基于区域极点配置电池荷电状态的估计方法

电池管理系统中蓄电池荷电状态的测量是非常重要的。在光伏系统中,蓄电池荷电状态决定了电池管理系统的充放电策略。根据一类电池等效电路模型,利用蓄电池荷电状态观测器误差系统的极点分布,给出蓄电池荷电状态观测器的设计方法。该方法可以根据圆盘极点位置的变化调整观测器荷电状态观测值的误差。通过仿真可以看到,基于极点配置的荷电状态观测器的有效性。     

铅酸蓄电池充电状态的测定

蓄电池是太阳能光电系统中的一个重要组成部分。光电系统中蓄电池的运行不同于其它用途的蓄电池而有其特殊性。蓄电池的充电状态在某种程度上反映了系统中各部份的匹配是否合理,以及光电系统的     

铅酸蓄电池开路电压和充电状态的关系的实验研究

利用计算机控制的蓄电池评估测试系统，对铅酸蓄电池的开路电压和充电状态之间的关系进行了实验研究。结果表明，它们之间具有很好的线性关系。这一特性非常有利于更有效地使用蓄电池和进一步优化配有蓄电池的光伏系统。     

机车铅酸蓄电池检测技术及开发应用

通过对赏蓄电池检测技术的分析,提出使用固定频率交流电测量蓄电池电导的方法检测蓄电池容量,成功研制QTK-Ⅱ型便携式电池检测仪,不论在线还是离线,均能判断畜电池状态的优劣,为铁路机车铅酸蓄电池的日常检测保养提供科学方法.     

基于稳态功率修正的混合储能新型控制策略研究

超级电容在响应系统功率波动时,荷电状态与额定值相比会产生一定偏移。针对该问题,文章在直流母线电压变化率进入稳定状态后,提出了在蓄电池电流内环增加与超级电容实际荷电状态有关的扰动项,改变蓄电池及超级电容的参考电流,实现稳态下蓄电池对超级电容的功率修正,最终使超级电容的荷电状态自动恢复至额定值。将所提的基于稳态功率修正的混合储能控制策略应用于直流微网并进行仿真,结果表明,该策略能够增强混合储能可靠性,减少超级电容配置容量,提高微网的稳定性和经济性。     

基于时空分布映射的大规模电池健康状态研究

针对传统方法难以对不间断电源系统、微网储能系统的蓄电池组进行高效准确的状态估计问题,提出了一种全新的基于数据驱动的方法应用于大规模电池的健康状态预测。首先,分析电池的历史数据,从电池健康状态（空间维度）和时间演变放电过程（时间维度）2个层面对电池状态进行有效聚类。其次,将数据分布映射到高维空间,设计相应的基于时空分布映射的电池健康状态预测深度神经网络模型。最后,实验模型验证了所提方法的有效性。     

蓄电池剩余容量(SOC)数学模型探讨和在线测试仪的开发

该文提出了铅酸蓄电池剩余容量(SOC)与蓄电池端电压、充放电电流、初始电液比重、环境温度等物理化学参数之间关系的数学模型，基于这个数学模型，就可通过测量蓄电池充放电过程中的各个物理参数得知蓄电池的当前容量。基于这样的原理，开发出了蓄电池容量在线测试仪。经过与大量的实测充放电数据对比，证明该文提出的数学模型能够较准确地表达蓄电池充放电过程中端电压和容量之间的关系，并能够很好地反映各个物理化学参数对充放电过程中端电压的影响。所开发出来的蓄电池容量在线测试仪，可以在线检测和显示蓄电池的当前容量，测量误差小于10％。     

独立光伏供电系统中多储能单元协调控制策略的研究

文章提出了一种由超级电容器和多个蓄电池储能单元组成的混合储能系统,并将该储能系统应用于独立光伏供电系统。其中,多个蓄电池储能单元能够增大混合储能系统的容量,并提高供电系统的可靠性。由于不同的蓄电池储能单元的荷电状态存在差异,因此,提出了一种改进SOC下垂控制方法,并利用该控制方法实现了不同蓄电池储能单元传输功率的优化分配和SOC的动态均衡,优化了蓄电池储能单元的能量传输过程。超级电容器可以补偿光伏系统传输功率缺额的高频部分,减少蓄电池储能单元充、放电的次数,维持直流母线电压的稳定。文章通过仿真模拟,验证了所提出的控制策略能够优化各储能单元的运行状态,并有效地维持了光伏系统传输功率的平衡和直流母线电压的稳定。     

