光伏发电功率持续时间特性的概率分布定量分析

随着光伏发电渗透率在电力系统中的快速增加,电网的规划和调度过程中均有必要对其进行精细化的考虑。但光伏发电功率具有较强的随机性,对其稳态功率特性的描述需要采用概率统计手段。首先根据光伏出力运行点及其波动限值定义了光伏出力状态,然后针对光伏出力维持在某一状态不变的时间长度进行了定量研究,提出了光伏发电功率持续时间分布的概念。基于德国和中国实测数据的分析表明:光伏出力的持续时间分布存在明显的双峰值特征,适合采用逆高斯分布和广义极值分布函数进行加权混合拟合;双峰值特征表明,光伏发电可能在局部云层扰动下出现快速功率波动,从而只能在数分钟内保持出力状态不变,也可能在天气条件良好时跟随日地运动缓慢变化,其出力可维持某一状态长达数小时。所述研究可用于光伏发电功率调度控制过程中测量和决策周期的选定、光伏电站输出波动限值检验等,进而为输电系统中设备的设计选型提供重要的参考依据。

基于风电场群汇聚演变趋势的场群持续功率特性预测方法

大规模开发、集中外送是我国风电开发的特有模式。由于风力发电具有随机性、波动性及低功率密度等特性,在进行大规模风电联网规划时,易造成输电通道配置过度或不足的问题。持续功率曲线能够有效表征风电场群输出功率的长期波动规律性,准确把握规划目标年风电场集群持续功率特性是科学配置外送输电容量的关键。为此,该文通过深入分析不同规模风电场群功率变化趋势,揭示了风电场群汇聚过程中'装机容量–功率'的关联关系,进而构建风电场群的汇聚演变模型,实现了已知未来风电场群总装机容量的条件下,规划目标年风电场群持续功率特性的准确预测。最后,分别应用东北、西北两大风电基地历史实测数据对预测方法进行校验,结果表明所提方法是易行、有效的。

适应、成长和可持续:当下成人教育的自然历史特性

本文从唯物史观出发分析当下成人教育发展的规律性。结合全球化、知识经济和学习型社会的社会历史条件,从社会及社会个体学习者角度进行的分析表明,社会及学习者的适应、成长和可持续发展是成人教育应该实现的意义。

基于AP聚类-跳转持续MC的风电出力时间序列模拟生成方法研究

模拟生成概率等效条件下的风电出力时间序列对分析未来场景下风电出力不确定性以及提高风电消纳水平具有重要意义。针对传统马尔科夫链存在的问题,文中提出一种基于AP聚类-跳转持续马尔科夫链(Affinity Propagation Clustering-Transition and Persistence Markov Chain,AP-TP MC)的风电出力时间序列模拟生成方法。首先,对历史风电出力数据进行AP聚类,并对每一聚类类别下的风电序列建立相应的状态跳转矩阵;其次,依据马尔科夫链模型,结合风电出力状态持续时间特性,抽样并叠加符合混合高斯分布的波动分量,形成某一聚类类别下的风电出力时间序列;然后,依托类间转移矩阵,模拟生成风电出力时间序列;最后,通过对比传统马尔科夫链法与文中方法生成的风电出力时间序列与历史序列之间的统计指标、概率分布指标及自相关性指标,验证所提方法的有效性和准确性。

从典型社区看重庆市公共租赁住房制度的创新性、独特性和可持续性

重庆市公共租赁住房政策和实践产生伊始就广受瞩目,其规模之大在国内不多见,同时重庆在运作管理、资金筹措、土地储备、加强退出机制实操性以及未来出售公租房等方面进行了制度创新。本文以重庆第一个公租房小区(民心佳园)作为案例,通过实地考察、地方政府相关认识走访以及居民调查等研究方法,详细阐述了重庆市公共租赁住房制度的创新性和独特性。同时文章也指出重庆公租房经验的普适性仍然亟待考量,而且如何实现公租房建设的可持续性、如何确定公租房的目标人群、未来如何确保公租房资金的连续性等问题,还需要重庆市在公租房的实践中不断摸索与思考。

含风电功率时域特性的风电功率序列建模方法

为了能够生成与已有风电功率序列数据特性一致的风特性的改进马尔可夫链蒙特卡罗(Markov chain Monte Carlo,PV-MC)法,即持续与波动蒙特卡罗(persistence and variation-Monte Carlo,PV-MC)法。该方法基于风电功率状态,首先生成满足状态跳变率矩阵的状态序列;而后,利用风电功率状态的持续特性,确定状态序列中状态的持续时间,得到满足持续特性的状态序列;最后,基于波动特性,将状态序列转换为风电功率序列。利用PV-MC方法与传统的MCMC法分别对全球6个不同地区共26座风电场生成风电功率序列,并与原始风电功率序列进行特性对比分析,结果表明:无论在基本统计特性(均值、标准差、概率密度函数和自相关系数)还是在时域特性(持续性和波动性)上,PV-MC法生成的风电功率序列都优于传统的MCMC法所生成的序列。

