CC BY
0УДК 621.317 Safiyev E.S., Aslanov Y.F
Safiyev E.S.
Lecturer
Azerbaijan State University of Oil and Industry (Baku, Azerbaijan)
Aslanov Y.F
Master's degrstudent Azerbaijan State University of Oil and Industry (Baku, Azerbaijan)
TRANSFORMERS WITH AMORPHOUS MAGNETIC CONDUCTIVE CORE
Аннотация: the article provides detailed information on amorphous magnetic-conductive materials, analyses their production process. It is shown that the use of amorphous metals as transformer cores is cost-effective. The article also indicates the technological difficulties in the production of transformers associated with the use of this material. It is noted that additives, including nanoadditives, can be introduced into the composition of the amorphous metal to improve its magnetic properties. It is shown the environmental feasibility of using such transformers.
Ключевые слова: amorphous metal, transformer core, idle mode, crystal lattice, spinning method, energy losses.
The function of a transformer is to increase the voltage in a power plant and reduce it to a safe level for operators at substations. The transformer operates continuously for a long time, during which time it experiences 2-4% energy losses. These losses are divided into two different categories: load losses in the transformer during the conversion of electrical energy and losses in no-load operation. Transformers are typically operated for twenty to thirty years. Over the years, load losses vary depending on the load, while no-load operating losses have a constant
value. Therefore, the solution to energy losses should be sought in reducing the losses in the no-load operating mode of the transformer [1-3].
No-load losses in transformers are reduced by using amorphous magnetically conductive steel alloys in their cores. Experience shows that the no-load losses in a standard sealed oil transformer with a capacity of 1000 kVA are 1600 W, and in its improved analogue - 1300 W. Over the course of a year, this transformer saves 2628 kWh of electricity. The transformer with an amorphous core works more economically. No-load losses in a 1000 kVA transformer are 450 W, which means that in one hour the "amorphous" transformer consumes 1,15 kW less energy than a standard transformer of the same power. It is clear that a huge amount of energy could be saved if hundreds of transformers in the country were replaced with energy-efficient ones.
Amorphous metallic materials are one of the latest inventions of the 20th century. Compared to crystalline materials, they have a number of superior magnetic, mechanical and chemical properties associated with their amorphous structure. The advantage of amorphous metals is a very simple scheme of their production. As a rule, it is carried out in two stages: melting the metal and casting the finished product. All this allowed amorphous metallic materials to enter the stage of industrial production and take their place in the market. Amorphous (from the Greek amorphos - shapeless) - a non-crystalline state of a solid, characterized by isotropy of properties and the absence of a melting point, that is, the melting process occurs in a certain temperature range (figure 1) [4-6].
Crystal structure Amorphous structure Figure 1. Ordered and disordered atomic structure in metals.
As the temperature increases, the amorphous substance softens and gradually turns into a liquid. In the amorphous state, there is no regularity in the arrangement of atoms, so its properties are isotropic without external influences. A solid in the amorphous state is usually considered as a supercooled liquid with a very high viscosity coefficient. Amorphous metal ribbon is obtained by the spinning (eng. spinning - pulling) alloying method. In this method, liquid metal emerging from the hole of the reservoir is formed by being fed to a rapidly moving and cooled surface
[7-11].
When the liquid metal touches the surface, a puddle is formed. In turn, the rapidly moving cold surface continuously draws a rapidly solidifying ribbon from the puddle (figure 2). Currently, the plane flow method is used in the production of amorphous ribbon, which is actually an improved spinning method. In this method, the stability of the puddle is achieved due to the small gap between the hole and the moving surface (about 0.2 mm). The symmetry of the process in the plane flow method does not limit the production of wide ribbons. Modern devices allow the production of amorphous ribbons with a width of 300 mm [12-16].
ш.
alloy pond
Figure 2. Schematic diagram of the device for the production of amorphous ribbon.
