多针-平板介质阻挡放电提高玻璃表面憎水性的研究

用大气压空气中多针-平板电极结构的DBD对玻璃表面进行憎水性改性。通过测量水接触角、表面电阻和湿闪电压等研究了这两种形式DBD产生的等离子体处理前后玻璃的表面特性以及处理电压和处理时间对改性效果的影响。结果表明：在玻璃表面涂一层二甲基硅油并经等离子体处理后，能在玻璃表面生成一层长效、致密的憎水膜。随处理电压和处理时间的不同，改性效果不同，当处理电压10kV、处理时间8min时提高憎水性效果最明显。     

污秽不均匀度对LXY4-160玻璃绝缘子串交流闪络特性的影响*

输电线路绝缘子表面污秽在自然条件下分布不均匀,污秽不均匀度是影响闪络电压的重要因素,因此研究输电线路绝缘子在不均匀污秽下的闪络特性具有重大意义。首先进行了LXY4 160玻璃绝缘子串的自然积污试验,然后研究了交流电压下污秽分布不均匀时7片LXY4 160玻璃绝缘子串的交流闪络特性,分析了不均匀污秽下绝缘子表面污层电导率和泄漏电流与污闪电压的关系,得到了不同盐密(SDD)、不同污秽不均匀度(T/B)下绝缘子串的闪络特性。研究结果表明：SDD和T/B对LXY4 160玻璃绝缘子串的污闪电压有影响,且二者对污闪电压的影响是相互独立的;随着T/B的减小,污闪电压会增大;7片LXY4 160玻璃绝缘子串的污闪电压(Uf)与T/B、SDD分别满足对数和幂函数关系,且污秽影响特征指数b为0.280,不均匀污秽下修正系数C为0.271;不均匀污秽下绝缘子表面污层电阻将增大是导致LXY4 160玻璃绝缘子串污秽交流污闪电压提高的主要原因。研究结果对输电线路外绝缘设计和选择具有一定的参考价值。     

适用于潮湿环境的聚酰亚胺复合薄膜的制备及性能研究

以水滴为模板,含氟聚酰亚胺为成膜材料,在聚酰亚胺薄膜的表面引入含氟聚酰亚胺多孔膜,制备了含多孔结构的聚酰亚胺复合薄膜,研究了多孔复合薄膜的成膜条件对其形貌和抗湿性能的影响。结果表明:聚酰亚胺多孔结构的引入使复合薄膜的接触角增加,疏水性增强,吸水率显著降低,在潮湿环境中介电常数的增量较小,复合薄膜的形貌和吸水性能还可通过改变成膜条件进行调节,进而满足不同领域的需求。     

VC对锂离子嵌脱过程动力学影响研究

以商品化LiNi1/3Co1/3Mn1/3O2为例,运用电化学阻抗谱(EIS)跟踪界面阻抗随实验条件的变化,从动力学角度研究碳酸亚乙烯酯(VC)添加剂对锂离子嵌脱过程的影响.研究得出VC在材料电导率的提高及利于锂离子嵌脱方面也有较大作用.VC可使电极表面形成高介电常数、稳定的SEI膜,可降低约22％的离子跳跃能垒,更易于锂离子通过和电极内部的保护;VC可降低电极约17％的热激活化能,并使电子电导率在高电压下维持在较高水平;VC可降低约16％的嵌入反应活化能,更利于锂离子的嵌脱.     

组合室温硫化硅橡胶对绝缘子电场分布的影响

户外运行的瓷或玻璃绝缘子在潮湿污秽的情况下容易发生污闪,而且在覆冰期中可能冰闪,这两种闪络均会对电力系统的正常运行造成很大的危害,绝缘子周围电场分布的均匀程度对于其闪络电压有很大的影响.为此,通过对110 kV下的瓷绝缘子串进行建模,对其表面涂覆不同种类的室温硫化硅橡胶(RTV)(包括长效RTV(PRTV)、半导体RT...     

