Microstructure-ionisation potential relationship analysis for understanding the molecular ionisation difference of natural esters during the impulse discharge via DFT calculation  

作　　者：Jingwen Zhang Jian Hao Wenyu Ye Junyi Zhang Ruijin Liao 

机构地区：[1]State Key Laboratory of Power Transmission Equipment Technology,School of Electrical/Engineering,Chongqing University,Chongqing,China

出　　处：《High Voltage》2024年第4期920-929,共10页高电压（英文）

基　　金：Science and Technology Project of State Grid Corporation of China,Grant/Award Number:5500-202327118A-1-1-ZN;National Natural Science Foundation of China,Grant/Award Number:52077015。

摘　　要：Understanding the impulse discharge behaviour of natural ester(NE)is crucial for its safe application in high-voltage transformers.The ionisation potential(IP)of triglycerides plays a significant role in the process of molecular ionisation during impulse discharge for NE.The correlation coefficients between molecular size,frontier orbital,electrostatic potential,polarity,and IP were analysed.And the quantitative microstructure-IP model for triglycerides were built,which revealed that IP is strongly related to the highest occupied molecular orbital(HOMO)energy EHM,as well as the average value of positive electrostatic potential V_(p)(t),the average value of negative electrostatic potential V_(p)(-),and the surface area of negative electrostatic potential S(-).The HOMO and negative electrostatic potentials of saturated triglycerides are predominantly linked to the carbonyl O atoms.Conversely,in unsaturated triglycerides,the influence of C=C double bonds on HOMO and negative electrostatic potentials is more pronounced.Therefore,the IP of unsaturated NE with C=C bonds is lower than that of saturated NE,rendering it more susceptible to ionisation under a strong electric field which is unfavourable for impulse breakdown voltage.The structure-property correlation analysis is valuable for understanding ionisation mechanism during the impulse discharge breakdown of NE at the microscopic level.

关 键 词：ELECTROSTATIC potential BONDS 

分 类 号：O62[理学—有机化学]