一起高厂变差动速断保护误动分析及建议  

Analysis and Suggestion of a Case of Differential Quick-Break Protection for High-Voltage Auxiliary Transformer Malfunction

作　　者：王华卫 WANG Hua-wei(HUADIAN Electric Power Research Institute Co.,Ltd,Hangzhou 310030,China)

机构地区：[1]华电电力科学研究院有限公司,浙江杭州310030

出　　处：《电工电气》2019年第2期44-47,共4页Electrotechnics Electric

摘　　要：针对一起因6 kV电缆故障导致高压厂用变压器(高厂变)误动的事故,从CT测量特性及保护定值校核等方面对误动原因进行了排查分析,指出本次差动误动是高低压侧故障电流的直流分量占比较大,造成相位差偏差较大,引发差动速断保护误动作,并建议差动速断保护定值在满足灵敏性的前提下尽量提高,不必拘泥于导则的推荐值。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.

关 键 词：高压厂用变压器 差动速断保护 保护误动 

分 类 号：TM403.5[电气工程—电器]