Evaluation of strand-to-strand capacitance and dissipation factor in thermally aged enamelled coils for low-voltage electrical machines

Madonna, Vincenzo; Giangrande, Paolo; Galea, Michael

Abstract

© The Institution of Engineering and Technology 2019. The dissipation factor (i.e. tanδ) and insulation capacitance (IC) measurements are conventional monitoring methods for assessing the aging level of insulation systems. These quantities provide an invaluable indication of the dielectric losses within the insulating materials. However, how these values are affected by the aging processes due to thermal stresses have until today never been investigated fully. Thus, this study exhibits the influence of thermal aging on tanδ and IC of windings for electrical machines (EMs). The work is performed for class 200, round enamelled magnet wire specimens. The study aims at improving the design process of EMs for short duty cycle applications; hence, its outcome might be included at the design stage for enhancing reliability and lifetime. Random wound coils are chosen in the performed study, because they are the most common winding arrangement for low-voltage EMs, which are employed in a wide range of applications (e.g. from home appliances to aerospace motors). Based on the collected data, considerations regarding the impact of relative humidity on both the dissipation factor and IC are presented. Finally, the correlation between the partial discharge inception voltage and the diagnostic measurements is experimentally verified.

Citation

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 and Technology, 13(8), 1170-1177. https://doi.org/10.1049/iet-smt.2019.0071

• Journal Article Type: Article
• Acceptance Date: Jul 9, 2019
• Online Publication Date: Jul 12, 2019
• Publication Date: Oct 1, 2019
• Deposit Date: Jul 16, 2019
• Publicly Available Date: Jul 16, 2019
• Journal: IET Science, Measurement and Technology
• Print ISSN: 1751-8822
• Electronic ISSN: 1751-8830
• Publisher: Institution of Engineering and Technology
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 8
• Pages: 1170-1177
• DOI: https://doi.org/10.1049/iet-smt.2019.0071
• Keywords: Electrical and Electronic Engineering; Atomic and Molecular Physics, and Optics
• Public URL: https://nottingham-repository.worktribe.com/output/2311590
• Publisher URL: https://digital-library.theiet.org/content/journals/10.1049/iet-smt.2019.0071
• Additional Information: "This paper is a postprint of a paper submitted to and accepted for publication in IET Science Measurement and Technology and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.