一起基于油色谱分析的变压器过热故障分析

Analysis of Transformer Overheating Fault Based on Oil Chromatography Analysis

通过变压器油色谱分析可以初步推断变压器内部缺陷的性质,再结合电气试验等手段进行综合分析,可提高变压器内部缺陷诊断的准确性。介绍了一起220 kV变压器总烃超标案例,应用三比值法判断内部存在高温过热,综合停电诊断试验数据,诊断变压器内部存在磁回路裸金属发热问题。检修人员对变压器进行内检,发现低压绕组串联的电抗器固定拉杆螺栓螺母处存在轻微烧伤,进一步拆解发现平垫片与螺母烧蚀明显,结构破损。更换烧蚀零件后,缺陷消除。缺陷分析诊断过程对此类变压器缺陷的诊断分析具有一定参考意义。

The transformer oil chromatographic analysis can be used to preliminarily infer the nature of the internal defects of the transformer.Combining electrical tests and other means for comprehensive analysis,the accuracy of the internal fault diagnosis of the transformer can be improved.A 220 kV transformer total hydrocarbon excess case was introduced.The three ratio method was used to judge the existence of high temperature overheating.Comprehensive power failure diagnostic test data was used to diagnose the existence of bare metal heating in the magnetic circuit of the transformer.The internal inspection of the transformer by the maintenance staff found that there was a slight burn at the bolts and nuts of the fixed rods of the reactor connected in series in the low-voltage winding.Further disassembly revealed that the flat gasket and nut were ablated obviously and the structure was damaged.Defects were eliminated after replacement of ablative parts.The process of defect diagosis and analysis has certain reference significance for the diagnosis and analysis of such transformer defects.