840 MV·A主变压器磁屏蔽故障分析及处理

某水电站1台840 MV·A主变压器在运行期间例行油色谱分析发现乙炔含量上升,影响主设备安全稳定运行。检修人员查找出故障点在上夹件磁屏蔽,并对结构进行分析,明确了故障原因是设计上的结构缺陷,提出了相应的改进设计,对该型所有主变压器的磁屏蔽进行了更换,防止了该家族性缺陷产生的安全风险。

Analysis and Treatment of a Magnetic Shielding Fault in 840 MVA Main Transformer

During the routine oil chromatographic analysis of an 840 MVA main transformer in a hydropower station, ab-normal rising of the acetylene content is observed, which could affect its safe and stable operation.Examination shows that it is caused by the magnetic shielding fault of the upper clamp.Further analysis on the structure shows that the mag-netic shielding is of certain structural defects in its design.Improvement design is then proposed correspondingly.In practice, all of the old type magnetic shielding for main transformers are replaced to prevent the safety risk due to the a-bove mentioned structural defects.