550 kV断路器灭弧室内电场的多重网格-有限元法分析

针对有限元法进行多介质电场计算过程中求解效率与场域离散精度矛盾问题,结合有限元(FEM)和自适应多重网格(AMG)两种技术,提出多介质电场的自适应多重网格-有限元法(AMG-FEM)求解技术,并在粗细网格之间转换时引入迭代自适应控制转换技术,解决了计算区域参数分布不规律性,避免了网格整体多层细化计算工作量大的问题。通过对550 k V断路器灭弧室电场数值计算,证明了AMGFEM算法的高精度、高效率以及良好适应性,得到了灭弧室内不同开距下的电场分布。     

550kVGIS用三工位隔离开关开合母线转换电流研究

开发了550 kV GIS用三工位隔离开关,通过对开断过程中绝缘配合设计,预判放电通道,保证电弧仅在抗烧蚀能力强的动、静弧触头之间燃烧。型式试验后样机的烧蚀工况分析表明,通过提高隔离开关分合闸速度,避免了开合过程中出现的电弧漂移现象,通过对电弧燃烧时间长短及分散性统计,合理解释了分、合闸速度对电弧漂移的影响,验证了所设计的三工位隔离开关的合理性。     

基于DBNs的轮毂电机机械故障在线诊断方法

为实现电动汽车用轮毂电机运行状态在线监测及其安全评估,提出一种基于动态贝叶斯网络(dynamic Bayesian networks,简称DBNs)的轮毂电机机械故障在线诊断方法。首先,以轮毂电机运行安全为目标,着重考虑车速对轮毂电机振动信号的影响程度,在时域和频域中提炼出多个敏感度高的特征参数来表征轮毂电机的运行状态,并将其作为DBNs的观测节点;其次,基于速度片构建轮毂电机机械故障诊断模型,解决其运行状态在相邻时间片之间无法构建转移概率分布的问题,根据不同速度片之间的转移概率分布,建立以二速度片展开的DBNs,实现对轮毂电机机械故障的在线诊断;最后,通过轮毂电机综合台架试验,验证了该方法对轮毂电机机械故障在线诊断的有效性。     

掺杂Au的ITO介孔材料的共沉淀法制备及气敏性能研究

采用共沉淀法制备了掺杂Au的ITO(Sn/In=0.6)介孔材料来制备H2敏感器,分析结果表明,制得的ITO(纯和掺杂样品)是菱形晶相,其中掺杂5 mol%Au的样品有较窄的孔分布,其孔径为7～8 nm,用其制作的元件在150 mA工作电流下对H2(10-3)的灵敏度达到40.6,且对CO,NH3选择性较高.响应时间和恢复时间均小于1 min.     

Effects of defect states on the performance of CuInGaSe2 solar cells

Device modeling has been carried out to investigate the effects of defect states on the performance of ideal CulnGaSe2 （CIGS） thin film solar cells theoretically. The varieties of defect states （location in the band gap and densities） in absorption layer CIGS and in buffer layer CdS were examined. The performance parameters： open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency for different defect states were quantitatively analyzed. We found that defect states always harm the performance of CIGS solar cells, but when defect state density is less than 10 14 cm-3 in CIGS or less than 10 18 cm-3 in CdS, defect states have little effect on the performances. When defect states are located in the middle of the band gap, they are more harmful. The effects of temperature and thickness are also considered. We found that CIGS solar cells have optimal performance at about 170 K and 2 μm of CIGS is enough for solar light absorption.     

弹簧触指在隔离开关中的应用研究

以ZF27-800气体绝缘金属封闭开关设备(GIS)产品为例,介绍了弹簧触指在隔离开关中的应用情况,构建了弹簧触指数学模型,进行了仿真分析,并通过摩擦力、机械寿命、温升试验等试验项目,对弹簧触指在隔离开关中的使用性能进行了验证,结果表明:采用弹簧触指的产品比采用梅花触指等传统结构的产品性能更加优越,使用寿命显著提升。     

含氧纳米多晶α-Ti拉伸力学性能与变形机制的分子动力学模拟

纳米纯Ti对间隙O原子具有强烈的敏感性,O含量可以很大程度上改变其力学性能和变形机制。采用分子动力学方法分别研究了O含量、变形温度、应变速率对纳米多晶α-Ti拉伸性能及变形机制的影响。结果表明,纳米多晶α-Ti的屈服应力随间隙O含量增加而升高。在O含量小于0.3%(原子分数)时,观察到变形孪晶■,该孪晶通过孪晶面上的“带状位错”协调长大;O含量大于等于0.3%时,被激活的滑移系类型向多元化转变,柱面、基面和锥面滑移系被激活,位错类型转变为以刃型位错为主。在含O纳米多晶α-Ti中,位错机制和晶界机制辅助塑性变形。晶界迁移率随变形温度和应变速率的增加明显增大。新晶粒形成过程伴随着不稳定的Ti_hcp→Ti_bcc→Ti_hcp相变,这种相变由晶粒的相对旋转所致,且生成新晶粒的数量随着应变速率的增大而增多。通过探索间隙O原子强化的本质,为优化纳米尺度纯Ti力学性能,拓展纯Ti应用范围提供理论依据。     

Effects of defect states on the performance of perovskite solar cells

We built an ideal perovskite solar cell model and investigated the effects of defect states on the solar cell''s performance. The verities of defect states with a different energy level in the band gap and those in the absorption layer CH₃NH₃PbI₃ (MAPbI₃), the interface between the buffer layer/MAPbI₃, and the interface between the hole transport material (HTM) and MAPbI₃, were studied. We have quantitatively analyzed these effects on perovskite solar cells'' performance parameters. They are open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency. We found that the performances of perovskite solar cells change worse with defect state density increasing, but when defect state density is lower than 10¹⁶ cm^-3, the effects are small. Defect states in the absorption layer have much larger effects than those in the adjacent interface layers. The perovskite solar cells have better performance as its working temperature is reduced. When the thickness of MAPbI₃ is about 0.3 μm, perovskite solar cells show better comprehensive performance, while the thickness 0.05 μm for Spiro-OMeTAD is enough.     

浅谈GIS设备后期扩建

气体绝缘金属封闭开关设备(GIS)因其占地面积小、与环境的协调性好、配置灵活、受外部条件影响小等优点受到电力用户的青睐,成为了电网的关键设备。随着GIS设备在电网中的大量应用,GIS设备后期扩建对正在运行的前期设备的影响就很值得关注。笔者通过对GIS常见扩建方式以及扩建时开关操作的分析,阐述了GIS设备后期扩建的方法,得出了GIS设备后期扩建如何减少现场对接工作的时间和拆解GIS设备本体的范围、如何能尽量减小因扩建过程而造成的设备停运或尽可能地减少停电时间的途径。     

介孔氧化铁的制备与表征

以氢氧化钠和三氯化铁为原料,通过控制碱和铁盐的比例来制备铁的聚合物溶液,然后以十二烷基硫酸钠（SDS）为模板剂制备了介孔氧化铁. 通过X射线粉末衍射、热重分析、红外光谱、氮气吸附脱附方法对不同焙烧温度下样品的晶体结构和表面结构进行表征. 结果显示,OH^-/Fe³⁺摩尔比为2.0,焙烧温度为450℃时,样品完全转化为α-Fe₂O₃. 制备的介孔氧化铁有较大的表面积（146.5m²·g^-1）,BJH平均孔径为6.9nm,孔体积为0.27cm³·g^-1. 所制备的介孔氧化铁有较好的热稳定性,经550℃高温焙烧表面积仍有110.2 m²·g^-1.