The influence of mechanical-electric loads on partial discharge in dielectric material containing a crack

This paper studies the influence of mechanical-electric loads on partial discharge (PD) of a crack in a dielectric material. According to the complex potential theory, the electric field inside the crack is first derived by taking the crack deformation into account, and then the critical condition for Townsend-type discharge is discussed based on the law of Paschen. Finally, the influence of mechanical and electric loads on the partial discharge is studied. It is found that the mechanical field decreases the electric field inside the crack and thus may retard the occurrence of PD, while the electric field may enhance the PD.