Investigation of surface discharge along interface between liquid and nanocomposite

Awarding institution
  • University of Strathclyde
Date of award
  • 2015
Thesis identifier
  • T14197
Person Identifier (Local)
  • 201168232
Qualification Level
Qualification Name
Department, School or Faculty
  • Surface discharge happened along the interface of liquid and solid insulation material can be considered the weakest link in an insulation system due to the lower breakdown voltage level than any individual insulating material. In recent years, solid nanocomposites have been discovered to possess improved dielectric properties, such as PD and aging resistance, breakdown strength and low dielectric losses. It is therefore important to investigate if the changes in the properties of a nanocomposite can change the behaviour of surface discharge along its surface. The objectives of this project are to develop a suitable method for making nanocomposite (composite materials which contain nanoscale fillers) in the laboratory, to produce samples and test their dielectric properties, then investigate the surface discharge behaviour of these samples. The matrix material used was HY5052/LY5052 epoxy resin. Two nanofiller materials were used in this project: ZnO and Al₂O₃3 at concentrations between 0.1 wt%, and 5 wt%. Over 100 samples were made (diameter: 8.5 cm, thickness: 1 cm). Dielectric properties were tested for some sample types over the frequency range of 10⁻² to 5x10⁶ Hz. Over 50 samples were tested for surface discharges and the behaviors were characterized by: calculated the fractal dimension of the discharge pattern; measuring the maximum length and total light emission of the discharge. Current pulses occurring during the discharge were also measured. For the samples examined no significant changes were observed in the fractal dimension or maximum length of the discharges for differing nanofillers and concentration of nanofiller. However changes did occur in the light emission and current pulse activity when nanocomposites were compared with the pure epoxy.
Resource Type