一起电压互感器故障引起主变跳闸事故的分析及处理  

Analysis and Treatment on a Main Transformer Out Accident Caused by a Voltage Transformer Fault

作　　者：魏锡年 WEI Xinian(Northeast Electric Power Design Institute Company Limited of China Power Engineering Consulting Group,Changchun 130021,China)

机构地区：[1]中国电力工程顾问集团东北电力设计院有限公司,长春130021

出　　处：《吉林电力》2024年第4期36-39,56,共5页Jilin Electric Power

摘　　要：针对某电厂发生的发电机出线侧电压互感器故障导致主变跳闸事故,对事故的整个过程进行了分析。通过对故障跳闸前和跳闸时的录波数据、保护跳闸报文以及故障设备的综合分析,判断本起事故是由于发电机出线侧电压互感器c相二次侧接地,进而导致电压互感器a、b相一次侧先后接地,最终演变为两相接地短路故障,并通过理论计算验证分析判断的正确性。在全面核查主设备参数时,又发现电压互感器的绝缘参数低于规程要求。为了彻底解决此问题,提出了相应的处理方案,采用国产电压互感器替换进口电压互感器。经过整改后,电压互感器的工频耐受电压水平得到了提高,从而提高了机组运行的可靠性和安全性。In response to the main transformer trip accident caused by a voltage transformer fault on the generator outlet of a certain power plant,a comprehensive review of the history and present recorded data,combined with the protection trip message and on-site equipment inspection information,it was conducted that the accident was caused by the grounding of the secondary side of phase c of the generator outlet voltage transformer,which led to the grounding of the primary side of phase a and phase b of the voltage transformer,and ultimately developed into a two-phase grounding short circuit fault,and the correctness of the analysis and judgment was verified through theoretical derivation and calculation.During a comprehensive inspection of the main equipment parameters,it was discovered that the insulation parameters of the voltage transformer did not meet the requirement of standards.Finally,an accident handling plan was proposed,replacing imported equipment with domestic voltage transformers.After rectification,the power frequency withstand voltage level of the voltage transformers was improved,and the reliability and safety of unit operation were increased.

关 键 词：电压互感器 两相接地短路 故障录波 波形图 工频耐受电压 

分 类 号：TM451[电气工程—电器]