X-蜡生成过程中自由基产生的分子动力学仿真  

Molecular dynamics simulation of free radical generation during X-wax generation

作　　者：沈殷和 齐波 林元棣[3] 张毅涛 SHEN Yinhe;QI Bo;LIN Yuandi;ZHANG Yitao(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Beijing 102206,China;Beijing Key Laboratory of High Voltage and Electromagnetic Compatibility,North China Electric Power University,Beijing 102206,China;State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206 [2]华北电力大学高电压与电磁兼容北京重点实验室,北京102206 [3]国网江苏省电力有限公司电力科学研究院,江苏南京211103

出　　处：《电力工程技术》2021年第1期142-146,共5页Electric Power Engineering Technology

基　　金：国家电网有限公司科技项目(SGJSDK00ZPJS1900269)。

摘　　要：油纸绝缘结构设备在解体时常有黄色蜡状沉积物存在,因其不具有固定化学式而被称为X-蜡。X-蜡在较低温度下形成,并伴有大量气体产生,形成后会依附在绝缘纸上并进入孔隙中使得介损增大,导致整体损耗增大,局部温度上升。文中基于分子动力学对X-蜡产生过程的第一步——自由基的产生进行了模拟,建立了含有30个分子的矿物绝缘油仿真模型,基于ReaxFF力场模拟了473 K,393 K,373 K下油模型的自由基产生情况,通过生成的轨迹文件捕捉各温度下第一个自由基的产生过程。仿真过程中发现环烷烃上的碳氢键易发生均裂形成2个自由基,大分子自由基之间重组能够形成X-蜡,氢自由基之间相互作用产生氢气。通过分析温度曲线可发现在仿真温度范围内,自由基产生速度和温度呈正相关。Oil-paper insulation structure equipment often has yellow waxy deposits when it disintegrates.It is called X-wax because it does not have a fixed chemical formula.X-wax will generate a large amount of gas during the formation process.After formation,X-wax will adhere to the insulation paper and enter the pores to increase the dielectric loss,resulting in an increase in overall loss and a rise in local temperature.However,there is no detailed report on the mechanism of X-wax production.Based on molecular dynamics,the first step of the X-wax production process is simulated:the generation of free radicals,and a mineral insulating oil simulation model containing 30 molecules is established.The free radical generation in the oil model is simulated based on the ReaxFF force field at 473 K,393 K and 373 K and the first free radical generation at each temperature with the generated trajectory file is captured.During the simulation process,it is found that the carbon-hydrogen bonds on the naphthenes are easily split into two free radicals,and the recombination between the macromolecular radicals could form X-wax,and the hydrogen radicals interacted to generate hydrogen.Through the analysis of the temperature curve,it is found that within the simulated temperature range,the free radical generation rate and temperature are positively correlated.

关 键 词：油纸绝缘 X-蜡 ReaxFF力场 自由基 分子动力学 

分 类 号：TM855[电气工程—高电压与绝缘技术]