与超高压输电线路加装串补装置有关的系统问题及其解决方案

文章结合我国南方电网河池固定串补及平果可控串补工程,对超高压输电线路装设串联电容补偿装置后的系统状况进行了比较深入的研究,指出一些系统问题,如过电压水平升高、潜供电流增大和可能发生的次同步谐振均源于串联电容补偿装置的固有特性,通过研究认为当串补所在输电线路发生内部故障时,采取强制触发旁路间隙等保护措施,是避免出现系统恢复电压水平超标和潜供电流增大等问题的有效途径.此外,还建议在串补站内装设抑制或监视次同步谐振的二次装置以抑制和避免系统发生次同步谐振.     

广义铰接板法分析弯桥

本文基于铰接板法原理,考虑各曲板梁的弯扭耦合效应及其跨长的横桥向变化,导出弯板桥荷载横向分布的简化分析公式。其计算值与模型桥加载试验结果相符较佳。     

电磁装置非线性动态过程的数值计算

本文阐述了一种直接耦合模型。可以用于分析由电压源激励的电磁装置中二维非线性暂态磁场,提出了计算电磁装置动态特性的有关数值方法。在这方法中,对机械运动、涡流、激磁电路和磁性材料的非线性问题进行了综合考虑。这一直接耦合方法可用于求解暂态磁场。采用将非对称系数矩阵转化为对称带状加边矩阵的数值技术可以大大减少所需计算机存储量和CPU时间。文中给出了对制动电磁铁的应用实例。     

十字万向联轴器的有限元分析

应用有限元方法和可靠的结构分析程序，对十字轴式万向联轴器进行了必要的分析计算，得出了避免共振的参考数据。     

多线圈耦合网络状态方程的系统编写法

本文根据替代定理，利用电阻网络系统的求解方法，建立了多线圈耦合网络的状态方程．此方程使得耦合网络与无耦合网络的时域分析具有类似的工作量．     

耦合电容器对短线路三相对地电容不平衡产生的影响及解决措施

66kV非直接接地系统是大杨树电网的主干系统,2008年10月12日大杨树电厂通过大东线并入呼伦贝尔电网。因大东线线路较短,线路两侧安装有耦合电容器,致使66kV系统三相电压不平衡。文章以大杨树地区66kV系统为例,采取了适当增加运行线路长度,以减小耦合电容器对线路三相对地电容不平衡产生的影响,从而降低66kV系统中性点电压偏移。经过实际运行表明,这一措施是切实可行和有效的。     

用于高频干扰计算的HVDC换流变压器模型

提出了两种用于换流站高频干扰计算的换流变压器模型.在传统的简单模型的基础上,考虑了换流变压器的绕组间电容和低压绕组的对地电容,提出了综合漏感和分布电容影响的改进模型,该模型在频率大于20kHz的高频段可简化为纯电容模型,同时给出了两种模型中参数的确定方法.最后给出了贵广工程的计算结果,证明所提出的两种模型是可行的.     

Polybutadiene-g-polypentafluorostyrene as a coupling agent for lignin-filled rubber compounds

This study investigated the role of polybutadiene-g-polypentafluorostyrene (PB-g-PPFS) as a coupling agent between lignin and styrene butadiene rubber (SBR) in preparation of compounds with higher mechanical strength and lower viscoelastic loss. Lignins are three-dimensional amorphous polymers consisting of benzene rings carrying alkyl, alkoxy, and hydroxyl groups as substituents. These substituents render lignin electron-rich. The PPFS domains in PB-g-PPFS provide an electron-deficient π-ring system that can couple lignin with rubber via arene–perfluoroarene interactions. PB-g-PPFS molecules were synthesized with 2:1 molar ratio of pentafluorostyrene and polybutadiene, respectively. The arene–perfluoroarene interactions were confirmed by UV–vis spectroscopy and the morphology was examined by scanning electron microscopy. The tensile strength improved by 20% and 10% for compounds of lignin and lignin–carbon black hybrid fillers, respectively. The loss tangent value reduced due to improved filler–rubber interactions promoted by PB-g-PPFS compounds.     

Recycled Polyolefin Blends: Effect of Modified Natural Zeolite on their Properties and Morphology

The purpose of this study is to investigate the effect of treated natural zeolite on the flow behavior, morphology, thermal, and mechanical properties in recycled polyolefin blends. A model polymer blend consisting of 95 wt% polyolefines and 5 wt% polystyrene was studied. Compositions from this recycled blend and dehydrated zeolite in a narrow concentration range (0–5 wt%) were treated with maleic anhydride-grafted polypropylene and initiator dicumyl peroxide. The compositions were characterized by capillary rheometry, wide-angle X-ray scattering, differential scanning calorimetry, scanning electron microscopy, and mechanical tests. The results show a compatibilizing effect of treated zeolite expressed by increase of shear viscosity and improvement of interfacial interactions and impact strength. The results can open wide possibilities for utilization of treated zeolite in recycling of unsorted polymer wastes.     

染料释放化合物及一当量成色剂浅谈

简述了染料释放化合物的发展过程 ,并由此引出一当量成色剂的概念 ,叙述了一当量成色剂应用和发展 ,对一当量成色剂应用前景做了预测。