Influence of Insulation Thermal Aging on the Temperature Assessment in Electrical Machines

Madonna, Vincenzo; Giangrande, Paolo; Galea, Michael

Abstract

Thermal modeling and temperature assessment of electrical machines often rely on the use of lumped-parameter thermal networks. A historic limitation of analytical thermal models is their need for an experimental fine-tuning, necessary for selecting the appropriate values of thermal conductivity and convection heat transfer coefficients. This evaluation procedure is commonly carried out at the design stage of a new machine, by assuming that its thermal behavior will remain unchanged throughout its whole lifetime. This paper demonstrates, through an in-depth experimental investigation, how the capability of heat extraction from a machine's hot spot towards the coolant can be strongly affected by the level of thermal aging of its insulation system. Based on the experimental findings, a decrement of the winding equivalent thermal conductivity is noted as the thermal aging accumulates, with a corresponding progressive increment in hot-spot temperature.

Citation

Madonna, V., Giangrande, P., & Galea, M. (2021). Influence of Insulation Thermal Aging on the Temperature Assessment in Electrical Machines. IEEE Transactions on Energy Conversion, 36(1), 456-467. https://doi.org/10.1109/tec.2020.3001053

• Journal Article Type: Article
• Acceptance Date: Jun 6, 2020
• Online Publication Date: Jun 9, 2020
• Publication Date: 2021-03
• Deposit Date: Jun 12, 2020
• Publicly Available Date: Jun 17, 2020
• Journal: IEEE Transactions on Energy Conversion
• Print ISSN: 0885-8969
• Electronic ISSN: 1558-0059
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 36
• Issue: 1
• Pages: 456-467
• DOI: https://doi.org/10.1109/tec.2020.3001053
• Keywords: Windings , Aging , Conductivity , Insulation , Copper , Convection
• Public URL: https://nottingham-repository.worktribe.com/output/4631669
• Publisher URL: https://ieeexplore.ieee.org/document/9112655
• Additional Information: © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.