摩托车蓄电池的常见故障检排

1蓄电池电量不足的检排摩托车蓄电池电量不足的故障现象,一般表现为蓄电池充电后时间不长,常感蓄电池存电不敷所用,转速很快变慢而无力,喇叭音量降低,空档灯灯光暗淡,转向灯不闪亮等。造成摩托车蓄电池电量不足的原因是:充电线路接头松动或锈蚀,使电阻增大,充电电流减小,蓄电池电量补充不足;发电机、硅整流器等有故障,从而使得蓄电池电量不足;线路某处搭铁,造成短路而长期处于放电状态;蓄电池内极板间短路;电解液液面过低,部分极板露在电解液外面而产生硫化;电解液密度过高,电池容量不足。检查与排除如下:1)检查充电线路各接头的连接、固定…     

一种新型光伏照明系统控制器

现有的太阳能照明系统中普遍存在不能准确、有效地检测蓄电池的充电状态和控制器大面积使用时的启停时差问题，为此提出了一种新型控制器。基于单片机89C2051和无线收发模块PTR2000的智能控制器，实现了系统工作状态控制和蓄电池的能量管理，能满足太阳能照明系统稳定运行和准确切换的要求，并实现多个控制器之间的启停一致。实验表明，该控制器效率高，运行稳定，基本解决之前提出的问题，达到了太阳能照明系统对控制器的要求。     

New amorphous molybdenum oxysulfide thin films their characterization and their electrochemical properties

New amorphous molybdenum oxysulfides have been obtained by r.f. sputtering using an MoS₂ target. Their chemical composition depends on the partial pressure of oxygen introduced in the plasma during the preparation. All the properties depend on their composition. By transmission electron microscopy some randomly oriented ordered domains were found and identified as a 2HMoS₂-like phase in which a partial substitution of oxygen for sulfur has been evidenced. The low oxygen content thin films have the best electrical conductivity but can intercalate only 1.7 lithium per molybdenum. On the opposite, the high oxygen content ones are able to intercalate up to 3.5 lithium. Whatever the composition of the material, the intercalation of the first lithium is never reversible. By X-ray photoelectron spectroscopy it was found that this phenomenon corresponds to the reduction of Mo⁶⁺ to Mo⁵⁺ and Mo⁴⁺, the reversible part is mainly due to the further redox process of Mo⁵⁺ and Mo⁴⁺ and also of disulfide pairs S₂²⁻.     

Transverse jets and their control

The jet in crossflow or transverse jet has been studied extensively because of its relevance to a wide variety of flows in technological systems, including fuel or dilution air injection in gas turbine engines, thrust vector control for high speed airbreathing and rocket vehicles, and exhaust plumes from power plants. These widespread applications have led over the past 50+ years to experimental, theoretical, and numerical examinations of this fundamental flowfield, with and without a combustion reaction, and with single or multi-phase flow. The complexities in this flowfield, whether the jet is introduced flush with respect to the injection wall or from an elevated pipe or nozzle, present challenges in accurately interrogating, analyzing, and simulating important jet features. This review article provides a background on these studies and applications as well as detailed features of the transverse jet, and mechanisms for its control via active means. Promising future directions for the understanding, interrogation, simulation, and control of transverse jet flows are also identified and discussed.     

Wind electricity in Denmark: A survey of policies,their effectiveness and factors motivating their introduction

This paper surveys the development of the policies supporting the introduction of wind electricity in Denmark in the last 15 years, with special attention to the new policy introduced after a 2-year long debate. The aim of this paper is to explore the roles of financial support, policy certainty and planning constraints in the diffusion of wind electricity in Denmark and the reasons prompting the change of the system in the current decade. It is discovered that political uncertainty has badly affected the effectiveness of the feed-in law in the years immediately after its introduction. With regard to the new system, it is concluded that the change has been prompted by generous conditions under the feed-in law and by the desire to facilitate the modernisation of old turbines. It is also concluded that incentive-based systems can be more effective than tradable quotas in promoting the modernisation of renewable plants. This finding is relevant to the development of energy policy in countries such as Germany and Spain, where the average age of wind turbines is much younger than those existing in Denmark.     

谈谈BIPV构件及其安装

阐述了太阳能发电与建筑的几种结合方式以及常用的一种与建筑结合的组件安装构件,并对实例进行了分析.指出光伏发电与建筑相结合将成为光伏应用最重要的领域之一,与建筑结合的(BIPV)组件安装结构件也将成为众多建筑、结构设计师关注的焦点.     

