Risk Assessment for Distribution Systems Using an Improved PEM-Based Method Considering Wind and Photovoltaic Power Distribution

Directory of Open Access Journals (Sweden)

Qingwu Gong

2017-03-01

Full Text Available The intermittency and variability of permeated distributed generators (DGs could cause many critical security and economy risks to distribution systems. This paper applied a certain mathematical distribution to imitate the output variability and uncertainty of DGs. Then, four risk indices—EENS (expected energy not supplied, PLC (probability of load curtailment, EFLC (expected frequency of load curtailment, and SI (severity index—were established to reflect the system risk level of the distribution system. For the certain mathematical distribution of the DGs’ output power, an improved PEM (point estimate method-based method was proposed to calculate these four system risk indices. In this improved PEM-based method, an enumeration method was used to list the states of distribution systems, and an improved PEM was developed to deal with the uncertainties of DGs, and the value of load curtailment in distribution systems was calculated by an optimal power flow algorithm. Finally, the effectiveness and advantages of this proposed PEM-based method for distribution system assessment were verified by testing a modified IEEE 30-bus system. Simulation results have shown that this proposed PEM-based method has a high computational accuracy and highly reduced computational costs compared with other risk assessment methods and is very effective for risk assessments.

Fault-Tolerant Consensus of Multi-Agent System With Distributed Adaptive Protocol.

Science.gov (United States)

Chen, Shun; Ho, Daniel W C; Li, Lulu; Liu, Ming

2015-10-01

In this paper, fault-tolerant consensus in multi-agent system using distributed adaptive protocol is investigated. Firstly, distributed adaptive online updating strategies for some parameters are proposed based on local information of the network structure. Then, under the online updating parameters, a distributed adaptive protocol is developed to compensate the fault effects and the uncertainty effects in the leaderless multi-agent system. Based on the local state information of neighboring agents, a distributed updating protocol gain is developed which leads to a fully distributed continuous adaptive fault-tolerant consensus protocol design for the leaderless multi-agent system. Furthermore, a distributed fault-tolerant leader-follower consensus protocol for multi-agent system is constructed by the proposed adaptive method. Finally, a simulation example is given to illustrate the effectiveness of the theoretical analysis.

Cosmological Final Focus Systems

International Nuclear Information System (INIS)

Irwin, J

2004-01-01

We develop the many striking parallels between the dynamics of light streams from distant galaxies and particle beams in accelerator final focus systems. Notably the deflections of light by mass clumps are identical to the kicks arising from the long-range beam-beam interactions of two counter-rotating particle beams (known as parasitic crossings). These deflections have sextupolar as well as quadrupolar components. We estimate the strength of such distortions for a variety of circumstances and argue that the sextupolar distortions from clumping within clusters may be observable. This possibility is enhanced by the facts that (1) the sextupolar distortions of background galaxies is a factor of 5 smaller than the quadrupolar distortion, (2) the angular orientation of the sextupolar and quadrupolar distortions from a mass distribution would be correlated, appearing as a slightly curved image, (3) these effects should be spatially clumped on the sky

Final Report - Cloud-Based Management Platform for Distributed, Multi-Domain Networks

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Pulak [Ennetix Inc.; Mukherjee, Biswanath [Ennetix Inc.

2017-11-03

In this Department of Energy (DOE) Small Business Innovation Research (SBIR) Phase II project final report, Ennetix presents the development of a solution for end-to-end monitoring, analysis, and visualization of network performance for distributed networks. This solution benefits enterprises of all sizes, operators of distributed and federated networks, and service providers.

Smart Distribution Systems

Directory of Open Access Journals (Sweden)

Yazhou Jiang

2016-04-01

Full Text Available The increasing importance of system reliability and resilience is changing the way distribution systems are planned and operated. To achieve a distribution system self-healing against power outages, emerging technologies and devices, such as remote-controlled switches (RCSs and smart meters, are being deployed. The higher level of automation is transforming traditional distribution systems into the smart distribution systems (SDSs of the future. The availability of data and remote control capability in SDSs provides distribution operators with an opportunity to optimize system operation and control. In this paper, the development of SDSs and resulting benefits of enhanced system capabilities are discussed. A comprehensive survey is conducted on the state-of-the-art applications of RCSs and smart meters in SDSs. Specifically, a new method, called Temporal Causal Diagram (TCD, is used to incorporate outage notifications from smart meters for enhanced outage management. To fully utilize the fast operation of RCSs, the spanning tree search algorithm is used to develop service restoration strategies. Optimal placement of RCSs and the resulting enhancement of system reliability are discussed. Distribution system resilience with respect to extreme events is presented. Test cases are used to demonstrate the benefit of SDSs. Active management of distributed generators (DGs is introduced. Future research in a smart distribution environment is proposed.

