某环氧浇注干式变压器在使用过程中发生开裂失效,为查明开裂原因,笔者对其进行了磁感应强度测试、导线电阻测试和X射线扫描分析。结果表明:该变压器开裂是由于其固定板设计不合理,未进行圆弧处理,灌封时尖角处应力集中,导致变压器在进行高、低温试验时于尖角处产生裂纹,最终引起变压器开裂并伴有黑色物质流出。

Cracking failure happened to epoxy-filled dry-type transformers during using procedure.In order tofind out the cracking reason,magnetic induction intensity measurement,wire resistance measurement and X-rayscanning analysis were done to the failure transformers.The results indicate that the cracking of the transformerwas caused by the irrational design on the fixing plate which wasnt arc processed.Stress concentration formed atthe sharp corner during the pouring seal and made cracks form at the sharp corner during the high & lowtemperature test and finally caused the transformer cracking and black material outflowing.