含风电并网系统鲁棒区间优化调度

随着风电渗透率的不断增大,风电功率的不确定性对电力系统的安全稳定运行带来了极大的挑战。为应对风电功率的不确定性,增强电力系统的大规模风电消纳能力,建立了含风电并网系统鲁棒区间优化调度模型。求解该模型得到风电场的最大允许输出功率区间及常规机组的最优经济调度计划。通过引入风电场最大允许输出功率区间作为控制目标,可有效降低弃风量、减少常规机组输出功率调节频次。在IEEE-RTS系统中进行仿真,仿真结果表明该模型所得系统调度策略的鲁棒性及安全性最优。最后以省级电网实际数据进行实例分析,验证了所提模型及方法的有效性。     

考虑风电出力偏差和调度经济性的风电接纳水平优化

采用威布尔风速分布模型,给出风电出力偏差期望值,并分析风电出力偏差给常规机组和风电并网运行的经济性带来的影响.在此基础上,建立综合考虑常规机组发电成本与风电场运行经济性的多目标经济调度模型,采用多目标粒子群优化算法,以风电出力预测值作为基准来定量优化与评估风电接纳水平.算例表明,该模型能够平衡常规机组与风电场运行的经济性,从经济性角度评估系统接纳风电的能力并为电网调度和风电场运行与规划提供一种依据.     

基于氢储能的含大规模风电电力系统经济调度

针对由大规模风力发电并网带来的消纳困难问题,文章利用由碱式电解槽、储氢罐、氢氧燃料电池构成的氢储能系统将弃风转换成氢气储存起来,用以满足外界氢气负荷需求或于负荷高峰期发电补充上网。文章先对风电出力的不确定性和氢储能系统进行建模。为了降低传统鲁棒优化求解的保守度,利用考虑保守度可调的鲁棒优化盒式集合描述风电出力。在此基础上,以降低弃风和提高系统总体的经济性为目标,建立了基于氢储能的含大规模风电电力系统经济调度模型。算例表明,文章所建立的优化调度模型兼顾求解的鲁棒性和经济性,并且可以显著减少弃风、降低系统的总成本。     

考虑不确定性的多能互补系统双层优化调度

为了降低新能源并网对电力系统影响,本文中提出了考虑源、荷不确定性的风光水火储多能互补系统调度方法。首先基于模糊机会约束法处理风电、光伏出力及负荷预测值的不确定性;然后建立了源荷相关度数学模型,以衡量联合发电系统出力与负荷的匹配程度;然后构建了多能互补系统双层优化调度模型,其中上层以源荷相关度最大为目标函数,下层以系统运行成本最小为目标函数;最后提出了改进的遗传算法求解双层调度模型。基于算例仿真验证了所提模型和算法的有效性,为互补发电系统提供可靠的调度方案。     

成本控制下考虑多商品物流配送线路安排的鲁棒优化模型

考虑单位运输成本具有不确定性条件下,基于总成本控制的目的,研究了多商品物流配送线路安排问题的鲁棒优化模型,并运用鲁棒优化思想,通过对含有不确定性的约束条件进行松弛后,获得了计算上可处理的鲁棒对应模型.     

考虑环境因素的分布式能源多目标优化配置

建立了分布式能源多目标优化配置模型,考虑了环境因素,以最小化传统发电与分布式能源发电的环境成本与发电成本之和、最小化配电网络损耗为目标函数.改变传统将多目标优化问题转化为单目标函数求解的做法,将粒子群算法扩展为多目标粒子群算法,并以此算法作为优化工具求解分布式能源的多目标优化配置.采用IEEE33节点系统作为算例,考虑将微型燃气轮机并网的优化配置问题.算例结果表明,该多目标优化配置策略能够为决策者提供可供个性化选择的多样化配置方案,各种优化配置方案与没有分布式电源安置相比,可降低系统网络损耗、改善系统可靠性指标和电压水平并降低污染气体排放.     

考虑不确定性和储能系统的虚拟电厂与能效电厂联合调度优化模型及仿真应用

为解决分布式电源难以分配、控制和管理的问题,引入虚拟电厂的基本概念,并考虑用户侧能效电厂参与下的系统发电调度优化问题。首先,构建电源输出功率模型,包括风力发电出力模型、太阳能发电出力模型以及储能系统出力模型;然后,构建虚拟电厂与能效电厂双层优化调度模型,其上层模型以虚拟电厂参与下系统发电成本最小为目标,综合考虑电能供需平衡约束、火电机组出力约束和系统备用约束等;下层模型以能效电厂参与调度获得的收益最大为目标,分析节能效率电厂(ESEPP)和需求响应效率电厂(DREPP)对虚拟电厂运行的优化效应。最后,选取3个风电场、2个太阳能发电站和2台燃气轮机发电机组构成仿真系统,并设定4种仿真情景。研究结果表明:虚拟电厂能够显著提升系统消纳随机性电源的能力,能效电厂能够实现负荷曲线的削峰填谷,基于双层优化调度模型能够发现发电成本最小和获得收益最大的最优调度结果。     

一种基于模糊控制的发电系统优化设计研究

本文提出一种多能源智能调度系统,能够对风光互补发电系统进行统一调度,根据电网用电负荷的波动来控制并网功率,使电网的供电质量更可靠。首先介绍光伏发电原理及其并网系统的结构,进而介绍风光互补发电系统的工作状态,最后研究对多能源的调度在MATLAB/simulink环境下建立了多种能源仿真模型,引入模糊控制算法,仿真结果达到了预期的目标。     

考虑设备风险和风光不确定性的园区综合能源随机优化运行

综合能源系统因其能源梯级利用的高效性被广泛应用,而在运行过程中各设备的潜在故障风险与风光出力波动会成为系统供能稳定性的安全隐患。为此本文首先基于设备负载率建立了故障概率模型与设备风险模型。其次针对风光出力的不确定性采取蒙特卡洛采样法生成典型场景,建立了考虑设备风险与风光不确定性的综合能源多目标随机优化模型,运用分段线性化、宽容分层序列法将该模型处理为混合整数模型。最后通过算例仿真表明所提优化模型能够兼顾运行风险与经济成本,相较于传统经济调度,在总成本仅上升了9.6%时、设备风险降低了79.3%,证明了模型的经济性与安全性。     

面向新能源并网的电力系统鲁棒调度模式的应用解析

在新能源并网的前提下,为了更好地调节电力系统的相关因素,我国电力领域经过不断探究及操作最终制定了多时间尺度鲁棒调度模式。本文对多时间尺度鲁棒调度模式进行阐述,并对多时间尺度鲁棒调度的实施过程进行模拟实验,并将传统的调度模式作为基础,进行相应的对比,进而凸显多时间尺度鲁棒调度模式的优势。随之对多时间尺度鲁棒调度模式所应用的相关技术进行分析探讨,以此为新能源并网的电力系统调度提供相应的参考依据。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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