一起断流阀误动引起的变压器跳闸事故分析  

Analysis of a Transformer Trip Accident Caused by the Misoperation of the Shut-off Valve

作　　者：江丹宇 杨贤 马志钦 周丹 蔡玲珑 JIANG Danyu;YANG Xian;MA Zhiqin;ZHOU Dan;CAI Linglong(Electric Power Research Institute of Guandong Power Grid Co.,Ltd.,Guandong Guangzhou 510080,China)

机构地区：[1]广东电网有限责任公司电力科学研究院

出　　处：《广西电力》2019年第5期47-51,共5页Guangxi Electric Power

基　　金：广东电网有限责任公司科技项目(GDDKJM20180230)

摘　　要：对一起变压器跳闸事故进行分析,通过现场检查与试验,逐步排除了油枕呼吸堵塞、油位过高和压力释放阀误动作的可能,初步判断该变压器跳闸的原因为断流阀误动作。为了验证此结论,采用ANSYS有限元搭建了变压器三维几何模型,对变压器空载合闸励磁涌流、励磁涌流下变压器绕组受力变化与油箱出口处油流涌动情况进行了仿真计算。结果表明:变压器断流阀在空载合闸造成的涌动油流下误关闭,后续运行中由于变压器内部压力增大造成压力释放阀动作喷油引起重瓦斯保护动作跳闸。为了确保变压器安全稳定运行,分析了断流阀在变压器运行中的必要性及存在的风险,并提出了相应的措施及建议。A transformer trip accident is analyzed.By field inspection and tests,possibilities including the outlet block of the fuel tank,the exceedingly high oil level and the misoperation of pressure relief valve are excluded step by step.It is preliminarily judged that the reason of the transformer trip is the misoperation of the shut-off valve.In order to verify the conclusion,a 3D geometric model of the transformer is built by the finite element model of ANSYS.The no-load closing inrush current of the transformer,the force variation of the transformer winding under the inrush current and the inrush oil at the outlet of the oil tank are simulated and calculated.The results show that the shut-off valve of the transformer is mistakenly closed under the inrush oil caused by the no-load closing.During the following operation,the increasing internal pressure of the transformer causes the action of the pressure relief valve which causes the oil discharge and thus the action of the heavy gas protection trip.In order to guarantee the secure and stable operation of the transformer,the necessity and risk of the shut-off valve in the transformer operation are discussed and the corresponding measures and suggestions are proposed.

关 键 词：断流阀 误动作 空载合闸 励磁涌流 

分 类 号：TM407[电气工程—电器]