Analysis on Aging Characteristics and Failure Cause of 10 kV Out-of-service Arresters

会议论文
发表日期：

2024年

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Ying Jin,
Peixuan Zhang,
Liyuan Zhu,
Jie Zhang,
Yongxia Han,
Huixian Xie,
Zhijun Zhang,
Lin Yang

摘要

Several 10 kV arresters in transformer substations have experienced failures and explosions in service. In this paper, 5 failed and out-of-service arresters were taken as the research objects and then the aging characteristics and failure cause were analyzed by measuring the electrical characteristic parameters of the complete arresters. Firstly, upon appearance inspection of the arresters, rust, surface pollution, and surface flashover were found. Secondly, the electrical characteristic parameters of each arrester were measured in the experiment, and it was found that there was polarity effect in the forward and reverse DC reference voltages of the arresters. Based on the phenomenon of side flashover of #3, #4, and #5 arresters, it is further confirmed that #3, #4, and #5 arresters frequently experience impulse during actual operation, and it is proposed that the polarity of applied DC voltage should be considered in preventive testing of arresters, as well as the problem of residual voltage exceeding the standard while the DC reference voltage of #1 and #2 arresters meets the standard. Therefore, the aging status of arresters should be evaluated by multiple parameters. Finally, FFT analysis was conducted on the leakage current resistive component current waveforms of the arresters under the AC reference voltage u1 mA. It was found that the positive and negative peaks of leakage current resistive component current waveform of the arresters with polarity effect of DC reference voltage are asymmetric, and the amplitude of even-order harmonics has increased. Combined with the phenomenon that lightning in nature is mostly negative polarity, it indicates that the arresters frequently bear the impulse current of negative polarity during operation, which accelerates the aging of the arrester. In addition, it is proposed that even-order harmonic characteristics can also be used as a new approach for online monitoring of aging status indicators of arresters.