Mobility-limited charge injection in cross-linked polyethylene under extra high electric field

High voltage

article

Xi Zhu¹  Yi Yin¹  Suman Peng¹  Jiandong Wu¹  Wenpeng Li³  Xin Chen³  Zhenyu Li⁴  Jianxin Guan⁴ 

[1] Department of Electrical Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University;Key Laboratory of Control of Power Transmission and Conversion, Shanghai Jiao Tong University, Ministry of Education;State Key Laboratory of Advanced Power Transmission Technology, Global Energy Interconnection Research Institute Corporation;State Grid of Corporation China

关键词: charge injection;    current density;    electric fields;    space charge;    space-charge-limited conduction;    XLPE insulation;   

DOI  :  10.1049/hve2.12039

学科分类：物理（综合）

来源: Wiley

【 摘 要 】

In this study, characteristics of charge injection under extra high electric field (above 100 kV/mm) in cross-linked polyethylene (XLPE) were investigated by experiments of conduction current and space charge. The results show that current density from low electric field to sample breakdown corresponds to space charge limited current (SCLC) theory. More specifically, Schottky current is similar to experiment current before 100 kV/mm, while the J – E curve conforms to a modified SCLC theory after 100 kV/mm. Besides, the non-linear coefficient of J – E curve from 100 kV/mm to extra high electric field is smaller than theoretical value, and the injection depth of space charge is restricted as the field becomes higher than 100 kV/mm, which may be caused by the negative differential mobility of charge. Driven by extra high electric field, charge collides with lattice of dielectric and scatters. As a result, mean free time of charge decreases and charge mobility is reduced with the increased field. Consequently, considering the decrease in charge mobility, a mobility-limited charge injection equation is proposed, and the validity of the proposed equation under extra high electric field is demonstrated by space charge simulation.

【 授权许可】

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