风电机组的开放移动控制结构和主控系统设计

针对风电机组点对点封闭结构和随机非线性问题,提出了风电机组的开放移动控制结构和功率曲线LUT线性化方法。在风电机组的线性化转矩和变桨开放移动控制结构框架里,采用PLCopen移动控制系统设计标准设计风电机组主控系统。基于PLCopen标准的风机主控系统设计方法明确了风机转矩和变桨控制器的设计依据和开发标准,对风电机组的主控系统设计和风机整机控制系统集成有指导意义。     

中国首个风电塔架地方标准在甘肃诞生

<正>国内第一个关于风电塔架的制造、安装、检验及验收的地方标准于6月29日经省质监局发布并实施,这意味着甘肃省打造"陆上三峡"又有了技术支撑。据了解,目前我国风电设备标准大多是采用欧洲或国际标准,符合我国国情的风电设备标准体系尚未完全形成,风电机组制造、检测和调试标准尚未形成完     

兆瓦级风电机组风力桨叶多学科设计优化

为了提高兆瓦级风电机组风力桨叶整体性能,以兆瓦级风电机组风力桨叶气动性能、质量、桨片根部的极限推力和噪声水平为目标函数建立多学科设计优化模型,并充分考虑各学科之间的耦合效应,采用自适应混沌优化算法对多学科设计优化模型进行求解.研究结果表明:兆瓦级风电机组风力桨叶风能利用系数Cp增加12.5％,质量M减小11.00％,桨叶根部的极限推力载荷F减少12.60％,噪声Stotal减小10.48％;兆瓦级风电机组风力桨叶翼型的升力系数和气动性能得到了较大优化.     

双馈风电机组传动链低电压穿越响应分析

为了分析双馈风电机组低电压穿越对传动链齿轮与轴承等部件冲击载荷的影响,分别采用转子有限元法与集中参数法对传动链中的盘、轴、轴承、联轴器以及齿轮等部件进行了动力学建模,结合风电机组气动载荷与控制模型,建立了传动链动态响应仿真程序。利用建立的仿真程序对风电机组稳态工况进行了仿真,筛选出齿轮啮合力与轴承力最大的部件。将风电机组低电压穿越测试曲线加载到仿真程序中,对低电压穿越各类工况动态响应进行了对比分析。结果表明：低电压穿越会对风电机组传动链的齿轮与轴承产生冲击,并且冲击载荷的大小与机组工况载荷、电压跌落幅值以及跌落形式相关,并且这三者的影响因素是依次递减的。     

海上风电机组基础的适用性与选择

海上风电基础在风电的正常建造和运营维护中占有重要的位置。它的选择与受力特点、海床的地质结构情况、海上风浪载荷以及海流、冰荷载等诸多因素有关。因此,海上风电机组的基础被认为是造成海上风电成本较高的主要因素之一,选择经济合理适用的基础结构及施工方法是海上风电场研究开发的主要课题。     

微电网永磁风力发电机的设计

小型风力发电市场潜力巨大。小型风电机组相关设备制造、小型风电技术研发、风电路灯等领域成为投资热点,市场前景看好。本文设计的永磁发电机,具有体积小,功率密度高等特点。     

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.     

风电机组气动载荷研究

风电机组的气动载荷计算极其复杂,涉及电器、结构及气动等多个方面,而且这几个方面的耦合作用会使问题更加复杂。为了仿真研究机组的气动载荷特性,本文联合应用TurbSim,AeroDyn及FAST软件,综合考虑电器、结构及气动等三个方面及其耦合影响,仿真研究风电机组的载荷动态。     

风电机组增速箱制造技术研究与进展

增速齿轮箱作为风力发电设备的核心部件,其制造质量是保证机组整体性能的关键。风电机组增速箱制造是一个涉及多学科的综合性技术,应充分利用现有技术条件,深入研究工艺基础理论,完善工艺控制方法,促进新技术、新工艺、新材料的应用,真正实现数字化精益制造。文章针对风电机组增速箱结构特点和使用工况,结合工程生产实践,总结风电齿轮箱的工艺技术要求和特点;分析风电齿轮箱齿轮、箱体及行星架等关键零部件的制造技术现状及存在的问题,提出提高加工效率和控制热处理变形的措施,最后介绍风电齿轮箱测试技术。文章对指导风电增速箱制造具有一定工程应用价值。     

变工况时频脊流形早期故障预警方法研究

针对风电机组齿轮箱工况复杂多变,提出了一种基于Gabor重排对数时频脊流形早期故障预警方法.该方法首先研究提取Gabor重排对数时频谱的脊线,构建早期故障高维特征向量;然后研究改进局部切空间流形学习方法,进行维数约简;最后采用K-近邻分类器,实现变工况风电机组齿轮箱的早期故障识别与预警.通过变转速、变载荷等多种工况的行星齿轮箱磨损试验与风电机组现场运行数据验证,结果表明该方法有效提高了复杂变工况风电机组齿轮箱早期故障预警准确率,可为其预知维护提供可靠依据.      

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.     

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.     

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.     

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.     

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.     

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.