Modeling and Characterization of Electrical Transport in Oxygen Conducting Solid Electrolytes

A model for the electrical conductivity in acceptor-doped oxides which involves an association between the acceptor-dopants and oxygen vacancies resulting in donor centers is considered. The model relates the behavior of the electrical conductivity with the temperature, ambient atmosphere and band structure. The predictions of the model are compared to experimental data for ZrO₂:16% Y and SrCeO₃:5% Yb oxygen conductors and some band structure parameters have been determined.     

Electrical Conductivity of Composite Solid Electrolytes Copper(I) Bromide-Titanium Dioxide

Electrical properties of two-phase mixtures of copper(I) bromidewith titanium dioxide are investigated by impedance spectroscopy coupledwith X-ray diffraction and scanning electron microscopy. An increase ofconductivity of more than an order of magnitude with respect to purecopper(I) bromide is detected in the extrinsic domain. The results can beinterpreted in the framework of the brick-layer space charge model. Theimportance of OH groups on the surface of titania particles as preferredsites for internal adsorption of copper ions is confirmed. A maximum effecton conductivity is revealed for about 15 mol% of second phase andrelated to the microstructure of the composites.     

电气开关计算机辅助三维实体造型研究

文章研究了一种汽车电气开关计算机辅助的三维实体造型的技术和方法。以Mechanical Desktop为基础,研制开发了一套H_CAD软件,建立了一套汽车电气开关三维实体零件图库,该图库具有尺寸驱动和参数绘图等功能。     

固态继电器开发的实体造型系统

在分析实体造型技术基本原理的基础上,基于面向对象的设计和分析方法,引入参数化设计等有关概念,开发出了基于AutoCAD图形平台和ObjectARX开发工具的固体继电器参数化实体造型系统.     

Physiological Modeling in Electrical Engineering Courses

The subject of physiological modeling has been introduced in two conventional electrical engineering courses. Models of the respiratory process, waste generation, oxygen exchange, enzyme kinetics, and blood flow have been introduced. Although most engineering students have little background in physiology, it has been possible to introduce models that can be useful in the design of medical devices that must be compatible with a complex system.     

面向对象技术在固态继电器实体造型系统中的应用

讨论了面向对象技术的特点和应用原理，论述了对固态继电器实体造型系统专业对象进行类定义的设计思想和办法、分析了固态继电器实体造型系统的主要特点．采用AutoCAD2000和ARX作为开发工具，结合参数化设计技术实现了该系统。     

固体电介质中电致陷阱产生的研究

本文提出用表面电位测试技术研究固体电介质在强电场作用下产生陷阱的规律,分析表明这种方法是可行的。对PET和PP介质薄膜,实验表明:在所进行的电场作用时间范围内,使介质产生陷阱的临界电场为1×10~8V/m;在一设定的电场作用下,场致陷阱产生与施加电场作用的时间成正比;在一设定的电场作用时间下,场致陷阱产生随施加电场的指数而变化。以陷阱产生发展到一定程度时介质便发生击穿作击穿的临界条件,则从理论上导出电场作用下电介质的寿命随电场的增强而指数下降。     

固体氧化物燃料电池建模及并网控制

建立6 kW固体氧化物燃料电池(solid oxide fuel cell,SOFC)的机理模型,在此基础上设计包括Boost变换器、逆变器和滤波器的SOFC发电系统。为Boost变换器设计了比例积分(proportional plus integral,PI)控制器,以保证升压变换后直流电压稳定在365 V;对逆变器采用PQ闭环控制策略,直流电经空间矢量脉冲宽度调制(space vector pulse width modulation,SVPWM)后成为220 V、50 Hz的交流电;通过所设计的LC滤波电路消除谐波干扰。以Simulink为仿真工具,分别对由96个单SOFC组成的电池组、Boost变换器、逆变器的工作性能进行测试,进一步研究了SOFC发电系统接入220 V低压配电网运行的性能。仿真结果表明:所构建的SOFC发电系统能正确反映SOFC的电化学特性,系统运行稳定,动态特性好。     

Electrical Characterization of PMNT Thin Films

This paper presents our investigation in characterization of thin films of lead magnesium niobate—lead titanate (PMNT). We deposited films by rf magnetron sputtering on platinized silicon. As-deposited films are annealed and electrical characterizations are performed with platinum top electrode. We present capacitance—voltage, current—field and permittivity versus thickness characteristics. These are analyzed in the view of structural and microstructural observations. Our primary aim in this work being the development of integrated capacitors, we draw some conclusions and future directions of study in the frame of this application.     

