特高压线路用玻璃绝缘子材料与性能研究

发布时间：2018-03-09 10:27

本文选题：绝缘子　切入点：钠钙硅玻璃　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：绝缘子作为电力运输线路上的主要支撑构件,起着支撑导线、增加爬电距离及防止电流回地等作用。它的性能和质量对于电网的稳定运行有着相当重要的影响。常见绝缘子包括陶瓷绝缘子,复合绝缘子和玻璃绝缘子三种。其中,玻璃绝缘子具有电压分布均匀、零值自破、易检验、使用寿命长等特点,在高压、超高压、特高压输电线路领域已成为首选。玻璃配方是决定绝缘子性能的关键。本文针对大吨位玻璃绝缘子对高性能玻璃材料的需求,以传统钠钙硅玻璃配方为基础,优化其基本配比,并进行掺杂改性,提高玻璃机械和电气性能。系统研究了基础组分、五氧二化铌与稀土掺杂对玻璃结构、机械性能和电气性能的影响,优化适合于大吨位玻璃绝缘子用钠钙硅玻璃配方。(1)研究K/Na比,CaO, Al2O3含量对玻璃结构性能的影响。K/Na含量比增大时,抗弯强度出现极大值,介电损耗减小,介电常数、体积电阻率、热膨胀系数增大。CaO的加入,可以修复玻璃中的网络断键,使其网络结构更加完整。随着CaO含量增大,其抗弯强度、体积电阻率出现极大值,介电损耗出现极小值,介电常数、热膨胀系数增大。A1203含量增大时,热膨胀系数和介电损耗和介电常数增大,体积电阻率降低。当A1203较小时,以[A104]形式存在,修复玻璃中的非桥氧,提高了玻璃的抗弯强度；当A1203过量时,以[A106]形式存在,破坏了玻璃的网络结构,降低了玻璃的抗弯强度。(2)使用Nb205对钠钙硅玻璃进行掺杂改性。Nb205能够对原有的玻璃结构起到修复作用,Nb-O-Si及Nb=O键具有更高的键强,使玻璃的网络结构更加稳定、紧密,从而可显著提高机械强度,并降低介质损耗。结果表明,当Nb205添加量达到3wt.%时具有最佳综合性能：抗弯强度117MPa,相对介电常数8.41,介电损耗为1.25×10-3。(3)研究了稀土元素La、Y对钠钙硅玻璃性能的影响。研究表明,随着La2O3、Y2O3含量的增加导致其热膨胀系数增加,抗弯强度与介电性能都降低。然而玻璃的介电常数得到明显上升。故稀土元素的掺杂降低了绝缘子玻璃的综合性能,但少量加入能有效调整玻璃材料的介电常数。
[Abstract]:The insulator, as the main supporting member on the power transportation line, plays the supporting wire. Increase creeping distance and prevent current from returning to the ground. Its performance and quality are very important to the stable operation of the power grid. Common insulators include ceramic insulators, composite insulators and glass insulators. Glass insulators have the characteristics of uniform voltage distribution, zero-value self-breaking, easy inspection, long service life, etc., in high voltage, ultra high voltage, The field of UHV transmission lines has become the first choice. The glass formula is the key to determine the performance of insulators. In this paper, the basic ratio of glass insulators with high performance is optimized based on the traditional formula of sodium calcium silicate glass, aiming at the demand of high performance glass materials for large tonnage glass insulators. The effects of basic components, niobium pentoxide and rare earth doping on the structure, mechanical and electrical properties of glass were systematically studied. Optimized for large-tonnage glass insulators with sodium calcium silicate glass formula. 1) study the effect of K / Na ratio on glass structure and properties. When the ratio of K / Na content to K / Na content increases, the flexural strength appears maximum, the dielectric loss decreases, the dielectric constant and volume resistivity decrease. With the increase of thermal expansion coefficient, the network breaking bond in glass can be repaired and the network structure is more complete. With the increase of CaO content, the flexural strength, volume resistivity, dielectric loss and dielectric constant of the glass are maximized. When the thermal expansion coefficient increases, the thermal expansion coefficient, dielectric loss and dielectric constant increase, and the volume resistivity decreases. When A1203 is small, the unbridged oxygen in the glass is repaired and the bending strength of the glass is improved. When A1203 is excessive, it exists in the form of [A106], which destroys the network structure of glass. The flexural strength of the glass is reduced. Nb205 is used to modify the sodium calcium silicate glass by Nb205. Nb205 can repair the original glass structure. Nb-O-Si and Nb=O bond have higher bond strength, so that the network structure of the glass is more stable and compact. The results show that the mechanical strength and dielectric loss can be significantly increased. When the content of Nb205 reached 3wt.%, the optimum comprehensive properties were obtained: flexural strength 117MPa, relative dielectric constant 8.41, dielectric loss 1.25 脳 10 ~ (-3)). The effect of rare earth element LaCoY on the properties of sodium calcium silicate glass was studied. With the increase of La _ 2O _ 3-Y _ 2O _ 3 content, the thermal expansion coefficient increases and the bending strength and dielectric properties decrease. However, the dielectric constant of the glass increases obviously. Therefore, the doping of rare earth elements decreases the comprehensive properties of the insulator glass. However, a small amount of addition can effectively adjust the dielectric constant of glass materials.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ171.7

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