玻璃磁控溅射镀膜生产线设计

为实现用真空磁控溅射镀技术对玻璃进行连续式镀膜,设计了一条基于PLC的自动化生产线。在精确控制镀膜时间和靶电流,保持电压不变的条件下,通过闭环控制实现镀膜室的工作气体气压恒定控制,从而得到稳定的沉积速率,最终在实验中利用真空磁控溅射镀膜方法制备出分布均匀,附着性强和特定厚度的膜层。通过上位机软件对参数值进行最优控制．在提高沉积速率的同时实现了玻璃大批量深加工的目的。     

湿法脱硫烟气中两种模拟颗粒物在CO_2吸收膜上的粘附特性研究

利用原子力显微镜分析湿法脱硫净烟气中燃煤飞灰、石膏颗粒在普通玻璃、硅晶片、PVDF、PP膜上的粘附特性及颗粒间的粘附力,考察膜表面粗糙度、相对湿度、颗粒表面特性等的影响;在此基础上,开展细颗粒物单独及其与水汽共存时PP中空纤维膜组件吸收CO_2性能试验。结果表明:干燥条件下,颗粒间的临界粘附力与颗粒–膜表面的临界粘附力大小并未明显差异;但在潮湿环境中,石膏颗粒–颗粒间的粘附力明显大于石膏颗粒–PP膜间的粘附力,且随相对湿度RH的提高,石膏颗粒–颗粒间的临界粘附力显著增加;颗粒单独存在时,连续运行7h后CO_2吸收效率下降17.9%;颗粒物和水汽共存时,脱除效率下降18.9%;石膏–飞灰颗粒间的粘附作用可加速颗粒在膜表面的粘附沉积,是导致CO_2吸收性能下降的主要因素。     

配电矩形管复合材料横担及其材料电气性能研究

为了更好地指导复合材料横担的应用,对矩形管聚氨酯复合材料横担及其材料样品的电气性能进行了研究。结果表明:在绝缘子挂点距离相同且与相同规格的绝缘子组合时,矩形管复合材料横担的干燥雷电闪络电压、潮湿工频闪络电压比角钢横担分别提高了约50%和39.9%,相应的潮湿工频耐受电压和污秽耐受电压比角钢横担分别提高了约117%和30%,且潮湿闪络和污秽闪络仅发生在复合材料横担表面。     

RTV涂层对220kV绝缘子表面电场分布的影响研究

为了预防电力系统污闪事故,重污秽地区的输电线路绝缘子表面通常喷涂室温硫化硅橡胶防污闪涂料,以提高输变电设备的外绝缘性能。带电运行的玻璃或瓷绝缘子串表面电场成"U型"分布,两端电场强度高、中间区域低。为了解RTV涂料对绝缘子表面电场分布的影响,本文利用电磁场仿真工具对未涂覆RTV涂层的绝缘子串、新涂覆RTV涂层的绝缘子串以及使用一段时间出现老化状况的绝缘子串进行仿真计算;并在实验室条件下实测了沿串电压分布,对仿真结果加以验证。仿真与试验结果表明,RTV涂料对绝缘子串的片电压分布影响很小。相同条件下RTV涂层的老化状态并不影响其沿串电压分布情况。绝缘子表面电场分布受绝缘子表面状态的影响不大,主要还是受绝缘子自身电容分布的影响。     

丧失憎水性的直流复合绝缘子耐污特性

通过人工污秽试验研究了丧失憎水性的复合绝缘子在直流电压下的污秽闪络特性,给出了两种憎水性状态下的复合绝缘子污闪电压,在憎水性完全丧失状态下时不同表面污秽度下的复合绝缘子50%闪络电压,文中还分析了表面污秽不均匀分布对污闪电压的影响。试验结果表明即使复合绝缘子完全丧失憎水性,其污闪电压较相同长度的瓷或玻璃绝缘子串高20%～50%。     

Surface treatment of plastic material by pulse corona inducedplasma chemical process-PPCP

