光伏发电接入电网在我国的适用性及存在问题的探讨

以太阳能光伏发电为例阐述了其接入电网的理论和技术。介绍了以太阳能光伏发电的最大功率跟踪技术解决功率输出不稳定的问题,以太阳能光伏发电并网控制方法和策略解决其并网控制的技术问题。说明了时太阳能光伏发电系统电网接入的保护问题和如何应对孤岛问题,并针对我国的情况进行了适用性分析。     

谈光伏发电接入系统设计要点

在国民经济的发展中,能源是重要的发展基础。我国能源的消耗占据世界前列,在能源的供给以及形式上存在着很多的问题。对光伏发电资源的开发,对于解决现存的问题以及促进社会经济的可持续发展具有重要的意义。光伏发电将成为未来发展的重点,加强对其的研究具有重要的意义。在进行光伏发电接入系统的设计时,应该根据光伏发电系统规模、接入电网条件和对配电网的影响,合理制定接入配电网方案,对规模小、接入电压等级低的光伏发电系统,应适当简化接入配电网设计。主要阐述了光伏发电的作用和设计原则,并且根据实例阐述了光伏发电接入系统设计方案。     

考虑新能源发电联合体接入的多目标优化模型

随着新能源发电规模的不断扩大和种类的不断增多,传统电网调度方式已无法满足运行要求。为解决新能源出力稳定性差、波动性大等问题,文中提出将小型风电场、光伏电站和蔗渣发电站等新能源组成发电联合体参与调度,并采用基于满意度和欧氏距离的交互式多目标决策方法对考虑发电联合体接入的多目标优化问题进行建模。基于IEEE30节点系统的仿真结果表明,考虑新能源联合发电体(new energy power generation groups,NG)接入的多目标优化模型能使以氮氧化合物为主要污染物的排污量最小和总成本最低,并能使系统满意程度上升12. 8%。基于IEEE30节点和IEEE118节点的系统仿真结果表明,所提模型能有效地提升计算效率,是可行和适用的。     

新能源发电接入下储能系统双层优化模型

针对风力发电、光伏发电等可再生分布式电源接入电网带来的网损增加、电能质量降低等问题,提出了一种风光接入下储能系统的双层优化模型.综合考虑储能规划和运行两个方面的耦合效应,上层模型考虑储能规划,以储能配置的位置和容量为决策变量,以储能系统规划成本为目标函数,下层考虑储能系统运行时电网的经济性和稳定性,以储能系统每一时刻（时间刻度为1 h）的出力为决策变量,以电网脆弱性、有功网损、购电成本为目标函数.采用改进鲸鱼算法与YALMIP+CPLEX联合方法在MATLAB中进行求解,选取改进后的IEEE33节点系统进行仿真验证,结果验证了所提模型的合理性,对比不同的场景与结果得到储能的最优配置方案与运行策略.     

浅谈新能源接入对智能配电网的影响

智能电网的核心内容之一是解决各种新能源的接入问题。风能、光伏、电动车充电站等新能源发、用电存在间歇性、波动性强,接入电网技术性能差和对电网注入谐波等一系列问题。本文主要介绍了风力、光伏发电、电动车充电站接入电网后对配电网的影响,希望可以通过建立智能配电网的模型,深入研究分析新能源供用电接入对智能配电网的综合影响,实现对配电网各组件的监控和最优供用电组合。     

分布式电源并网的应用研究

本文简单介绍了分布式电源的应用背景及发展现状,并且针对分布式发电并网运行给配电网运行带来的问题进行了一些研究和分析,并提出了通过无线网络将DG信息接入配电网自动化系统的构想,这对实现DG安全高效的并网运行有着重要意义。     

青藏高原家用太阳能光伏发电系统的设计及应用研究

家用太阳能光伏发电系统是将一个太阳能发电站的发电规模和容量缩小到一个家庭用电水平,并应用到家庭的发电系统.太阳能光伏发电系统是个相对成熟的系统,但是在家用过程中,在与家庭低压电网并网时,会出现太阳能发电量不能满足家庭用电需求或光伏发电量过剩等技术设计和规划方案问题.在青藏高原,还存在地理环境的特殊性,都会影响到家用太阳能光伏发电系统功能的发挥,如果解决好这些问题,不仅可以实现再生能源的最大化利用,而且会带来良好的经济效益.本文从系统结构、电池组件、逆变器和控制器等方面对青藏高原家用太阳能光伏发电系统的设计方案进行了分析,并从资源、经济等角度对其应用前景进行了分析,以期为能源建设的决策和设计提供相关参考.     

分布式电源并网的应用研究

本文简单介绍了分布式电源的应用背景及发展现状,并且针对分布式发电并网运行给配电网运行带来的问题进行了一些研究和分析,并提出了通过无线网络将DG信息接入配电网自动化系统的构想,这对实现DG安全高效的并网运行有着重要意义。     

柴油发电装置的能量综合利用

针对柴油机作为原动机的电站系统的能量特点，根据能量综合利用的原则．从经济性、环保性等角度给出了柴油机作为原动机的发电装置能量综合利用的一些方法：热电联产；利用废热进行吸收式制冷；利用废热进行海水淡化；柴油机和热原组合，采用这些方法能使整个装置效率大大提高，具有较好的节能应用效果．     

城轨柔性直流牵引供电系统光伏发电并入方式研究

针对城市轨道交通光伏发电功率并网问题,开展城轨柔性直流牵引供电系统光伏发电接入方式研究.基于柔性直流牵引供电系统结构,分析了光伏发电功率不同接入方式及其特点,建立了光伏接入柔性直流牵引供电系统情况下系统动态运行仿真模型,进行了多列车动态运行时光伏发电功率接入的仿真分析,阐明了光伏接入柔性直流牵引供电系统后潮流参数的变化规律及节能效果.研究结果表明,光伏发电并入城轨柔性直流牵引供电系统的功率会优先被附近列车吸收,有效降低了双向变流机组从交流电网吸收的能量,提高了系统运行的经济性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with