电力系统无功优化研究综述

介绍了考虑多目标函数时无功优化模型的建立与解决方法,在总结了传统优化算法的基础上着重介绍了已经改进的智能优化算法和混合的智能优化算法在无功优化上的应用,简单介绍了动态无功优化的几种优化算法,并对今后无功优化的研究方向做出了展望。     

电除尘排灰方式优化原则的可行性分析

阐述了电除尘排灰方式优化的必要性 ,提出其优化的方向 ,编制了其优化原则 ,并对优化原则的可行性进行了分析 ,预测了优化后的直接与间接效益     

分布式电源优化配置研究现状与展望

对分布式电源的优化配置问题进行了综述,对其国内外发展现状做了概括和分析。介绍目前主要的优化配置模型,详细地总结了经典数学优化方法、启发式优化算法、智能优化算法、复合算法在分布式电源优化配置中的应用。对分布式电源优化配置中存在的问题进行探讨,并展望了分布式电源优化配置的未来发展方向。     

智能配电网优化调度设计及关键技术

含多类型分布式电源和多样性负荷的智能配电网迫切需要优化调度以实现各种资源的优化配置,近些年配电自动化系统和信息系统的建设也为配电网优化调度的实现提供了基础。根据智能配电网实际需求,文中提出了配电网优化调度设计框架,以实现对智能配电网多种元素的全局优化调度。首先分析了配电网态势感知和配电网运行趋势分析两个配电网优化调度基础技术,然后提出了配电网优化调度的总体目标,给出了配电网优化调度的框架设计和基本功能,主要包括优化手段、优化内容、人工决策等方面,并分析了实现配电网优化调度的6项关键技术。     

电工领域几种常用优化方法比较和选取

本文对电工领域中几种常用的新优化方法的特点,优点和适用范围等进行了综合比较,分析了在选择优化方法时应考虑的因素,指出了今后优化方法发展趋势是多种优化方法综合应用,最后结合电动汽车驱动电机优化问题给出了优化方法造反和多种优化方法综合应用的实例。     

基于地理信息系统的配电网优化设计

配电网优化是当前电力系统规划的研究热点,为了获得更加合理的配电网优化方案,提出一种基于地理信息系统的配电网优化方法。首先对当前配电网优化研究现状进行了分析,并针对配电网特点构建了配电网优化数学模型;然后采用粒子群算法对配电网优化数学模型进行了求解,并与地理信息系统结合得到了配电网优化的最优结果;最后采用仿真模拟实验对其性能进行了测试。结果表明,此方法可以准确找到最优配电网优化方案,且方案更加科学和合理,为复杂配电网提供了一种新的优化工具。     

电力系统无功优化方法分析

本文介绍了无功优化的历史,总结了各种无功优化模型,分析了静态、动态两种无功优化方式,比较了当前存在的多种优化算法,提出了目前电力系统无功优化研究中存在的问题及发展趋势。     

电力成本综合优化的系统学方法研究--运行优化

电力成本综合优化包括规划优化、建设优化、运行优化、维修优化等,运行优化是其中最重要的部分,文中对运行优化进行了深入探讨.分析了火电厂发电成本构成;贮煤与配煤的模式;电力系统中发电机组组合优化、启停优化、水电与火电机组之间经济调度的数学模型等.     

电力系统无功优化综述

介绍了考虑风电场接入后、交直流混合输电系统以及电力市场下多个无功优化数学模型,探讨了现有传统优化算法、人工智能优化算法以及改进的混合优化算法,并对其中常用的优化算法进行了分析比较。针对电力系统无功优化在线运行的实用性问题,综合评价了现有无功优化控制策略及其适用情况,提出了当前电力系统无功优化研究中仍需解决的问题及未来的研究方向。     

电力系统无功优化算法综述

为全面概括电力系统无功优化算法研究的现状、取得的成果和存在的不足,介绍了通用的无功优化模型,总结了多种目前电力系统无功优化中常用的传统优化算法和人工智能优化算法,包括线性规划法、非线性规划法、动态规划法、现代启发式搜索方法、专家系统等。对每种算法的原理和优缺点进行了分析,并针对列出的每种基本优化算法存在的缺陷,介绍了几种改进的优化算法。最后,介绍了几种效果良好的混合优化算法,并对未来无功优化研究的方向提出了建议。     

Closure to discussion of "An efficient technique for the evaluation of lightning-induced voltage in a cylindrical vessel containing charged oil"

For original article by C. Buccella and A. Orlandi see ibid., vol.39, no.2, p.368-73, Mar./Apr. 2003 and for discussion by B. J. C. Burrows see ibid., vol.42, no.2, p.535 Mar./Apr. 2005.     

Closure to discussions of "Electric arcing burn hazards"

For original article and discussions see ibid., vol.42, no.1, p.134-45, Jan./Feb. 2006. The authors respond to discussion comments by C.M. Wellman (p.142), P.S. Hamer (p.143-4) and T.E. Neal (p.145).     