A novel plasma chemical process PPCP (pulse corona induced plasma chemical process) can produce copious active radicals in air under NTP (normal temperature and pressure) by using an extremely fast rising narrow high voltage pulse between corona electrodes and grounded counter electrodes so that intense streamer coronas are generated. This provides an effective means of surface treatment to a plastic material placed between the two electrodes through generation of free bonds on the surface directed to the corona electrodes. Special features of this method are that it can cope with a complex shape of the material to be treated, and that it does not spark even at the periphery near the grounded counter electrode. This method is suitable for the surface treatment of polypropylene bumpers so as to provide a strong adhesion of color paint to it. The adhesion strength of a paint film is raised from zero to ca. 1000 g/cm² by PPCP treatment for 60 seconds     

Preparation and Properties of a Thermal Insulating Layer and a Buffer Layer for Multilayer Pyroelectric Film Infrared Detector

A thermal insulating layer and a buffer layer play a key role in the multilayer pyroelectric thin film infrared detector. In this work, a porous SiO 2 film serving as thermal insulating layer and a dense SiO 2 film serving as buffer layer were prepared by sol-gel method. The porosities of the porous film and the dense film are about 50% and 6%, respectively. Maximum thickness values of a single layer porous film and that of a single layer dense film all come up to 1.5 w m. Rms (root-mean-square) surface roughness of the porous film is about 40 nm and that of the dense film is about 1.5 nm. Experimental result shows 0.4 w m dense SiO 2 film can flatten rough surface of the porous SiO 2 film, and the rms surface roughness is less than 5 nm. The composite SiO 2 film can effectively block thermal diffusion.     

电流源和电压源型谐振变换器在聚丙烯薄膜表面处理中的对比

文中给出了应用于材料表面处理的电流源与电压源型谐振变换器的分析,并进行了聚丙烯薄膜表面处理效果对比实验。较传统电压源型谐振变换器,电流源型具有良好的抗短路特性,保护了开关器件并延长了系统寿命。同时,电流源系统具有更长的单位周期放电时间,应用于材料表面处理时,可获得更大的表面张力。设计并搭建了两个9 kW/26 kHz的电流源型和电压源型谐振变换器,并分别进行了聚丙烯薄膜表面处理实验。结果表明,聚丙烯薄膜表面经电流源型系统处理之后具有更好的处理效果。     

Decrease in ac partial discharges on insulating materials by use ofdye additives

The purpose of this study is to decrease PD at a triple junction by addition of a dye to an insulating material. PD is produced on a test specimen subjected to ac voltage under a sphere-plane electrode configuration. The specimen is composed of two layers: a PMMA film with additive, which is 100 μm thick; the lower layer a PMMA board 3 mm thick. The film with the additive was prepared by the solution-grown casting method. Five kinds of dye were used as the additive; p-aminoazobenzene (Ab), p-nitrobenzeneazoresorcinol (Nb), methyl yellow (My), methylene blue (Mb) and methyl red (Mr). In the case of the films with Ab and Mb at 0.05% wt, the magnitude and number of PD pulses were reduced to ~50% less than those in the case of the films without the additive. The decrease in PD was effective under an electric field strength slightly higher than the PD inception. In the case of the other dyes, decrease in PD was not observed. The surface voltage distribution due to the charge by PD depended on the kind of dye additive. The decrease in PD for the Ab and Mb films was explained from the dependence of the surface voltage distribution on the dye. It was concluded that ionization of the dye molecules in the film changes the distribution of surface voltage     

玻璃纤维-碳纳米管共掺杂环氧树脂复合材料绝缘性能的研究

为研究玻璃纤维、碳纳米管共掺杂环氧树脂复合材料的绝缘性能,制备了纤维不同掺杂量和排布方式时的玻璃纤维-碳纳米管环氧树脂复合材料,并分别测试了其介电常数、介质损耗因数及交流短时击穿电压,研究了掺杂工艺参数对复合材料绝缘性能的影响。研究发现,玻璃纤维掺杂量在15~20wt%、纤维束间距在1.0~1.2mm时,复合材料介电常数和介质损耗因数均达到最小值,分别为3.63和0.0303;而其交流短时击穿电压在40wt%掺杂量、1.5mm纤维束间距时,达到最大值39.6k V。与单向排布方式相比,正方形网格排布的复合材料击穿电压更高。研究表明,玻璃纤维的引入改善了碳纳米管-环氧树脂复合材料的绝缘性能,玻璃纤维、碳纳米管与环氧树脂之间的界面效应在复合树脂绝缘性能的改善中发挥主要作用。     

