摘要详情

ID / 提交时间

20 / 2021-05-24 10:41:31

标题

LIGHTNING IMPULSE BREAKDOWN BEHAVIOR ANALYSIS FOR THREE-ELEMENT MIXED INSULATION OIL USING DENSITY FUNCTIONAL THEORY

关键字

主题及专题

电力装备绝缘与放电基本物理过程

状态

全文录用

作者

YeWenyu / 重庆大学

GaoChenyu / 重庆大学

XuQing / 重庆大学

zhangjingwen / Southwest University

JianHao / China； Chongqing； 400044；?State Key Laboratory of Power Transmission Equipment & System Security and New Technology ? Chongqing University

RuijinLiao / State Key Laboratory of Power Transmission Equipment & System Security and New Technology； China； Chongqing； 400044； Chongqing University

摘要

The mixed insulation oil has received extensive attention from domestic and foreign researchers, which can take into account the advantages of mineral oil and natural ester insulation oil. In this paper, taking mineral oil as a reference to conduct a comparative study on the lightning impulse breakdown of a new type of three-element mixed insulation oil. The difference in lightning impulse breakdown voltage for the two kinds of oils was analyzed under both positive and negative lightning impulse. At the same time, based on the density functional theory, the front-line orbit distribution, energy band, density of state and electrostatic potential of the two kinds of insulation oil molecules were calculated to analyse difference in lightning behaviour. Results show that the lightning impulse breakdown voltage of the three-element mixed insulation oil and mineral oil is not much different under the positive lightning impulse, while the lightning impulse voltage of the mineral oil is about 1.5 to 3.5 times higher than that of the three-element mixed insulation oil under the negative lightning impulse. Based on the density functional theory, the simulation results show that the electric conductivity of natural ester molecules is stronger than that of mineral oil molecules, which makes the electric conductivity of three-element mixed insulation oil stronger than that of mineral oil. The electrostatic potential of mineral oil is smaller than that of natural ester, and the area of positive electrostatic potential is less. There are many regions with positive electrostatic potential in natural esters molecules These regions will attract electrons close to them and ionize by them during discharge. The research in this paper will be of great help to enhance the insulation oil lightning impulse property in the future.