用变汽温法检验300MW机组高中压缸中间轴封改造效果

介绍利用变汽温法测量高中压缸中间轴封漏汽量的原理和方法,并列举了在某电厂300MW汽轮机高中压缸中间轴封改造前后的应用实例。提出可以用此方法测量高中压缸中间轴封改造前后的漏汽量,从而可以量化地检验轴封改造效果。     

Discretization Scheme for the Density-Gradient Equation and Effect of Boundary Conditions

In recent years, the density gradient theory (DG) (M.G. Ancona and H.F. Tiersten 1987, Phys. Rev. B. 35(15): 7959–7965, M.G. Ancona 1990, Phys. Rev. B. 42: 1222) has been established as a viable alternative to the solution of the Schrödinger equation for solving problems such as charge density distribution in MOS inversion layers and MOS tunneling (M.G. Ancona 1998, J. Tech. CAD(11), M.G. Ancona et al. 2000, IEEE Trans. Electron Devices 47: 1449). Primary advantages of the DG method over the Schrödinger method are flexibility in extending to multi-dimension and easiness in incorporating into the conventional drift-diffusion or hydrodynamic solver (C.S. Rafferty et al. 1998, Proc. SISPAD, p. 137, A. Wettstein et al. 2001, IEEE Trans. Elec. Dev. 48: 279). However, the DG term that represents the quantum effects is a singular perturbation term and requires special care for discretization (X. Wang 2001, Master's thesis, University of Massachusetts, Amherst). In this work, we examine the validity of the linear vs. the nonlinear discretization scheme and the effect of boundary conditions on the scheme used.     

面向对象技术及其在电力系统中的应用

详细讨论了面向对象建模技术、面向对象方法学以及面向对象技术的优越性。重点介绍了面向对象技术在潮流计算、电力系统仿真、电力系统安全分析与控制、数据库、人机界面、人工智能、调度员培训仿真中的应用。     

Beiträge zur Elektrodynamik des Elektroschocks

Inhaltsübersicht I. Ziel der Arbeit. —II. Das Grundmodell. —III. Das Grundpotential. —IV. Wirkung kleiner Inhomogenitäten: 1. Analyse des Innenbereiches; 2. Analyse des Außenbereiches. —V. Einfluß der Randschicht auf das Strömungsfeld. —VI. Zusammenfassung.Mit 33 Textabbildungen     

Discussion of `Analysis of a new variable-speed singly salientreluctance motor utilizing only two transistor switches' by L. Xu et al

C. Patak maintains that the motor analyzed by L. Xu et al. in the above-titled paper (see ibid., vol.26, no.2, p.229-36 (1990)) cannot operate as specified by the authors. R.M. Davis, in a separate discussion points out that the above-titled paper is based on earlier work by L. Xu and T.A. Lipo (1987, 1988) that had prompted him to publish a paper in which he reached a completely opposite conclusion, and that L. Xu et al. have neither noted nor referenced his work. In reply, L. Xu et al. point out that Patak has been misled by Fig. 4 of their paper and provide clarification. They also explain why they did not consider Davis's paper and rebut his arguments. They also note that the captions for Figs. 14 and 15 of their paper should be reversed     

High voltage AC resistive current measurements using a computerbased digital watts technique

A computer-based technique is described which can accurately determine high-voltage AC resistive currents by obtaining the watts loss of the test specimen and dividing by the true r.m.s. (t.r.m.s.) value of the applied voltage Therefore, the normal concern for guarding against stray capacitive currents and for the exact repetition of test setup geometry on successive testing are not required for accurate measurements of AC resistive current. The watts loss calculation is based on the general formula for average watts so that the resistive current can be measured accurately with some harmonics of the fundamental present in both the test current and the supply voltage. A digital oscilloscope is used to acquire the test voltage and current so that special-purpose amplifiers are not required. The overall system accuracy is verified to less than ±1.21% of full-scale current. A microprocessor was used to compute the following parameters: average power, t.r.m.s. voltage, t.r.m.s. resistive current, t.r.m.s. capacitive current, total t.r.m.s. current, and the magnitude of calculated measurement error. The waveforms displayed are volt-ampere, voltage, and total current. An EHV aerial lift boom, a 115 kV station post insulator, and a metal-oxide surge arrester are evaluated using this technique to illustrate the measurement advantages     

Historical highlights in cardiac pacing

The benchmarks in cardiac pacing are identified, beginning with F. Steiner (1871), who rhythmically stimulated the chloroform-arrested hearts of 3 horses, 1 donkey, 10 dogs, 14 cats, and 8 rabbits. The chloroform-arrested heart in human subjects was paced by T. Greene in the following year (1872) in the UK. In 1882, H. Ziemssen in Germany applied cardiac pacing to a 42-year old woman who had a large defect in the anterior left chest wall subsequent to resection of an enchondroma. Intentional cardiac pacing did not occur until 1932, when A.A. Hyman in the US demonstrated that cardiac pacing could be clinically practical. Hyman made a batteryless pacemaker for delivery in induction shock stimuli (60-120/min) to the atria. His pacemaker was powered by a hand-wound, spring-driven generator which provided 6 min of pacemaking without rewinding. Closed-chest ventricular pacing was introduced in the US in 1952 by P.M. Zoll et al. Zoll (1956) also introduced closed-chest ventricular defibrillation. W.L. Weirich et al. (1958) demonstrated that direct-heart stimulation in closed-chest patients could be achieved with slender wire electrodes. S. Furman and J.B. Schwedel (1959) developed a monopolar catheter electrode for ventricular pacing in man. In the same year, W. Greatbatch and W.M. Chardack developed the implantable pacemaker.     

Über eine Meßeinrichtung für Dauermagnete mit unmittelbarer Kurvenaufzeichnung

Zusammenfassung In der vorliegenden Arbeit wurde eine neue Meßeinrichtung beschrieben, mit der beliebige magnetische Zustandskurven photographisch aufgenommen werden können.Zum Schluß möchte ich Herrn Professor Dr. ing. e. h. Dr. techn. h. c. F. Emde und Herrn Professor Dr. ing. habil. W. Bader danken, die mich mit Anregungen und großem Interesse an der Arbeit unterstützten und mir die Einrichtungen des Elektrotechnischen Institutes der T. H. Stuttgart zur Verfügung stellten. Ebenso danke ich dem Stiftungsrat der C. Bach-Stiftung, der durch Stiftungsmittel die Durchführung der Arbeit ermöglichte.