Amorphous alloys have been produced for 30 years. The first distribution transformers with amorphous cores with a capacity of 630-1000 kVA were developed 10 years ago. The USA, China and India have made greater progress in this area. In recent years, distribution companies in several European countries have put several 400 kVA transformers with amorphous tape cores into trial operation. However, the
widespread use of "amorphous" transformers in Europe is constrained by a number of factors, including high requirements for equipment reliability [17-20].
According to Metglas (USA), annual losses in power transformers of distribution networks using magnetic cores made of electrical steel are about 8% of their purchase price. Table 1 shows no-load losses for power transformers with a rated voltage of 10 kV and a capacity of 25 to 2500 kVA. Amorphous alloys have high mechanical properties and elasticity. To further increase the mechanical properties, phosphorus, silicon, carbon, boron are added to them . The comparative strength and elasticity of various materials are shown in figure 3 [21-25].
Table 1. Average values of no-load operating losses for power transformers.
Power of a three-phase 10 kV transformer High operating losses, magnetic conductor -transformer steel SiFe High working losses, magnetically conductive -amorphous alloy Comparative reduction in losses, %
25 kVA 100 28 72 %
40 kVA 140 39 72 %
63 kVA 180 50 72 %
100 kVA 260 66 75 %
250 kVA 520 150 71 %
630 kVA 1000 280 77 %
1000 kVA 1700 350 80 %
1600 kVA 2100 490 77 %
2500 kVA 2700 550 80 %
Figure 3. Tensile strength and elasticity of various materials.
Currently, amorphous metallic materials (metallic glasses) are mainly used in the manufacture of transformer cores as soft magnetic materials. Table 2 shows the typical properties of some of the "GAMMET" amorphous alloys. All amorphous magnetic alloys have high resistivity (p ~ 1.340-6 Ohm-m) and crystallization temperature (t = 520...540°C). High magnetic permeability is observed in iron-based nanocrystalline alloys (QM 414 and QM 412). In power devices of electrical engineering and electronics, amorphous alloys can be effectively applied up to a frequency of 100 kHz. For weakly powerful electrical signals, their application range extends to 10 MHz. The iron-based amorphous alloy QM 440 has a high saturation magnetic induction and low specific magnetic losses. This alloy can be operated more efficiently at a frequency of 0.05 - 5 kHz. In cobalt-based amorphous alloys (QM 503, QM 515), the magnetic permeability has a high stable value at a magnetic field strength of up to 300 A/m [26-29].
Table 2. Magnetic properties of the "GAMMET" magnetoconductor.
Type of magnetoconductor B800, Tl До,08 №max Kn800 Hc P0,2/20, Vt/kg Tc Density, kg/m3
GM 503A 0,58 5000 1500000 0,92 0,2 8,5 260 7700
GM 412A 1,17 10000 600000 0,9 1,2 10 610 7400
GM 440A 1,5 1000 200000 0,9 4 30 420 7300
GM 515A 0,95 150 250000 0,94 1,5 60 500 7900
GM 503B 0,58 40000 50000 0,03 0,25 2,6 260 7700
GM 412B 1,17 30000 45000 0,07 1,2 3 610 7400
GM 440B 1,5 8000 20000 0,06 4 8 420 7300
GM 515B 0,95 1500 1550 <0,01 1,5 12 500 7900
B800 - magnetic induction, at a magnetic field strength of 800 A/m,magnetic induction, at a magnetic field strength of 800 A/m, ^0>08 - relative magnetic permeability, at a magnetic field strength of 0.08 A/m, ^max - maximum relative magnetic permeability,
Kn800 - the rectangularity coefficient of the magnetic hysteresis loop, the residual magnetic induction (Bq), B800- is the ratio, Hc - static coercive force, P0,2/20 - specific magnetic losses, at maximum magnetic induction (0.2 Tl) and frequency 20 kHz,
Tc - Cure temperature.
