Charge Accumulation in the Homo-Crosslinked-Polyethylene Bilayer

Materials

Wenpeng Li¹  Xin Chen¹  Wei Zhao²  Huaqiang Li²  Jinghui Gao²  Lisheng Zhong² 

[1] State Grid Smart Grid Research Institute Co., Ltd., Beijing 102202, China;State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049, China;

关键词: homo-crosslinked-polyethylene bilayer;    charge accumulation;    homo-junction region;    factory joint return insulation;   

DOI  :  10.3390/ma15093024

来源: DOAJ

【 摘 要 】

The homo-crosslinked-polyethylene (H-XLPE) bilayer simplifies the returned insulation structure of the factory joint in submarine cables, and its dielectric property is key to the reliability of the power transmission system. In this paper, we investigated the charge accumulation phenomenon in a secondary thermocompression H-XLPE bilayer using the pulse electro-acoustic method. The charge accumulation reduces its overall breakdown strength when compared with XLPE. According to X-ray diffraction measurement and thermal analysis results, the specimen forms a homo-junction region between the bilayers, which has overlapping spherulites with a thick lamella, high crystallinity, and high surface free energy. The charge accumulation can be ascribed to fused lamellas and the crystal imperfection of the homo-junction region, which restricts the charge transport process and exhibits a higher number of deep traps. This study emphasizes the importance of the homo-junction region in the H-XLPE bilayer, which should be considered in the design and operation of factory joint insulation.

【 授权许可】

Unknown