An international comparison of polymers and their alternatives

Energy analysis is now developed to the point at which we can make useful comparisons among the patterns of energy use in different nations. The first aim of this article is to start making these comparisons. The authors' attention has been focussed on polymers, especially the packaging materials, both to help fill out the overall perspective being developed in this series on Energy Budgets and because the polymer industry, with all its technological diversity, displays a rich spectrum of patterns of energy use, from which one can draw some useful object lessons.     

Simulation of photovoltaic power systems and their performanceprediction

A number of photovoltaic (PV) performance-analysis models are tested for their ability to estimate the AC power output and validated against historical observations from a PV test facility. A method to estimate meteorological parameters is developed for use in PV performance models for predicting future AC power output from a PV test site. Twelve such PV performance models are examined, and the PVFORM system analysis program and lifetime cost and performance models are extensively tested. These two models are tested using the typical meteorological year and the VPI model-generated estimates of long-term data. Performance prediction results are compared against actual observations at a 4 kW PV test facility. Results show that the VPI model-generated data, when used with the PVFORM model, provide the best predictions for AC power output from this 4 kW PV test facility     

Dislocations and their reduction in GaN

Abstract

Gallium nitride (GaN) is a semiconductor used to make light emitting diodes, a technology that could decrease global energy demands significantly if used worldwide. Yet there are barriers to making high efficiency GaN based devices: defects, including threading dislocations (TDs), hamper the quality of the GaN crystalline film. The hypotheses proposed to explain the origin of TDs are critically reviewed. It has been suggested that TDs form upon GaN island coalescence during initial stages of crystalline film growth, yet some transmission electron microscopy and atomic force microscopy studies have shown few TDs at coalescence boundaries. Although harmful, TDs have a lesser effect on nitride based devices than on other compound semiconductors. Thus, GaN based devices are able to produce light despite high dislocation densities. This phenomenon has led to debate over the role of TDs in charge carrier recombination, which is reviewed. Some suggest that charge carriers arrive at TDs and recombine in a non-radiative manner, whereas others claim that they are repelled from the dislocations because the dislocation cores are electrically charged. The reduction of TDs in GaN films furthers the drive towards high efficiency devices. The final sections of this review address ways to effect reductions in TD density. Methods include changing growth conditions (including temperature and pressure), dosing the substrate with silane, and the exploitation of interlayers deposited during growth.     

Nanostructural thermoelectric materials and their performance

In this review, an attempt was made to introduce the traditional concepts and materials in thermoelectric application and the recent development in searching high-performance thermoelectric materials. Due to the use of nanostructural engineering, thermoelectric materials with a high figure of merit are designed, leading to their blooming application in the energy field. One dimensional nanotubes and nanoribbons, two-dimensional planner structures, nanocomposites, and heterostructures were summarized. In addition, the state-of-the-art theoretical calculation in the prediction of thermoelectric materials was also reviewed, including the molecular dynamics (MD), Boltzmann transport equation, and non-equilibrium Green’s function. The combination of experimental fabrication and first-principles prediction significantly promotes the discovery of new promising candidates in the thermoelectric field.     

Parabolic-trough solar collectors and their applications

This paper presents an overview of the parabolic-trough collectors that have been built and marketed during the past century, as well as the prototypes currently under development. It also presents a survey of systems which could incorporate this type of concentrating solar system to supply thermal energy up to 400 °C, especially steam power cycles for electricity generation, including examples of each application.     

Thermodynamic model of viscosity of hydrocarbons and their mixtures

Activation hypothesis suggested by Eyring for modeling viscosity of liquids is generalized for calculation coefficient of dynamic viscosity of pure hydrocarbons and their mixtures in wide region of temperature, pressure and concentrations. Energy of vacancy activation is modeled as difference between enthalpy of ideal gas and enthalpy of real substance. Enthalpy and other thermodynamic parameters for pure substances and mixtures are calculated on the base of well-known Lee–Kesler equation of state. Thermodynamics of mixture calculated in the frame of pseudofluid hypothesis with pseudocritical thermodynamic constants. Pseudocritical thermodynamic constants are estimated with the help of mixing rules offered also by Lee–Kesler. Two additional constants are including in the suggested model of viscosity. For normal paraffin these constant have universal value. For other substances, for example, oxygen containing hydrocarbons values of the constant are installed in accordance to the experimental data. The model with sufficiently accuracy reproduces viscosity experimental data as pure substances in vapor and liquid phases and also solutions in the wide regions of thermodynamical parameters and concentrations. Calculation results are compared with the literature experimental data.