一起高廠變差動(dòng)速斷保護(hù)誤動(dòng)分析及建議
王華衛(wèi)
（華電電力科學(xué)研究院有限公司，浙江 杭州 310030）
摘 要：針對一起因6 kV電纜故障導(dǎo)致高壓廠用變壓器（高廠變）誤動(dòng)的事故，從CT測量特性及保護(hù)定值校核等方面對誤動(dòng)原因進(jìn)行了排查分析，指出本次差動(dòng)誤動(dòng)是高低壓側(cè)故障電流的直流分量占比較大，造成相位差偏差較大，引發(fā)差動(dòng)速斷保護(hù)誤動(dòng)作，并建議差動(dòng)速斷保護(hù)定值在滿足靈敏性的前提下盡量提高，不必拘泥于導(dǎo)則的推薦值。
關(guān)鍵詞：高壓廠用變壓器；差動(dòng)速斷保護(hù)；保護(hù)誤動(dòng)
中圖分類號：TM403.5 文獻(xiàn)標(biāo)識碼：B 文章編號：1007-3175(2019)02-0044-04
Analysis and Suggestion of a Case of Differential Quick-Break Protection for
High-Voltage Auxiliary Transformer Malfunction
WANG Hua-wei
（HUADIAN Electric Power Research Institute Co., Ltd, Hangzhou 310030, China）
Abstract: Aiming at a case of an accident caused by a 6 kV cable fault causing high-voltage auxiliary transformer malfunction, this paper carried out troubleshoot and analysis for the malfunction from the aspects of current transformer measurement characteristic and protection constant value check etc and pointed out that in this differential malfunction the direct current component of failure current at high and low voltage sides had bigger proportion, so as to cause bigger phase differences and to trigger differential quick-break protection malfunction. It is suggested that the constant value of differential quick-break protection should be enhanced to the greatest extent and needn’t stick to the recommended value of guide rule under the precondition satisfying sensitivity.
Key words: high-voltage auxiliary transformer; differential quick-break protection; protection malfunction
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