Amorphous steel is as brittle as glass. This places special demands on the manufacturing process of transformers, and also requires that the manufactured product undergo precise testing under certain conditions. It is important to study whether amorphous steel has small losses in no-load operation and whether these losses do not change over time. In addition, the compatibility of various parameters of amorphous transformers with standard power transformers should be investigated. Also, its design solution and technological measures should be evaluated. Since
amorphous steel is brittle, special requirements are imposed on the design of the transformer core and its manufacturing conditions. In traditional transformers, the core made of electrical steel is the main structural element that holds the entire active part. The amorphous core, on the other hand, does not accept large loads. It is attached to the windings and requires additional measures to ensure the strength of the structure. In addition, a number of special equipment are required for the production of an "amorphous" transformer. This equipment is necessary for cutting the amorphous tape, heat treatment of the core structu.re, impregnating the magnetic conductor with a protective coating, etc. [30].
Modern technologies allow the manufacture of magnetic conductors from amorphous alloys with dimensions up to 1000 mm, but in this case they should be in the form of a circle, oval, rod, P and W. The operation of an amorphous core transformer is also of environmental importance. Such a transformer significantly reduces the damage to the environment, since as a result of energy saving, the carbon dioxide CO2 and other gases released in the transformer are significantly reduced.
Conclusion.
1. The use of amorphous metal magnetic conductor as a core of transformers is promising, it significantly reduces losses in no-load operation and thus allows saving energy.
2. There are technological difficulties in the production of "amorphous" transformers related to the mechanical properties of amorphous metal, these difficulties are gradually being eliminated.
3. Attention should be paid to the use of amorphous magnetic conductor materials in transformer manufacturing enterprises in Azerbaijan.
СПИСОК ЛИТЕРАТУРЫ:
1. Н.М. Пириева. Асинхронный электродвигатель с эффективной системой охлаждения. Проблем Энергетика №4, Баку, 2020 с 34-40;
2. Стародубцев Ю.Н., Сон Л.Д., Цепелев В.С., Тягунов Г.В., Тишкин А.П., Коробка О.Б. Влияние температуры нагрева расплава на механические и магнитные свойства аморфной ленты // Расплавы. 1992. № 4;
3. Пириева Н.М., Гусейнов З.Х. Анализ неисправностей в силовых трансформаторах. Международный научный журнал «Вестник науки» № 7 Том 4 (64) 2023 г. С 297-304;
4. Глезер А.М., Молотилов Б.В. Структура и механические свойства аморфных сплавов. М.: Металлургия, 1992;
5. Стародубцев Ю.Н., Белозеров В.Я. Магнитные свойства аморфных и нанокристаллических сплавов. Екатеринбург: Издательство Уральского университета, 2002;
6. Мамедова Г.В., Пириева Н.М., Ширинова М.Ч. Диагностика силовых трансформаторов // Интернаука: электрон. научн. журн. 2023. № 6(276);
7. Н.М. Пириева. Минимизация потерь активной мощности в обмотках электрических аппаратов «Инновационные научные исследования», Научно-издательский центр Вестник науки, №3-2(17) mart 2022, г. Уфа, стр.11-21;
8. Пириев Г.С. Методы снижения и ограничения несимметричных режимов трансформаторов. «Инновационные научные исследования», Научно-издательский центр Вестник науки № 9 (66) Том 4. 2023. С328-334;
9. N.M.Piriyeva, G.S. Kerimzade "Methods for increasing electromagnetic efficiency in induction levitator". PRZEGLAD Elektrotechniczny Publishing house of magazines and technical literature Warszawa. №10, pp s.192-196;