GeoCEGAS: natural gas distribution management system

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Lorena C.J. [Companhia de Gas do Ceara (CEGAS), Fortaleza, CE (Brazil); Targa, Fernando O. [Gestao Empresarial e Informatica Ltda. (GEMPI), Sao Paulo, SP (Brazil)

2009-07-01

This Technical Paper approach the conception, architecture, design, construction, and implementation of GeoCEGAS, a spatially enabled corporate management information system, oriented to store and provide Web access, to information associated with the natural gas distribution network, owned by CEGAS. This paper reports business processes, business entities and business intelligence approached on the project, as well as an overview of system architecture, applications, and technology used on the implementation of GeoCEGAS. Finally, is presented an introduction to the work methodology used, as well a synopsis of benefits achievements. (author)

Cardea: Dynamic Access Control in Distributed Systems

Science.gov (United States)

Lepro, Rebekah

2004-01-01

Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems

National Research Council Canada - National Science Library

Zhao, Wei; Bettati, Riccardo; Vaidya, Nitin

2005-01-01

This document is the final report for Providing Survivable Real-Time Communication Service for Distributed Mission Critical Systems, a Texas A AND M project funded through the DARPA Fault Tolerant Networks Program...

Fuzzy comprehensive evaluation for grid-connected performance of integrated distributed PV-ES systems

Science.gov (United States)

Lv, Z. H.; Li, Q.; Huang, R. W.; Liu, H. M.; Liu, D.

2016-08-01

Based on the discussion about topology structure of integrated distributed photovoltaic (PV) power generation system and energy storage (ES) in single or mixed type, this paper focuses on analyzing grid-connected performance of integrated distributed photovoltaic and energy storage (PV-ES) systems, and proposes a comprehensive evaluation index system. Then a multi-level fuzzy comprehensive evaluation method based on grey correlation degree is proposed, and the calculations for weight matrix and fuzzy matrix are presented step by step. Finally, a distributed integrated PV-ES power generation system connected to a 380 V low voltage distribution network is taken as the example, and some suggestions are made based on the evaluation results.

Agent Services for Situation Aware Control of Power Systems With Distributed Generation

DEFF Research Database (Denmark)

Saleem, Arshad; Heussen, Kai; Lind, Morten

2009-01-01

Electric Power system of Denmark exhibits some unique characteristics. An increasing part of the electricity is produced by distributed generators (DGs). Most of these DGs are connected to the network at the distribution level. At the same time the concept of vehicle to grid (V2G) is already...... in the process of realization. This situation has created an incentive in electric power industry to utilize modern information and communication technologies (ICT) for improving the distribution system automation. This paper describes our work on how significantly increased amount of distributed generation...... services. We present results from several experiments where agents offer and utilize services in order to achieve distributed and autonomous control for subgrid operation of a distribution system. Finally it is discussed how the service oriented architecture can be combined with knowledge based reasoning...

Photovoltaic subsystem marketing and distribution model: programming manual. Final report

Energy Technology Data Exchange (ETDEWEB)

1982-07-01

Complete documentation of the marketing and distribution (M and D) computer model is provided. The purpose is to estimate the costs of selling and transporting photovoltaic solar energy products from the manufacturer to the final customer. The model adjusts for the inflation and regional differences in marketing and distribution costs. The model consists of three major components: the marketing submodel, the distribution submodel, and the financial submodel. The computer program is explained including the input requirements, output reports, subprograms and operating environment. The program specifications discuss maintaining the validity of the data and potential improvements. An example for a photovoltaic concentrator collector demonstrates the application of the model.

First Experiences Using XACML for Access Control in Distributed Systems

Science.gov (United States)

Lorch, Marcus; Proctor, Seth; Lepro, Rebekah; Kafura, Dennis; Shah, Sumit

2003-01-01

Authorization systems today are increasingly complex. They span domains of administration, rely on many different authentication sources, and manage permissions that can be as complex as the system itself. Worse still, while there are many standards that define authentication mechanisms, the standards that address authorization are less well defined and tend to work only within homogeneous systems. This paper presents XACML, a standard access control language, as one component of a distributed and inter-operable authorization framework. Several emerging systems which incorporate XACML are discussed. These discussions illustrate how authorization can be deployed in distributed, decentralized systems. Finally, some new and future topics are presented to show where this work is heading and how it will help connect the general components of an authorization system.

Energy and enthalpy distribution functions for a few physical systems.

Science.gov (United States)

Wu, K L; Wei, J H; Lai, S K; Okabe, Y

2007-08-02

The present work is devoted to extracting the energy or enthalpy distribution function of a physical system from the moments of the distribution using the maximum entropy method. This distribution theory has the salient traits that it utilizes only the experimental thermodynamic data. The calculated distribution functions provide invaluable insight into the state or phase behavior of the physical systems under study. As concrete evidence, we demonstrate the elegance of the distribution theory by studying first a test case of a two-dimensional six-state Potts model for which simulation results are available for comparison, then the biphasic behavior of the binary alloy Na-K whose excess heat capacity, experimentally observed to fall in a narrow temperature range, has yet to be clarified theoretically, and finally, the thermally induced state behavior of a collection of 16 proteins.

Distributed processor systems

International Nuclear Information System (INIS)

Zacharov, B.

1976-01-01

In recent years, there has been a growing tendency in high-energy physics and in other fields to solve computational problems by distributing tasks among the resources of inter-coupled processing devices and associated system elements. This trend has gained further momentum more recently with the increased availability of low-cost processors and with the development of the means of data distribution. In two lectures, the broad question of distributed computing systems is examined and the historical development of such systems reviewed. An attempt is made to examine the reasons for the existence of these systems and to discern the main trends for the future. The components of distributed systems are discussed in some detail and particular emphasis is placed on the importance of standards and conventions in certain key system components. The ideas and principles of distributed systems are discussed in general terms, but these are illustrated by a number of concrete examples drawn from the context of the high-energy physics environment. (Auth.)