确定风电场群功率汇聚外送输电容量的静态综合优化方法

风电大规模集中并网是实现风能大规模开发利用的重要途径。由于风电电源具有输出易变、能量密度低等特点,在进行风电外送配套输电系统的容量规划时,必须考虑风电功率整体波动特性的影响。对多个风电场汇聚成风电场群后的功率波动特性进行量化分析,以风电场群的持续出力曲线描述其变化规律;在此基础上,提出一种风电场群功率汇聚外送输电容量的静态优化方法,该方法综合考虑了诸如电网输电收益、输电工程建设成本以及可能的阻塞造成弃风损失等因素对风电外送输电工程综合收益的影响。算例表明该方法与以风电场群总装机容量来规划外送输电容量的方法相比,能够显著提高输电工程的综合效益。

试论法语计量补语与数字限定的相互转换

试论法语计量补语与数字限定的相互转换方仁杰Ｒｅｓｕｍｅ：Ｕｎｃｏｎｇｅｄｅｔｒｏｉｓｊｏｕｒｓ（ｕｎｃｏｍｐｌｅｍｅｎｔｄｅｄｕｒｅｅ），ｔｒｏｉｓｊｏｕｒｓｄｅｃｏｎｇｅ（ｕｎｅｑｕａｎｔｉｆｉｃａｔｉｏｎｅｎｔｅｒｍｅｓｄｅｄｕｒｅｅ），ｃｅｓｄ...

风电场群出力的汇聚效应分析

分析大规模风电场群的汇聚效应特性,找出其中的规律,可以帮助电网更为合理的接纳风电,提高新能源利用效率。通过实测某省级电网的风电场群运行数据,基于时间序列、频谱分析、概率统计等方法,分析风电场、风电场群的风电功率变化特征,获取风电场群出力的汇聚效应特性。

Effect of discontinuities characteristics on coal mine stability and sustainability： A rock fall prediction approach

Rock fall related accidents continue to occur in coal mines,although artificial support mechanisms have been used extensively. Roof stability is primarily determined in many underground mines by a limited number of methods that often resort to subjective criteria. It is argued in this paper that stability conditions of mine roof strata,as a key factor in sustainability in coal mines,must be determined by a survey which proactively investigates fundamental aspects of said mine. Failure of rock around the opening happens as a result of both high rock stress conditions and the presence of structural discontinuities. The properties of such discontinuities affect the engineering behavior of rock masses causing wedges or blocks to fall from the roof or sliding out of the walls. A practical rule-based approach to assess the risk of a roof fall is proposed in the paper. The method is based on the analysis of structural data and the geometry and stability of wedges in underground coal mines. In this regard,an accident causing a huge collapse in a coal mine leading to 4 fatalities is illustrated by way of a case study. Horizontal and vertical profiles are prepared by geophysical methods to define the falling zone and its boundaries. The collapse is then modeled by the use of sophisticated computer programs in order to identify the causes of the accident.

Amman＇s Land Typology： The Importance of Site Characteristics on the Delivery of Sustainable Buildings

Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.

Integration and Innovation of the Urban Water Cycle： The Waternet Experience

Waternet is the first water cycle company in the Netherlands, responsible for drinking water treatment and distribution, wastewater collection and treatment, and water system management and control in and around Amsterdam. Waternet started on 1 January 2006 to overcome the disadvantages of the rather fragmented organisation of the Dutch public water sector. The water cycle concept offers better opportunities to meet the future challenges in the water sector. The first four years of operation of Waternet show very promising results with respect to efficiency, customer orientation and quality improvement. To further develop the water cycle concept and to find sustainable solutions for the challenges the water sector is confronted with, Waternet focuses on six strategic innovation areas the coming years： water resources and water system; closing the water cycle; sustainability; new sanitation concepts; new products and services; management innovations.

Functioning Hydraulic and Morphological Sustainability of River Training Works in Bangladesh

River dynamics play the most vital role in the socio-economic of the country. These rivers are highly dynamic in nature which causes extensive riverbank erosion. Active river bank erosion and bed scouring, is apprehended to change the scenario, leading to loss of limited valuable land of Bangladesh. River training is being practiced in Bangladesh since 1960s but the process is very expensive especially in the Ganges and the Jamuna Rivers. Five types of river training works were selected at different reaches. Hydro-morphological characteristics of the major rivers are being evaluated not only in engineering concepts but also in socio-economic and environmental aspects. PRA （participatory rural appraisal） tools were applied to evaluate protection safety, hydraulic and hydrological connectivity, ecological and environmental characteristics, causes of failure and social acceptability. This comparative study is being carried out for closing the gap between the modem river training works and in country experience through adaptation of research findings with a view to effectively arresting river bank erosion. Sirajganj Hardpoint, Chandpur Town Protection work and Nakalia Revetment are found to be suitable and effective. A technically suitable structure may not have good social acceptance without IWRM （integrated water resource management）.

