Adaptive intelligent techniques for microgrid control systems: A survey

This paper introduces a survey on the adaptive and intelligent methods that have been applied to microgrids systems. Interestingly, the adaptive technique is effectively exercised in various control issues including stability, tracking error, and parameter uncertainties. Adaptive control has been extremely developed by using intelligent algorithms to automatically tune the control parameters namely fuzzy logic, particle swarm optimization, bacterial search algorithm, and etc. The objective is to evaluate and classify the design control methods and evaluation algorithms for the microgrid systems to maintain stability, reliability, and load variations by adjusting the controller parameters especially in standalone operation mode. The stability of islanded microgrids are constantly impacted by the related loads. A significant part of the research on an islanded microgrid involves droop control technique. In normal operation, distributed generation units and storage units provide power quality control. Once a shutdown is occurred, microgrid can be isolated from the main grid and operate in a local grid to support the local loads. Thus, distributed generations co-operate storage units to sustain the stability of the islanded microgrid.     

形式的理性创造——“现代造型语言：椭圆界与信息造型”中日合作教学实践评析

国际合作教学是当今建筑教育培养国际化人才、拓展多元化教学实践、建设“高水平研究型大学”的必然要求.通过对2012年重庆大学建筑城规学院一年级“椭圆界与信息造型”中日合作教学过程的回顾,指出信息造型作为形式创造的一种理性设计方法和思维方式在设计教学与实践中的必要性,着重分析其在形式的句法、表达、思维等方面的方法机制,进而探讨合作教学在衔接、反馈、导入等关键环节中的经验和问题,以期对基础造型教学的改革创新及国际合作教学交流有所裨益.     

Dynamic modeling of the quantitative risk allocation in construction projects

Allocation of construction risks between owners and their contractors has a significant impact on the total construction costs. This research presents an integrated fuzzy-system dynamics approach for quantitative risk allocation. All the factors affecting the risk allocation process are modeled using system dynamics approach. Fuzzy logic is integrated into system dynamics modeling structure to account for the existing uncertainties. The values of different factors that have an uncertain nature are determined by fuzzy numbers. The application of Zadeh's extension principle and interval arithmetic is proposed for the system dynamics to enable the system outcomes to be presented considering uncertainties in the input variables. Using the proposed integrated fuzzy-SD model, the project cost is simulated at different percentages of risk allocation. The optimum percentage of risk allocation is determined as a point in which the project cost is minimized. The performance of the proposed method is assessed by employing the method in a tunneling project.     

适用于高频连接方式的直流配电系统分层逻辑控制

基于模块化的高频隔离功率变换系统为基础,搭建了含有光储系统和工频负载的直流配电系统实验模型。设计了实验模型的3种运行模式,并通过对系统电压、功率关系及各并网接口模块工作特性的分析,提出一种以直流母线电压为主要控制量的分层逻辑控制系统。分层逻辑控制系统分为数据采集、模式识别、逻辑组合和指令执行4个控制层,各层间无需互联通信,通过各并网接口模块所离散出的12个子控制器,以就地控制方式保证系统功率平衡、电压稳定及各接口模块间的协调配合。最后通过Matlab/Simulink仿真实验,验证了所提出的控制策略在直流配电系统运行控制中的正确性和有效性。     

排油注氮灭火装置控制系统设计研究

电力变压器是电力系统安全稳定运行的关键,也是电网中最重要的一次设备。正常运行时,继电保护装置能为变压器安全提供可靠保障。然而针对变压器内部故障可能引发的火灾和爆炸恶性事故,采用排油注氮装置是目前最常用的手段之一。控制系统设计是保证排油注氮装置可靠工作的关键。首先介绍了排油注氮装置的工作原理,然后从双重化架构、自动启动逻辑、其他辅助措施等方面对控制系统的设计进行了研究,并提出了改进的超压启动判据,保证控制系统能够更加灵活的适应不同的压力变化情况。     

威尼斯城市场所营造研究

威尼斯古城本身是一个复杂的场所系统,其中包含着不同层级的场所形态。本文通过对威尼斯城市场所形态的观察、研究,对其场所空间生长机制、场所结构逻辑以及场所空间特征进行分析总结。     

Hybrid intelligent inference model for enhancing prediction accuracy of scour depth around bridge piers

Bridge-pier scouring is a main cause of bridge failures. Thus, accurately predicting the scour depth around bridge piers is critical, both to specify adequate depths for new bridge foundations and to assess/monitor the safety of existing bridges. This study proposes a novel artificial intelligence (AI) model, the intelligent fuzzy radial basis function neural network inference model (IFRIM), to estimate future scour depth around bridge piers. IFRIM is a hybrid of the radial basis function neural network (RBFNN), fuzzy logic (FL), and the artificial bee Cclony (ABC) algorithm. In the IFRIM, FL is used to handle the uncertainties in input information, RBFNN is used to handle the fuzzy input–output mapping relationships, and the ABC search engine employs optimisation to identify the most suitable tuning parameters for RBFNN and FL based on minimal error estimation. A 10-fold cross-validation method finds that the IFRIM model achieves at least 21% and 14.5% reductions in root mean square error and mean absolute error values, respectively, compared with other AI techniques. Study results support the IFRIM as a promising new tool for civil engineers to predict future scour depth around bridge piers.     

Andalusia,Spain: An Assessment of Coastal Scenery

The 1101 km length of the Andalusian coast (Spain) was assessed for coastal scenery at 45 specific locations. Selected areas covered resort (3), urban (19), village (8), rural (10) and remote (5) bathing areas. Scenery was analyzed for physical and human parameters via 26 selected parameters. These parameters were obtained by interviews of >500 people on European beaches. Each parameter was assessed via a one-to-five-point attribute scale, which essentially ranged from presence/absence or poor quality (1), to excellent/outstanding (5). Results were subsequently weighted by interviewing >600 bathing area users (not all 26 parameters have equal weight) and subjected to fuzzy logic mathematics in order to reduce recorder subjectivity. High weighted averages for attributes 4 and 5 (excellent/outstanding) reflected high scenic quality, vice versa for attributes 1 and 2. Sites were classified into five classes ranging from Class 1 sites having top grade scenery to Class 5, poor scenery. Seven sites each were found in Classes 1 and 2; 10 sites each in Classes 3 and 5; 11 sites in Class 4. The finest coastal scenery was found in remote areas whilst urban areas scored mainly as Class 3 or 4. Three out of the ten rural sites had Class 3 and 4 values assigned them whereas the rest scored as Class 1 and 2; village sites invariably had scores within Class 3 and 4. Of the three resort sites investigated, one scored as a Class 1 site, the others as Class 3.     

建筑中柱的力与形

从建筑构件中柱的受力特性出发,通过解析其水平力、侧向力、截面应力和力的矢量等,厘清柱形态衍生的内在力学动力,拓展出一条基于结构逻辑的形态设计方法。由此揭示出结构力学特性与建筑构件形态的关系,使结构思维真正在建筑设计中得以体现,实现建筑结构与形态的整合,技术与艺术的统一。