The Design of Distributed Micro Grid Energy Storage System

Science.gov (United States)

Liang, Ya-feng; Wang, Yan-ping

2018-03-01

Distributed micro-grid runs in island mode, the energy storage system is the core to maintain the micro-grid stable operation. For the problems that it is poor to adjust at work and easy to cause the volatility of micro-grid caused by the existing energy storage structure of fixed connection. In this paper, an array type energy storage structure is proposed, and the array type energy storage system structure and working principle are analyzed. Finally, the array type energy storage structure model is established based on MATLAB, the simulation results show that the array type energy storage system has great flexibility, which can maximize the utilization of energy storage system, guarantee the reliable operation of distributed micro-grid and achieve the function of peak clipping and valley filling.

77 FR 23396 - Revisions to the Requirements for Authority To Manufacture and Distribute Postage Evidencing Systems

Science.gov (United States)

2012-04-19

... Distribute Postage Evidencing Systems AGENCY: Postal Service TM . ACTION: Final rule. SUMMARY: This rule establishes the responsibility of the providers of Postage Evidencing Systems (PES) to notify the U.S. Postal... as follows: PART 501--AUTHORIZATION TO MANUFACTURE AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS 0 1. The...

Innovative Distributed Power Grid Interconnection and Control Systems: Final Report, December 11, 2000 - August 30, 2005

Energy Technology Data Exchange (ETDEWEB)

DePodesta, K.; Birlingmair, D.; West, R.

2006-03-01

The contract goal was to further advance distributed generation in the marketplace by making installations more cost-effective and compatible with existing systems. This was achieved by developing innovative grid interconnection and control systems.

MODELING AND IMPLEMENTATION OF A DISTRIBUTED SHOP FLOOR MANAGEMENT AND CONTROL SYSTEM

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

Adopting distributed control architecture is the important development direction for shop floor management and control system,is also the requirement of making it agile,intelligent and concurrent. Some key problems in achieving distributed control architecture are researched. An activity model of shop floor is presented as the requirement definition of the prototype system. The multi-agent based software architecture is constructed. How the core part in shop floor management and control system,production plan and scheduling is achieved. The cooperation of different agents is illustrated. Finally,the implementation of the prototype system is narrated.

Final Focus Systems in Linear Colliders

International Nuclear Information System (INIS)

Raubenheimer, Tor

1998-01-01

In colliding beam facilities, the ''final focus system'' must demagnify the beams to attain the very small spot sizes required at the interaction points. The first final focus system with local chromatic correction was developed for the Stanford Linear Collider where very large demagnifications were desired. This same conceptual design has been adopted by all the future linear collider designs as well as the SuperConducting Supercollider, the Stanford and KEK B-Factories, and the proposed Muon Collider. In this paper, the over-all layout, physics constraints, and optimization techniques relevant to the design of final focus systems for high-energy electron-positron linear colliders are reviewed. Finally, advanced concepts to avoid some of the limitations of these systems are discussed

Initial and Final State Interaction Effects in Small-x Quark Distributions

Energy Technology Data Exchange (ETDEWEB)

Xiao, Bo-Wen; Yuan, Feng

2010-08-30

We study the initial and final state interaction effects in the transverse momentum dependent parton distributions in the small-x saturation region. In particular, we discuss the quark distributions in the semi-inclusive deep inelastic scattering, Drell-Yan lepton pair production and dijet-correlation processes in pA collisions. We calculate the quark distributions in the scalar-QED model and then extend to the color glass condensate formalism in QCD. The quark distributions are found universal between the DIS and Drell-Yan processes. On the other hand, the quark distribution from the qq'-->qq' channel contribution to the dijet-correlation process is not universal. However, we find that it can be related to the quark distribution in DIS process by a convolution with the normalized unintegrated gluon distribution in the CGC formalism in the large Nc limit.

Final-photon angular distributions in Compton double-ionization

International Nuclear Information System (INIS)

Kornberg, M.A.

1999-01-01

Angular distributions of the scattered-photon in two-electron ionization of helium by Compton scattering are reported. Our calculations are performed as a direct integration over Compton profiles. We show that backward scattering is adequately described using an uncorrelated final-state approximation, as compared with impulse approximation (IA) results. The relation dσ c 2+ /dΩ = R c dσ c + /dΩ is fulfilled within IA at high-photon energies, with R c the asymptotic shake-off ratio. (orig.)

A concept of distributed architecture for maintenance robot systems

International Nuclear Information System (INIS)

Asama, Hajime

1990-01-01

Aiming at development of a robot system for maintenance tasks in nuclear power plants, a concept of distributed architecture for autonomous robot systems is discussed. At first, based on investigation of maintenance tasks, requirements for maintenance robots are introduced, and structures to realize multi-functions are discussed. Then, as a new design strategy of maintenance robot system, an autonomous and decentralized robot systems is proposed, which is composed of multiple robots, computers, and equipments, and concept of ACTRESS (ACTor-based Robots and Equipments Synthetic System) including communication framework between robotic components is designed. Finally, as a model of ACTRESS, a experimental system is developed, which deals with object-pushing tasks by two micromice and an environment modeler with communicating with each other. Both of parallel independent motion and cooperative motion based on communication is reconciled, and the efficiency of the distributed architecture is verified. (author)

Final focus system for TLC

International Nuclear Information System (INIS)

Oide, K.

