基于分子模拟的外电场对电力电容器绝缘油的影响机理研究  

Study on the Mechanism of External Electric Field on Insulating Oil of Power Capacitors Based on Molecular Simulation

作　　者：李洪坤 李毅 覃锐 LI Hongkun;LI Yi;QIN Rui

机构地区：[1]中国南方电网超高压输电公司柳州局,广西柳州545000 [2]柳州职业技术大学,广西柳州545000 [3]广西电网柳州供电局,广西柳州545000

出　　处：《青海电力》2024年第4期10-17,41,共9页Qinghai Electric Power

摘　　要：由于苄基甲苯具有良好的物理和电学性能,它是电力电容器的首选液体介质。本研究构建了苄基甲苯的分子模型,采用分子模拟方法研究了外加电场对苄基甲苯绝缘油微观变化机理的影响。结果表明,外加电场强度的增加导致苄基甲苯分子的总能量降低,其偶极矩和极化率增大导致分子稳定性的下降。同时,当受到外电场拉伸时,苄基甲苯分子链会伸长,从而降低几何结构稳定性,影响电学性能。在较高的外电场强下,苄基甲苯分子中前线轨道的能隙减小,导致分子的反应性增加。当遇到极端场强时,苄基甲苯分子结构会发生破坏,导致红外光谱发生显著变化。这些发现为材料改性方向、高压击穿试验、绝缘状态评估等提供了理论支持。Benzyl toluene is the preferred liquid medium for power capacitors due to its good physical and electrical properties.In study,the molecular model of benzyl toluene was constructed,and the molecular simulation method was used to study the effect of external electric field on the microscopic mechanism of benzyl toluene insulating oil.The results show that the increase in the strength of the external electric field leads to a decrease in the total of the benzyl toluene molecules,and an increase in their dipole moment and polarizability,which decreases molecular stability.Meanwhile,when stretched by external electric field,the benzyl toluene molecular chain will elongate,thereby reducing geometric structural stability and affecting electrical performance.Under higher external electric field strengths the energy gap between the frontier orbitals of the benzyl toluene molecules decreases,leading to an increase in molecular reactivity.When encountering extreme field strengths the molecular structure of benzyl toluene will be destroyed,resulting in significant changes in the infrared spectrum.These findings provide theoretical support for material modification directions,-voltage breakdown tests,and insulation condition assessment.

关 键 词：分子模拟 M/DBT 绝缘油 微观特性 

分 类 号：TM214[一般工业技术—材料科学与工程]