Yağlı tip transformatörde termal ve yapısal analiz

Year 2024, Volume: 13 Issue: 1, 84 - 93, 15.01.2024

Beyza Nur Dursun Bulent Ekici

https://doi.org/10.28948/ngumuh.1359866

Abstract

Bu çalışmada, 1600 kVA gücünde hermetik olarak kapatılmış bir transformatör kullanılarak mekanik hesaplamalar yapılmış ve enerji iletiminden kaynaklanan ısıya göre analizleri yapılmıştır. Transformatörde oluşan ısı izolasyon yağının ısınmasına ve hacminin artmasına neden olur. Buna bağlı olarak trafo tankında artan izolasyon yağı hacmi tank üzerinde basınç artışına neden olur. Çalışmamızda sıcaklığın oluşturduğu mekanik gerilmeler ve oluşan ısıya bağlı olarak basınç artışı hesaplanmıştır. Bu hesaplamalar, oluklu duvarlı tankın mukavemet, soğutma ve yapım yaklaşımlarına göre incelenmiş ve sonlu elemanlar yöntemine dayalı ANSYS@FLUENT ve ANSYS@MECHANICAL kombinasyon simülasyon yazılımı kullanılarak tasarımdaki etkisi analiz edilmiştir. Sıcaklık dağılımı ve termal sınırlamalar doğru tasarım için kritik öneme sahiptir. İzin verilen termal sınırları aşan sıcaklıklar, transformatör bileşenlerinde ciddi hasara neden olabilir. Öte yandan sayısal, analitik ve deneysel değerlerin karşılaştırılması için test edilmiş bir prototip tank sağlanmıştır. Ancak sonuçlara göre, kritik bağlantı noktalarında gerilme yoğunlaşmaları gözleniyor, bu da ekstra beklenmedik bir yükün gerçek olması durumunda sorun olasılığını gösteriyor.

Keywords

sargı, dizayn, trafo, yapısal ve termal analiz, akış

Project Number

-

Thermal and structural analysis of oil-based type transformer

Abstract

In this paper, a hermetically sealed transformer with a power of 1600 kVA is used to make the mechanical calculations and analysed according to the heat generated by energy transmission. The heat generated on the transformer causes the insulation oil to heat up and increase in volume. Accordingly, the increasing insulation oil volume in the transformer tank causes a pressure increase on the tank. In our study, mechanical stresses created by the temperature and pressure increase due to the heat generated are calculated. These calculations are investigated according to strength, cooling, and construction approaches of tank with the corrugated wall and analysed its effect in design using ANSYS@FLUENT and ANSYS@MECHANICAL combination simulation software based on Finite Element Method. Temperature distribution and thermal limitations are critical to correct design. Temperatures exceeding the permissible thermal limits can cause serious damage to transformer components. On the other hand, a tested prototype tank is provided to compare the numerical, analytical, and experimental values. However according to the results, the stress concentrations are observed at the critical connection points, indicating the possibility of failure if an extra unexpected load is real.

