一起换流变压器真空有载分接开关乙炔异常分析

Analysis on An Abnormal Acetylene of Vacuum On-load Tap-changers for Converter Transformer

真空有载分接开关是特高压换流变压器最关键的组部件之一。在某换流站年度检修中,首次报告某厂商特高压换流变压器真空有载分接开关油室乙炔异常增大,经过油色谱分析和现场吊芯检查后,发现过渡电阻与中性点连接处紧固螺栓与螺孔的配合松动引起的放电烧蚀是有载分接开关独立油室乙炔值超标的直接原因。根据异常现象的机理分析,文中针对有载分接开关的检修规程和日常运维提出了建议,为后续类似工作处置提供了宝贵经验。

The vacuum on-load tap-changer is one of most important components of UHV converter transformers.During an annual maintenance for converter stations,the abnormal increase of acetylene in the oil chamber of vacuum on-load tap-changers[JP+3]of UHV converter transformer is reported for the first time.Based on the oil chromatographic analysis and hanging-core inspec-tion,it is found that the discharge ablation caused by the loose fit between the bolt and the screw hole directly leads to the abnormal acetylene.According to the mechanical analysis of abnormal phenomenon,the suggestions for maintenance standards and daily operation of on-load tap-changers are put forward,which provides precious experiences for the follow-up similar works.