10. N.M. Piriyeva, G.S. Kerimzade. "Electromagnetic efficiency in induction levitators and ways to improve it" Przeglad Elektrotechniczny. R.99 NR 06/2023, Poland, pp.204-207;
11. Пириева Н.М., Ахмадли А.Н. Сравнения электрических генераторов применяемые в ветроэлектрических установках. Международный научный журнал «ВЕСТНИК НАУКИ. № 1 (70) Том 3. 2024 с.975-986;
12. S.A. Khanahmedova, S.Y. Shikhaliyeva, S.J. Alimamedova, S.M. Kerimova "Some issues of designing a hybrid electric machine", Dimensions 3 (3), 2023, p. 34;
13. S.V.Rzayeva, N.M.Piriyeva, I.A.Guseynova "Analysis of reliability of typical power supply circuits". Reliability: Theory & Applications, RTA, №3(79) Volume 19, 173-178 September 2024;
14. Пириева Н.М., Тагизаде Л.Н. «Ограничители перенапряжения и защита трансформаторов от перенапряжений». Международный научный журнал «ВЕСТНИК НАУКИ. № 1 (70) Том 3. 2024. С 772-778;
15. Safiyev E.S, Piriyeva N.M. On the issue of assessing the temperature index and the range of heat resistance of polymeric electrical insulating materials News of Azerbaijan Higher Technical Schools No. 1 ASOIU Baku, 2022 p. 49-51;
16. Маруфов Н.М., Пириева Н.М., Ганиева Н.А., Мухтарова К.М Повреждение изоляции обмотки статора в электрических машинах. Проблемы Энергетики №2, Баку, 2019, стр. 82-85;
17. S. Shikhaliyeva "Ways to increase the efficiency of electric machines", Научный журнал «Интернаука», 2024, p. 11-14;
18. Piriyeva N.M., Abdullayeva G.K., Bakhtiyarov A.L. Engineering approaches to minimizing the environmental impact of thermal power plants. international Journal on "Technical and Physical Problems of Engineering" (IJTPE) - Issue 61, Volume 16, Number 4, december 2025. Pp.231-243;
19. Shikhaliyeva Sdat Yashar, Hasanova Indzhi Kamal "Modes of operation of the loading device during research electric drive of the portal manipulator" UNiVERSUM: Технические науки, 2(131), 2025;
20. N.M. Piriyeva, G.S. Kerimzade "Mathematical model for calculation of electrical devices based on induction levitators". International Journal on "Technical and Physical Problems of Engineering" IJTPE, Issue 55, Vol. 15. No 2. s. 274-280;
21. Маруфов И.М., Пириева Н.М., Алиева Г.A., Ганиева H.A. Анализ надежности энергетической системы. Научно-технический журнал, Проблемы энергетики №3. Баку, 2020. с.70-75;
22. Rzayeva S.V., Ganiyeva N.A., Piriyeva N.M. Modern approaches to electrical equipment diagnostics. international Journal on "Technical and Physical Problems of Engineering" - Issue 58, Volume 16, Number 1, March 2024;
23. Пириева Н.М., Рзаева С.В., Талибов С.Н. Анализ устройств защиты от перенапряжений электрических сетей. «Интернаука»: научный журнал - № 43(266). Часть 3. Москва, 2022. с.14-17;
24. Safiev E.S, Piriyeva N.M., Bagirov Q.T Analysis of the application of active lightning rods in lightning protection objects. Интернаука: электрон. научн. журн.
2023. № 6(276). Pp 14-17;
25. Пириева Н.М., Гусейнов З.Ф. Характеристики синхронных двигателей. Международный научный журнал «Вестник науки» № 3 (60) Том 4. С.241-246;
26. Н.М.Пириева. Асинхронный электродвигатель с эффективной системой охлаждения. Проблем Энергетика №4, Баку, 2020 с 34-40;
27. Mammadov N., Rzayeva S., Ganiyeva N. Analysis of synchronized asynchronous generator for a wind electric installation //Przeglad Elektrotechniczny. - 2023. - Т. 99. - №. 5;
28. Mammadov N.S., Mukhtarova K.M. Methodology for assessing the reliability of ags based on renewable energy sources //Reliability: Theory & Applications. -
2024. - Т. 19. - №. 4 (80). - С. 648-653;
29. Ismayilova G.G., Mufidzade N.A., Khanakhmedova S.K. Improvement of electrochemical protection of oil and gas pipelines. International Journal on "Technical and Physical Problems of Engineering" (IJTPE) Published by International Organization of IOTPE, Vol. 15, No 3, September 2023, pp-165-160
