Investigation of the causes and prevention of corrosion in the 11 megawatt electric motor of the KhatunAbad copper melt oxygen plant

Subject Areas : Smart buildings and renewable energies

mohammad jalal shadman ¹ , Mahdiyeh Eslami ² , Mehdi Jafari Shahbazadeh ³

1 -
2 - Department of Electrical Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran.
3 - ِDemartment of Electrical Engineering. Kerman Branch. Islamic Azad University. Kerman. Iran

Received: 2025-01-25 Accepted : 2025-10-01 Published : 2025-09-18

Keywords: Ozone, Nitric Acid, Partial Discharge, Corrosion, High Voltage, Ionization.,

Abstract :

Today, high-power and high-voltage electric motors are facing an increasing demand and application in the industry. Due to high costs and the complexity and sensitivity of the subject, it is essential to minimize power losses, reduce energy consumption, and improve the reliability of these types of electric motors as much as possible. Partial discharge occurring in high-voltage equipment consists of very small sparks on a micron scale, which arise due to the high intensity of the electric field in high-voltage machines. Partial discharge has several effects, including thermal, chemical, and electrical effects. It is always associated with several physical characteristics, one of which is chemical reactions in the cooling gases, such as air or hydrogen. Among the harmful factors for the internal components of high-voltage electric machines that cause issues such as ozone generation, this gas is formed due to the ionization phenomenon inside the motor housing and the cooling components. This paper examines the causes of corrosion, prevention, and presents suitable solutions originating from the impact of the corona phenomenon and partial discharge in the 11-megawatt electric motor of the Khatunabad Copper Smelting Oxygen Plant, along with planning for periodic maintenance and repairs (PM).

References:

[A1] Fault detection in components of synchronous motors through online partial discharge measurements GL Cestaro, MF Fernandes… - 2024 IEEE Petroleum …, 2024 - ieeexplore.ieee.org
[A2] [BOOK] Electrical insulation for rotating machines: design, evaluation, aging, testing, and repair GC Stone, I Culbert, EA Boulter, H Dhirani 2014•books.google.com
[A3] A review on analysis and modeling of electrical machine insulation system Hira Raziq,Munira Batool,Fawad Nawaz,Ali Akgül ,Farkhanda fzal &Murad Khan HassaniArticle: 2400614 | Received 12 Feb 2024, Accepted 31 Aug 2024, Published online: 12 Sep 2024
[A4] Bin Lee, S., Kang, T.-J., Kim, H., Kong, T., & Lim, C. (2017). Case studies of stator winding turn insulation failures in medium voltage motors. In 2017 Annual Pulp, Paper and Forest Industries Technical Conference (PPFIC), pp. 1–8.
[A5] Bin Lee, S., Tallam, R. M., & Habetler, T. G. (2003). A robust, on-line turn-fault detection technique for induction machines based on monitoring the sequence component impedance matrix. IEEE Transactions on Power Electronics, 18(3):865–872. https://doi.org/10.1109/TPEL.2003.810848
[A6] Bruning, A. M., Kasture, D. G., Campbell, F. J., & Turner, N. H. (1991). Effect of cavity sub-corona current on polymer insulation life. IEEE Transactions on Electrical Insulation, 26(4), 826–836. https://doi.org/10.1109/14.83709
[A7] Cavallini, A., Versari, L., & Fornasari, L. (2013). Feasibility of partial discharge detection in inverter-fed actuators used in aircrafts. In 2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, pp. 1250–1253.
[A8] Esfahani, A. N., Shahabi, S., Stone, G., & Kordi, B. (2018). Investigation of corona partial discharge characteristics under variable frequency and air pressure [Paper presentation]. In 2018 IEEE Electrical Insulation Conference (EIC), pp. 31–34. https://doi.org/10.1109/EIC.2018.8481047
[A9] Guo, Z., Huang, A. Q., Hebner, R. E., Montanari, G. C., & Feng, X. (2022). Characterization of partial discharges in high-frequency transformer under PWM pulses. IEEE Transactions on Power Electronics, 37(9), 11199–11208. https://doi.org/10.1109/TPEL.2022.3169747
[A10] Hildinger, T., & Weidner, J. R. (2017). Progress in development of a nanocomposite stator winding insulation system for improved generator performance [Paper presentation]. In 2017 IEEE Electrical Insulation Conference (EIC), pp. 139–142. https://doi.org/10.1109/EIC.2017.8004655
[A11] Lee, S.-B., Habetler, T. G., Harley, R. G., & Gritter, D. J. (2002). An evaluation of model-based stator resistance estimation for induction motor stator winding temperature monitoring. IEEE Transactions on Energy Conversion, 17(1): 7–15. https://doi.org/10.1109/60.986431
[A12] Lee, S. B., Younsi, K., & Kliman, G. B. (2005). An online technique for monitoring the insulation condition of AC machine stator windings. IEEE Transactions on Energy Conversion, 20(4), 737–745. ttps://doi.org/10.1109/TEC.2005.853760
[A13] Madonna, V., Giangrande, P., & Galea, M. (2019). Evaluation of strand-to-strand capacitance and dissipation factor in thermally aged enamelled coils for low-voltage electrical machines. IET Science, Measurement & Technology, 13(8), 1170–1177. https://doi.org/10.1049/iet-smt.2019.0071
[A14] Maslougkas, S., & Danikas, M. G. (2018). Study of water droplets behavior on electrical machine insulation under the influence of uniform electric fields: The influence of some parameters on mica sheets. Engineering, Technology & Applied Science Research, 8(1), 2351–2355. https://doi.org/10.48084/etasr.1691
[A15] Wang, P., Zhou, W., Zhao, Z., & Cavallini, A. (2018). The limitation of partial discharge inception voltage tests at repetitive impulsive voltages using ultra-high frequency antenna and possible solutions [Paper presentation]. In 2018 IEEE Electrical Insulation Conference (EIC), pp. 192–195.
[1] Mohseni, H. Advanced High Voltage Engineering, Publications and Printing Institute of Tehran University, 1994.
[2] Soltani, M. Power Plant Equipment, Publications and Printing Institute of Tehran University, 1995.
[3] Bahar Kazemi, Soheil. Faradars Journal, January 15, 2023. Available at
https://b.fdrs.ir/1wu