气体继电器误动作分析及处理

气体继电器保护是电力变压器的一种基本保护。如何正确选型、使用和维护有一定现实意义。以河南郑州供电公司一起220 kV变压器进口双浮球气体继电器误动作为实例进行了分析,叙述了气体继电器的动作原理,对这次误动作的具体原因做了详细分析,得出了人民2号主变重瓦斯动作是由于双浮球气体继电器反向动作起动值低,在小油流冲击下误动作的结论,并进行了相应试验予以验证。总结提出了电力企业在进行气体继电器选型、验收和校验的注意事项:加强变压器附件的选型、验收等工作;新安装的气体继电器、压力释放装置和温度计等须经校验合格后方可使用;在高温负荷到来之前,应对主变压器特别是室内变压器的散热器进行清理清洗工作,并加强运行巡视。

Analysis and Elimination of Gas Relay Misoperation

This paper analyzes a misoperation case of double-floating ball gas relay of a 220 kV transformer in Zhengzhou Power Supply Company,Henan Province.The operation mechanism of the gas relay is described,and the cause of this misoperation is discussed.The misoperation is found to be due to lower reverse start value of the double-floating ball gas relay,leading to its misoperation under impact of small oil flow.A test is conducted to verify this conclusion.Some suggestions about selection,acceptance and checkout of gas relay are offered:1) Pay more attention to the selection and acceptance of transformer accessories.2) The newly installed gas relay,pressure release device,and thermometer,etc.should be checked before putting them into operation,e.g.,double-contact gas relay needs the reverse operating test.3) The radiators of main transformer,specially of indoor transformer ought to be cleaned before high-temperature load.4) During the period of high-temperature load,monitoring of transformer and its oil level must be carried out,and aeration and heat dissipation of indoor transformer be strengthened.