浅析微机故障录波器通信网络的设计

分析了故障录波器中故障信息传输的特点，提出了故障录波器通信网络各部分的通信形式和采用的通信协议，以及故障录波器与电力管理信息系统(MIS)互联采用双网卡设计的解决方案。     

恒压复位双管正激DC-DC变换器

介绍了一种新型的恒压复位双管正激DC-DC变换器。通过外加恒压复位电路，双管正激DC-DC变换器能扩展工作占空比。恒压复位电路由一个开关与二极管并联后与一个复位电容串联组成，并联在直流母线上。在正常工作时，恒压复位电路的开关一直导通， 复位电容直接并联在直流母线上。 当输入掉电时，恒压复位电路的开关关断，复位电容从直流母线断开。这样， 该变换器就有比较恒定的复位电压，可以增大变压器匝数比设计。 与通常的双管正激变换器相比，该变换器的元件应力较低，效率更高。最后，给出了 80V 输入 12V/18A输出的 实验结果。     

由DTMF通信实现远程测控

本介绍一种ＤＴＭＦ通信方式的远程测试系统，本系统采用总线星型复合结构，特别适用于缺电源供应的现场设施的多点测控。     

二像重合色感的实验研究

阐述了由红、蓝二滤色片分色记录的景物像，分别在红、白两种光照明的条件下重合时，人眼色感问题的进一步实验研究，同时简单讨论了其成色的可能原因及应用途径。     

Thermodynamics of Hydrogen Production Based on Coal Gasification Integrated with a Dual Chemical Looping Process

The performance of an innovative hydrogen production technology, which is based on a coal gasification system integrated with a dual chemical looping process, namely, chemical looping air separation (CLAS) and calcium looping CO₂ absorption (CaL), is evaluated. CLAS offers an advantage over other mature technologies in that it can reduce capital costs considerably. CaL is an efficient method for hydrogen production and CO₂ capturing. The proposed technologies are studied by Aspen Plus based on the Gibbs free energy minimization principle. The key factors in terms of reduction temperature, gasification pressure, temperature of water‐gas shift reaction, and water consumption, which proved to have a significant impact on the performance of the whole hydrogen generation process, are discussed.     

Influence of ring-type internals on the solids residence time distribution in the fuel reactor of a dual circulating fluidized bed system for chemical looping combustion

The intensification of gas-solids contact in the fuel reactor of a chemical looping combustion system is enhanced with the installation of ring-type internals. This can be a key issue for achieving the necessary fuel conversion rates. Wedged rings, previously designed and tested, were found to increase the particle concentration in the counter current section of the fuel reactor and hence, to achieve a more homogeneous particles concentration along this zone. The present work investigates the effect of the mentioned internals on the residence time distribution of particles in the fuel reactor of a dual circulating fluidized bed system for chemical looping. The study was carried out in a cold flow model especially designed for the fluid-dynamic analysis of the system equipped with a recently developed residence time measurement device based on the detection of ferromagnetic tracer particles through inductance measurement. Ring internals proved the positive effect on the particles residence time, the residence time distribution is more symmetric and shows lower dispersion, the flow pattern is more plug-flow-like, these effects are intensified with the reduction of the aperture ratio of the rings. On the other hand, the upward particle transport in the counter-current zone of the fuel reactor also increases with the installation of the rings, increasing the bypass flow of solids through the fuel reactor's return loop (internal circulation). For high internal circulation rates the solids residence time distribution of the fuel reactor is dominated by the bypass effect. The findings may be used for focused design improvement of the investigated fluidized bed system.     

Status,challenges and opportunities of dual fuel hybrid approaches-a review

Consumers conventionally adopt diesel generation to meet the energy needs where the grid connection is unreliable or unavailable. While electrification has provided these communities a variety of economic and social opportunities, diesel consumption has resulted in adverse costs and environmental pollution. Two technologies available to reduce the expense and emissions of diesel fuel reliance include dual fuel or hybrid diesel applications. The dual-fuel approach involves a supplementary gas fuel charge in support of reduced diesel fuel consumption. Hybrid applications involve the integration of renewable generation to displace diesel fuel consumption. This paper reviews the potential for hybrid dual-fuel applications, identifying engine flexibility as a major integration barrier. In comparing the flexibility of various dual-fuel technologies to operate dynamically, this paper presents a critical review across hydrogen, liquified petroleum gas (LPG), natural gas (NG) and blended hydrogen and NG derivatives. The results identify a range of approaches able to improve engine flexibility and thus reduce the cost and carbon intensity of diesel-fired internal combustion engines. At low load conditions, while NG and LPG exhibit similar performance, the use of hydrogen and hydrogen blends provide improved engine performance and response. Unfortunately, given the current cost of hydrogen fuel, significant commercial barriers exist to the adoption of hydrogen or hydrogen blended fuels. Despite this, this review indicates the potential of hydrogen-NG blends to offer additional flexibility in comparison to alternative dual-fuel technologies. This position is furthered considering near term cost targets associated with the development of a global green hydrogen industry, coupled with its ability to serve as a demand-side management approach within isolated power systems, one of the multiple future research themes.     

Efficient computational method for transient EM response of large-loop source over layered earth

Calculations of the ElectroMagnetic （EM） response produced by a large horizontal loop placed over layered medium are rather complex because its integral expression contains the product of two Bessel functions and has a divergent term. In this paper, an improved fast Hankel and Gaver-Stehfest transforms are introduced to solve the strong-oscillation and slow-decay properties of the integrand, where one Bessel function in the product is substituted by a carefully chosen polynomial of high accuracy and the other used as the digital filter coefficients in the convolution integral. Comparisons prove the validity and the efficiency of the proposed method.     

含2个S副间隙6-SPS机构奇异性分析

6-SPS机构位姿矩阵采用四元数法描述,并将该矩阵和矢量坐标扩展为4维形式,推导出无间隙机构的运动方程,得到了机构运动的新型雅克比矩阵J_A和J_B;在此基础上,利用连续接触模型得到了两个含间隙S副共连杆和异杆时机构的运动系数矩阵。分别把各个运动系数的行列式展开,得到含间隙机构第一类奇异和第二类奇异的轨迹方程,利用MATLAB得到了机构在给定位置时的第一类位姿奇异轨迹和第二类位姿奇异三维轨迹曲面;通过将两类含间隙机构奇异轨迹曲面的比较,发现机构间隙对第二类奇异的影响大于对第一类奇异的影响;在两类奇异轨迹中,当S副异杆时,机构间隙的影响均大于S副共连杆时的影响。以无间隙机构奇异轨迹曲面上奇异点作为参考点,通过含间隙机构奇异轨迹曲面上与参考点相对应奇异点的相互比较,发现存在一个关于参考点的奇异域。