含风电场的电力系统环保经济调度研究

在节能减排的电力市场环境下,清洁能源发电因其发电成本较低,环境污染小,而具有日益重要的地位。本文研究风电接入系统后的电力系统动态经济调度,建立了含风电场的环保经济调度数学模型,提出以系统总发电成本最低为目标函数,并考虑常规火电机组和风电场的各种约束条件。根据某地区的实际负荷数据,利用搜索能力强、寻优速度快的粒子群优化算法进行仿真验证,结果表明数学模型与优化算法的正确性与有效性。最后,应用相对熵均衡性理论,对优化调度的决策结果进行评价与选择。     

基于需求响应的含光伏电力系统优化及其算法改进

为解决光伏并网发电的不稳定性以及发电调度成本高的问题,建立了以发电调度成本最小为目标的含光伏电力系统优化模型。该模型借助电价的需求响应来增加对负荷的调控能力,以减少光伏的不稳定性对发电调度优化结果造成的影响。为求解该模型,对经典的遗传算法进行了改进。仿真结果表明:考虑需求响应有利于含光伏电力系统负荷削峰填谷,提高机组发电的稳定性,并且降低了含光伏电力系统机组的发电调度成本,验证了所建模型的正确性和有效性。     

差分进化算法在电力系统环境经济调度中的应用

以求解环境经济调度(EED)这一复杂的多目标约束优化问题为背景,研究了一种改进的多目标差分进化算法(EMODE),该算法依据多目标优化问题的特点重新设计了差分进化算法(DE)的进化算子并引入自适应二次变异算子来有效避免DE存在的"早熟"收敛现象;同时,针对EED问题约束条件复杂且难以处理这一问题,依据不同类型约束的特点提出一种启发式的约束处理方法.将EMODE应用到某电力系统的多目标环境经济调度中,仿真计算结果以及与其他求解方法的对比分析表明,EMODE可以有效兼顾全局收敛性和Pareto非劣调度方案的多样性,具有较高的效率以及鲁棒性.     

分时电价下考虑需求响应的微电网经济调度方法

为了实现微电网发电侧和用户侧双赢,提出一种考虑需求响应的孤岛微电网多目标经济调度模型。该模型在分时电价机制下引入需求响应,构建含用电效用和用电成本的负荷侧效益目标函数,同时,建立微电网发电侧成本最小目标函数。基于上述目标函数,通过调整使得微型燃气轮机的增量成本一致,实现微电网发电总成本最小。同时,根据分时电价调节可调负载的最优接入量,使得用户侧总收益在每个时段达到最大。为了验证模型的有效性,建立孤岛微电网仿真平台对需求响应的效果进行测试。仿真结果表明:所提出的经济调度模型能够在实现发电侧成本最小化的同时,实现负荷侧效益的最大化;在分时电价机制下引入需求响应后,用户侧效益提高了104%。     

基于有限步一致性算法的交直流混联微电网分布式动态经济调度

以可控单元的日运行成本最低为优化目标,构建了交直流混合微电网的动态经济调度模型,提出了一种基于有限步一致性的完全分布式算法,设置各分布式发电单元的成本微增率为一致性变量,各单元通过与邻居单元交互信息实现全局优化调度,并且算法可在有限步内收敛,极大地缩短了收敛时间。最后,通过仿真算例验证了所提模型和算法的有效性。     

基于混合智能算法的电力系统经济调度优化模型研究

在以电力系统的发电总燃料量、氮氧化物排放量和电价等3个因素为目标函数,以系统有功平衡、系统正负备用、输出功率以及输出功率上升速率等相关约束条件的基础上建立了电力系统经济调度的加权优化模型.同时,在综合了粒子群-人工鱼群算法的基础上构建了混合智能算法.最后,用10个机组所组成的火电厂的优化调度问题作为案例,采用混合算法进行求解及结果分析,以说明电力系统经济调度加权优化模型的有效性以及综合智能算法的收敛性和稳定性.     

含蓄电池的孤立微电网系统运行优化研究

针对微电网系统在孤立运行方式下的优化问题,提出了一种含蓄电池的微电网多目标运行优化方法.求解方法分为2步:储能单元运行方式的确定及可控型微电源的优化调度.微电网储能单元的运行方式根据当前调度时刻的负荷需求、可再生能源发电期望、储能单元的荷电状态等因素,采用功率差控制策略对储能单元进行管理.可控型微电源的出力分配,在考虑系统功率平衡、微电源出力限值和爬坡约束等条件下,以经济成本和环境成本为目标,利用改进的遗传算法进行求解.该方法不仅发挥了蓄电池削峰填谷的作用,提高了储能单元的经济价值,而且实现了孤立微电网的经济、环保优化运行.以典型微电网系统的日优化调度为算例,验证了所提方法的可行性和有效性.     

基于灰色PSO算法的分布式电网多目标调峰调度优化

针对目前新能源大规模并网,传统的调峰调度运行方式不能满足新能源出力消纳要求的问题,提出一种用户侧主动参与调峰调度的方案.将可调度分布式电源、储能单元和可中断负荷纳入分布式电网系统管理中,引入虚拟电厂的概念对可控负荷以及分布式电源进行控制,以负荷方差最小以及运行成本最小为目标,建立多目标调峰调度模型,并用改进灰色PSO算法对调峰调度模型进行优化求解.以IEEE33节点配电系统为算例进行仿真,结果表明该方法能够有效提高系统调峰能力、增加新能源消纳和降低运行成本.     

基于节能减排多目标优化的发电调度模型研究

为响应国家节能减排的号召,提高能源利用效率,该文选取的目标函数为煤耗量和污染物排放量,将整个发电系统的有功平衡和发电机组的出力作为约束条件,在此基础上,建立了基于等能耗水平、考虑排污费成本累加以及环境优化的节能发电调度模型,同时建立了基于系统安全运行条件下的节能减排多目标优化发电调度模型。通过验证,该模型能够使污染物排放量和煤耗量两个目标函数同时达到帕累托最优,从而实现整个系统的节能减排发电调度。     

电网关口外送电交易能力的多目标分层优化研究

研究电网的外送电交易能力的内涵;建立了以系统发电成本最小和关口外送电交易最大为目标并考虑机组约束、网络约束以及节点负荷水平约束等的评估模型;利用分层优化结合粒子群算法求解.该模型第一层以电网的电力系统经济调度为前提,第二层在极小化本系统发电成本的基础上,求取关口最大外送电交易能力.通过IEEE30节点系统仿真计算,表明该方法能有效获取关口外送电交易能力指标.     

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.     

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.     

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.     

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.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.