英国区域绿色空间控制管理的发展与启示

从国家到地方层面,对英国2011年以前区域绿色空间的实施控制方法进行了分析与总结。国家层面,通过制定系列的规划法令和规划指引政策体系,并结合部门导则性的文件,保护和调控区域绿色空间的区域整体发展;地方层面,通过地方发展框架编制过程中绿色基础设施(GI)规划的程序化引导,地区性的规划指引对国家层面政策指南的补充和细化,以及采用规划管理过程中的多元控制管理工具,保障区域绿色空间规划实施的控制管理。最后,通过分析我国近年来的相关规划与实施现状,讨论英国的这一体系对今后中国区域绿地规划管理发展的重要启示。     

合同能源管理模式下既有住宅节能改造收益分配研究——基于华北地区的分析

针对合同能源管理模式下既有住宅节能改造收益分配问题,明确不同采暖条件下既有住宅的改造适宜程度及改造收益分配主体,以最适宜改造的非市政集中供暖住宅小区为研究对象,采用合作博弈理论建立收益分配模型并使用不同方法求解。研究结论可为既有住宅节能改造收益分配的市场化提供借鉴。     

铁路继电器触点表面形貌及失效机理分析

目的深入研究铁路继电器触点的失效机理。方法在直流条件下进行铁路继电器电寿命试验,自动识别静触点表面与动触点的接触区域。利用三维形貌扫描仪和扫描电镜扫描触点,选定平面基准面,计算触点表面粗糙度参数,分析触点表面形貌变化。对触点烧蚀后的表面进行元素分析,研究触点表面的微观组织结构和失效机理。结果 Sa/Sq的值小于0.8表示随机性较强的表面,Sa/Sq(静)=0.246Sa/Sq(动)=0.291,即继电器触点在额定运行后,表面凹凸形貌均具有很强的随机性,静触点表面的随机性明显强于动触点。分析继电器动、静触点起伏变化(Sp+Sv),静触点为109.786,远大于动触点26.08,表明静触点的起伏变化明显,幅度较大,动触点幅度变化较小,相对平坦。继电器表面基本以Ag和Cd元素为主,Cd含量变化平稳,在明显裂缝处含量极低。相对于动触点,静触点表面凹坑和龟裂状裂纹清晰可见,腐蚀严重。裂缝凹坑区域和凹坑边缘区域Ag和Cd的原子百分比约为2∶1,磨损颗粒区域Ag和Cd的原子百分比约为0.5∶1。相对平坦区域腐蚀程度很浅,Ag和Cd的原子百分比约为5∶1。触点阴极,即静触点表面,存在反应Cd+2OH~-→Cd(OH)_2+2e,部分Ag被磨损,附着在动触点凸起表面。另一部分Ag进行反应Ag++Cl-→Ag Cl,绝大多数Ag进行了Ag+O→Ag_2O反应。结论归纳出了表面形貌和失效之间的联系,动触点表面有微小颗粒沉积,表面高度变化区域性明显。静触点表面凹凸裂痕分界清晰,表面高度变化呈现横向规律性。触点在裂缝凹坑和凹坑边缘区域元素腐蚀情况相当,磨损颗粒区域存在一部分材料从阴极转移到阳极,相对平坦区域存在一部分材料从阳极转移到阴极。     

探究智能变电站的继电保护二次回路故障诊断问题

本文即针对当前智能变电站中的故障诊断问题展开分析,主要以继电保护二次回路故障检测为主,就诊断检测系统进行阐述,总结了能够针对各种故障问题进行检测手段,意在能够借此提升变电站的智能化发展水平。     

Adaptive actuator failure compensation for cooperative robotic manipulators with parameter uncertainties

This article develops a new framework of adaptive actuator failure compensation control for cooperative manipulator systems with parameter uncertainties in addition to actuator failures, and designs and analyzes effective actuator failure compensation schemes for such robotic systems. The new adaptive control design uses an integration of multiple individual failure compensators and direct adaptation to handle various types of uncertainties in such robotic systems. The design can also be used for concurrent actuator failure cases, to expand the capability of adaptive actuator failure compensation. With a complete proof and performance analysis, it is shown that the proposed control scheme guarantees the desired closed-loop stability and asymptotic output tracking, despite actuator failures whose patterns, time instants and values are all unknown. Simulation results of a benchmark cooperative manipulator system are presented to verify the desired control performance of the system with both typical constant and square-wave actuator failure signals.     

