UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin

Chen, S; Rowland, S; Carr, J; Storm, M; Choy, K-L; Clancy, AJ; (2021) The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin. International Journal of Electrical Power & Energy Systems , 129 , Article 106838. 10.1016/j.ijepes.2021.106838. Green open access

[thumbnail of Clancy_The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin_AAM.pdf]
Preview
Text
Clancy_The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin_AAM.pdf - Accepted Version

Download (570kB) | Preview

Abstract

The addition of nano-fillers has been widely proposed as a method to enhance the dielectric properties of high voltage polymeric insulation, though there are mixed reports in the literature. Here the potential of silica nano-particles to extend the time to failure specifically through resistance to electrical tree growth in epoxy resin is determined. The benefit of silane treating the nano-particles before compounding is clearly established with regard to slowing tree growth and subsequent time to failure. The growth of trees in needle-plane samples is measured in the laboratory with loadings of 1, 3 and 5 wt% nano-filler. In all cases the average times to failure are extended, but silane treatment of the nano-particles prior to compounding yields much superior results. The emergence of a pronounced inception time before tree growth is also noted for the higher-filled, silane-treated cases. The average time to failure of silane-treated 5 wt% filled material was 28 times that of the unfilled resin. The improvement in performance between the nanocomposites with untreated and treated fillers is attributed to fewer agglomerations and improved dispersion of the filler in the treated cases. Measurements of Partial Discharge (PD) indicated significant differences in PD patterns during the growth of trees in the treated and untreated cases. This distinction may provide a quality control method for monitoring materials. In particular, long periods in which PDs were not measured were observed in the silane-treated cases. Visual imaging of tree growth in the unfilled material allowed the changing nature of the tree from fine to tree to dark tree to be observed as it grew. Corresponding PD measurements suggest the dark tree is gradually becoming conductive, and that growth of maximum PD measured is dependent on the relative rates of the growth of the tree and its carbonization. X-ray computer tomography identified significant differences in average tree channel diameters (a reduction from 2.8 µm to 2.0 µm for 1 wt% and 3 wt% cases). This implies that in addition to tree length changes, evaporated tree volumes also change and may explain the change in partial discharge characteristics observed.

Type: Article
Title: The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.ijepes.2021.106838
Publisher version: https://doi.org/10.1016/j.ijepes.2021.106838
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher's terms and conditions.
Keywords: Electrical tree, Partial discharge, Breakdown, Nanocomposite, Silane
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > MAPS Faculty Office > Institute for Materials Discovery
URI: https://discovery.ucl.ac.uk/id/eprint/10127454
Downloads since deposit
84Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item