纳米粒子类型和微观特性对变压器油纸绝缘的改性研究
发布时间：2018-08-28 18:26
【摘要】：近来国内外的研究发现纳米粒子可以提高变压器油和油纸绝缘的绝缘性能,但纳米粒子的类型、尺寸以及微观形貌对变压器油纸系统的改性作用尚缺乏系统研究,对于纳米改性油纸绝缘的老化特性也未见报道,因此,本论文以TiO_2、Fe_3O_4和Al_2O_3纳米粒子为研究对象,研究纳米粒子的类型和微观特性对变压器油纸绝缘的改性作用,并进一步研究了TiO_2纳米粒子对变压器油纸热老化特性的改性作用。本文系统研究了纳米粒子材料类型(半导体材料、导体材料、绝缘体)、尺寸(5nm、10nm、15nm、30nm)、微观形貌(球形、棒状)对油浸纸板的沿面爬电特性的影响,实验结果表明:半导体型(TiO_2)、导体型(Fe_3O_4)纳米粒子对油纸的沿面爬电特性均有改性作用,而绝缘体型(Al_2O_3)纳米粒子并未明显油纸界面沿面爬电性能;纳米粒子尺寸越小对油浸纸板沿面爬电的改性效果越好;球形纳米粒子对油浸纸板沿面爬电性能的改性效果优于与其等宽的棒状纳米粒子。测试了油的介电常数、油纸界面电荷的传输特性和油浸纸板热刺激去极化电流(TSDC),分析纳米粒子材料类型、尺寸、微观形貌对纳米油浸纸板沿面爬电特性改性的原因。加入半导体型(TiO_2)、导体型(Fe_3O_4)纳米粒子会提高油的介电常数及电荷在油纸界面的消散速率,但绝缘体型(Al_2O_3)纳米粒子并未提高油的介电常数和电荷在油纸界面的消散速率;不同的粒径和微观形貌纳米粒子的比表面积不同,一方面,比表面积大的纳米粒子由于表面更多的缺陷偶极子可在电场的作用下发生取向极化因此纳米油的相对介电常数更高,这有利于降低油中的电场强度;另一方面,比表面积大的纳米粒子提高了油浸纸板表面的浅陷阱的数量,浅陷阱密度的增加有利于电荷的消散,从而缓解了电荷对电场的畸变作用,提高沿面爬电特性。为研究纳米粒子对油纸老化的影响,对纯油浸纸板和纳米油浸纸板进行了130℃下为期36天的加速热老化试验。试验结果表明:在整个老化过程中纳米油的酸值始终低于纯油,而其工频击穿电压始终高于纯油;在老化前期,纳米油浸纸板的沿面爬电性能高于纯油浸纸板,但在老化后期,两种油浸纸板的沿面爬电性能没有明显区别。
[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，
本文编号：2210229
[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，
本文编号：2210229
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