石灰石-石膏湿法烟气脱硫方案的模糊综合评价

对于一个燃煤电厂,如何在同一种脱硫技术的不同设计方案中选择既经济又可行的脱硫工艺,是一个非常重要的问题。首先利用专家评议法得到了各评价因素的重要程度;利用模糊分布的方法得到了这些因素与脱硫效率、单位kW造价和单位kW运行费用的隶属关系;最后利用模糊综合评价方法对石灰石-石膏湿法烟气脱硫技术的多个设计方案进行了模糊综合评价,选出最优方案。     

石灰石石膏湿法烟气脱硫方案的模糊综合评价

对于一个燃煤电厂,如何在同一种脱硫技术的不同设计方案中选择既经济又可行的脱硫工艺,是一个非常重要的问题。首先利用专家评议法得到了各评价因素的重要程度;利用模糊分布的方法得到了这些因素与脱硫效率、单位kW造价和单位kW运行费用的隶属关系;最后利用模糊综合评价方法对石灰石石膏湿法烟气脱硫技术的多个设计方案进行了模糊综合评价,选出最优方案。     

220千伏输电工程造价评价指标研究

随着输电工程新技术的不断应用,技术方案复杂性,多样性不断增加,而目前采用的输电工程单位造价评价指标不能全面准确反映工程造价水平.本文主要以现有某地区220kV输电工程单位造价评价指标为基础,综合考虑影响工程造价的关键因素,采用一定的方法,构建新的输电造价评价指标模型,对原有的单位造价评价指标进行补充和完善,以期建立反映输变电工程造价规律、更为合理的输变电工程遗价评价指标.     

供电企业防控业务外包安全风险探讨

针对供电企业业务外包常态化、规模化的新形势,梳理分析了当前业务外包安全管理面临的风险,提出了构建外包单位安全管理体系、强化外包作业现场风险管控、强化外包单位评价优选等风险防控方法,提高了外包单位的安全管理能力水平,有效规范了供电企业业务外包管理活动。     

开关柜局放测试设备测评方法

针对目前运维单位使用的开关柜局放测试仪质量参差不齐,部分产品标称技术参数与实际技术参数不符的现状,结合运维单位在现场应用中发现问题,提出了暂态对地电压技术参数检测方法、非接触式超声波技术参数检测方法和模拟放电检测方法,通过在实验室对不同厂家的13套开关柜局放测试设备进行现场实测试验,验证了该方法的有效性,同时依据测试结果作出了评价,为运维单位提供了优选顺序。     

智能投影寻踪方法在能效分级测评中的应用

为了深入研究电力能效测评系统采集海量数据并精细量化节能方案,根据电能质量国际标准,引入能效等级概念从多维度评测电力能效状态。首先建立能效的投影寻踪等级评价模型,采用人工鱼群算法寻求最佳投影方向,并将该模型应用于电力能效等级的评价。研究表明,基于人工鱼群算法的投影寻踪等级评价模型对用电单位进行能效分析及评级,能精细量化反映用电单位的能效状态。评测过程无需人为确定权重,避免了传统评价方法因主观原因造成的误差。实例计算表明,评价结果具有较高的准确性和可行性。测评方法简捷高效,为能效分级与测评提供了新算法。     

模糊评价法在电网企业安全绩效评价中的应用

由于同一单位不同部门之间的工作性质差异较大,很难对其安全管理绩效进行较精确的度量,本文拟采用模糊综合安全评价方法对同一单位不同部门之间的安全管理情况进行定量综合测评,最后得出一个奖励系数,进而客观评价该单位不同部门之间员工的年度安全奖励绩效,达到奖惩目的。     

国网北京经济技术研究院

正"大电网利用效率评价方法研究"通过专家验收2013年11月29日,国网北京经济技术研究院承担的国家电网公司科技项目"大电网利用效率评价方法研究"顺利通过国网科技部组织的专家验收。国家发改委,国网发展部,国网北京、天津、冀北电力公司,国网新源公司,中国电力企业联合会等单位的专家参加了验收会。"大电网利用效率评价方法研究"首次构建了涵盖宏观指标和微观指标的大电网利用效率评价指标体系,提出了基于几何分布关联度优化模型和基于优化柯布-道格拉斯模型的大电网利用率指标评价方法,并对国网     

