A Three-Factor Accelerated Aging Test Platform of Thermal, Mechanical Compression, Pressured SF6, and a Leakage Test System for GIS O-Ring Seals

Zhimin Zhang,Guoli Wang,Fusheng Zhou,Hangyu Cao,Licheng Li,Chao Gao,Jiahao Peng,Yun Yang,Yanpeng Hao,Lin Yang

doi:10.1109/tim.2021.3053983

Abstract

The multifactor accelerated aging test is an important means to predict the lifetime of gas-insulated switchgear (GIS) O-ring seals, while the leakage rate (LR) is a potential index for failure evaluation. This article proposed a three-factor accelerated aging test platform and a leakage test system (LTS) for GIS seal rings. The aging factors are thermal, mechanical compression, and pressured SF 6 gas. The pressure aging vessel (PAV) can be filled with various gases to simulate the operating conditions of the GIS and age multiple samples simultaneously. During the aging process, leakage tests are conducted on flange pairs without disassembling and separating the seal rings. After the test, the aging can be continued so as to study the evolution of LR with aging time. In order to analyze the properties of leakage test and validate the platform, a three-factor accelerated aging and a traditional two-factor accelerated aging (thermal and compression) were conducted on GIS O-ring seals of EPDM material. Compression set (CS) and LR were tested. The result showed that a steady inherent LR F 0 exists for the LTS. The LR rose linearly with accumulating time, allowing simplified calculation of LR. The three-factor aged samples had significantly smaller CS than those of the two-factor aged samples, indicating that the working condition of GIS with SF 6 atmosphere significantly slows the aging rate of GIS seal rings. The findings proved that the three-factor accelerated aging test platform and LTS effectively simulate the operating conditions of GIS seal rings and evaluate their properties.

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