Keywords

winding, design, transformer, structural ad thermal analysis, flow

Project Number

-

References

• D. Çelen, A New Plug-In Core Design for Three Phase Transformers. MSc Thesis, Yıldız Technical University Institute of Science, Istanbul, Türkiye, 2019.
• C. M. Fonte, J. C. B. Lopes, M. M. Dias, R. G. Sousa, H. M. Campelo and R. C. Lopes, CFD Analysis of Core Type Power Transformers. 21st International Conference on Electricity Distribution, Frankfurt, Germany, 6-9 June 2011.
• O. Kaymaz, Investigation of Oil Flow and Heat Transfer in Transformer Radiator. MSc Thesis, Sciences of Izmir Institute of Technology, Izmir, Türkiye, 2015.
• S. Lee, J. Y. Lee, J. C. Yun, J. Y. Park and J. H. Woo, Development of Thermal and Structural Design Technology for a Hermetically Sealed Oil Transformer. WIT Transactions on the Built Environment, 126, 179-190, 2012. https://doi.org/10.2495/SU120161.
• A. M. Abd-Elhady, M. E. Ibrahim, T. A. Taha and M. Izzularab, Effect of temperature on AC breakdownvoltage of nanofilled transformer oil. IET Science, Measurement & Technology, 12, 138-144, 2017. https://doi.org/10.1049/iet-smt.2017.0217.
• D. Dalcalı, H. Demirel and E. Celik, Microcontroller-based cooling of a single-phase transformer with thermoelectric module. The International Journal of Energy & Engineering Sciences, 1(2), 4-14, 2016.
• V. M. Montsinger, Loading Transformers By Temperature. Transactions of the American Institute of Electrical Engineers, 49 (2), 776-790, 1930. https://doi.org/10.1109/T-AIEE.1930.5055572
• E. Yiğit and C. Uçak, Investigation of Oil and Winding Temperature Models of Power Transformers. National Conference on Electrical, Electronics and Biomedical Engineering (ELECO), New York, USA, 2016.
• Y. Ozupak and M. S. Mamis, Thermal Field Analysis of Power Transformer by Combined Electromechanical Finite Element Method. Erzincan University Journal of Science and Technology, 934-941, 2019. https://doi.org/10.18185/erzifbed.513969
• M. Toren, FEM and CFD Analysis of a Hybrid Cooling System Design in Oil-Type Transformers. Niğde Ömer Halisdemir University Journal of Engineering Sciences, 11 (3), 611-619, 2022. https://doi.org/ 10.28948/ngumuh.1122317
• W. C. Young and R. G. Budynas, Roark’s Formulas for Stress and Strain Seventh Edition. McGraw-Hill, pp. 424-500, New York, USA, 2002.
• D. Herfati, B. A. Kamvar, A. Tavakkol and K. R. Milani, Calculation of mechanical stresses in hermetically sealed transformers. 19th International Conference on Electricity Distribution, Vienna, Austria, 21-24 May 2007.
• C. Canse, Investigating of Transformer Cooling Systems. MSc Thesis, Yildiz Technical University Institute of Science, Istanbul, Türkiye, 2016.
• G. Dombek, Z. Nadolny and P. Przybyłek, The role of the type of insulating liquid in the transformer temperature distribution. Computer Applications in Electrical Engineering, 14, 148-157, 2016. https://doi.org/10.21008/j.1508-4248.2016.0013.
• Z. Nadolny and G. Dombek, Thermal properties of mixtures of mineral oil and natural ester in terms of their application in the transformer. E3S Web of Conferences, 23 October 2017. https://doi.org/10.1051/e3sconf/20171901040
• C. Sun, C. Xiao, J. Hou, L. Kong, J. Ye and W. Yu, Analysis of Factors Affecting Temperature Rise of Oil-immersed Power Transformer. ICETAC Journal of Physics: Conference Series, 2020. https://doi.org/10.1088/1742-6596/1639/1/012087
• A. Ahmad and M. A. Shadid, Environmental effect on temperature rise of transformer. 21st International Conference on Electricity Distribution, Frankfurt, Germany, 6-9 June 2011.
• O. Ozgonenel, D. Thomas and U. Kurt, SF6-Gas Insulated 50kVA Distribution Transformer Design. Turkish Journal of Electrical Engineering and Computer Sciences (TUBITAK), 26 (4), 2140-2150, 2018. https://doi.org/10.3906/elk-1708-28
• H. Howard, Fluid Mechanics Fifth Edition. Pijush K. Kundu, Ira M. Cohen, David R. Dowling, Elsevier, pp. 425-450, Waltham, USA, 2012.
• H. K. Versteeg and W. Malalasekera, An Introduction to Computational Fluid Dynamics Second Edition, Pearson Education, pp. 427-437, New York, USA, 2007.
• H. Wang, F. Gao, P. Zhou and Z. Zhai, Literature review on pressure–velocity decoupling algorithms applied to build environment CFD simulation. Building and Environment, 143, 671-678, 2018. https://doi.org/10.1016/j.buildenv.2018.07.046
• Ansys Theory Guide, Choosing the Pressure-Velocity Coupling Method. https://www.afs.enea.it/project/neptunius/docs/fluent/index.htm , Accessed 23.01.2009.