500 kV變壓器無(wú)勵(lì)磁分接開(kāi)關(guān)放電故障診斷分析
丁凱，李文燕，張翾喆，劉昌標(biāo)，周杰，謝斯晗
(國(guó)網(wǎng)浙江省電力公司超高壓分公司，浙江 杭州 311232)
摘 要：無(wú)勵(lì)磁分接開(kāi)關(guān)出現(xiàn)放電性故障會(huì)嚴(yán)重危害變壓器安全運(yùn)行。介紹了一起 500 kV 變壓器交接試驗(yàn)過(guò)程中脈沖局部放電試驗(yàn)異常的案例，應(yīng)用脈沖電流法、特高頻法、超聲波法等多維局部放電檢測(cè)技術(shù)進(jìn)行時(shí)差定位，成功診斷了變壓器無(wú)勵(lì)磁分接開(kāi)關(guān)內(nèi)部異物放電故障；通過(guò)材質(zhì)成分分析判斷異物為動(dòng)觸頭旋轉(zhuǎn)軸壓環(huán)的機(jī)加工碎屑，異物位于無(wú)勵(lì)磁分接開(kāi)關(guān)動(dòng)觸頭旋轉(zhuǎn)軸位置，隨擋位切換而移動(dòng)，導(dǎo)致各個(gè)擋位均可檢測(cè)到局部放電，且脈沖局部放電量隨擋位變化而變化。
關(guān)鍵詞： 變壓器；無(wú)勵(lì)磁分接開(kāi)關(guān)；局部放電；脈沖電流法；特高頻法；超聲波法；時(shí)差定位；異物放電故障
中圖分類號(hào)：TM403.4 文獻(xiàn)標(biāo)識(shí)碼：B 文章編號(hào)：1007-3175(2024)06-0049-05
Fault Diagnosis and Analysis of 500 kV Transformer
Non-Excitation Tap-Changer Discharge
DING Kai, LI Wen-yan, ZHANG Xuan-zhe, LIU Chang-biao, ZHOU Jie, XIE Si-han
（State Grid Zhejiang Electric Power Company Ultra High Voltage Branch, Hangzhou 311232, China）
Abstract: The discharge failure of the non-excitation tap-changer will seriously endanger the safe operation of the transformer. In this paper, a case of abnormal pulse partial discharge test during the handover test of 500 kV transformer is introduced, and the multi-dimensional partial discharge detection technologies such as pulse current method, ultra-high frequency method, and ultrasonic method are used to locate the time difference, and the internal foreign body discharge fault of the transformer,s non-excitation tap-changer is successfully diagnosed.Through the analysis of material composition, it is judged that the foreign body is the machined debris of the rotating shaft pressure ring of the moving contact, and the foreign body is located at the position of the rotating shaft of the moving contact of the non-excitation tap-changer and moves with the gear switching, resulting in partial discharge being detected in each gear, and the amount of pulse partial discharge changes with the change of gear.
Key words: transformer; non-excitation tap-changer; partial discharge; pulse current method; ultra-high frequency method; ultrasonic method; time difference localization; foreign body discharge fault
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