Experimental Study on Damage Mechanism of Partial Discharge of Oil-Immersed Laminated PMIA Paper

PMIA (Poly-m-phenylene isophthalamide) is an ideal substitute for traditional cellulose paper in oil-immersed paper insulating scenarios. This paper studies the partial discharge characteristics of oil-immersed laminated PMIA. According to the $\mathrm{q}{-}\varphi$ scatter diagram, discharge quantity and discharge phenomenon, the partial discharge process of PMIA is divided into 3 stages: creeping discharge, co-existence discharge and pre-breakdown. The micro-structure and chemical components of damaged PMIA are presented. The carbon trace, functional groups, carrier trap characteristics and residual insulation strength in different stages of partial discharge are studied. This paper provides a theoretical basis for the application of PMIA in electrical insulation.