statistics, the log-normal nature of the mesoscale inhomogeneity was established at the stage of separation of the primary solid solution and during the subsequent eutectic transformation. 10.18721/JEST.29211 621.74.01:681.3.06 multicomponent aluminum alloy lognormal distribution structural inhomogeneity AK12 dendrites eutectic https://engtech.spbstu.ru/article/2023.124.9/ Dobosh%2C-Golod.pdf

RAR RUS 175-188 Repnin Arseniy Borisov Evgenii Popovich Anatoliy popovicha@mail.ru Shamshurin Аlexey SELECTIVE LASER MELTING OF MULTI-MATERIAL VZH159-CUCR1ZR SAMPLES Multi-material approach in the design and manufacture can improve performance of parts. Additive manufacturing can be a promising technology when it comes to creating complex multi-material products. The emerging field of the research is producing multi-material parts from heat-resistant alloys, including nickel alloys, which can be used in the aerospace industry. Therefore, the study analyzed the influence of selective laser melting parameters of multi-material VZh159-CuCr1Zr samples and their heat treatment on porosity, structure, chemical and phase composition, as well as the hardness in interface zone. The multi-material samples were fabricated on SLM 280HL selective laser melting machine. Different process parameters were used for studying the effect on the porosity in the interface zone of multi-material samples. The results of the study showed that only a significant increase in energy leads to a decrease in porosity in the interface zone of multi-material samples. For the CuCr1Zr/VZh159 interface zone, it was 325 or 375 J/mm3 (with 12 layers of the interface zone), and for the VZh159/CuCr1Zr transition zone, it was 120 or 140 J/mm3 (with 8 layers of the interface zone). Heat treatment did not significantly affect the microstructure and chemical composition of the transition zones. The sizes of the transition zones were 300 µm when the CuCr1Zr alloy was built on VZh159 and 250 µm when the VZh159 alloy was built on CuCr1Zr, respectively. After the heat treatment, phase peaks in interface zone corresponded to phases from both alloys used. Various heat treatments have a significant effect on the microhardness of the alloys they are intended for. 10.18721/JEST.29212 621.762 selective laser melting Multi-materials Interface characteristic VZh159-CuCr1Zr https://engtech.spbstu.ru/article/2023.124.10/ Repnin%2C-Borisov%2C-Popovich%2C-Shamshurin.pdf