Effect of TiO2 nanoparticle on partial discharge characteristics and lifetime of polyimide films under high frequency voltage

Abstract

Polyimide (PI) is a promising, widely used insulating material in high frequency power transformers, due to its magnificent mechanical, thermal and electrical properties. Partial discharge (PD) is considered to be a vital cause of insulating material deterioration which can lead to degradation in electrical performance and failure of solid insulating materials. For the sake of investigating the impact of nanoparticles on insulation lifetime and PD behavior, an experimental set up had been arranged in order to conduct the aging test. The pure polyimide and titanium oxide (TiO 2 ) nanocomposite films with different weight percentage (2%, 3% and 5%) were exposed to surface discharge at 1kV–15kHz applied voltage. In this paper, the surface erosion, insulation lifetime and discharge characteristics has been paid special consideration. Discharge characteristics comprising the maximum and average PD amplitudes, total PD number per cycle and total PD number per second. It is obvious from the experimental results that the insulation lifetime, surface discharge and erosion of surface are greatly influenced by nanoparticles contents.