Abnormal Breakdown Process and Mechanism of High-performance Epoxy Insulation

In recent years, various faults caused by insufficient mechanical properties of high-performance epoxy insulating parts occur from time to time. The breakdown position is epoxy metal interface, in which an obvious mechanical failure form is found. It is speculated that the failure mechanism may be the failure process caused by combined electrical mechanical breakdown. An insulation failure of epoxy insulating parts was analysed and he similarities and differences of bending and tensile properties of single column leg of different batches of products was studied, which is used to put forward the bulk insulation failure process of epoxy insulating parts under mechanical electrical coupling. In this paper, the bending test and tensile test of single column leg of high-performance insulation are designed, and the bonding strength of column leg insert is studied and analyzed. It is found that the bonding strength of column leg inserts of high-performance insulating parts in the fault batch is insufficient and has great dispersion. The bonding strength of column leg inserts is mainly affected by the knurling shape, knurling width and the coating shape of semi-conductive adhesive on the surface of the insert.