等离子体射流快速改性促进表面电荷衰减

随着高压直流输电迅猛发展,绝缘材料在直流电压下表面电荷积聚现象严重威胁直流输电系统的安全可靠运行。为加快绝缘材料表面电荷的消散,采用大气压等离子体射流,以TEOS为前驱物,在环氧树脂表面沉积SiO_x薄膜。对改性前后材料表面化学组成、表面电导率、表面电荷特性、表面陷阱分布以及耐压特性进行多参数测量,研究等离子体射流改性前后环氧树脂表面特性。实验结果表明:等离子体处理在环氧树脂表面引入大量以Si-O-Si及Si-OH基团为主的无机基团,且表面电导率提高2个数量级。随着改性时间的延长,表面电荷的初始积聚量减少,消散速度加快,陷阱能级深度变浅;沿面闪络电压呈现先增后降的趋势,在改性180s时闪络电压提高到最高值9.0k V。研究结果表明:通过大气压等离子体射流在聚合物表面沉积薄膜能够提高环氧树脂绝缘性能,为其工程应用提供了有效的改性方法。     

电磁继电器贮存期接触电阻增长的动力学模型

电磁继电器贮存过程中,触点间的接触电阻超标是主要的失效模式,而触点间的阴离子扩散是导致触点表面绝缘膜增长、接触电阻增加的主要原因。本文分析了纯金属触点表面腐蚀膜的成膜机理,并根据扩散理论给出了接触电阻增长与触点间压力、接触压降以及环境温度的函数关系,建立了常闭触点间单个导电斑点的接触电阻增长动力学模型。该模型与其他学者的实测数据趋势一致,最后通过该模型的计算值与试验结果进行对比,进一步验证了提出的动力学模型的正确性,为进行触点贮存寿命的预测提供了新的思路和参考。     

Self-controlled pre-breakdown discharges in planar symmetry

In measurements on Teflon FEP films charged in ⩽50 μm air gaps by microsecond impulse voltages, a uniform charge deposition on the films was observed. A regular increase of the film surface potential from a threshold value of the peak impulse voltage was found. However, for 300 μm air gap it was observed that abrupt charging occurs at a lower threshold voltage, indicating breakdown, and the charge deposition on the film becomes nonuniform. The behavior in air gaps <50 μm is explained here using Townsend's theory of pre-discharges. It is shown how and why the interposed insulating film acts to make the system self-controlled, thus avoiding breakdown in the air gap, despite the large values of the applied peak impulse voltage     

<<控制电缆耐受过电压特性试验>>

对几种典型控制电缆在工频、直流及雷电冲击过电压下的耐压特性进行了试验研究,结果表明：电缆末端沿面闪络电压随沿面距离的增大呈饱和趋势;电缆头部处理的好坏,对整个电缆的耐压水平有较大影响;屏蔽层对芯线的绝缘水平是控制电缆绝缘中最薄弱环节,在30s以内可耐受工频交流18kV以上,正极性直流45kV以上,负极性雷电冲击40kV以上。工程中应控制地网的允许地电位升高在其耐受范围之内。     

Control of charge on insulating glass in vacuum by plasma processing

In order to control the charging of insulating glass used in HV vacuum equipment, the effect of H/sub 2/ plasma processing on the glass surface was studied. The electron-beam irradiation method was used to verify the effectiveness of the charging control. Borosilicate glass plates were used as test samples. When the glass was exposed to H/sub 2/ plasma produced by ac (60 Hz) voltage application, the surface resistivity of the glass was decreased, varying with H/sub 2/ plasma processing time. By exposure to H/sub 2/ plasma for 20 min, the surface resistivity was reduced from /spl sim/10/sup 17/ to /spl sim/10/sup 12/ /spl Omega/. Due to the reduction of the surface resistivity, charging of the glass can be controlled to a level below that which could cause surface flashover.