广东电网信息安全风险评价及其指标体系的研究

信息安全风险评价是发现潜在问题．判断安全形势、提出安全防范与整改方案的基础,是加强信息网络宏观调控的一项基础性工作。从广东电网信息安全风险评价工作出发,提出了广东电网公司信息安全评价指标体系框架,详细阐述了评价指标和评价方法,通过对所有指标进行定量转化,得出综合指标值,以此来评估各单位的信息安全工作整体水平。     

用高分辨h指数评价学校二级业务单位的学术成就和影响力

在 Hirsch h指数基础上,提出一种高分辨h指数（hhr）的概念和计算方法,并用hhr指数评价学校二级业务单位的学术水平和影响力。以上海电机学院所属二级学术单位的数据进行计算表明,本文提出的高分辨h指数有更高的分辨率,使原来不能分辨的单位分辨开来。同时还提出了h效率的概念,以比较各单位的科技工作效率。     

汽轮机汽缸热应力的试验研究

汽缸的热应力，对汽轮机的运行安全很重要。本文对此进行了试验研究。在试验中，对一台多机汽轮机的汽缸进行了模拟加热，测量了热应力的变化情况。找出某些部位热应力的理论计算值与实测值比较一致，而另一些部位有较大差距。这一结果可作为建立热应力监视数学模型时参考。此外还测量了不同温升速度下法兰的热应力，并用理论方法修正到适于不同法兰厚度的情况。     

Hydraulic turbine and turbine control models for system dynamicstudies

A number of different models for hydraulic turbines and for their speed controllers are presented. The models vary in complexity, and are meant to be used for the study of power system problems of different types. Hydraulic models suitable for a relatively wide range of studies are recommended. Models are provided for prime movers including water supply conduit and prime mover speed controls. Nonlinear models are required where speed and power changes are large, such as in islanding, load rejection, and system restoration studies. One of the objectives is to present the basic physics of hydraulic turbines and their controls recognizing that, in the state of the art, the development of a code for a particular model is routine once the physics are well defined     

Voltage Drop Calculations for Electrically Short Insulated Conductors

The equivalent circuit of an insulated conductor is described and a definition given for circuits that are electrically short in length. Two ``short-line' methods for calculating voltage drop and regulation for alternating current power systems are outlined, and example calculations are included. Accuracy of the short-line treatment is compared with a long-line analysis. Data are provided to facilitate the calculations, including a nomograph for the determination of series reactance.     

SRM inverter topologies: a comparative evaluation

Several inverter power circuits suitable for switched reluctance motor (SRM) drives are analyzed and compared. Five inverter circuits are considered with the objective of establishing the most appropriate topology for an SRM drive. The comparison is based on the peak voltage and peak current ratings of the DC link components. Because the power converter choice depends on the motor design, the converter analysis and selection are done for a high-speed, 6/2 SRM suitable for a spindle drive and a high-torque 8/6 motor. Experimental results obtained for a high-torque drive are included     

无刷直流电机电容储能型变换器的参数设计

:建立了c dump变换器的等效电路模型 ,分析了由这种变换器供电的无刷直流电机的控制特性 ,在此基础上对c dump变换器主要参数选取进行了详细的讨论 ,推导出了计算公式。以实验室一台永磁无刷直流电机作为设计实例 ,说明了变换器主要参数的选择过程并简要分析了对系统的影响 ,最后给出了实验结果。可为无刷直流电动机c dump变换器提供设计依据     

Partial vacuum breakdown characteristics of helium at 20 kHz for inhomogeneous field gap

In general, power devices and systems operating in vacuum or space environment are more susceptible to partial discharges, corona, or volume discharges due to the partial vacuum conditions. Additionally, high frequency operation of a power system is a contributing factor in lowering the breakdown voltage of insulation. In this paper we present our studies on the breakdown characteristics of helium operating in DC and 20 kHz AC field in partial vacuum, for a point-to-point and point-to-plane electrode configurations. Breakdown voltage as a function of pressure in the range of 27 to 400 Pa (0.2 to 3 torr) for both the DC and 20 kHz AC cases is presented. Voltage and current waveforms along with the optical emission waveform of the breakdown events are also presented. A variable DC power supply for DC and an in-house built variable DC-offset-AC power supply for the high frequency breakdown experiments are used. A high voltage probe and a Pearson current sensor are used for the voltage and current detection, and a photo-multiplier-tube with a digital pico-ammeter and a video camera are used for the optical signal detection of this set-up. The breakdown voltage as a function of pressure for both the AC and DC experiments, along with voltage breakdown waveforms for both electrodes are presented.     

