Methyl Ester-Mineral Oil Mixture under Thermal Aging
Main Article Content
Keywords
Dielectric properties, monoester, retrofilling, thermal aging, transformer oil
Abstract
Replacement with natural esters (retrofilling) is an alternative solution to extend the life expectancy of an oil-filled transformer containing mineral oil. During the retro-filling process, some portions of the mineral oil remain inside the transformer's tank, forming a mixture between the used mineral oil and the new vegetable oil. In this investigation, methyl ester was mixed with a relatively low percentage of mineral oil to simulate the retro-filling process. The aim is to examine the characteristics of a mixture of mineral and vegetable oils under thermal aging. Thermal aging treatments were carried out at 120°C for 28 days and 140°C for 14 days. Kraft paper and copper wire were incorporated during the aging test. After thermal aging, the characteristics of the oil mixture were evaluated based on electrical, physical, and chemical characteristics. The result shows that physical and chemical characteristics are significantly influenced by the increase in mineral oil content and the temperature of thermal aging. However, the breakdown voltage increased after thermal aging, but at a higher temperature, the breakdown voltage dropped as the mineral oil content increased.
References
[2] K. Bandara, C. Ekanayake, T. K. Saha, and P. K. Annamalai, "Understanding the aging aspects of natural ester-based insulation liquid in power transformer," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 23, no. 1, pp. 246–257, 2016, doi: 10.1109/TDEI.2015.004744.
[3] Mc Shane Patrick, "Vegetable Oil Based Dielectric Coolants," IEEE Industry Applications Magazine, vol. 8, no. 3, pp. 34–41, 2002.
[4] K. Bandara, C. Ekanayake, T. K. Saha, and P. K. Annamalai, "Understanding the aging aspects of natural ester-based insulation liquid in power transformer," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 23, no. 1, pp. 246–257, 2016, doi: 10.1109/TDEI.2015.004744.
[5] Mc Shane Patrick, "Vegetable Oil Based Dielectric Coolants," IEEE Industry Applications Magazine, vol. 8, no. 3, pp. 34–41, 2002.
[6] T. V. Oommen, "Vegetable oils for liquid-filled transformers," IEEE Electrical Insulation Magazine, vol. 18, no. 1, pp. 6–11, 2002, doi: 10.1109/57.981322.
[7] J. Rouabeh, L. M'barki, A. Hammami, I. Jallouli, and A. Driss, "Studies of different types of insulating oils and their mixtures as an alternative to mineral oil for cooling power transformers," Heliyon, vol. 5, no. 3, pp. 1–19, 2019, doi: 10.1016/j.heliyon.2019.e01159.
[8] N. A. Mohamad, N. Azis, J. Jasni, M. Z. A. A. Kadir, R. Yunus, and Z. Yaakub, "Ageing study of palm oil and coconut oil in the presence of insulation paper for transformers application," Materials, vol. 11, no. 4, pp. 6–12, 2018, doi: 10.3390/ma11040532.
[9] A. Reffas et al., "Influence of thermal aging and electrical discharges on uninhibited olive oil properties," IET Science, Measurement and Technology, vol. 10, no. 7, pp. 711–718, 2016, doi: 10.1049/iet-smt.2016.0045.
[10] CIGRE_A2.35, "Experience in Service with New Insulating Liquids," 2010. doi: 10.1201/9781482290035-7.
[11] A. Rajab, H. Gumilang, M. Tsuchie, M. Kozako, M. Hikita, and T. Suzuki, "Study on static electrification of the PFAE-mineral oil mixture," IOP Conference Series: Materials Science and Engineering, vol. 602, no. 1, 2019, doi: 10.1088/1757-899X/602/1/012016.
[12] C. P. Mcshane and K. J. Rapp, "Dielectric Coolant for Safety and Life Extension," Cement Industry Technical Conference, 2003. Conference Record. IEEE-IAS/PCA 2003, pp. 141–147, 2003.
