【摘要】：近來國內(nèi)外的研究發(fā)現(xiàn)納米粒子可以提高變壓器油和油紙絕緣的絕緣性能,但納米粒子的類型、尺寸以及微觀形貌對(duì)變壓器油紙系統(tǒng)的改性作用尚缺乏系統(tǒng)研究,對(duì)于納米改性油紙絕緣的老化特性也未見報(bào)道,因此,本論文以TiO_2、Fe_3O_4和Al_2O_3納米粒子為研究對(duì)象,研究納米粒子的類型和微觀特性對(duì)變壓器油紙絕緣的改性作用,并進(jìn)一步研究了TiO_2納米粒子對(duì)變壓器油紙熱老化特性的改性作用。本文系統(tǒng)研究了納米粒子材料類型(半導(dǎo)體材料、導(dǎo)體材料、絕緣體)、尺寸(5nm、10nm、15nm、30nm)、微觀形貌(球形、棒狀)對(duì)油浸紙板的沿面爬電特性的影響,實(shí)驗(yàn)結(jié)果表明:半導(dǎo)體型(TiO_2)、導(dǎo)體型(Fe_3O_4)納米粒子對(duì)油紙的沿面爬電特性均有改性作用,而絕緣體型(Al_2O_3)納米粒子并未明顯油紙界面沿面爬電性能;納米粒子尺寸越小對(duì)油浸紙板沿面爬電的改性效果越好;球形納米粒子對(duì)油浸紙板沿面爬電性能的改性效果優(yōu)于與其等寬的棒狀納米粒子。測試了油的介電常數(shù)、油紙界面電荷的傳輸特性和油浸紙板熱刺激去極化電流(TSDC),分析納米粒子材料類型、尺寸、微觀形貌對(duì)納米油浸紙板沿面爬電特性改性的原因。加入半導(dǎo)體型(TiO_2)、導(dǎo)體型(Fe_3O_4)納米粒子會(huì)提高油的介電常數(shù)及電荷在油紙界面的消散速率,但絕緣體型(Al_2O_3)納米粒子并未提高油的介電常數(shù)和電荷在油紙界面的消散速率;不同的粒徑和微觀形貌納米粒子的比表面積不同,一方面,比表面積大的納米粒子由于表面更多的缺陷偶極子可在電場的作用下發(fā)生取向極化因此納米油的相對(duì)介電常數(shù)更高,這有利于降低油中的電場強(qiáng)度;另一方面,比表面積大的納米粒子提高了油浸紙板表面的淺陷阱的數(shù)量,淺陷阱密度的增加有利于電荷的消散,從而緩解了電荷對(duì)電場的畸變作用,提高沿面爬電特性。為研究納米粒子對(duì)油紙老化的影響,對(duì)純油浸紙板和納米油浸紙板進(jìn)行了130℃下為期36天的加速熱老化試驗(yàn)。試驗(yàn)結(jié)果表明:在整個(gè)老化過程中納米油的酸值始終低于純油,而其工頻擊穿電壓始終高于純油;在老化前期,納米油浸紙板的沿面爬電性能高于純油浸紙板,但在老化后期,兩種油浸紙板的沿面爬電性能沒有明顯區(qū)別。
[Abstract]:Recent studies at home and abroad have found that nano-particles can improve the insulation performance of transformer oil and oil-paper insulation. However, there is no systematic study on the modification of transformer oil paper system by the type, size and micro-morphology of nanoparticles. The aging properties of nano-modified oil-paper insulation are not reported. Therefore, in this paper, TiO_2,Fe_3O_4 and Al_2O_3 nanoparticles are taken as research objects to study the modification of transformer oil-paper insulation by the types and microscopic properties of nano-particles. The effect of TiO_2 nanoparticles on the thermal aging properties of transformer oil paper was further studied. In this paper, the effects of material type (semiconductor material, insulator), size (5nmO10nm10nm15nm) and micromorphology (spherical, rod shape) on the creeping properties of oil-impregnated paperboard have been systematically studied. The experimental results show that semiconductor type (TiO_2) and conductor type (Fe_3O_4) nanoparticles can modify the surface creeping properties of oil paper, while Al_2O_3 nanoparticles have no obvious creeping performance along the oil-paper interface. The smaller the size of nanoparticles, the better the effect of surface creeping of oil-immersed paperboard, and the effect of spherical nanoparticles on the creeping performance of oil-immersed paperboard is better than that of rod-like nanoparticles of the same width. The dielectric constant of oil, the transfer characteristics of interface charge of oil paper and the thermal stimulated depolarization current (TSDC),) of oil-impregnated paperboard were measured. The reasons for the modification of surface creeping properties of oil-impregnated paperboard were investigated by (TSDC), analysis of the type, size and micromorphology of nano-sized oil coated paperboard. With the addition of semiconductor type (TiO_2), conductor type (Fe_3O_4) nanoparticles can increase the dielectric constant of oil and the dissipation rate of charge at the oil-paper interface, but Al_2O_3 nanoparticles do not increase the dielectric constant of oil and the dissipation rate of electric charge at the oil-paper interface. The specific surface area of nano-particles with different particle size and micromorphology is different. On the one hand, the relative dielectric constant of nano-particles with large specific surface area is higher because more defect dipoles on the surface can produce orientation polarization under the action of electric field. On the other hand, nano-particles with large specific surface area increase the number of shallow traps on the surface of oil-impregnated paperboard, and the increase of density of shallow traps is beneficial to the dissipation of electric charge. Thus, the distortion of electric field caused by charge is alleviated, and the creeping characteristic is improved. In order to study the effect of nanoparticles on the aging of oil paper, the accelerated thermal aging tests were carried out for 36 days at 130 鈩，

本文編號(hào)：2210229