1988-11-01

A limit of the chromaticity correction for the final focus system of a TeV Linear Collider (TLC) is investigated. As the result, it becomes possible to increase the aperture of the final doublet with a small increase of the horizontal β function. The new optics design uses a final doublet of 0.5 mm half-aperture and 1.4 T pole-tip field. The length of the system is reduced from 400 m to 200 m by several optics changes. Tolerances for various machine errors with this optics are also studied. 5 refs., 7 figs., 2 tabs

Electric distribution systems

CERN Document Server

Sallam, A A

2010-01-01

"Electricity distribution is the penultimate stage in the delivery of electricity to end users. The only book that deals with the key topics of interest to distribution system engineers, Electric Distribution Systems presents a comprehensive treatment of the subject with an emphasis on both the practical and academic points of view. Reviewing traditional and cutting-edge topics, the text is useful to practicing engineers working with utility companies and industry, undergraduate graduate and students, and faculty members who wish to increase their skills in distribution system automation and monitoring."--

Energy Storage and Distributed Energy Generation Project, Final Project Report

Energy Technology Data Exchange (ETDEWEB)

Schwank, Johannes; Mader, Jerry; Chen, Xiaoyin; Mi, Chris; Linic, Suljo; Sastry, Ann Marie; Stefanopoulou, Anna; Thompson, Levi; Varde, Keshav

2008-03-31

This report serves as a Final Report under the “Energy Storage and Distribution Energy Generation Project” carried out by the Transportation Energy Center (TEC) at the University of Michigan (UM). An interdisciplinary research team has been working on fundamental and applied research on: -distributed power generation and microgrids, -power electronics, and -advanced energy storage. The long-term objective of the project was to provide a framework for identifying fundamental research solutions to technology challenges of transmission and distribution, with special emphasis on distributed power generation, energy storage, control methodologies, and power electronics for microgrids, and to develop enabling technologies for novel energy storage and harvesting concepts that can be simulated, tested, and scaled up to provide relief for both underserved and overstressed portions of the Nation’s grid. TEC’s research is closely associated with Sections 5.0 and 6.0 of the DOE "Five-year Program Plan for FY2008 to FY2012 for Electric Transmission and Distribution Programs, August 2006.”

Distributed cooperative regulation for multiagent systems and its applications to power systems: a survey.

Science.gov (United States)

Hu, Jianqiang; Li, Yaping; Yong, Taiyou; Cao, Jinde; Yu, Jie; Mao, Wenbo

2014-01-01

Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper.

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Erickson, R.A.

1987-11-01

The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs

LEDA RF distribution system design and component test results

International Nuclear Information System (INIS)

Roybal, W.T.; Rees, D.E.; Borchert, H.L.; McCarthy, M.; Toole, L.

1998-01-01

The 350 MHz and 700 MHz RF distribution systems for the Low Energy Demonstration Accelerator (LEDA) have been designed and are currently being installed at Los Alamos National Laboratory. Since 350 MHz is a familiar frequency used at other accelerator facilities, most of the major high-power components were available. The 700 MHz, 1.0 MW, CW RF delivery system designed for LEDA is a new development. Therefore, high-power circulators, waterloads, phase shifters, switches, and harmonic filters had to be designed and built for this applications. The final Accelerator Production of Tritium (APT) RF distribution systems design will be based on much of the same technology as the LEDA systems and will have many of the RF components tested for LEDA incorporated into the design. Low power and high-power tests performed on various components of these LEDA systems and their results are presented here

Distributed Data Management and Distributed File Systems

CERN Document Server

Girone, Maria

2015-01-01

The LHC program has been successful in part due to the globally distributed computing resources used for collecting, serving, processing, and analyzing the large LHC datasets. The introduction of distributed computing early in the LHC program spawned the development of new technologies and techniques to synchronize information and data between physically separated computing centers. Two of the most challenges services are the distributed file systems and the distributed data management systems. In this paper I will discuss how we have evolved from local site services to more globally independent services in the areas of distributed file systems and data management and how these capabilities may continue to evolve into the future. I will address the design choices, the motivations, and the future evolution of the computing systems used for High Energy Physics.

Large distributed control system using Ada in fusion research

International Nuclear Information System (INIS)

Van Arsdall, P J; Woodruff, J P.

