All-source bidding: Extending integrated competition to utility resource procurement

When facing a resource need, utilities should use all-source bidding to help identify the highest value resources to procure. By soliciting proposals from suppliers across all resource options, the utility applies to procurement the same important principles that guide integrated resource planning. All-source bidding is not new, but many utilities have not used it. This article explains how all-source bidding works, describes the benefits, and offers practical recommendations for utilities and utility regulators.     

Rebranding the robot

Robotics scientists are counteracting a perceived negative fictional image of robots by re-imagining them as a new infant species, reports social anthropologist Kathleen Richardson     

照明光源的寿命特性和改进

在绿色照明工程中提高和延长照明光源的光效十分重要。该文介绍了白炽灯、荧光灯、高压放电灯的寿命特性和长寿命化的措施。延长这些照明光源的方法有改进灯丝和电极的材料与结构，蒸镀二向色性法反光镜，使用同频电子整流点灯线路等。     

虚拟微波网络分析仪与自动测量

一些早期精密网络分析仪只是部分功能不足,但仍有很高测量精度,为了使它们继续发挥作用,本文通过GPIB接口建立了典型微波网络分析仪与PC间的通信,并在PC上利用LabVIEW集成环境开发了虚拟微波网络分析仪程序;该虚拟程序采用通道测量字技术扩展了原仪器的测量通道;置换并升级了其数据存储方式,增加了反向存储能力;另外,还利用指令存储数组使典型网络分析仪实现了一键式自动测量。这样不仅弥补了其原来的不足,还扩展了其部分功能。除使其更便于操作外,还提高了测试效率。     

MSI优先编码器的扩展设计方法

８－３线优先编码器是ＭＳＩ典型电路之一。本文给出了ＭＳＩ优先编码器简捷，快速，实用的扩展设计方法，从而为ＭＳＩ优先编码器的扩展应用，提供规范化，系统化便捷有效途径。     

浅析NAT技术在网络扩展中的应用

IP地址是一种有限的资源，它的使用受到严格控制。NAT(网络地址转换)技术可以在不申请新的网络地址和更新路由表的情况下，使不具备合法IP地址的私有网络与公用网络之间互相访问，从而实现网络扩展。     

Extending the perturbation technique to the modal representation of nonlinear systems

After a brief review of perturbation technique, using this method an approach is developed to represent and study the behavior of nonlinear dynamic power systems. For the first time in this field, perturbation technique is applied to obtain an approximate closed form expression for the zero input response of stressed power systems. In order to show the superiority of the proposed method, it has been applied to a typical nonlinear system which is a single machine infinite bus (SMIB) power system with unified power flow controller (UPFC). The accuracy and competency of this method in comparison with Modal Series method will also be validated.     

基于蛇类生物的仿生变体机器人研究

基于仿生机械学的原理,提出了仿生变体机器人的物理结构,讨论了仿生变体机器人的运动机理,分析了仿生变体机器人线形运动的基本步态,并根据以上原理研制出了实验样机。对该机器人系统进行了实验,实验结果证明这种运动步态的可行性,最后指出了这种基本运动步态的局限性和改进的方向。     

Extending the applicability of insulator flashover models by regression analysis

A combination of experiments and regression analysis has been utilized to extend the useful range of models for estimating flashover performance of insulators under contaminated conditions. Experiments were performed on distribution class insulators employing porcelain, silicone rubber and ethylene propylene diene monomer (EPDM) rubber as housing materials. It has been shown that it is possible to include important factors such as hydrophobicity, aging and contamination accumulation in the assessment of insulator performance. The results from this work are useful for selecting the appropriate insulator design (dimensions and material) for different system voltages     

Simulation of the dynamics of an industrial robot

The authors describe the design, dynamical analysis, and control simulation of an industrial robot manipulator. The choice of links and motors is explained in practical terms. Dynamics modeling is done in terms of the Lagrange-Euler formulation. Proportional-integral-differential and computed-torque-controllers are then used to simulate the control of the arm. Simulation results are provided for different parameters values and different control commands. A complete overview of the design, dynamic modeling, and control of a robot manipulator such as the one presented by the authors should be of benefit for undergraduate students, because many do not have a formal course on robotics in their curriculum     

Identification for the robust control of robot manipulators

In this paper an identification scheme, which yields bounds on unmodelled dynamics along with an estimate for the parameters of a nominal dynamic model, has been presented. These estimates are useful for designing a robust controller for trajectory control of robot manipulators, if they satisfy certain conditions. These conditions have been stated mathematically. Guidelines are provided for selecting a data set for identification such that the obtained estimates satisfy the above conditions. Simulation results are presented for a two‐link serial manipulator, when frictional torques are treated as unmodelled. Copyright © 2001 John Wiley & Sons, Ltd.     

