电工技术学报2025，Vol.40Issue(7)：2282-2294,13.DOI:10.19595/j.cnki.1000-6753.tces.240552
TiO2@SiO2与蒙脱土纳米材料协同提升聚丙烯薄膜绝缘性能研究
TiO2@SiO2 Research on Synergistically Improving the Insulation Performance of Polypropylene Film with Montmorillonite Nanomaterials
摘要
Abstract
Polypropylene(PP)exhibits excellent insulation properties and recyclability,making it a valuable material for promoting the green transformation of power grids.Polypropylene film possesses high dielectric strength and superior heat resistance,making it a widely utilized component in dry film capacitors.These capacitors are primarily employed in ultra-high voltage DC transmission systems,where they provide essential functions such as damping,voltage support,and commutation assistance.The performance of dry film capacitors is largely dependent on the insulation quality of the polypropylene film.During operation,these capacitors must endure transient overvoltages and harmonics.A breakdown in the internal polypropylene film can lead to the failure of the entire capacitor group,compromising power stability.Therefore,enhancing the insulation performance of polypropylene film is critical for ensuring the reliable operation of ultra-high voltage transmission systems. Physical doping involves the incorporation of nanoparticles into a matrix to produce composite dielectric materials.Common nanofillers are categorized based on their dimensions,typically including zero-dimensional particles and two-dimensional sheet structures.Zero-dimensional particles generally possess a high dielectric constant.When these particles are used as dopants,they enhance the electric field distribution within the matrix,thereby increasing the breakdown strength.However,the considerable dielectric constant difference at the nanoparticle interface can induce interface distortion,which limits the improvement in breakdown strength.In contrast,two-dimensional sheet structures have a large surface area that can impede the development of breakdown paths within the matrix.This blocking effect is most effective when the sheets are densely distributed,as they form a network that effectively obstructs breakdown paths.Nonetheless,high-density distribution also facilitates carrier mobility,which can adversely affect the increase in breakdown strength.Therefore,zero-dimensional nanofillers and two-dimensional nanofillers possess complementary advantages and disadvantages.Currently,there is limited research on how to effectively combine the advantages of these two types of nanofillers. This study combines zero-dimensional TiO2@SiO2 and two-dimensional montmorillonite(MMT)through sintering to create a multidimensional nanofiller.Experimental results demonstrate that two-dimensional MMT introduces additional interfaces,leading to an increase in the melting temperature and crystallinity of the polypropylene(PP)film.The incorporation of TiO2@SiO2 nanoparticles creates more traps,thereby improving the dispersion of the two-dimensional MMT and enhancing the dielectric properties of the PP film.Furthermore,the SiO2 shell mitigates the extent of electric field distortion.Breakdown testing results indicate that at a 1.0%filler ratio,the insulation performance is optimal.Specifically,at 25℃,the breakdown strength of the PP film increased by 34.50%,while at 50℃and 75℃,the breakdown strength increased by 33.51%and 31.96%,respectively.To elucidate the microscopic interaction mechanisms of the two-dimensional nanoparticles,phase field simulation was employed.The variable η(r,t)represents the evolution of the matrix,where η(r,t)=1 corresponds to the breakdown phase,η(r,t)=0 denotes the non-breakdown phase,and values of η(r,t)between 0 and 1 represent the transition region.Simulation results indicate that doping with two-dimensional MMT probabilistically inhibits the development of breakdown paths.When the matrix is filled with a combination of two-dimensional MMT and TiO2@SiO2 nanoparticles,TiO2@SiO2 attracts the growth of electric trees.This shifts the blocking mechanism from probabilistic to directional,making it more difficult for the polypropylene film to undergo complete breakdown,thereby enhancing its breakdown strength.关键词
聚丙烯薄膜/纳米复合材料/烧结/击穿强度/相场模拟Key words
Polypropylene films/nanocomposite material/sintering/breakdown strength/phase field simulation分类
动力与电气工程引用本文复制引用
谢军,刘麒,李霖,刘子谦,谢庆..TiO2@SiO2与蒙脱土纳米材料协同提升聚丙烯薄膜绝缘性能研究[J].电工技术学报,2025,40(7):2282-2294,13.基金项目
国家重点研发计划资助项目(2021YFB2401503). （2021YFB2401503）