1998-01-01

Construction of the National Ignition Facility laser at Lawrence Livermore National Laboratory features a distributed control system that uses object-oriented software engineering techniques. Control of 60,000 devices is effected using a network of some 500 computers. The software is being written in Ada and communicates through CORBA. Software controls are implemented in two layers: individual device controllers and a supervisory layer. The software architecture provides services in the form of frameworks that address issues common to event-driven control systems. Those services are allocated to levels that strictly prescribe their interdependency so the levels are separately reusable. The project has completed its final design review. The delivery of the first increment takes place in October 1998. Keywords Distributed control system, object-oriented development, CORBA, application frameworks, levels of abstraction

Final results for the excitation function and angular distributions of the 3H(d,n)4He reaction

International Nuclear Information System (INIS)

Tang Hongqing; Zhou Zuying; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Chen Zemin; Chen Zhenpeng; Chen Yingtang

1998-01-01

The final relative excitation function of the 3 H(d,n) 4 He rection at 0 degree is shown out. For comparison, a curve calculated from Drosg's HI-13 tandem is in progressplotted. The angular distributions of the 3 H(d,n) 4 He reaction at E d =13.36, 16.50 and 19.50 Mev in the center-of-mass system are shown out. A comparison of the legendre polynomial coefficients obtained from the present angular distribution data with Drosg's evaluation are reported

District heating and cooling systems for communities through power plant retrofit distribution network. Final report, September 1, 1978-May 31, 1979

Energy Technology Data Exchange (ETDEWEB)

None

1979-10-01

This Final Report (Volume 2) of Phase 1 of District Heating for Communities Through Power Plant Retrofit Distribution Network contains 3 tasks: (1) Demonstration Team; (2) Identify Thermal Energy Sources and Potential Service Areas; and (3) Energy Market Analysis. Task 2 consists of estimating the thermal load within 5 and 10 miles of Public Service Electric and Gas Company steam power plants, Newark, New Jersey; estimating the costs of supplying thermal services to thermal loads of varying densities; a best case economic analysis of district heating for single-family homes; and some general comments on district-heating system design and development. Task 3 established the potential market for district heating that exists within a 5-mile radius of the selected generating stations; a sample of the questionnaire sent to the customers are shown. (MCW)

Multi-agent system for energy resource scheduling of integrated microgrids in a distributed system

International Nuclear Information System (INIS)

Logenthiran, T.; Srinivasan, Dipti; Khambadkone, Ashwin M.

2011-01-01

This paper proposes a multi-agent system for energy resource scheduling of an islanded power system with distributed resources, which consists of integrated microgrids and lumped loads. Distributed intelligent multi-agent technology is applied to make the power system more reliable, efficient and capable of exploiting and integrating alternative sources of energy. The algorithm behind the proposed energy resource scheduling has three stages. The first stage is to schedule each microgrid individually to satisfy its internal demand. The next stage involves finding the best possible bids for exporting power to the network and compete in a whole sale energy market. The final stage is to reschedule each microgrid individually to satisfy the total demand, which is the addition of internal demand and the demand from the results of the whole sale energy market simulation. The simulation results of a power system with distributed resources comprising three microgrids and five lumped loads show that the proposed multi-agent system allows efficient management of micro-sources with minimum operational cost. The case studies demonstrate that the system is successfully monitored, controlled and operated by means of the developed multi-agent system. (author)

Multi-agent system for energy resource scheduling of integrated microgrids in a distributed system

Energy Technology Data Exchange (ETDEWEB)

Logenthiran, T.; Srinivasan, Dipti; Khambadkone, Ashwin M. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

2011-01-15

This paper proposes a multi-agent system for energy resource scheduling of an islanded power system with distributed resources, which consists of integrated microgrids and lumped loads. Distributed intelligent multi-agent technology is applied to make the power system more reliable, efficient and capable of exploiting and integrating alternative sources of energy. The algorithm behind the proposed energy resource scheduling has three stages. The first stage is to schedule each microgrid individually to satisfy its internal demand. The next stage involves finding the best possible bids for exporting power to the network and compete in a whole sale energy market. The final stage is to reschedule each microgrid individually to satisfy the total demand, which is the addition of internal demand and the demand from the results of the whole sale energy market simulation. The simulation results of a power system with distributed resources comprising three microgrids and five lumped loads show that the proposed multi-agent system allows efficient management of micro-sources with minimum operational cost. The case studies demonstrate that the system is successfully monitored, controlled and operated by means of the developed multi-agent system. (author)

The Newcastle connection: A software subsystem for constructing distributed UNIX systems

International Nuclear Information System (INIS)

Randell, B.

1985-01-01

The Newcastle connection is a software subsystem that can be added to each of a set of physically interconnected UNIX or UNIX look-alike systems, so as to construct a distributed system which is functionally indistinguishable at both the user and the program level from a conventional single-processor UNIX system. The techniques used are applicable to a variety and multiplicity of both local and wide area networks, and enable all issues of inter-processor communication, network protocols, etc., to be hidden. A brief account is given of experience with such distributed systems, the first of which was constructed in 1982 using a set of PDP11s running UNIX Version 7, and connected by a Cambridge Ring - since this date the Connection has been used to construct distributed systems based on various other computers and versions of UNIX, both at Newcastle and elsewhere. The final sections compare our scheme to various precursor schemes and discuss its potential relevance to other operating systems. (orig.)

Distance Protection for Microgrids in Distribution System

DEFF Research Database (Denmark)

Lin, Hengwei; Liu, Chengxi; Guerrero, Josep M.