Role of hydro-geochemical functions on karst critical zone hydrology for sustainability of water resources and ecology in Southwest China

Focusing on sustainability of water resources and ecology in the complex karst critical zone, we illustrated functions of the hydro-geochemical analysis on hydrology from the aspects of connection and interaction among hydrology–vegetation–soils/rock fractures along the karst subsurface profile. We reviewed isotopic and geochemical interpretations on tracing water sources for plant uptake, quantifying watershed outlet flow composition and residence times, and evaluating long-term evolution among climate–landscape–hydrology in the karst critical zone. In this paper, the application of the hydro-geochemical analysis on the above aspects in the karst areas of southwest China was summarized.

Research on the road landscape evaluation system with the emphasis on the landscape ecology

As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the rationality of the road construction fi＇om the multiple angles of the landscape ecology, and the visual art and so on. From the point of view of the landscape ecology, combined with the characteristics of the landscape ecology and the overall targets and requirements of the evaluation, this article constructs a three-tier system of indicators, uses the fuzzy comprehensive evaluation model based on the analytic hierarchy process to evaluate the road landscape, and makes an empirical analysis with the evaluation of the road landscape fi＇om the Luoshi Road to the East Lake Road in the Second Loop of Wuhan City as an example.

Characteristics of Far-field Precursory Anomalies Before the M_S8.1 Earthquake in the West of Kunlun Mountains Pass

In this study, a number of typical precursory anomalies recorded by stations in Qinghai, Gansu, Sichuan, Xinjiang, Ningxia, Hebei and Shaanxi provinces and autonomous regions before the Ms8.1 earthquake in the west of Kunlun Mountains Pass are collected and checked. According to the standards of earthquake cases in China, the criteria of the precursory anomalies are determined, and 53 distinguished. The characteristics of these anomalies before the Ms S. 1 earthquake are analyzed, with results showing a very large earthquake affected area. The precursory anomalies recorded by instruments were 2900 km away from the epicenter, and according to the study in this paper, reached 2100 km away. The results also show that the anomalies present characteristics of long duration, multi-measurement items and large-amplitude variation. The authors believe that in large earthquake monitoring, attention should be paid to the variation of data over a large area, ranging up to thousands kilometers, with much denser earthquake observation networks.

An investigation of the persistence property of wind power time series

Mining the inherent persistence property of the time series of wind power is crucial for forecasting and controlling wind power.Few common methods exist that can fully depict and quantify the persistence property.Based on the definition of the active power output state of a wind farm,this paper describes the statistical persistence property of the duration time and state transition.Based on the results of our analysis of significant amounts of wind power field measurements,it is found that the duration time of wind power conforms to an inverse Gaussian distribution.Additionally,the state transition matrix of wind power is discovered to yield a ridge property,the gradient of which is related to the time scale of interest.A systemaic methodology is proposed accordingly,allowing the statistical characteristics of the wind power series to be represented appropriately.

Feature analysis of LIDAR waveforms from forest canopies

Airborne light detection and ranging (LIDAR) can detect the three-dimensional structure of forest canopies by transmitting laser pulses and receiving returned waveforms which contain backscatter from branches and leaves at different heights.We established a solid scatterer model to explain the widened durations found in analyzing the relationship between laser pulses and forest canopies,and obtained the corresponding rule between laser pulse duration and scatterer depth.Based on returned waveform characteristics,scatterers were classified into three types:simple,solid and complex.We developed single-peak derivative and multiple-peak derivative analysis methods to retrieve waveform features and discriminate between scatterer types.Solid scatterer simulations showed that the returned waveforms were widened as scatterer depth increased,and as space between sub-scatterers increased the returned waveforms developed two peaks which subsequently developed into two separate sub-waveforms.There were slight differences between the durations of simulated and measured waveforms.LIDAR waveform data are able to describe the backscatter characteristics of forest canopies,and have potential to improve the estimation accuracy of forest parameters.

The effect of finite duration inputs on the dynamics of a system： Proposing a new approach for cancer treatment

In this paper, a principal question regarding the effect of inputs on the characteristics of dynamic systems is discussed. Whether an input implemented only for a limited duration, can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input？ In this paper, it is shown that a limited time acted input is not able to change the dynamical properties of a system after its elimination. Regarding the proposed approach, a novel finite duration treatment method is developed for a tumor-immune system. The vaccine therapy is used to change the parameters of the system and the chemotherapy is applied for pushing the system to the domain of attraction of the healthy state. For optimal chemotherapy, an optimal control is used based on state-dependent Riccati equation （SDRE）. It is shown that, in spite of eliminating the treatment （therapeutic inputs）, the system approaches to healthy state conditions. The present analysis suggests that a proper treatment method must change the dynamics of the cancer instead of only reducing the population of cancer cells.