Wei Zhao¹, Miao Jiang², Jun Dong¹, Lee Li^2,*

Energy Engineering, Vol.118, No.6, pp. 1755-1766, 2021, DOI:10.32604/EE.2021.015467

Abstract In recent years, more and more high-voltage overhead transmission lines were built passing through the karst regions in southwestern China. This type of special landform seems to have an adverse effect on the aging of the sheds of the line suspension composite insulators, which may lead to unexpected flashover and line tripping. In order to find out the particularity of the aging characteristics of insulators operating in the karst regions, samples in operation were selected from both the karst regions and the flatlands. Hydrophobicity, amount of surface contamination, and contaminant composition of the sheds were studied, then a comparison of… More >

Jie Chen¹, Wei Zhang¹, Man Ding^2,*, Libin Hu¹, Jinpeng Wang², Chenying Li¹, Jingying Cao¹

Energy Engineering, Vol.118, No.5, pp. 1537-1548, 2021, DOI:10.32604/EE.2021.015439

Abstract The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper. The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods, from which the degradation state of XLPE under multiple stresses during operation was derived. The broadband dielectric spectrum test taken from 10^–1 to 10⁶ Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time, which show obvious variation until 10 years of operation. The AC… More >

Shuang Si, Qian Tang, Xingong Li^*

Journal of Renewable Materials, Vol.9, No.12, pp. 2209-2222, 2021, DOI:10.32604/jrm.2021.015506

Abstract This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment. The effect of time, temperature and humidity during the treatment on their mechanical, chemical and morphology properties were evaluated. The composite was prepared from melted wood fibers and modified polycaprolactone by a molding process. A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the composite. The thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on it. According to the spectra of Fourier Transform Infrared (FTIR) and Gel… More > Graphic Abstract