一起超高壓變電站低抗絕緣油檢測異常缺陷分析
王從剛，錢苗旺，郁飛
(國網江蘇省電力有限公司連云港供電分公司，江蘇 連云港 222000)
摘 要：針對一起在超高壓變電站油浸式低壓并聯電抗器 (低抗) 絕緣油檢測中發現總烴超標的事故，通過對絕緣油溶解氣體含量分析，借助三比值法初步推斷低抗內部存在中溫過熱故障，進行包含直流電阻、絕緣電阻、阻抗、介損及電容量等項目的診斷性試驗，分析低抗缺陷原因，并對低抗進行解體驗證。結果表明，低抗缺陷的原因為接地屏中存在銅箔片異常搭接，進而引起環流引發局部過熱，造成異常搭接處被灼燒，導致總烴超標。
關鍵詞： 變電站；油浸式低壓并聯電抗器；總烴；過熱故障；缺陷分析
中圖分類號：TM472 ；TM855 文獻標識碼：B 文章編號：1007-3175(2023)02-0047-04
Analysis on Abnormal Detection of Low-Voltage Parallel Reactor
Insulating Oil of a Ultra-High Voltage Substation
WANG Cong-gang, QIAN Miao-wang, YU Fei
（Lianyungang Power Supply Branch, State Grid Jiangsu Electric Power Co., Ltd, Lianyungang 222000, China）
Abstract: An accident which the total hydrocarbon from insulating oil of the oil-immersed low-voltage parallel reactor of a ultra-high voltage substation exceeded standard happened, so the paper analyzes the dissolved gas content of insulating oil, and it is preliminarily inferred through three-ratio method that medium temperature overheat fault exists inside of the low-voltage parallel reactor. Then, diagnostic tests are conducted on DC resistance, insulation resistance, impedance, medium loss, and capacitance to analyze why the low-voltage parallel reactor has defects, and disassembling the low-voltage parallel reactor verifies the correctness of this analysis. According to the results, the reason for defects of the low-voltage parallel reactor is that copper foils in the earthing panel are connected abnormally. As a consequence, circulating current contributes to local overheating and the abnormal connection burns, causing the total hydrocarbon exceeding standard.
Key words: substation; oil-immersed low-voltage parallel reactor; total hydrocarbon; overheat fault; defect analysis
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