2015-01-01

protection decreased. This paper adopts distance protection for one mid-voltage level microgrid in Aalborg, Denmark. Different operation modes of the network are analyzed and tested in the paper. The simulation results show that the variations of the fault currents seen by the forward relays are much larger...... than the backward relays. Meanwhile, the fault currents change little with the randomness of renewable energy except the intermittence. Finally, it shows that the designed distance protection has satisfactory performance to clear the various faults.......Owing to the increasing penetration of distributed generation, there are some challenges for the conventional protection in distribution system. Bidirectional power flow and variable fault current because of the various operation modes may lead to the selectivity and sensitivity of the overcurrent...

A Performance Comparison of Tree and Ring Topologies in Distributed System

Energy Technology Data Exchange (ETDEWEB)

Huang, Min [Iowa State Univ., Ames, IA (United States)

2004-01-01

A distributed system is a collection of computers that are connected via a communication network. Distributed systems have become commonplace due to the wide availability of low-cost, high performance computers and network devices. However, the management infrastructure often does not scale well when distributed systems get very large. Some of the considerations in building a distributed system are the choice of the network topology and the method used to construct the distributed system so as to optimize the scalability and reliability of the system, lower the cost of linking nodes together and minimize the message delay in transmission, and simplify system resource management. We have developed a new distributed management system that is able to handle the dynamic increase of system size, detect and recover the unexpected failure of system services, and manage system resources. The topologies used in the system are the tree-structured network and the ring-structured network. This thesis presents the research background, system components, design, implementation, experiment results and the conclusions of our work. The thesis is organized as follows: the research background is presented in chapter 1. Chapter 2 describes the system components, including the different node types and different connection types used in the system. In chapter 3, we describe the message types and message formats in the system. We discuss the system design and implementation in chapter 4. In chapter 5, we present the test environment and results, Finally, we conclude with a summary and describe our future work in chapter 6.

Dynamic Protective Control Strategy for Distributed Generation System with Fixed-speed Wind Turbines

Institute of Scientific and Technical Information of China (English)

2012-01-01

The characteristics of induction generator based fixed-speed wind turbines （FSWT） are investigated. The impacts of different execution time in protective operations are studied under different fauit duration and various wind velocity situations, e.g. , FSWT stabilities of load shedding in distribution systems. Based on this research, a dynamic protective control strategy for a distributed generation system （DGS） with FSWT is proposed. Finally, simulation results demonstrate the effectiveness of the strategy.

Distributed Cooperative Regulation for Multiagent Systems and Its Applications to Power Systems: A Survey

Science.gov (United States)

Li, Yaping; Yong, Taiyou; Yu, Jie; Mao, Wenbo

2014-01-01

Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper. PMID:25243199

76 FR 77149 - Authority To Manufacture and Distribute Postage Evidencing Systems

Science.gov (United States)

2011-12-12

... POSTAL SERVICE 39 CFR Part 501 Authority To Manufacture and Distribute Postage Evidencing Systems AGENCY: Postal Service\\TM\\. ACTION: Final rule. SUMMARY: This rule clarifies the responsibility of the... reasons stated, 39 CFR part 501 is amended as follows: PART 501--AUTHORIZATION TO MANUFACTURE AND...

A Study of Strong Stability of Distributed Systems. Ph.D. Thesis

Science.gov (United States)

Cataltepe, Tayfun

1989-01-01

The strong stability of distributed systems is studied and the problem of characterizing strongly stable semigroups of operators associated with distributed systems is addressed. Main emphasis is on contractive systems. Three different approaches to characterization of strongly stable contractive semigroups are developed. The first one is an operator theoretical approach. Using the theory of dilations, it is shown that every strongly stable contractive semigroup is related to the left shift semigroup on an L(exp 2) space. Then, a decomposition for the state space which identifies strongly stable and unstable states is introduced. Based on this decomposition, conditions for a contractive semigroup to be strongly stable are obtained. Finally, extensions of Lyapunov's equation for distributed parameter systems are investigated. Sufficient conditions for weak and strong stabilities of uniformly bounded semigroups are obtained by relaxing the equivalent norm condition on the right hand side of the Lyanupov equation. These characterizations are then applied to the problem of feedback stabilization. First, it is shown via the state space decomposition that under certain conditions a contractive system (A,B) can be strongly stabilized by the feedback -B(*). Then, application of the extensions of the Lyapunov equation results in sufficient conditions for weak, strong, and exponential stabilizations of contractive systems by the feedback -B(*). Finally, it is shown that for a contractive system, the first derivative of x with respect to time = Ax + Bu (where B is any linear bounded operator), there is a related linear quadratic regulator problem and a corresponding steady state Riccati equation which always has a bounded nonnegative solution.

A Geo-Distributed System Architecture for Different Domains

Science.gov (United States)

