A Contribution to Thermal Ageing Assessment of Glass Fiber Insulated Wire Based on Partial Discharges Activity

Naderiallaf, Hadi; Giangrande, Paolo; Galea, Michael

Abstract

This paper aims to evaluate a Type-II insulated wire (i.e., Glass fibre insulated wire) as a function of thermal ageing time based on partial discharges (PD) activity. Partial discharge inception voltage (PDIV), partial discharge extinction voltage (PDEV), and repetitive partial discharge inception voltage (RPDIV) measurements have been performed on both unaged and thermally aged specimens. Each specimen modelled the turn-to-turn insulation; hence it was made by a pair of Glass fibre wires wrapped in PTFE tape for a mechanical purpose. The PD tests have been carried out under positive and negative unipolar square waveform excitations using different rise times: 80, 400 and 800 ns. The trend of PD quantities vs exposure time demonstrates that the effect of space charge accumulation under unipolar excitation must be taken into account when unaged and thermally aged specimens are compared. Results revealed that although sometimes thermally aged samples might show a temporary superiority in the short run, unaged ones always present a better performance after space charge accumulation, as expected. Following the statistic postprocessing of the collected data, shape/slope parameters of the Weibull distribution relevant to PDIV can be used as an ageing indicator for Glass fibre insulated wire. Finally, the permittivity evaluation vs thermal and electrical stresses have been performed, relying on the measured capacitance of each specimen just after every PD test. Such analysis revealed that thermal ageing increases permittivity in the long run. However, electrical stress has different impacts on permittivity depending on the rise time, polarity, and magnitude of the applied voltage.

Citation

Naderiallaf, H., Giangrande, P., & Galea, M. (2022). A Contribution to Thermal Ageing Assessment of Glass Fiber Insulated Wire Based on Partial Discharges Activity. IEEE Access, 10, 41186-41200. https://doi.org/10.1109/ACCESS.2022.3167698

• Journal Article Type: Article
• Acceptance Date: Apr 11, 2022
• Online Publication Date: Apr 18, 2022
• Publication Date: Apr 18, 2022
• Deposit Date: May 5, 2022
• Publicly Available Date: May 6, 2022
• Journal: IEEE Access
• Electronic ISSN: 2169-3536
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Pages: 41186-41200
• Series ISSN: 2169-3536
• DOI: https://doi.org/10.1109/ACCESS.2022.3167698
• Keywords: General Engineering; General Materials Science; General Computer Science
• Public URL: https://nottingham-repository.worktribe.com/output/7787609
• Publisher URL: https://ieeexplore.ieee.org/document/9758731