某220kV变压器短路损坏的原因分析

Analysis of Short Circuit Damage of a 220kV Transformer

介绍了一起近区短路引起220kV变压器损坏的事故。事故中,C相低压绕组在3个导线换位处(S弯)发生了短路、断股,分析认为绕组工艺问题、楔形垫块松动、未考虑S弯处自粘换位导线在高温下的粘合强度是主要原因,并对事故后变比试验的错误数据进行了说明。通过查阅文献,发现曾发生若干起类似事故,建议该共性问题引起重视。

An accident involving a 220 kV transformer damage caused by short circuit in the near area was analyzed.After accidents,it is found that three cases of short-circuit and strand breakage occurred at where wires transposed at C-phase low-voltage windings.Analysis led to the conclusion that the winding process problem,loose wedge-shaped block,and less consideration on the adhesive strength of self-adhesive transposed wires under high-temperature are the main reasons for the accident.Erroneous data of the post-accident ratio test was expounded.By consulting the literature,it is found that several similar accidents have ever happened and it is suggested that the common problems should be aroused attention.