Impacts of Ambient Temperature Change on the Breakdown Voltage of a Distribution Transformer
The aim of this paper is to determine the effects of ambient temperature variation on the breakdown voltage of a distribution transformer. Three different insulation oil samples (naphtha mineral, paraffin mineral and silicon base transformer oil) were collected from six distribution transformers (300 – 500 kVA) across two business units (Asaba and Ugbowo) of Benin Electricity Distribution Company during May and June, 2017. The oil samples were analysed using the 60 kV Megger OST60PB portable oil tester, to determine the trend of breakdown voltage of the oil insulation under varying temperature. A 3rd order polynomial model was deduced for each sample type with coefficient of determination within the range of 96.99 – 99.95 %. The observed average breakdown voltage is 43.6 kV (for naphtha base mineral transformer oil), 42.2 kV (for paraffin base mineral transformer oil) and 46.8 kV (for silicon base transformer oil) within the temperature range (26˚C – 32˚C). The result indicates that the breakdown voltages of the considered transformer oil types are satisfactory but the silicon base transformer oil has the best breakdown voltage.
M. Darveniza, “Investigations into effective methods for assessing the condition of insulation in aged power transformers,” IEEE Transaction on Power Delivery, vol. 13, no. 4, pp. 1214-1223, 1998.
A. J. Vandermaar, “Condition assessment of power transformers,” IEEE Power and Energy Society General Meeting – Conversion and Delivery of Electrical Energy in the 21st Century, 2008.
A. J. Christina, M. A. Salam, Q. M. Rahman, F. Wen, S. P. Ang, and W. Voon, “Causes of transformer failures and diagnostic methods – A review,” Renewable and Sustainable Energy Reviews, vol. 82, no. 1, pp. 1442-1456, 2018.
K. S. Senthil, M. Willjuice Iruthayarajan, and M. Bakrutheen, “Analysis of vegetable liquid insulating medium for applications in high voltage transformers,” 2014 International Conference on Science Engineering and Management Research, 27-29 November, 2014, Chennai, India.
M. Wang, A. J. Vandermaar, and K. D. Srivastava, “Review of condition assessment of power transformers in service,” IEEE Electrical Insulation Magazine, vol. 18, no. 6, pp. 12-25, 2002.
J. Singh, S. Singh, and A. Singh, “Distribution transformer failure modes, effects and criticality analysis,” Engineering Failure Analysis, vol. 99, pp. 180–191, 2019.
R. Madavan, and S. Balaraman, “Failure analysis of transformer liquid-solid insulation system under selective environmental conditions using Weibull statistics method,” Engineering Failure Analysis, vol. 65, pp. 26–38, 2016.
Y. Hong, W. Q. Meeker, and J. D. McCalley, “Prediction of remaining life of power transformers based on left truncated and right censored lifetime data,” The Annals of Applied Statistics, pp. 857-879, 2009.
P. Verma, M. Roy, A. Verma, and V. Bhanot, “Changes in electrical and chemical properties of transformer oil under accelerated thermal stress,” International Journal of COMADEM, vol. 8, no. 1, pp. 42-48, 2005.
P. Verma, M. Roy, A. Verma, and V. Bhanot, “Trends in condition monitoring of transformers,” Electrical Review, vol. 11, no. 6, pp. 10-18, 2004.
S. T. Jan, R. Afzal, and A. Z. Khan, “Transformer failures, causes and impact,” International Conference: Data Mining, Civil and Mechanical Engineering, 2015, Bali, Indonesia, 49 – 52.
M. Akbari, P. Khazaee, and S. P. Karimifard, “Failure modes and effects analysis for power transformers,” 28th International Power System Conference, 2013, Tehran, Iran.
M. Hashmi, M. Lehtonen, and S. Hanninen, “Effect of climate change on transformers loading conditions in the future smart grid environment,” Open Journal of Applied Sciences, vol. 3, pp. 24-29, 2013.
V. Mehta, and J. Vajpai, “Analysis of hotspot development in power transformer and its life estimation,” In: M. Shorif Uddin, A. Sharma, K. L. Agarwal, and M. Saraswat, (eds), Intelligent Energy Management Technologies. Algorithms for Intelligent Systems. Springer, Singapore, 2021.
J. Vajpai, and V. Mehta, “Estimation of loss of life due to hot spot development in power transformer using MATLAB,” International Journal of Computing, Communications & Instrumentation Engineering, vol. 3, no. 1, pp. 29 – 35, 2016.
Waluyo, S. Saodah, and Rohana, “Investigation of transformer losses and temperature rise,” Electrotehnica, Electronica, Automatica, vol. 66, no. 2, pp. 37-44, 2018.
M. I. Hasan, “Using the transformer oil-based nanofluid for cooling of power distribution transformer,” International Journal of Energy and Environment, vol. 8, no. 3, pp .229-238, 2017.
A. A. Baba, J. S. Ayodele, O. M. Ameen, A. Jimoh, U. Johnson, B. A. Jimoh, and A. Lawal, “Characterisation and treatment of spent deposited sludge of transformer oil (DSTO) by acid leaching and solvent extraction,” Mineral Processing and Extractive Metallurgy, vol. 127, no. 4, pp. 228-235, 2018.
Suwarno, and A. P. Rahman, “Power transformer insulation assessment based on oil-paper measurement data using svm-classifier,” June 2018, doi:10.20944/preprints201806.0002.v1
M. S. Okundamiya, O. S. Udeozor, and O. J. Imade, “Investigation and evaluation of voltage drops: A case study of Guinness and Ikpoba Dam injection substations,” International Journal of Electrical and Power Engineering, vol. 3, no. 2, pp. 105–111, 2009.
M. S. Okundamiya, Modelling and Optimization of a hybrid energy system for GSM base transceiver station sites in emerging cities, Ph.D. Thesis, University of Benin, Benin City, Nigeria, 2015.
M. S. Okundamiya, and I. E. Okpamen, “A linear regression model for global solar radiation on horizontal surfaces at Warri, Nigeria,” International Journal of Renewable Energy Development, vol. 2, no. 3, pp. 121-126, 2013.
The megger guide to insulating oil dielectric breakdown testing, Art No. 2003-149 - OTS_tg_en_vol. 2, pp. 14, 2013.
Polynomial regression, In: J. O. Rawlings, S. G. Pantula, and D. A. Dickey, (eds), Applied Regression Analysis, Springer Texts in Statistics, Springer, NY, 1998, pp. 235-268, https://doi.org/10.1007/0-387-22753-9_8
J. L. Peixoto, “A property of well-formulated polynomial regression models,” The American Statistician, vol. 44, no. 1, 1990, pp. 26–30, https://doi.org/10.2307/2684952
M. S. Okundamiya, and A. N Nzeako, “Estimation of diffuse solar radiation for selected cities in Nigeria,” ISRN Renewable Energy, vol. 2011, no. 439410, doi:10.5402/2011/439410
Copyright (c) 2021 M. S. Okundamiya, E. Esekhaigbe, J. L. Owa, H. I. Obakhena
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.