Optimum Filter Design for a Single-Phase Solid-State UPS System

A systematic design procedure for the output filter of a singlephase uninterruptible power supply (UPS) system is developed. The basic specifications for the UPS system are first established. Four different output filter configurations are then analyzed and compared for sinusoidal pulsewidth and single-pulse modulated inverter output (i.e., filter input) voltage. On the basis of the above comparison, ``optimum' filters are selected for both modulation techniques. Using a minimization function for filter cost and size, a set of filter design parameters corresponding to each type of modulation are obtained on the per unit basis. The theoretical results are verified on an experimental breadboard utilizing a current commutated thyristor inverter. Finally, the overall filter design procedure is outlined and a design example is presented.     

Power Electronic Drives,Controls, and Electric Generators for Large Wind Turbines–An Overview

Abstract—Wind represents a major and growing source of renewable energy for the electric power systems. This article provides an overview of state-of-the-art technologies and anticipated developments in the area of power electronic drives, controls, and electric generators for large multi-megawatt wind turbine systems. The principal components employed in a turbine for energy conversion from wind to electricity are described, and the main solutions that are commercially available are briefly reviewed. The specific issues of complex mission profiles, power codes, and reliability are discussed. Topics of power electronics, ranging from devices to circuit topologies, and similar matters for electric generators, together with results of optimal design studies are included. It is shown that the individual power rating of wind turbines has increased over the years, and technologies required to reach and exceed a power rating of 10 MW are discussed. The role of power electronics for improving the operation of wind turbines and ensuring compliance with power grid codes is analyzed with a view at producing fully controllable generation units suitable for tight integration into the power grid and large-scale deployment in future smart power systems.     

A generalized dielectric polarization evolution equation

In this paper a non-equilibrium statistical-mechanical theory of dielectric relaxation is developed. This approach differs from previous work in that a generalized nonlocal evolution equation for the polarization is constructed. General equations of motion are presented for the polarization, internal energy, and entropy which include effects of memory. These equations can be expressed in terms of reduced-correlation functions, and are valid for non-equilibrium and arbitrary field strengths. Expressions for an effective local field also are developed. The Fourier transform of the evolution equation yields a general compact expression for the Fourier transform of the memory function and a specific form for the susceptibility. The kernel, Fourier transform of the memory function are developed, and relaxation-time functions for special cases. In the limit of a single relaxation time, a Debye response is obtained. In the subsequent special cases exponential and Gaussian forms for the memory functions are assumed. The final special case relates a power-law circuit transfer function to the theory of Dissado and Hill. In this case the memory kernel and relaxation times are derived from the Dissado-Hill response function     

Analytical modeling of device-circuit interactions for the powerinsulated gate bipolar transistor (IGBT)

The device-circuit interactions of the power insulated gate bipolar transistor (IGBT) for a series resistor-inductor load, both with and without a snubber, are simulated. An analytical model for the transient operation of the IGBT, previously developed, is used in conjunction with the load circuit state equations for the simulations. The simulated results are compared with experimental results for all conditions. Devices with a variety of base lifetimes are studied. For the fastest devices studied (base lifetime=0.3 μs), the voltage overshoot of the series resistor-inductor load circuit approaches the device voltage (500 V) for load inductances greater than 1 μH. For slower devices, though, the voltage overshoot is much less, and a larger inductance can therefore be switched without a snubber circuit (e.g. 80 μH for a 7.1 μs device). The simulations are used to determine the conditions for which the different devices can be switched safely without a snubber protection circuit. Simulations are also used to determine the required values and ratings for protection circuit components when protection circuits are necessary