偶联剂用量对聚酰亚胺杂化薄膜结构与性能的影响

用不同用量硅烷偶联剂处理纳米Al2O3粉体,并借助超声波以一定方式将其均匀分散于聚酰胺酸溶液中,制备出不同偶联剂用量的PI/纳米Al2O3杂化薄膜,并对该杂化薄膜的断面形貌、聚集态结构、热稳定性、力学性能、电击穿场强进行表征测试分析.结果表明,偶联剂用量对PI杂化薄膜的聚集态结构影响较小,但对无机纳米粒子在PI基体中的分散状态有较大影响,当偶联剂AE3012的用量为无机粒子质量分数的4%时,该PI杂化薄膜的热稳定性、力学性能、电击穿场强均最高.     

聚合物的击穿(综述摘要)

固体电介质电击穿理论,是以晶体(石英金刚石、硅、锗,特别是碱卤化合物)为中心发展起来的。但是,与晶体相比,聚合物电介质在高压电气绝缘技术中应用日趋广泛,且具有更为复杂的化学组成和结构。因此,研究聚合物的分子链结构、分子聚集态     

用于空间电荷陷阱能量测量的热刺激放电法与光刺激放电法的比较(英文)

The space charge behavior of a dielectric under HVDC is influenced by the charge trap energy distribution in it. Hence, we in- vestigated the charge trap distributions in several kinds of typical polymer materials using thermally stimulated discharge (TSD) and photo-stimulated discharge (PSD) methods, respectively. The experimental results show that,there is a significant difference between the trap energy distributions obtained by the two methods, but the difference decreases with the increase of the melting point of polymers. This is attributed to the change of the trap center environment during TSD caused by the increasing movements of both main chains and branched chains in polymers. PSD method is more accurate for investigating charge trap distribution in dielectrics, especially for polymers with low melting points.     

基于统计分析和模糊推理的运行交联聚乙烯电力电缆绝缘老化诊断(英文)

Cables that have been in service for over 20 years in Shanghai, a city with abundant surface water, failed more frequently and induced different cable accidents. This necessitates researches on the insulation aging state of cables working in special circumstances. We performed multi-parameter tests with samples from about 300 cable lines in Shanghai. The tests included water tree investigation, tensile test, dielectric spectroscopy test, thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), and electrical aging test. Then, we carried out regression analysis between every two test parameters. Moreover, through two-sample t-Test and analysis of va- riance (ANOVA) of each test parameter, we analyzed the influences of cable-laying method and sampling section on the degradation of cable insulation respectively. Furthermore, the test parameters which have strong correlation in the regression analysis or significant differ- ences in the t-Test or ANOVA analysis were determined to be the ones identifying the XLPE cable insulation aging state. The thresholds for distinguishing insulation aging states had been also obtained with the aid of statistical analysis and fuzzy clustering. Based on the fuzzy in- ference, we established a cable insulation aging diagnosis model using the intensity transfer method. The results of regression analysis indicate that the degradation of cable insulation accelerates as the degree of in-service aging increases. This validates the rule that the in- crease of microscopic imperfections in solid material enhances the dielectric breakdown strength. The results of the two-sample t-Test and the ANOVA indicate that the direct-buried cables are more sensitive to insulation degradation than duct cables. This confirms that the tensile strength and breakdown strength are reliable functional parameters in cable insulation evaluations. A case study further indicates that the proposed diagnosis model based on the fuzzy inference can reflect the comprehensive aging state of cable insulation well, and that the cable service time has no correlation with the insulation aging state.     

聚酯薄膜中的热释光与热激电流

同时测量了聚酯薄膜的热释光与热激电流谱，用作者提出的自动分离法对光强或电流与温度的关系进行了分析。发现低温峰（150－250K）具有复杂的能级分布，其分布宽度近似为0．24－0．46eV，受陷载流子的初始浓度分布函数呈近高斯型。将TSC及TL谱中低温宽峰归结为薄膜中－COO－基团的局部运动导致受陷载流子的热释放。     

量子力学的希尔伯特空间矢量表示法

本文概述了希尔伯特空间矢量的性质,并指出其与函数的相似性,从而介绍了狄喇克左矢及右矢的表达形式,以及这种形式表达出来的若干量子力学基本原理.     

“电缆系统及基础材料”专题特约主编寄语

<正>电缆系统主要由电缆导体、绝缘层、内外半导电屏蔽层、缓冲层、护套及附件等所构成,它们影响着电缆的电学、热学、力学和老化等综合性能。电缆系统是城市地下电网和清洁能源接入的关键基础设备,直接关系到电力系统的安全稳定运行,是制约输配电技术提升的瓶颈。目前,电缆绝缘材料的基础理论、研发和制造技术等都落后于发展需要,     

高压电缆半导电屏蔽料关键问题及研究进展

半导电屏蔽层作为高压电缆的重要组成部分,在电缆结构中起到均匀电场的作用。目前,我国高压电缆制造技术快速发展,然而高电压等级电缆料严重依赖进口,存在较多的技术壁垒。该文从高压电缆屏蔽料发展历程及关键问题、屏蔽料组成及关键性能参数、屏蔽料性能提升及改性3个方面综述了高压电缆屏蔽料的研究进展。首先,梳理高压电缆半导电屏蔽料发展历程,提炼当前屏蔽料面临的主要技术瓶颈和关键问题;其次,探讨屏蔽料导电和导热机理,从基体树脂、导电填充物和添加剂3个方面分析屏蔽料组成及性能,分析不同电压等级屏蔽料关键性能参数与技术要求;最后,探讨半导电屏蔽层配方,半导电屏蔽层–绝缘层界面特性和半导电屏蔽层性能对绝缘层电荷积聚特性的影响,并提出通过半导电屏蔽层改性抑制高压直流电缆绝缘层电荷积聚的方法。该文所做工作可为我国高压电缆半导电屏蔽料的研发、高压电缆性能评估提供理论参考。     

空间电荷对PE薄膜电击穿的影响

本文通过对干、湿两种LDPE薄膜试样在不同模式电压作用下电击穿场强的试验研究,说明了脉冲击穿的预直流效应.脉冲击穿场强为直流击穿场强的88%,助场时击穿场强上升到与直流击穿场强相等,而反场时击穿场强随预应力的增加而线性下降.试样吸潮后其直流击穿场强几乎未发生变化,脉冲击穿场强下降,反场时其空间电荷对电击穿的影响更加显著.干、湿试样的反场击穿时延远大于脉冲和助场对的击穿时延.脉冲发生器输出1/15000μs的准方波且采用记忆示波器观察电压幅值和击穿时延.     

纳米二氧化硅/聚酰亚胺耐电晕薄膜的研究

通过超声机械混合方法制备纳米二氧化硅／聚酰亚胺复合耐电晕薄膜，并对其耐电晕性进行测量。用红外光谱(IR)和原子力显微镜(AFM)观察无机纳米粒子的分散情况及其电晕前后变化。结果表明：纳米二氧化硅／聚酰亚胺复合薄膜耐电晕性比普通的聚酰亚胺薄膜高。