Failure analysis of polymeric outdoor insulators used in HVDC converter stations

Halloum, M-R and Subba Reddy, B (2024) Failure analysis of polymeric outdoor insulators used in HVDC converter stations. In: Engineering Failure Analysis, 158 .

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Abstract

This study presents the performance of polymeric outdoor insulators used in high-voltage direct current (HVDC) converter stations. These insulators typically encounter voltage polarity reversal based on the power flow direction, which may occur within days or months. The accelerated aging investigations are conducted on composite insulators adopting the rotating wheel experimental facility and considering the voltage polarity reversal effect. A two-dimensional model for the evaluated insulators is developed and simulated in COMSOL Multiphysics to comprehensively understand their performance under various environmental conditions. It is observed that the voltage polarity reversal significantly impacts the degradation and aging of composite insulators�the leakage current increases after each polarity reversal with higher surface temperatures. Additionally, unique patterns were observed on both sides of the housing sheds. However, these patterns were only observed on one side in the case of a single polarity. The failure of insulators was noticed after 625 h with multiple consecutive flashovers, indicating the severe deterioration of the silicone rubber housing. In addition, physicochemical analyses were conducted on the aged samples collected from various locations to identify their degradation level. Results obtained indicate a significant deterioration of silicone rubber housing, especially near the shank areas. Moreover, aged samples showed a substantial deterioration of the mechanical and hydrophobicity properties. © 2024 Elsevier Ltd

Item Type:	Journal Article
Publication:	Engineering Failure Analysis
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to Elsevier Ltd .
Keywords:	Deterioration; Electric insulators; Electric load flow; Failure (mechanical); Housing; HVDC power transmission; Rubber; Silicones, Converter station; Direct current converter; Finite element method; FTIR; High-Voltage Direct Current; High-voltage direct current converter station; Polarity reversal; Polymeric outdoor insulator; Voltage polarity; Voltage polarity reversal, Finite element method
Department/Centre:	Division of Electrical Sciences > Electrical Communication Engineering Division of Electrical Sciences > Electrical Communication Engineering > Electrical Communication Engineering - Technical Reports Division of Electrical Sciences > Electrical Engineering
Date Deposited:	04 Mar 2024 05:41
Last Modified:	04 Mar 2024 05:41
URI:	https://eprints.iisc.ac.in/id/eprint/84132

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