高压电力电缆故障分析及其探测技术

针对高压电缆运行中各种类型故障,介绍电缆故障现场测试方法和测试经验.     

The Role of Interfaces in Polyethylene/Metal‐Oxide Nanocomposites for Ultrahigh‐Voltage Insulating Materials

Recent progress in the development of polyethylene/metal‐oxide nanocomposites for extruded high‐voltage direct‐current (HVDC) cables with ultrahigh electric insulation properties is presented. This is a promising technology with the potential of raising the upper voltage limit in today's underground/submarine cables, based on pristine polyethylene, to levels where the loss of energy during electric power transmission becomes low enough to ensure intercontinental electric power transmission. The development of HVDC insulating materials together with the impact of the interface between the particles and the polymer on the nanocomposites electric properties are shown. Important parameters from the atomic to the microlevel, such as interfacial chemistry, interfacial area, and degree of particle dispersion/aggregation, are discussed. This work is placed in perspective with important work by others, and suggested mechanisms for improved insulation using nanoparticles, such as increased charge trap density, adsorption of impurities/ions, and induced particle dipole moments are considered. The effects of the nanoparticles and of their interfacial structures on the mechanical properties and the implications of cavitation on the electric properties are also discussed. Although the main interest in improving the properties of insulating polymers has been on the use of nanoparticles, leading to nanodielectrics, it is pointed out here that larger microscopic hierarchical metal‐oxide particles with high surface porosity also impart good insulation properties. The impact of the type of particle and its inherent properties (purity and conductivity) on the nanocomposite dielectric and insulating properties are also discussed based on data obtained by a newly developed technique to directly observe the charge distribution on a nanometer scale in the nanocomposite.     

大中功率节调速传动的合理电压等级

大中功率风机和泵采用变频调速可节约大量电能，大部分功率在0．2－2MW范围中，我国现在200kW以上的电机多是中压，现行中压电网多为10kV，选用10kV直接变频从技术和经济角度看都不太合理。由于变频器输入侧都有变压器，因此电机和变频器没有必要和电网一致。章讨论不同功率段的合理电压等级以及在电机电压和电网电压不同情况下当变频器出现故障时如何实现旁路工作。     

高压脉冲电容器性能参数优选实验方法研究

文章针对高压脉冲电容器的参数、特性以及性能等问题,利用国内目前所用到的不同种类材料的高压脉冲电容器,提出高压脉冲电容器性能参数的优选实验方法。优选实验结果表明：作为冲击片雷管发火的储能元件高压脉冲电容器,陶瓷电容器的性能参数最优,耐压和使用寿命很难满足使用要求;云母电容器性能参数次之,体积却相对较大,能够满足目前的爆炸箔起爆器的储能元件使用要求。     

柔性直流接入海上风电并网选址综合优化

随着海上风电的大规模开发,合适的海上风电柔性直流并网位置更有利于其优势的发挥。针对大规模海上风电经柔性直流接入陆地电网的并网选址,通过分析其并网主要影响因素,提出风电消纳能力、电网电压稳定性、并网点脆弱度和建设成本的评估指标。基于信息熵和模糊层次分析法,建立综合赋权模型确定各指标权重,提出并网点综合优化评估方法。某海上风电接入山东电网的仿真结果表明,所提方法增强了风电消纳能力,提高了电网安全稳定性。     

某发电厂高压变频器室空调系统改造设计探讨

介绍了火力发电厂高压变频器室的热工环境要求;利用Airpak软件对空调系统进行了CFD仿真模拟,根据显示的结果和高压变频器室的特点,提出了更适合高压变频器室的空调系统方案。     

基于迭代算法的有源电力滤波器谐波电流实时检测新方法

目前，已经提出了多种有源电力滤波器谐波及无功电流检测方法，尽管这些方法各有特点，但都存在着难以克服的问题，如计算量大，实时性差，检测精度不高等。文章在负载电流分析的基础上，提出了一种基于迭代算法的有源电力滤波器谐波电流实时检测方法，该方法具有计算量非常小，实时性好，检测精度高等特点。理论分析与仿真研究证实了该方法的正确性。     

高压电力计量箱窃电方式分析

根据当前对高压电力计量箱的窃电方式，具体分析、计算损失的电量值。     

Discovery of Rapid and Reversible Water Insertion in Rare Earth Sulfates: A New Process for Thermochemical Heat Storage

Thermal energy storage based on chemical reactions is a prospective technology for the reduction of fossil‐fuel consumption by storing and using waste heat. For widespread application, a critical challenge is to identify appropriate reversible reactions that occur below 250 °C, where abundant low‐grade waste heat and solar energy might be available. Here, it is shown that lanthanum sulfate monohydrate La₂(SO₄)₃?H₂O undergoes rapid and reversible dehydration/hydration reactions in the temperature range from 50 to 250 °C upon heating/cooling with remarkably small thermal hysteresis (<50 °C), and thus it emerges as a new candidate system for thermal energy storage. Thermogravimetry and X‐ray diffraction analyses reveal that the reactions proceed through an unusual mechanism for sulfates: water is removed from, or inserted in La₂(SO₄)₃?H₂O with progressive change in hydration number x without phase change. It is also revealed that only a specific structural modification of La₂(SO₄)₃ exhibits this reversible dehydration/hydration behavior.     

A domain coupling method for finite element digital image correlation with mechanical regularization: Application to multiscale measurements and parallel computing

A general method is proposed to couple two subregions analyzed with finite element digital image correlation even when using a mechanical regularization (regularized digital image correlation). A Lagrange multiplier is introduced to stitch both displacements fields in order to recover continuity over the full region of interest. Another interface unknown is introduced to ensure, additionally, the equilibrium of the mechanical models used for regularization. As a first application, the method is used to perform a single measurement from images at two different resolutions. Secondly, the method is also extended to parallel computing in regularized digital image correlation. The problem is formulated at the interface and solved with a Krylov‐type algorithm. A dedicated preconditioner is proposed to significantly accelerate convergence. The resulting method is a good candidate for the analysis of large data sets. Copyright © 2016 John Wiley & Sons, Ltd.     

ANTARES: The first undersea neutrino telescope

The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.     

Advances in piezoelectric thin films for acoustic biosensors,acoustofluidics and lab-on-chip applications

Recently, piezoelectric thin films including zinc oxide (ZnO) and aluminium nitride (AlN) have found a broad range of lab-on-chip applications such as biosensing, particle/cell concentrating, sorting/patterning, pumping, mixing, nebulisation and jetting. Integrated acoustic wave sensing/microfluidic devices have been fabricated by depositing these piezoelectric films onto a number of substrates such as silicon, ceramics, diamond, quartz, glass, and more recently also polymer, metallic foils and bendable glass/silicon for making flexible devices. Such thin film acoustic wave devices have great potential for implementing integrated, disposable, or bendable/flexible lab-on-a-chip devices into various sensing and actuating applications. This paper discusses the recent development in engineering high performance piezoelectric thin films, and highlights the critical issues such as film deposition, MEMS processing techniques, control of deposition/processing parametres, film texture, doping, dispersion effects, film stress, multilayer design, electrode materials/designs and substrate selections. Finally, advances in using thin film devices for lab-on-chip applications are summarised and future development trends are identified.