Moßgraber, Jürgen; Middleton, Stuart; Tao, Ran

2013-04-01

The presentation will describe work on the system-of-systems (SoS) architecture that is being developed in the EU FP7 project TRIDEC on "Collaborative, Complex and Critical Decision-Support in Evolving Crises". In this project we deal with two use-cases: Natural Crisis Management (e.g. Tsunami Early Warning) and Industrial Subsurface Development (e.g. drilling for oil). These use-cases seem to be quite different at first sight but share a lot of similarities, like managing and looking up available sensors, extracting data from them and annotate it semantically, intelligently manage the data (big data problem), run mathematical analysis algorithms on the data and finally provide decision support on this basis. The main challenge was to create a generic architecture which fits both use-cases. The requirements to the architecture are manifold and the whole spectrum of a modern, geo-distributed and collaborative system comes into play. Obviously, one cannot expect to tackle these challenges adequately with a monolithic system or with a single technology. Therefore, a system architecture providing the blueprints to implement the system-of-systems approach has to combine multiple technologies and architectural styles. The most important architectural challenges we needed to address are 1. Build a scalable communication layer for a System-of-sytems 2. Build a resilient communication layer for a System-of-sytems 3. Efficiently publish large volumes of semantically rich sensor data 4. Scalable and high performance storage of large distributed datasets 5. Handling federated multi-domain heterogeneous data 6. Discovery of resources in a geo-distributed SoS 7. Coordination of work between geo-distributed systems The design decisions made for each of them will be presented. These developed concepts are also applicable to the requirements of the Future Internet (FI) and Internet of Things (IoT) which will provide services like smart grids, smart metering, logistics and

Planning Systems for Distributed Operations

Science.gov (United States)

Maxwell, Theresa G.

2002-01-01

This viewgraph representation presents an overview of the mission planning process involving distributed operations (such as the International Space Station (ISS)) and the computer hardware and software systems needed to support such an effort. Topics considered include: evolution of distributed planning systems, ISS distributed planning, the Payload Planning System (PPS), future developments in distributed planning systems, Request Oriented Scheduling Engine (ROSE) and Next Generation distributed planning systems.

Characterization of the loss allocation techniques for radial systems with distributed generation

International Nuclear Information System (INIS)

Carpaneto, Enrico; Chicco, Gianfranco; Sumaili Akilimali, Jean

2008-01-01

In the restructured electricity industry, meaningful loss allocation methods are required in order to send correct signals to the market taking into account the location and characteristics of loads and generations, including the local sources forming the distributed generation (DG). This paper addresses the issues related to loss allocation in radial distribution systems with DG, with a three-fold focus. First, the key differences in the formulation of the loss allocation problem for radial distribution systems with respect to transmission systems are discussed, specifying the modeling and computational issues concerning the treatment of the slack node in radial distribution systems. Then, the characteristics of derivative-based and circuit-based loss allocation techniques are presented and compared, illustrating the arrangements used for adapting the various techniques to be applied to radial distribution systems with DG. Finally, the effects of introducing voltage-controllable local generation on the calculation of the loss allocation coefficients are discussed, proposing the adoption of a ''reduced'' representation of the system capable of taking into proper account the characteristics of the nodes containing voltage-controllable DG units. Numerical results are provided to show the time evolution of the loss allocation coefficients for distribution systems with variable load and local generation patterns. (author)

A distributed database view of network tracking systems

Science.gov (United States)

Yosinski, Jason; Paffenroth, Randy

2008-04-01

In distributed tracking systems, multiple non-collocated trackers cooperate to fuse local sensor data into a global track picture. Generating this global track picture at a central location is fairly straightforward, but the single point of failure and excessive bandwidth requirements introduced by centralized processing motivate the development of decentralized methods. In many decentralized tracking systems, trackers communicate with their peers via a lossy, bandwidth-limited network in which dropped, delayed, and out of order packets are typical. Oftentimes the decentralized tracking problem is viewed as a local tracking problem with a networking twist; we believe this view can underestimate the network complexities to be overcome. Indeed, a subsequent 'oversight' layer is often introduced to detect and handle track inconsistencies arising from a lack of robustness to network conditions. We instead pose the decentralized tracking problem as a distributed database problem, enabling us to draw inspiration from the vast extant literature on distributed databases. Using the two-phase commit algorithm, a well known technique for resolving transactions across a lossy network, we describe several ways in which one may build a distributed multiple hypothesis tracking system from the ground up to be robust to typical network intricacies. We pay particular attention to the dissimilar challenges presented by network track initiation vs. maintenance and suggest a hybrid system that balances speed and robustness by utilizing two-phase commit for only track initiation transactions. Finally, we present simulation results contrasting the performance of such a system with that of more traditional decentralized tracking implementations.

The Stationary Distribution and Extinction of Generalized Multispecies Stochastic Lotka-Volterra Predator-Prey System

OpenAIRE

Yin, Fancheng; Yu, Xiaoyan

2015-01-01

This paper is concerned with the existence of stationary distribution and extinction for multispecies stochastic Lotka-Volterra predator-prey system. The contributions of this paper are as follows. (a) By using Lyapunov methods, the sufficient conditions on existence of stationary distribution and extinction are established. (b) By using the space decomposition technique and the continuity of probability, weaker conditions on extinction of the system are obtained. Finally, a numer...

Control and management of distribution system with integrated DERs via IEC 61850 based communication

Directory of Open Access Journals (Sweden)

Ikbal Ali

2017-06-01

Full Text Available Distributed Energy Resources (DERs are being increasingly integrated in the distribution systems and resulting in complex power flow scenarios. In such cases, effective control, management and protection of distribution systems becomes highly challenging. Standardized and interoperable communication in distribution systems has the potential to deal with such challenges to achieve higher energy efficiency and reliability. Ed. 2 of IEC 61850 standards, for utility automation, standardizing the exchange of data among different substations, DERs, control centers, PMUs and PDCs. This paper demonstrates the modelling of information and services needed for control, management and protection of distribution systems with integrated DERs. This paper has used IP tunnels and/or mapping over IP layer for transferring IEC 61850 messages, such as sample values (SVs and GOOSE (Generic Object Oriented Substation Event, over distribution system Wide Area Network (WAN. Finally performance of the proposed communication configurations for different applications is analyzed by calculating End-to-End (ETE delay, throughput and jitter.

