一起變電站直流串入交流回路的異常分析與處理
申濤
（國(guó)網(wǎng)浙江省電力公司檢修分公司，浙江 杭州 310000）
摘 要：針對(duì)某500 kV 變電站2 號(hào)主變復(fù)役操作過程中，當(dāng)拉開2 號(hào)主變220 kV 側(cè)接地閘刀后，出現(xiàn)直流接地報(bào)警，合上該接地閘刀，直流接地告警消失的異常情況，經(jīng)過分析查找，發(fā)現(xiàn)與該主變220 kV側(cè)接地閘刀有聯(lián)閉鎖關(guān)系的2 號(hào)主變2 號(hào)電容器3221 閘刀機(jī)構(gòu)箱內(nèi)的熱繼電器F1 兩副接點(diǎn)間內(nèi)絕緣異常，導(dǎo)致直流串入閘刀交流控制回路。闡述了具體的故障處理過程，并給出了變電站在設(shè)計(jì)、施工、運(yùn)維過程中防止直流接地的注意事項(xiàng)。
關(guān)鍵詞：直流接地；熱繼電器；直流串交流；閉鎖邏輯
中圖分類號(hào)：TM631 文獻(xiàn)標(biāo)識(shí)碼：B 文章編號(hào)：1007-3175(2016)07-0027-03
Abnormal Analysis and Processing of a Direct Current String into
Alternating Current Circuit in Substation
SHEN Tao
（State Grid Zhejiang Maintenance Company, Hangzhou 310000, China）
Abstract: In the process of #2 main transformer recommision operation of certain 500 kV substation, after the grounding switch blade of #2 main transformer at 220 kV side was pulled open, the direct current grounding alarm occurred; while the grounding switch blade of #2
main transformer was closed, the direct current grounding alarm disappeared. After analysis and search, the abnormal insulation between two pairs of contact in thermal relay F1 was the cause of alarm events in 3221 switch blade operation box of #2 main transformer, which has electric locking relationship with the grounding switch blade at 220 kV side. The concrete fault treating procedure was expounded. This paper gave the matters need attention to prevent direct current grounding in the process of substation design, construction, operation and maintenance.
Key words: direct current grounding; thermal relay; direct current string into alternating current; blocking logic
參考文獻(xiàn)
[1] 黨小宇，趙闊，林安靜，等. 一起由遙控回路引起的直流接地故障原因分析與處理[J]. 電力系統(tǒng)保護(hù)與控制，2010，38(13)：116-118.
[2] 牛雪媛， 王磊， 宣玉紅， 等. 對(duì)一起變電站直流接地查找引起其它異常的思考[J]. 電工技術(shù)，2015(3)：67-68.
[3] 趙春香. 直流接地的故障分析與查找[J]. 華北電力技術(shù)，2012(6)：45-47.
[4] 徐玉鳳，張煥清. 交流竄入直流電源故障分析與檢測(cè)[J]. 供用電，2015(2)：28-30.
