Surface Corona Aging of Epoxy/SiO2 Nanocomposites

  • Jiao Xiang
  • , Chuang Zhang
  • , Shihang Wang
  • , Hang Fu
  • , Zhaoliang Xing
  • , Jianying Li

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Epoxy resin has been widely used in electronic and electrical equipment due to its excellent electrical and mechanical properties. However, prolonged corona discharge may cause deterioration of the surface, and finally lead to failure of insulation structure. Extensive researches have indicated that addition of nano fillers can improve corona resistance of polymers. In this paper, epoxy/SiO2 nanocomposites are prepared to study the micro development of corona erosion and surface trapping performance during corona aging. AC breakdown strength of epoxy/SiO2 nanocomposites is measured firstly and 2 wt% epoxy/SiO2 nanocomposite with highest AC breakdown strength of 64.11 kV/mm is selected to conduct corona resistance test with pure epoxy. It was observed by polarizing microscope that the degradation was severer for pure epoxy resin with corrosion area from about 0.27 mm2 at 10 min to 0.57 mm2 at 30 min, while the area of 2 wt% nano-SiO2 nanocomposite is nearly invariable about 0.21 mm2. With the increase of corona duration, the corrosion regions become darker which indicates thicker channel and more intensive corrosion density. Additionally, the corona damage extends from the center to edge of samples in shape of 'branch', and 'branch' channels of degradation develop denser in the center. The isothermal surface potential decay (ISPD) results show that shallow trap ranges from 0.90 to 1.00 eV, whereas the deep trap locates at 1.05∼1.15 eV. The deep energy density of pure epoxy decreases dramatically from 7.2x1014 m-3 to 4.9x1014 m-3 with corona aging time, while that of 2 wt% epoxy/SiO2 nanocomposite maintains constant about 6.9x1014 m-3. Both of the shallow trap density of epoxy and nanocomposite increases after corona aging, while pure epoxy increases more obvious from 1.6x1013 m-3 to 3.8x1013 m-3. Therefore, charges are more difficult to inject and move in epoxy nanocomposites because of more deep traps even after corona exposure, which illustrates why nanocomposites have higher corona resistance.

Original languageEnglish
Title of host publicationICEMPE 2019 - 2nd International Conference on Electrical Materials and Power Equipment, Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages317-320
Number of pages4
ISBN (Electronic)9781538684344
DOIs
StatePublished - Apr 2019
Event2nd International Conference on Electrical Materials and Power Equipment, ICEMPE 2019 - Guangzhou, China
Duration: 7 Apr 201910 Apr 2019

Publication series

NameICEMPE 2019 - 2nd International Conference on Electrical Materials and Power Equipment, Proceedings

Conference

Conference2nd International Conference on Electrical Materials and Power Equipment, ICEMPE 2019
Country/TerritoryChina
CityGuangzhou
Period7/04/1910/04/19

Fingerprint

Dive into the research topics of 'Surface Corona Aging of Epoxy/SiO2 Nanocomposites'. Together they form a unique fingerprint.

Cite this