Nash bargaining model for direct electricity trading on distribution side with multi-microgrids participation

随着售电侧电力市场改革的不断深入，研究多微电网参与下的配电侧直接电能交易具有重要意义。针对多微电网与负荷聚合商之间的直接电能交易，以各主体在传统交易方式下的最优效益作为谈判破裂点，提出了一种基于合作博弈论的纳什议价模型，模型中博弈参与者可获得帕累托最优效益。模型为非线性非凸问题，不易直接求解，将其分成求解支付和联盟效益最大化两个子问题。为保护交易主体内部隐私，联盟效益最大化问题采用交替方向乘子法进行分布式求解，交易双方在求解过程中仅需相互交换期望的交易电量。仿真结果表明该模型可以有效地提升交易双方的运营效益。     

Ground robotics in tunnels: Keys and lessons learned after 10 years of research and experiments

The work reported in this article describes the research advances and the lessons learned by the Robotics, Perception and Real‐Time group over a decade of research in the field of ground robotics in confined environments. This study has primarily focused on localization, navigation, and communications in tunnel‐like environments. As will be discussed, this type of environment presents several special characteristics that often make well‐established techniques fail. The aim is to share, in an open way, the experience, errors, and successes of this group with the robotics community so that those that work in such environments can avoid (some of) the errors made. At the very least, these findings can be readily taken into account when designing a solution, without needing to sift through the technical details found in the papers cited within this text.     

Asymmetric relay autotuning – Practical features for industrial use

The relay autotuner provides a simple way of finding PID controller parameters. Even though relay autotuning is much investigated in the literature, the practical aspects are not that well-documented. In this paper an asymmetric relay autotuner with features such as a startup procedure and adaptive relay amplitudes is proposed. Parameter choices and handling of noise, disturbances, start in non-steady state and other possible error sources are discussed. The autotuner is implemented and tested on an industrial air handling unit to show its use in practice. The experiments show good results, and prove that the proposed simple autotuner is well-suited for industrial use. But the experiments also enlighten possible error sources and remaining problems.     

Cooperative games with nontransferable utility on antimatroids

This paper introduces a new family of nontransferable utility (NTU) games with partial cooperation. Games with transferable utility (TU) restricted by antimatroids were studied since 2004. Antimatroids are known combinatorial structures which are interpreted in games as dependency situations among a group of agents, and they generalize several other hierarchical structures studied in the literature. Now we define projected NTU games over antimatroids following the same idea. We have needed to build a new theory about projections between two coalitions. In this case, an outcome is feasible for a coalition if and only if its projection is feasible in the NTU game. This paper studies several properties of the projected games and the relations between these games and the original game for some interesting cases: TU games, hyperplane games and bargaining problems.     

A new approach for mitigating blackout risk by blocking minimum critical distance relays

Electric power systems are complex and commonly run near their operational limits. Power systems are basically designed based on the (N − 1) criterion. In these systems, total or partial blackouts are unavoidable. Cascading failures following an initial event is recognized as the main mechanism for power system blackouts. Undesirable activation of zone 3 of distance relays due to their local function has been identified as one of the major causes for propagation of cascading failures. In this paper, in order to mitigate the risk of power system blackouts, a novel approach is proposed for recognizing the critical line outages with the highest contribution in cascading failure and preventing their undesirable outage by blocking zone 3 of their distance relay. In this paper, based on the statistical activation of distance relays, a deterministic–probabilistic approach is developed for identifying the critical lines with the highest contribution in blackouts due to activation of zone 3 of their distance relays. In order to avoid interference of relay blocking with the main protection duty of distance relays, the proposed approach recognizes the minimum critical lines with the highest contribution in cascading failure for blocking zone 3 of their distance relays. The proposed approach is demonstrated on the New England 39-bus system and detailed simulation studies carried out to examine the validity and effectiveness of the proposed approach.