熔融碳酸盐燃料电池的电气建模

熔融碳酸盐燃料电池目前是高温燃料电池研究领域的一个难点,其严格的热启动过程和运行状态对电池性能和寿命的影响至关重要。针对这一问题,建立了基于机理的熔融碳酸盐燃料电池电气模型,详细给出了采用电化学方程的熔融碳酸盐燃料电池电气特性的模型结构、算法、训练、仿真和试验。实验结果证明其快速准确,为熔融碳酸盐燃料电池的系统控制提供了一个实际工程应用模型。     

电工用铜中氧含量测定方法的研究

在电工用铜的氧含量测定方法中,惰气熔融-红外吸收法是目前普遍采用的测定方法。与传统酸洗法制备的测试样品相比,采用物理法制备的样品,其测定结果的准确性和一致性更好。对于氧含量较低的无氧铜以及高纯铜,测定的不确定度主要来源于标准物质,通过选用低氧含量的标准物质建立校准曲线,可以提高测定的准确性。在测定样品的氧含量前,特别是测定高纯铜样品前,根据所使用的仪器设备确定合适的分析参数,能够降低不确定因素引起的偏差。     

Mn-doped BaTiO3: Electrical Transport Properties in Equilibrium State

The electrical conductivity and thermoelectric power of Mn-doped BaTiO₃ (1 mole%) and undoped BaTiO₃ have been measured as functions of oxygen partial pressure (in the range of 10^-16 to 1 atm) and temperatures (in the range of 900 to 1200°C), and compared with each other to differentiate the effect of the Mn-addition. It is found that the isothermal conductivity of Mn-doped BaTiO₃ varies with increasing Po₂ as to to , unlike previously reported. This behavior is well explained by the shift of the ionization equilibrium, . The corresponding equilibrium constant, K_A, is determined from the Po₂ values demarcating those three different Po₂ regions as =3.19×10²² exp(–1.69 eV/kT). Basic parameters involving carrier density and mobility, and defect structure of Mn-doped BaTiO₃ are discussed in comparison with those of undoped BaTiO₃.     

Electrical Characterization of Airborne Vehicle Exhaust Plume

The induced current and voltage on the skin of an airborne vehicle due to the coupling of external electromagnetic field could be altered in the presence of ionized exhaust plume. So in the present work, a theoretical analysis is done to estimate the electrical parameters such as electrical conductivity and permittivity and their distribution in the axial and radial directions of the exhaust plume of an airborne vehicle. The electrical conductivity depends on the distribution of the major ionic species produced from the propellant combustion. In addition it also depends on temperature and pressure distribution of the exhaust plume as well as the generated shock wave. The chemically reactive rocket exhaust flow is modeled in two stages. The first part is simulated from the combustion chamber to the throat of the supersonic nozzle by using NASA Chemical Equilibrium with Application (CEA) package and the second part is simulated from the nozzle throat to the downstream of the plume by using a commercial Computational Fluid Dynamics (CFD) solver. The contour plots of the exhaust parameters are presented. Eight barrel shocks which influence the distribution of the vehicle exhaust parameters are obtained in this simulation. The computed peak value of the electrical conductivity of the plume is 0.123 S/m and the relative permittivity varies from 0.89 to 0.99. The attenuation of the microwave when it is passing through the conducting exhaust plume has also been presented.     

复杂电力电子电机系统的建模与仿真

采用单独建模、联合仿真的方法,研究了复杂电力电子电机系统的建模与仿真方法,并采用VisualC 编制了一个三电平逆变器控制的长定子直线同步电机系统的仿真程序,验证了所建立模型的正确性。     

汽车继电器计算机辅助三维实体造型研究

研究了一种汽车继电器的计算机辅助三维实体造型的技术和方法。以Mechanical Desktop为基础,研制开发了一套HCAD软件,建立了一套汽车继电器三维实体零件图库。该图库具有尺寸驱动和参数绘图等功能。     

弓网系统滑动电接触特性

弓网系统接触电阻不仅是表征其电接触性能的重要指标,而且对弓网系统的受流质量和使用寿命有着重要影响。因此开展了不同牵引电流、运行速度和接触压力条件下的动态接触电阻试验,分析了上述3个因素对接触电阻的影响机理。研究表明:当接触压力小于100 N时,弓网系统接触电阻随着接触压力的增大而减小,当接触压力大于100 N时,接触电阻的变化趋于平缓;弓网系统接触电阻随着运行速度和牵引电流的增大而增大,且上升趋势较陡峭;在运行速度和牵引电流一定时,当接触压力大于80 N时,受电弓滑板的磨损量随着接触压力的增大而增大。     

低压电器三维结构造型中VRML的应用

虚拟现实建模语言ＶＲＭＬ是一种三维图形描述语言,同时也是一种在Ｉｎｔｅｒｎｅｔ上传输ＶＲ图像的规范格式,研究了这种建模语言在低压电器产品三维结构造型中的应用。     

智能变电站电量信号传输特性及建模

文章介绍了智能变电站结构体系,通过研究电子式互感器二次信号传输过程及其建模方法,指出智能变电站电量二次信号传输过程存在的失真问题。根据建立的信号传输模型,对智能变电站电量信号传输过程进行仿真,通过对比输入、输出信号波形,得出不同频率下二次信号传输特性。