非线性硅橡胶的热老化特性研究

发布时间：2018-05-19 06:34

  本文选题：非线性硅橡胶 + 热老化　； 参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：高压直流输电具有输送容量大,输送距离远,线路走廊窄,能够实现电网异步互联,运行稳定性好,有功损耗小,可控性好等优势,广泛应用于大容量、远距离输电线路及异步交流系统互联等场合。随着高压直流输电技术在电网中应用地位的不断提升,电缆附件(终端及接头)作为高压直流输电系统中的主要配套设备也被大量使用,但是由于电缆附件中的电场分布不均匀,极其容易发生电场畸变,与电缆本体相比,其发生故障的概率高得多,因此电缆终端及接头是高压电缆应用的薄弱环节,电缆终端及接头的性能好坏将直接关系到高压直流电缆能否安全运行。硅橡胶材料因其具有优良的绝缘特性、较好的力学性能、工作温度区间大、易于加工成型等特点,近年来被大量应用于高压电缆附件中。非线性硅橡胶基复合材料更是解决了电缆附件中电场畸变的问题,但是在其运行的过程中,不可避免会受到热、电、氧等因素的影响而发生老化,降低高压直流电缆附件的使用寿命。如果不能及时判定高压直流电缆附件材料的老化程度,极易引起附件绝缘的击穿,进而降低高压直流电缆运行的稳定性,危及整个电力系统的安全可靠供电。因而,研究非线性硅橡胶的热老化特性并分析其热老化机理,不仅具有十分重要的工程意义,同时也具有重要的经济和社会价值。本论文以应用于高压直流电缆附件增强绝缘材料中的非线性硅橡胶为研究对象,选取了130℃、150℃、170℃三个热老化温度对非线性硅橡胶试样进行加速热老化实验,对经历不同热老化时间的非线性硅橡胶试样进行电导率、直流击穿强度、空间电荷、介电常数和损耗因数、表面形貌、溶胀指数、TGA热重分析、拉伸、热延伸等测试,研究了热老化对非线性硅橡胶电性能、理化性能、力学性能的影响。研究结果表明,在热老化的过程中,分子的再交联反应以及热降解反应同时存在于非线性硅橡胶材料中,热老化初期阶段,分子的再交联反应占主导地位,非线性硅橡胶材料的电导特性、空间电荷分布、表面形貌、交联度、力学性能等都未发生劣化;随着老化时间的延长,热降解反应逐渐起主导作用,热老化对其电性能、理化性能、力学性能产生了明显的破坏作用。
[Abstract]:High voltage direct current transmission (HVDC) has the advantages of large capacity, long distance, narrow corridor, asynchronous interconnection, good stability, low active power loss, good controllability and so on. It is widely used in large capacity. Long-distance transmission lines and asynchronous AC system interconnection and other occasions. With the increasing application of HVDC technology in the power network, cable accessories (terminals and connectors), as the main supporting equipment of HVDC transmission system, are also widely used. However, because the electric field distribution in the cable accessory is not uniform and the electric field distortion is very easy to occur, compared with the cable body, the probability of its failure is much higher, so the cable terminal and the connector are the weak links in the application of the high-voltage cable. The performance of cable terminals and connectors will be directly related to the safe operation of HVDC cables. Silicone rubber has been widely used in high-voltage cable accessories in recent years because of its excellent insulation properties, good mechanical properties, large working temperature range and easy processing. Nonlinear silicone rubber matrix composites solve the problem of electric field distortion in cable accessories, but in the process of its operation, it will inevitably be affected by heat, electricity, oxygen and other factors and aging. Reduce the service life of HVDC cable accessories. If the aging degree of the accessory material of HVDC cable can not be judged in time, it is easy to cause breakdown of the accessory insulation, which will reduce the stability of HVDC cable operation and endanger the safety and reliable power supply of the whole power system. Therefore, studying the thermal aging characteristics of nonlinear silicone rubber and analyzing its thermal aging mechanism not only have very important engineering significance, but also have important economic and social value. In this paper, the nonlinear silicone rubber used in the insulation material of HVDC cable accessories is studied. Three thermal aging temperatures, 130 鈩，

本文编号：1909076