核電廠500 kV主變壓器局部放電異常分析
郭述志,段琰璞,楊慶學
(國核示范電站有限責任公司,山東 榮成 264300)
摘 要:介紹了某核電廠500 kV 主變壓器局部放電量超標情況,通過現場試驗、返廠解體檢查及試驗、生產過程排查,全面地分析了變壓器局部放電量超標原因。結果表明:由于變壓器長期充氮儲存,導致外部潮氣進入變壓器本體,疊加內部繞組撐條位置紙板受力變形,形成絕緣薄弱點,在試驗過程產生局部放電。為避免此類事故的發生,針對核電廠主變壓器制造、存儲、安裝周期長等特點,提出了應對措施。
關鍵詞:主變壓器;局部放電;油色譜分析
中圖分類號:TM411 文獻標識碼:B 文章編號:1007-3175(2021)01-0043-04
Analysis on Abnormal Partial Discharge of 500 kV Main
Transformer in Nuclear Power Plant
GUO Shu-zhi, DUAN Yan-pu, YANG Qing-xue
(State Nuclear Power Demonstration Plant Co., Ltd, Rongcheng 264300, China)
Abstract: This paper introduces the situation of partial discharge exceeding the standard of 500 kV main transformer in a nuclear powerplant. Through field test, disassembly inspection, test and production process investigation, the causes of over standard of partial discharge oftransformer are comprehensively analyzed. The results show that: due to the long-term storage of nitrogen in the transformer, the external moistureenters the transformer body, and the paperboard at the position of the internal winding stay bar is deformed under stress, forming an insulationweak point and producing partial discharge during the test. In order to avoid the occurrence of such accidents, the countermeasures are putforward according to the characteristics of long manufacturing, storage and installation period of main transformer in nuclear power plant.
Key words: main transformer; partial discharge; oil chromatogram analysis
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