AC and DC Pre-stressed Electrical Trees in LDPE and its Aluminum Oxide Nanocomposites
Journal article, 2016

Resistance of pure low density polyethylene (LDPE) and its aluminum oxide nanocomposites (up to 3.0 wt%) to degradation by electrical treeing under AC stress and DC pre-stress is analyzed. The experiments were carried out on wire-plane electrode specimens before and after exposure to thermal and DC electro-thermal ageing at 80 °C. The obtained results showed enhanced resistance of the nanocomposites to electrical tree inception under AC stress and the tree inception voltage (TIV) increased with nanoparticles content. It has been shown that there was an improved partial discharge (PD) resistance in the nanocomposites compared to the unfilled LDPE. The results also showed that the AC TIV in the nanocomposites consistently increased with the ageing and especially the DC electro-thermally aged specimens had about 30% higher the AC TIV as compared to the unaged material. This effect is attributed to significantly reduced mobility of charge carriers in the nanocomposites. The DC pre-stressed electrical trees generated in the investigated materials were of filamentary-branch structure and the branch channels content increases with the addition of nanoparticles. The mean tree number of the DC pre-stressed electrical trees decreased in the LDPE and its nanocomposites while the mean maximum tree length increased with the ageing treatments. It is postulated that material recrystallization and a very high electric field level on the wire electrode during the DC pre-stressed electrical tree test are the main reasons for the observed effects.

aluminum oxide nanocomposites

partial discharge

AC electrical treeing


DC pre-stressed electrical trees


Xiangrong Chen

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Deni Murdany

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Dongming Liu

Royal Institute of Technology (KTH)

Mattias Andersson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Polymer Technology

Stanislaw Gubanski

Chalmers, Materials and Manufacturing Technology, High Voltage Engineering

Ulf Gedde

Royal Institute of Technology (KTH)


Institut Teknologi Bandung

IEEE Transactions on Dielectrics and Electrical Insulation

1070-9878 (ISSN)

Vol. 23 3 1506-1514

Areas of Advance


Subject Categories

Polymer Technologies

Electrical Engineering, Electronic Engineering, Information Engineering

Nano Technology



More information

Latest update