抽水蓄能电站在发电工况下旋转备用效益的测算

以抽水蓄能电站各项辅助服务中最为重要一项———旋转备用辅助服务为对象,利用蒙特卡罗随机生产模拟技术,研究抽水蓄能电站最优抽水策略下发电工况下旋转备用容量的定价理论,给出了以边际成本确定旋转备用容量电价的模型方法,以及抽水蓄能电站在发电工况下旋转备用的效益模型。并结合算例说明了模型的正确性和合理性。目的在于使各厂家在发电工况下机组提供备用时能够在提供电能和提供备用之间作出合理的选择,充分体现出其容量的市场价值,使旋转备用的效益达到最优。     

风电-抽水蓄能联合系统的优化运行模型

拟定了风电-抽水蓄能联合系统3种可行的运行方案:全部风电供给抽水蓄能电站抽水;根据电网容量和风电场出力情况,部分风电直接输入电网,其余风电供给抽水蓄能电站抽水;风电全部直接输入电网.建立了风电-抽水蓄能联合系统的优化运行模型,计算得出了常规发电厂稳定运行的最小容量以及含一定容量风电的电网所需的抽水蓄能电站装机容量,建立了经济评价模型,根据综合经济评价结果,优选出了风电-抽水蓄能联合系统的最佳运行方案.     

我国抽水蓄能电站系统的建设

抽水蓄能电站是解决电力系统调峰 ，调频，备用容量的最佳方案之一，我国电力系统的容量越来越来大，调峰调频，提高系统设备利用率，减少能耗以及提高高供电质量和可靠性等问题愈益突出，发展抽水蓄能电站势在必行。     

电力市场背景下抽水蓄能电站交易机制设计

抽水蓄能电站具有运行灵活、反应迅速、清洁低碳等特点,可以为电力系统中提供调峰、填谷和备用电源等多种优质的辅助服务。目前中国已有河北、山东等省份开展了抽水蓄能电站抽水电量招标采购等市场化交易。随着各试点省份现货市场的逐步建立,抽水蓄能电站的市场化交易有待进一步完善提升,并形成常态化交易机制,以提升抽水蓄能电站的运行效益。对比总结了中国外抽水蓄能电站的运营模式和电价机制;针对中国现有政策机制下抽水蓄能电站运营面临的问题,提出了电力市场背景下抽水蓄能电站参与市场交易的具体方案;并以浙江省为例,进行了模拟测算。结果表明,抽水蓄能电站市场化交易机制对于引导抽水蓄能电站参与市场交易获取合理收益,提升电力市场环境下抽水蓄能电站运营效益,促进抽水蓄能电站长期健康发展具有积极意义。     

抽水蓄能电站经济效益分析——山西兴建抽水蓄能电站的必要性

本文论述了火电机组调峰存在的主要问题和抽水蓄能电站作为调峰容量具有的多方面效益。井以太原市汾河二库抽水蓄能电站为例,进行了工程评价和效益分析。提出了山西电网迫切需要兴建抽水蓄能电站的建议,对山西的能源决策将有参考价值。     

考虑风电机组旋转备用的风电系统备用容量计算

文章提出变速风电机组旋转备用概念和实现算法,设置风电场出力上限,利用风电机组出力可控性,实现风电场间互补备用,减少常规机组提供的备用容量。采用 K-均值聚类算法对风电场历史数据进行聚类分析,分析风电场功率预测偏差引起的风电系统备用需求的概率分布。设定电网安全运行置信度,计算常规机组所需提供的备用容量值。结果证明,风电机组旋转备用和良好的风场风资源互补性可以减少常规机组所需提供的旋转备用容量,多风场聚合为一个等值风场,可以减少调度出力给定值。     

我国抽水蓄能电站发展与展望

我国节能减排、能源结构调整和电力系统发展要求建设一定规模的抽水蓄能电站。分析了我国抽水蓄能电站开发潜力,以全社会电力供应总成本最低为目标,满足国家能源发展战略和电力行业发展规划,考虑各地区负荷预测、跨区电力交换、以及各类电源建设技术经济条件,提出了我国抽水蓄能电站的合理开发规模、布局、政策建议,为促进抽水蓄能电站可持续发展提供参考。     

我国抽水蓄能电站发展中的若干问题

抽水蓄能电站的最初概念,是将火电站非峰荷时的低价电能转化为峰荷时的高价电能。这一概念现已发展到利用抽水蓄能电站来控制电力系统中电力的流动,并从中获得更大的效益。从电网负荷曲线可以看出,电力需求变化非常剧烈,因此要求电网很快地对此作出反应。设计适当的抽水蓄能电站是满足这一运行要求的理想手段。     

用随机生产模拟方法计算抽水蓄能电站的节煤效益

应用随机生产模拟理论,建立了等效电量函数法分段模型,从抽水蓄能的主要功能－调峰填谷作用以及较高的可靠性出发,以安徽琅琊山抽水蓄能电站为例,首先对抽水蓄能电站在电力系统中运行产生的节煤效益进行了计算和评价,然后对抽水蓄能电站最优运行方式进行了研究,从而证明了随机生产模拟方法的实用性,并由此得出了抽水蓄能电站的最佳运行方式。     

华中电网兴建抽水蓄能电站的技术经济分析

从华中电网整体技术经济性出发，采用运行模拟计算和技术经济分析法进行直接搜索寻优，研究了抽水蓄能电站在华中电网中的作用，提出了华中电网兴建抽水蓄能电站的合理装机规模和运行方式．研究结果表明：２０１０年三峡电站建成发电后，华中电网兴建抽水蓄能电站的合理装机规模可达６．２９％～９．４４％，抽水蓄能电站的合理运行方式为“按需抽发”，即以承担系统备用任务为主．     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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