Effect of mechanical vibration on surface discharge along Epoxy resin under AC electric field

Many high-voltage power apparatuses are accompanied by continuous mechanical vibration during operation which may give rise to an additional electrical effects to accelerate the deterioration of insulation. In this paper, we focus on the behaviors of the surface discharge along epoxy resin under different vibration conditions. The variation of PD current with vibration frequency as well as amplitude are investigated by experiment within the actual range of vibration mode. The experimental results show that at the vibration condition of 50Hz and 100Hz, the PD activity of the epoxy resin first significantly increases with the increase of the vibration amplitude then presents a decrease with the amplitude. Preliminary analysis demonstrated that the vibration may promotes or suppresses the occurrence and development of discharge via changing the state of field emission, the dissipation of charges, and the conduction current, and the impact is not monotonous with the frequency or the amplitude, mainly depending on the vibration mode. This paper exemplified this fact by the experiment on the surface discharge along the polymer material and presented the significant additional electrical hazard induced by mechanical vibration.