A Stroke-Limitation AMD Control System with Variable Gain and Limited Area for High-Rise Buildings

Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a strokelimited AMD control system with a fixed limited area shortens the available AMD stroke and leads to significant control power.To solve this problem,the design approach with variable gain and limited area(VGLA)is proposed in this study.First,the boundary of variable-limited areas is calculated based on the real-time status of the moving mass.The variable gain(VG)expression at the variable limited area is deduced by considering the saturation of AMD stroke.Then,numerical simulations of a stroke-limited AMD control system with VGLA are conducted on a high-rise building structure.These numerical simulations show that the proposed approach has superior strokelimitation performance compared with a stroke-limited AMD control system with a fixed limited area.Finally,the proposed approach is validated through experiments on a four-story steel frame.

DETERMINATION ABOUT THE NORTHWESTERN AREA LIMIT OF PINUS KORAIENSIS AND THE GEOGRAPHIC OCCURRENCE OF PINUS SIBIRICA

By investigation, studying and discussion for 9 years, the determination that it should be Pinus sibirica growing in the Mohe county, Daxing'anling Mountains area, China, rather thanpinus koraiensis there, is made to correct a false argument in some works from 1950s' till now that Pinus koraiensis area limit reach Daxing'anling Mountain. The results are as follows: (1) The species so called as Pinus koraiensis found in northwest of Daxing'anling Mountain is Pinus Sibirica indeed; There arc no natural distribution of Pinus Koraiensis in Daxing'anling Mountain. Its northwest area limit only reach Shcngshan, Aihui county; (3) There is about 500km of space between the area limits of Pinus koraiensis and that of Pinus sibirica, no mixed growing area. According to above, a sketch map is made to describe different area limit of the two species at Daxing'anling Mountain and nearby.

有限广域继电保护系统的分区原则与实现方法

对于结构复杂的实际大电网,合理的保护分区是基于集中式结构的广域继电保护工程应用中需要重点解决的关键技术之一。文中基于广域继电保护的有限性概念,论述了广域继电保护系统的分区原则,涵盖变电站中心站的选取、有限广域继电保护范围、边界区域的交互等基本分区原则,满足每条线路在至少一个分区内能实现远后备保护,同时,广域区域内保护分区数目达到最少。将图论技术应用于广域继电保护系统分区的实现,提出基于4级邻接矩阵的搜索方法,原理简单,运算方便,易于实现。IEEE10机39节点系统的仿真结果验证了该保护分区原则与实现方法的可行性。

IMPACT OF HUMIDITY DATA ON THE PREDICTION OF ONSET VORTEX WITH A LIMITED AREA MODEL

A limited area model has been applied to study the impact of satellite-derived relative humidity data on the predic- tion of onset vortex of monsoon 1979.The results show that inclusion of satellite-derived relative humidity data im- proved the prediction of track of the cyclonic circulation and the rainfall rates in the region of the vortex.

THE LIMITED AREA ANALYSIS AND FORECAST SYSTEM AND ITS OPERATIONAL APPLICATION

The limited area analysis and forecast system(LAFS)was developed and has been put into operational use at National Meteorological Center since January 1991.This system can be regarded as a branch system attached to the global assimilation and medium-range forecast system which is based on a spectral model T42L9.The main advancements as an upgrade operational system are as follows:the use of a regional fine mesh optimum interpolation(OI)analysis scheme:the realiza- tion of the nonlinear normal mode initialization for the regional model:the development of a 15L- spherical grid primitive equation model(with real topography and enstrophy conservation)and its nesting forecast with the spectral model T42L9.

BMC LIMITED AREA MODEL GENERAL DESCRIPTION AND OPERATIONAL RESULTS

The limited area 5-level primitive equation model,as the first operational precipitation forecast model in China,has been run at Beijing (National) Meteorological Center (BMC) for more than four years.The opera- tional results show that this model gives continuous services,and the forecast skill is satisfied for the forecast of some weather situations,such as extratropical cyclone,front and the precipitation associated with them. The forecast guides are widely used at the local weather services now.

An adaptive limited wide area differential protection for power grid with microsources

The operation mode of power grids with intermittent distributed generations(DGs)changes frequently due to the bidirectional power flow.In comparison with the conventional grids,the protection relays in power grids with micro-sources are more difficult to set.To tackle this problem,this paper proposes an extended bus differential protection(EBDP)strategy based on the limited wide area(LWA).In this method,the micro-grids are divided into several protection areas at the core of the bus.The whole protection areas are protected by the wide area current differential relays,which are also configured to protect each component in this protection area.Moreover,the protection areas can be changed adaptively according to the power flow direction.Finally,a micro-grid model with multiple DGs is developed using the PSCAD/EMTDC platform.The simulation results indicate that the proposed adaptive limited wide area differential protection(LWADP)has better performance than the traditional relaying protection in detecting the faulty area in micro-grids and isolating the fault,and can be widely utilized in larger micro-grids.

The research and the development of the wide area relaying protection based on fault element identification

The urgent problem of the relaying protection in the modern AC/DC hybrid connected grid and the development of the wide area communication,the information process and the intelligent technology powerfully promotes the development of the technology of the wide area relaying protection(WARP),which has become a research hotspot that attracts extensive attention.Originated from the basic concept of the wide area relaying protection,this paper analyses the advantages,the effects and the functions of the wide area relaying protection.The two main approaches to realize the wide area protection,which are on-line adaptive setting(OAS)principle and fault element identification(FEI),are introduced in this paper.Aimed at improving the performance of the backup protection,the research content and the technology demand of the wide area protection are proposed,meanwhile,the basic principle and the algorithm of the fault element identification are introduced.At last,the scheme of the limited wide area relaying protection based on the existing pilot channel of the main protection is discussed.

Key limitations in the assessment of global roadless areas

Subject Code:C03 With the support by the National Natural Science Foundation of China and Ministry of Science and Technology of China,the research team led by Dr.Wu Ruidong(武瑞东)from Yunnan University reveals several key limitations in the study of global roadless areas mapping and assessment,which was

ON THE SENSITIVITY OF PRECIPITATION FORECASTS TO THE MOIST PHYSICS AND THE HORIZONTAL RESOLUTION OF NUMERICAL MODEL

The impacts of the enhanced model's moist physics and horizontal resolution upon the QPFs (quantitative precipitation forecasts)are investigated by applying the HIRLAM(high resolution limited area model)to the summer heavy-rain cases in China.The performance of the control run, for which a 0.5°×0.5°grid spacing and a traditional“grid-box supersaturation removal+Kuo type convective paramerization”are used as the moist physics,is compared with that of the sensitivity runs with an enhanced model's moist physics(Sundqvist scheme)and an increased horizontal resolution(0.25°×0.25°),respectively.The results show: (1)The enhanced moist physics scheme(Sundqvist scheme),by introducing the cloud water content as an additional prognostic variable and taking into account briefly of the microphysics involved in the cloud-rain conversion,does bring improvements in the model's QPFs.Although the deteriorated QPFs also occur occasionally,the improvements are found in the majority of the cases,indicating the great potential for the improvement of QPFs by enhancing the model's moist physics. (2)By increasing the model's horizontal resolution from 0.5°×0.5°,which is already quite high compared with that of the conventional atmospheric soundings,to 0.25°×0.25°without the simultaneous enhancement in model physics and objective analysis,the improvements in QPFs are very limited.With higher resolution,although slight amelioration in locating the rainfall centers and in resolving some finer structures of precipitation pattern are made,the number of the mis- predicted fine structures in rainfall field increases with the enhanced model resolution as well.