Thermal Defect Analysis on Transformer Using a RLC Network and Thermography


Electrical transformers are vital components found virtually in most power-operated equipments. These transformers spontaneously radiate heat in both operation and steady-state mode. Should this thermal radiation inherent in transformers rises above allowable threshold a reduction in efficiency of operation occurs. In addition, this could cause other components in the system to malfunction. The aim of this work is to detect the remote causes of this undesirable thermal rise in transformers such as oil distribution transformers and ways to control this prevailing thermal problem. Oil transformers consist of these components: windings usually made of copper or aluminum conductor, the core normally made of silicon steel, the heat radiators, and the dielectric materials such as transformer oil, cellulose insulators and other peripherals. The Resistor-Inductor-Capacitor Thermal Network (RLCTN) model at architectural level identifies with these components to have ensemble operational mode as oil transformer. The Inductor represents the windings, the Resistor representing the core and the Capacitor represents the dielectrics. Thermography of transformer under various loading conditions was analyzed base on Infrared thermal gradient. Mathematical, experimental, and simulation results gotten through RLCTN with respect to time and thermal image analysis proved that the capacitance of the dielectric is inversely proportional to the thermal rise.

Share and Cite:

G. Asiegbu, A. Haidar and K. Hawari, "Thermal Defect Analysis on Transformer Using a RLC Network and Thermography," Circuits and Systems, Vol. 4 No. 1, 2013, pp. 49-57. doi: 10.4236/cs.2013.41009.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] D. Susa, M. Lehtonen and H. Nordman, “Dynamic Thermal Modeling of Distribution Transformers,” IEEE Transactions on Power Delivery, Vol. 20, No. 3, 2005, pp 1919-1929.
[2] M. Matian, A. J. Marquis and N. P. Brandon, “Application of Thermal Imaging to Validate a Heat Transfer Model for Polymer Electrolyte Fuel Cells,” International Journal of Hydrogen Energy, Vol. 35, No. 22, 2010, pp 12308-12316. doi:10.1016/j.ijhydene.2010.08.041
[3] Infraspection Institute, “Standard for Infrared Inspection of Electrical Systems & Rotating Equipment,” In: Infraspection Institute, Infrared Training and Infrared Certification, Infraspection Institute, Burlington, 2008.
[4] T. M. Lindquist, L. Bertling and R. Eriksson, “Estimation of Disconnectors Contact Condition for Modeling the Effect of Maintenance and Ageing,” Power Tech IEEE Conference, St. Petersburg, 27-30 June 2005, pp. 1-7.
[5] N. Rada, G. Triplett, S. Graham and S. Kovaleski, “High-Speed Thermal Analysis of High Power Diode Arrays,” Solid-State Electronics ISDRS, Vol. 52, No. 10, 2008, pp. 1602-1605. doi:10.1016/j.sse.2008.06.009
[6] Y. Cao, X. M. Gu and Q. Jin, “Infrared Technology in the Fault Diagnosis of Substation Equipment,” China International Conference on Electricity Distribution, Guangzhou, 10-13 December 2008, pp. 1-6.
[7] A. M. A. Haidar, G. O. Asiegbu, K. Hawari and F. A. F. Ibrahim, “Electrical Defect Detection in Thermal Image,” Advanced Materials Research, Vol. 433-440, 2012, pp 3366-3370.
[8] Y. Cao, X. M. Gu and Qi Jin, “Infrared Technology in the Fault Diagnosis of Substation Equipment,” Technical Session 1 Distribution Network Equipment, Shanghai Electric Power Company Shanghai Branch Southern Power, 200030, SI-17 CP1377, CICED2008.
[9] J. G. Smith, B Venkoba Rao, V. Diwanji and S. Kamat, “Fault Diagnosis—Solation of Malfunctions in Power Transformers,” Tata Consultancy Services Limited, Vol. 10, No. 1, 2009, pp. 1-12.
[10] R. M. Button, “Soft-Fault Detection Technologies Developed for Electrical Power Systems,” 2005.
[11] Martin Technical Electrical Safety & Efficiency, “Infrared Thermography Inspection,” 2012.
[12] G. Biswas, R. Kapadia, D. Xu and W. Yu, “Combined Qualitative—Quantitative Steady-State Diagnosis of Continuous-Valued Systems,” IEEE Transactions on Systems, Man, and Cybernetics—Part A: Systems and Humans, Vol. 27, No. 2, 1997,pp. 167-185. doi:10.1109/3468.554680
[13] N. Radaa, G. Tripletta and S. Graham, “High-Speed Thermal Analysis of High Power Diode Arrays,” Solid-aState Electronics ISDRS, College Park, 12-14 December 2007.
[14] K. C. P. Wong, H. M. Ryan and J. Tindle, “Power System Fault Prediction Using Artificial Neural Networks,” International Conference on Neural Information Processing, Hong Kong, 24-27 September 1996, Article ID: 17762.
[15] M. S. Jadin, S. Taib, S. Kabir and M. A. B. Yusof, “Image Processing Methods for Evaluating Infrared Thermographic Image of Electrical Equipment,” Progress in Electromagnetics Research Symposium Proceedings, Marrakesh, 20-23 March 2011, p. 1299.
[16] Electric Power Engineering Center “Guide to Power Transformer Specification Issues,” University of Canterbury, 2007.
[17] K. Harwood, “Modeling a RLC Circuit’s Current with Differential Equations,” 2011.
[18] A. P. Ferreira, D. Mossé and J. C. Oh, “Thermal Faults Modeling Using a RC Model with an Application to Web Farms,” 19th Euromicro Conference on Real-Time Systems (ECRTS 07), Pisa, 4-6 July 2007, pp. 113-124.
[19] M. Holt, “Understand the National Electricity Codes,” Cengage Learning, Delmar, 2002.
[20] R. W. Hurst, “Electrical Safety and Arc Flash Handbook,” Vol. 6, Electricity Forum, 2007.
[21] T. Crnko and S. Dyrnes, “Arcing Flash/Blast Review with Safety Suggestions for Design and Maintenance,” Proceeding of the IEEE conference on Industry Technical, Atlanta, 19-23 June 2000, pp. 118-126.

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.