[13] IEC 62770, "Fluids for electrotechnical applications – Unused natural esters for transformers and similar electrical equipment Fluides," 2013.
[14] Y. Xu, S. Qian, Q. Liu, and Z. Wang, "Oxidation stability assessment of a vegetable transformer oil under thermal aging," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 21, no. 2, pp. 683–692, 2014, doi: 10.1109/TDEI.2013.004073.
[15] L. S. Nasrat, N. Kassem, and N. Shukry, "Aging Effect on Characteristics of Oil Impregnated Insulation Paper for Power Transformers," Engineering, vol. 05, no. 01, pp. 1–7, 2013, doi: 10.4236/eng.2013.51001.
[16] N. A. Mohamad, N. Azis, J. Jasni, M. Z. A. A. Kadir, R. Yunus, and Z. Yaakub, "Physiochemical and electrical properties of refined, bleached and deodorized palm oil under high temperature aging for application in transformers," Energies, vol. 11, no. 6, 2018, doi: 10.3390/en11061583.
[17] A. Rajab, M. Tsuchie, M. Kozako, M. Hikita, and T. Suzuki, "Properties of thermally aged natural esters used as insulating liquid," International Journal on Electrical Engineering and Informatics, vol. 10, no. 2, pp. 220–231, 2018, doi: 10.15676/ijeei.2018.10.2.2.
[18] I. Fofana, A. Bouaïcha, M. Farzaneh, and J. Sabau, "Ageing behavior of mineral oil and ester liquids: A comparative study," Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP, pp. 87–90, 2008, doi: 10.1109/CEIDP.2008.4772843.
[19] M. L. Coulibaly, C. Perrier, M. Marugan, and A. Beroual, "Aging behavior of cellulosic materials in the presence of mineral oil and ester liquids under various conditions," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 20, no. 6, pp. 1971–1976, 2013, doi: 10.1109/TDEI.2013.6678843.
[20] K. J. Rapp, C. P. McShane, and J. Luksich, "Interaction mechanisms of natural ester dielectric fluid and Kraft paper," 2005 IEEE International Conference on Dielectric Liquids, ICDL 2005, pp. 393–396, 2005, doi: 10.1109/icdl.2005.1490108.
[21] K. Bandara, C. Ekanayake, T. K. Saha, and P. K. Annamalai, "Understanding the aging aspects of natural ester-based insulation liquid in power transformer," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 23, no. 1, pp. 246–257, 2016, doi: 10.1109/TDEI.2015.004744.
[22] N. A. Mohamad, N. Azis, J. Jasni, M. Z. A. A. Kadir, R. Yunus, and Z. Yaakub, "Ageing study of palm oil and coconut oil in the presence of insulation paper for transformers application," Materials, vol. 11, no. 4, pp. 6–12, 2018, doi: 10.3390/ma11040532.
[23] A. Reffas et al., "Influence of thermal aging and electrical discharges on uninhibited olive oil properties," IET Science, Measurement and Technology, vol. 10, no. 7, pp. 711–718, 2016, doi: 10.1049/iet-smt.2016.0045.
[24] J. Tokunaga, H. Koide, K. Mogami, and T. Hikosaka, "Comparative study on the aging of Kraft paper insulation in palm fatty acid ester and mineral oil in air sealed tank," IEEJ Transactions on Fundamentals and Materials, vol. 136, no. 8, pp. 541–546, 2016, doi: 10.1541/ieejfms.136.541.
[25] A. C. M. Wilson, Oxidation stability of insulating oil, vol. 112, no. 3. 1965. doi: 10.1049/piee.1965.0105.
Article Sidebar
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
The authors declare that:
1. This paper has not been published in the same form elsewhere.
2. It will not be submitted anywhere else for publication prior to acceptance/rejection by this Journal.
3. A copyright permission is obtained for materials published elsewhere and which require this permission for reproduction.