纳米TiO_(2)改性纤维素绝缘纸板热老化特性  

Thermal Aging Characteristics of Cellulose Insulating Pressboard Modified by Nano-TiO_(2)

作　　者：刘道生 郭正阳 赵子明 周春华 LIU Daosheng;GUO Zhengyang;ZHAO Ziming;ZHOU Chunhua(School of Electrical Engineering and Automation,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学电气工程与自动化学院,赣州341000

出　　处：《高电压技术》2021年第9期3134-3143,共10页High Voltage Engineering

基　　金：国家自然科学基金(51767008);江西省自然科学重点基金(20192ACBL20016)。

摘　　要：为探究纳米TiO_(2)改性纤维素纸板长期热老化条件下的电气特性,制备了不同质量分数与粒径的纳米TiO_(2)复合绝缘和普通绝缘纸板。利用两参数威布尔(Weibull)分布模型计算纳米复合纸板的绝缘失效率,讨论了击穿电压与TiO_(2)掺杂质量分数之间的关系,确定最佳掺杂质量分数为5%,粒径为10 nm。将样品进行加速热老化试验,测量分析其交直流击穿场强、相对介电常数和电阻率等参数以及油纸颜色和表面微观结构的变化规律;采用有限元软件计算交直流电场分布。仿真结果表明:与未改性绝缘纸板相比,老化后的纳米复合油纸绝缘中,纸板承受的交、直流场强占比更高。试验结果表明:在不同热老化阶段,纳米复合绝缘纸板的交直流电气特性和抗热老化性能始终优于未改性纸板,纳米TiO_(2)减弱了纸板内部纤维素链的极化,降低了载流子迁移率,改善了绝缘纸板内部场强,提高了电气性能,有效延缓了油纸绝缘的热老化过程,与仿真结果一致。In order to study the electrical properties of cellulose pressboard modified by nano-TiO_(2) under thermal aging,composite pressboard modified by nano-TiO_(2) with different mass fractions and particle diameters were prepared. The two-parameter Weibull distribution model was used to calculate the insulation failure possibility of nanocomposite pressboard, and the relationship between breakdown voltage and doping amount of TiO_(2) was analyzed. The insulating pressboards modified by 10 nm TiO_(2) with 5% were determined as optimal modified samples. After thermally aging of the pressboard samples, the variation of AC and DC breakdown strength, relative dielectric constant, resistivity, oil immersed pressboard color and surface micro-structure with aging time were obtained. The electric field distributions of AC and DC were calculated by finite element simulation software. The simulation results show that the pressboard has a higher proportion of AC and DC field strength in oil-pressboard nanocomposite insulation. The experimental results show that the AC and DC electrical properties and anti-thermal aging performance of the composite pressboard are always superior to that of the unmodified pressboard under different thermal aging stages. The nano-TiO_(2) can weaken the polarization of the cellulose chains, and decrease the carrier mobility. Thus, the internal field strength and electrical performance of the insulating pressboard are improved, and the thermal aging process of oil immersed pressboard insulation is effectively delayed,which are consistent with the simulation results.

关 键 词：绝缘纸板 纳米TiO_(2) 热老化 WEIBULL分布 有限元分析 

分 类 号：TM215.6[一般工业技术—材料科学与工程]