电力市场环境下AGC机组评估指标的仿真

通过在电力市场环境下AGC控制的仿真研究，讨论了目前有代表性的AGC机组考核指标方法：AGC机组调节效能定量评估方法，AGC机组指令／出力相关系数法等的特点．结果表明：AGC机组调节效能评估方法的3个指标中，只有控制偏差P可以反映机组的实际运行能力；相关系数法可以反映机组的跟踪能力．但是这两种方法都与CPS1，CPS2的区域控制指标不存在明确的联系：即可能会出现所有机组都满足要求，而区域性能指标却不满足要求的情况．故需要进一步建立合适的机组评估指标与区域指标之间的联系。     

大唐国际张家口发电厂二期MAX系统机组AGC系统优化

从2010年起电网按照《华北区域发电厂并网运行管理实施细则(试行)》、《华北区域并网发电厂辅助服务管理实施细则(试行)》及《华北区域发电厂辅助服务及并网运行管理实施细则的有关修改条款》文件(简称:两个细则)对并网发电厂进行管理。对于火电厂特别是老厂来说系统结构和设备性能难以满足两个细则的要求,AGC性能偏差尤为突出。本文阐述了张家口发电厂二期MAX系统4台机组AGC运行现状,分析了制约该机组AGC运行方式下负荷变化的因素,对该机组协调控制逻辑及参数进行了优化,使该机组AGC调节品质得到了改善。     

电力市场下基于改进遗传算法的AGC机组的选择

针对电力市场下参与竞标的各AGC机组的选择问题,提出了一种基于实数和二进制数混合编码,个体分段交叉变异的改进遗传算法.该算法采用实数模拟AGC机组的调节容量,无需解码,具有较高的收敛精度,同时采用二进制编码模拟AGC机组中标状态,充分利用了两种编码方式的优点;对群体中的个体采用了轮盘赌选择,并按容量段、状态段分别进行交叉、变异的遗传操作方法,较好的解决了电力市场下AGC机组选择这一0-1混合整数非线性规划问题.最后通过对某省实际电网的算例分析,验证了该算法的可行性.     

基于Matlab GUI的电力系统自动发电控制仿真平台设计

利用Matlab中的图形用户界面(GUI),设计了一个电力系统自动发电控制(AGC)仿真平台.该平台应用于电力系统单区域一次、互联电网二次调频,同时加入控制策略模块,用于经典PID和模糊PID控制策略的分析.该仿真平台可直观地反映AGC系统调节下的频率变化趋势,以及两种控制策略的性能优劣,同时可便捷地设置参数.     

基于改进遗传算法的AGC机组优化组合研究

为降低发电成本,该文对自动发电控制(AGC)机组优化组合问题进行了研究.基于改进遗传算法,建立了包含AGC的机组优化组合模型;针对遗传算法存在的不足,结合包含AGC机组优化组合模型的特殊性,提出了可变长二进制编码;设计了专门的遗传操作,并采用等微增法对其中的连续变量进行了处理.将所研究的算法和模型应用于包含16台机组24时段的机组优化系统中,仿真结果表明该改进遗传算法的计算结果优于实数编码方法结果11.33%,并在搜索区间及收敛速度等方面都具有较好的性能,适用于大、中型发电系统.     

基于趋势提取的火电机组负荷响应能力评价

自动发电控制(AGC)技术是维持电力系统发电与负荷实时平衡,保证电力系统频率质量和安全运行的重要技术手段。为解决当前电网调度中心所使用的AGC性能评价方法受噪声影响大与机组出力超出目标死区无法读数的问题,提出一种新的AGC性能评价方法,通过分段线性表达技术提取机组实发功率的变化趋势,自动划分静态、动态等不同响应阶段,进而获得关键数据点计算性能指标。与现有方法相比较,基于趋势提取评价AGC性能指标的方法受噪声影响较小、评价结果更加准确。本方法可较好地解决目前性能评价方法中受噪声影响大与超出调节死区无法读数的问题,并且剔除了一次调频对AGC性能评价的影响。     

水电站AGC中的惩罚函数及虚拟机组技术

针对影响水轮机使用寿命与运行安全的气蚀和振动问题,从经济角度出发,用惩罚函数方法,有效地避开了机组的气蚀和振动区.在水电站自动发电控制AGC中,为避免负荷调整时频繁通过气蚀和振动区,以及机组的频繁开停,将机组的安全运行区以虚拟机组形式加入电厂的AGC优化计算中.     

DEH—ⅢA型纯电调装置在200MW机组上的应用

200MW机组参加调峰运行后,对机组的自动化水平提出了更高的要求。为能更好地实现机组协调控制和AGC自动负荷控制,克服模拟电调与液压调节系统并存方式的弊端(故障率高,灵敏度差,迟缓率大,负荷响应慢),进行了DEH纯电调改造。本文将以浑江发电公司#5机组DEH改造实践为基础,重点从DEH的组成、功能及投入AGC两个方面对DEH-ⅢA型数字电调在200WM机组上的应用进行论述。     

300MW火电机组协调控制优化的研究和应用

介绍了山西大唐国际临汾热电有限责任公司1号、2号机组基建调试及转入商业运行后,通过不断地优化和改进机组协调控制,使机组在安全稳定的前提下具有优秀的负荷调节性能的经验,探讨了如何在频繁的AGC变负荷工况下减少机组蒸汽压力、蒸汽温度等主要参数的波动。     

溴化锂空调监控系统设计与实现

本文基于氯碱化工的实际生产需求，设计并实现对6台溴化锂空调机组的集中监控该系统结构采用Hostlink通讯网络，利用组态王软件实时地采集空调的启停、压力、温度等各种反映空调运行状态的参数，并对空调机组的各种故障及时显示并报警     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-