International Scientific Journal

Thermal Science - Online First

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Simulation research on ONAN transformer winding temperature field based on temperature rise test

Studying the ONAN (Oil-Natural-Air-Natural) transformer's temperature field distribution characteristics and hot spot temperature rise during operation is a key step to evaluate the thermal insulation life of this type of transformer. Firstly, considering the transverse oil passages between the windings and the guiding effect of the oil baffle on the oil flow, this paper takes 35kV ONAN transformer windings as the research object, which establishes the corresponding electromagnetic-thermal-fluid coupling model and uses the finite element method to calculate the overall distribution of the internal winding temperature field. The calculation results show that when the ONAN transformer reaches thermal equilibrium, the axial temperature distribution of the windings is extremely uneven due to the influence of the transformer oil flow rate, whose difference between both ends is as high as 17.4ºC. However, the existence of the oil baffle increases the flow velocity of the inter-turn transverse oil passage to 12 times of the original. Affected by this, the oil temperature difference between the two ends of the oil baffle is as high as 2.42ºC. Secondly, this paper conducted a short-circuit temperature rise test on the test prototype, and selected the different axial heights (18%, 72%, 96%, etc.) of the windings on both sides of the transformer as the characteristic sample points for embedding temperature measurement fiber for real-time temperature monitoring. After comparison, it is found that the simulation calculation is basically consistent with experiment data, and the relative error of the two is less than 3.3%.
PAPER REVISED: 2022-02-01
PAPER ACCEPTED: 2022-02-16
  1. Tao C., et al., Transition mode from overhead transmission line to cable of different voltage levels, Power and Energy, 33(2012), 6, pp. 590-592
  2. Wu, S., Study and evaluation of clustering algorithm for solubility and thermodynamic data of glycerol derivatives, Thermal Science, 23,(2019), 5, pp. 2867-2875
  3. Arabul A. Y., et al., Development of a hot-spot temperature calculation method for the loss of life estimation of an ONAN distribution transformer, Electrical Engineering, 100(2018), 3, pp. 1651-1659
  4. Arabul A. Y., et al., Experimental thermal investigation of an ONAN distribution transformer by fiber optic sensors, Electric Power Systems Research, 155(2018), 100, pp. 320-330
  5. Swift G,. et al., A fundamental approach to transformer thermal modeling-Part I: Theory and equivalent circuit, IEEE Transactions on Power Delivery, 16(2001), 2, pp. 171-175
  6. Wang F., et al., Improved thermal circuit model of hot spot temperature in oil-immersed transformer based on heat distribution of winding," High Voltage Engineering, 41(2015), 3, pp. 895-901
  7. Quan Y., et al., Transformer hot-spot temperature inversion method based on streamline and support vector regression, Advanced Technology of Electrical Engineering and Energy, 37(2018), 11, pp. 23-31
  8. Córdoba P. A., et al., A 3D numerical model of an ONAN distribution transformer, Applied Thermal Engineering, 148(2019), pp. 897-906
  9. Xu D., et al., Analysis of winding temperature field under dynamic variable load of oil-immersed transformer, Thermal Science, 25(2021), 4 Part B, pp. 3009-3019
  10. Ruan J., et al., HST calculation of a 10kV oil-immersed transformer with 3D coupled-field method, IET Electric Power Applications, 14(2020), 5, pp. 921-928
  11. Torriano F., et al., Numerical investigation of 3D flow and thermal effects in a disc-type transformer winding, Applied Thermal Engineering, 40(2012), pp. 121-131
  12. Liao C., et al., Comprehensive analysis of 3-D electromagnetic-fluid-thermal field of oil-immersed transformer, Electric Power Automation Equipment, 35(2015), 9, pp. 150-155
  13. Tao W., Numerical Heat Transfer. Xi'an , Xi'an Jiaotong University Press, 2001.
  14. Zhang J., Advanced Heat Transfer. Nanjing, Nanjing University of Aeronautics and Astronautics, Nanjing, China, 2015
  15. Hu Q., Transformer test technology, China Electric Power Press, Beijing, China, 2010
  16. Moonhee L., et al., Temperature distribution in foil winding for ventilated dry-type power transformers, Electric Power Systems Research, 80(2010), 9, pp. 1065-1073
  17. Li Y., et al., Research on a method for optical fiber fluorescence specture temperature measurement, Sensor World, 20(2014), 11, pp. 23-26
  18. Oil--immersed transformer design manual, Shenyang Transformer Co., Ltd, Shenyang, China, 2002