Electrical tree growth in microsilica-filled epoxy resin

DOI: 10.1109/TDEI.2020.008671

Authors: Siyuan Chen (The University of Manchester) , Zepeng Lv (The University of Manchester; Jiaotong University) , James Carr (The University of Manchester) , Malte Storm (Diamond Light Source) , Simon M. Rowland (The University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Ieee Transactions On Dielectrics And Electrical Insulation , VOL 27 , PAGES 820 - 828

State: Published (Approved)
Published: May 2020
Diamond Proposal Number(s): 18215

Abstract: Epoxy resin is widely deployed as a high voltage electrical insulation material when compounded with inorganic fillers. However, in the laboratory, the filler prevents visual observation of the long-term degradation known as electrical treeing. To date therefore, much laboratory testing has been conducted on unrepresentative unfilled materials. Here, the impact of micro-sized fillers on the treeing phenomenon in an epoxy system has been explored. Sub-micrometre resolution 3D reconstructions of electrical trees are reported from X-ray computed tomography (XCT) using an advanced ‘pink beam’ synchrotron light source imaging system. The role of filler particles between 1 and 10 μm in size on tree channel propagation is reported. In highly filled materials (30% by weight) a radical change in tree growth behavior is seen, leading to bush tree rather than branch tree growth. The dielectric breakdown time at constant stress was also found to increase as the square root of the filler level. The change in geometry of tree growth may explain the extended life of filled materials in high voltage applications.

Journal Keywords: Epoxy resins; Three-dimensional displays; Needles; Electric breakdown; Optical imaging; Silicon compounds; Optical device fabrication

Subject Areas: Materials, Physics


Instruments: I13-2-Diamond Manchester Imaging

Added On: 01/06/2020 10:29

Discipline Tags:

Physics Materials Science Polymer Science

Technical Tags:

Imaging Tomography