一种机器人轨迹规划的优化算法

为了使机器人运动轨迹平滑且工作时间最优,以SCARA机器人为研究对象,在考虑各关节速度、加速度和加速度变化约束的基础上,对机器人在关节空间中进行轨迹规划.采用遗传算法对关节空间中各关键点间的运行时间间隔进行规划.利用ADAMS/View搭建的机器人仿真模型,以遗传算法产生的最优时间间隔为机器人轨迹规划仿真的依据,在ADAMS中进行机器人运动学仿真.仿真结果表明,所设计的机器人轨迹规划方法既能保证工作时间最优,又可使机器人的轨迹平滑.     

通过GPIB接口扩展数字存储示波器功能

介绍了基于虚拟仪器思想扩展数字存储示波器功能的设计过程。计算机通过GPIB接口与数字存储示波器进行通信,根据示波器编程指令控制数字存储示波器进行数据采集,利用VB和MATLAB语言混合编程对采集的数据做出进一步分析和处理,从而有效地扩展了数字存储示波器的功能。并能方便地推广到其他GPIB接口设备中。构建功能更多的GPIB自动测试系统。     

Extending the functionality of power supply systems with photovoltaic energy converters

Features of photovoltaic power supply systems are described. A structure of a photovoltaic power supply system with enhanced functionality is proposed.     

有机硅注入技术延长运行电缆使用寿命的研究

交联聚乙烯(crosslinked polyethylene,XLPE)电缆运行数年后其绝缘层内部普遍会出现水树缺陷,电缆修复是提升运行电缆绝缘水平合理有效的方法.对工业运行电缆进行了绝缘修复,修复时使用压力注入系统从电缆样本缆芯注入硅氧烷修复液,修复液渗透到绝缘层中与水树缺陷中的水分发生反应,生成一种有机硅树脂对水树空洞进行有效填充,达到水树修复的目的.之后对工业运行电缆样本进行了电镜能谱分析、通大电流实验以及工频击穿实验,并使用仿真软件对水树区域进行了电场仿真.结果表明,修复液能迅速渗透到绝缘层内部并有效地修复水树缺陷,改善水树区域电场分布,抑制水树进一步生长,提升其击穿电压,且对运行电缆散热及通流能力没有影响.通过分析研究发现,硅氧烷修复液能安全、迅速、有效地提升工业运行电缆的绝缘水平,延长其使用寿命.     

Self-tuning control of robot manipulators

We consider the tracking control problem for robot manipulators whose parameters are not exactly known. It is assumed that some unmodelled friction is acting at the actuated joints. The proposed solution guarantees that the disturbances on the outputs (the joint positions) can be attenuated by an arbitrary factor k. For the setpoint regulation problem a self-tuning controller is proposed. In this case the disturbances (uncertain parameters and unmodelled non-linearities) on the outputs are completely rejected asymptotically. Some simulation results are included.     

延长电解槽大修周期的方法

从影响电解槽大修周期的因素入手，分析影响电解槽大修周期的原因，并从制造工艺和运行控制两方面介绍了延长电解槽大修周期的具体措施。     

拓展输配电国外市场的若干问题

本文简要地论述了不同的国家和地区的输配电市场的一些特点和要求,提出了拓展输配电国外市场的必须进行的一些基础工作,并对开展国外输配电工程总承包(EPC)项目的相关问题进行了探讨.     

不确定刚性机械臂的鲁棒输出控制

针对不确定刚性机械臂系统的鲁棒控制和抖振问题,在仅有精确关节位置反馈的情况下,通过引入速度滤波器生成伪速度信号,并利用反推补偿设计滤波增益,提出了一种基于速度估计的鲁棒输出反馈控制策略。滤波器-控制器设计中不合有开关控制项,有效避免了控制抖振现象。该算法对采样频率无严格限制,最终可确保系统闭环半全局一致有界收敛。通过两关节机械臂的仿真实例验证了所提算法的有效性。     

Extending the optimization of the rotating transformer brushless excitation to all rectifier modes

Brushless excitation of a synchronous machine has a significant advantage: no slip-rings are necessary. The rotating transformer method is investigated: the excitation machine is a wound rotor induction machine with controllable voltage supply on the stator side. The synchronous machine is excited by a diode bridge, connected to the rotor of the excitation machine. The operation of the system is essentially determined by the commutation of the rotating diode bridge. It has different rectifier modes in such a configuration (possibly long commutation process caused by the variable, possibly lower voltage; larger commutation inductance). With justified simplifications, a model is derived to investigate the operation. The classical converter theory is applicable for the variable voltage, variable frequency supply of the diode bridge. Optimal operation considering the utilization of the excitation machine is introduced, developed and extended to all rectifier modes. The result is a matching rule for the parameters of the system, which can be satisfied by complex design of the system elements.