World-wide distribution automation systems

International Nuclear Information System (INIS)

Devaney, T.M.

1994-01-01

A worldwide power distribution automation system is outlined. Distribution automation is defined and the status of utility automation is discussed. Other topics discussed include a distribution management system, substation feeder, and customer functions, potential benefits, automation costs, planning and engineering considerations, automation trends, databases, system operation, computer modeling of system, and distribution management systems

Distributed Operating Systems

NARCIS (Netherlands)

Mullender, Sape J.

1987-01-01

In the past five years, distributed operating systems research has gone through a consolidation phase. On a large number of design issues there is now considerable consensus between different research groups. In this paper, an overview of recent research in distributed systems is given. In turn, the

Pervasive Electricity Distribution System

Directory of Open Access Journals (Sweden)

Muhammad Usman Tahir

2017-06-01

Full Text Available Now a days a country cannot become economically strong until and unless it has enough electrical power to fulfil industrial and domestic needs. Electrical power being the pillar of any country’s economy, needs to be used in an efficient way. The same step is taken here by proposing a new system for energy distribution from substation to consumer houses, also it monitors the consumer consumption and record data. Unlike traditional manual Electrical systems, pervasive electricity distribution system (PEDS introduces a fresh perspective to monitor the feeder line status at distribution and consumer level. In this system an effort is taken to address the issues of electricity theft, manual billing, online monitoring of electrical distribution system and automatic control of electrical distribution points. The project is designed using microcontroller and different sensors, its GUI is designed in Labview software.

Economic Assessment of Network-Constrained Transactive Energy for Managing Flexible Demand in Distribution Systems

Directory of Open Access Journals (Sweden)

Junjie Hu

2017-05-01

Full Text Available The increasing number of distributed energy resources such as electric vehicles and heat pumps connected to power systems raises operational challenges to the network operator, for example, introducing grid congestion and voltage deviations in the distribution network level if their operations are not properly coordinated. Coordination and control of a large number of distributed energy resources requires innovative approaches. In this paper, we follow up on a recently proposed network-constrained transactive energy (NCTE method for scheduling of electric vehicles and heat pumps within a retailer’s aggregation at distribution system level. We extend this method with: (1 a new modeling technique that allows the resulting congestion price to be directly interpreted as a locational marginal pricing in the system; (2 an explicit analysis of the benefits and costs of different actors when using the NCTE method in the system, given the high penetration of distributed energy resources. This paper firstly describes the NCTE-based distribution system that introduces a new interacting scheme for actors at the distribution system level. Then, technical modeling and economic interpretation of the NCTE-based distribution system are described. Finally, we show the benefits and costs of different actors within the NCTE-based distribution system.

Distributed Containment Control for Multiple Unknown Second-Order Nonlinear Systems With Application to Networked Lagrangian Systems.

Science.gov (United States)

Mei, Jie; Ren, Wei; Li, Bing; Ma, Guangfu

2015-09-01

In this paper, we consider the distributed containment control problem for multiagent systems with unknown nonlinear dynamics. More specifically, we focus on multiple second-order nonlinear systems and networked Lagrangian systems. We first study the distributed containment control problem for multiple second-order nonlinear systems with multiple dynamic leaders in the presence of unknown nonlinearities and external disturbances under a general directed graph that characterizes the interaction among the leaders and the followers. A distributed adaptive control algorithm with an adaptive gain design based on the approximation capability of neural networks is proposed. We present a necessary and sufficient condition on the directed graph such that the containment error can be reduced as small as desired. As a byproduct, the leaderless consensus problem is solved with asymptotical convergence. Because relative velocity measurements between neighbors are generally more difficult to obtain than relative position measurements, we then propose a distributed containment control algorithm without using neighbors' velocity information. A two-step Lyapunov-based method is used to study the convergence of the closed-loop system. Next, we apply the ideas to deal with the containment control problem for networked unknown Lagrangian systems under a general directed graph. All the proposed algorithms are distributed and can be implemented using only local measurements in the absence of communication. Finally, simulation examples are provided to show the effectiveness of the proposed control algorithms.

Harmonic Analysis of Electric Vehicle Loadings on Distribution System

Energy Technology Data Exchange (ETDEWEB)

Xu, Yijun A [University of Southern California, Department of Electrical Engineering; Xu, Yunshan [University of Southern California, Department of Electrical Engineering; Chen, Zimin [University of Southern California, Department of Electrical Engineering; Peng, Fei [University of Southern California, Department of Electrical Engineering; Beshir, Mohammed [University of Southern California, Department of Electrical Engineering

2014-12-01

With the increasing number of Electric Vehicles (EV) in this age, the power system is facing huge challenges of the high penetration rates of EVs charging stations. Therefore, a technical study of the impact of EVs charging on the distribution system is required. This paper is applied with PSCAD software and aimed to analyzing the Total Harmonic Distortion (THD) brought by Electric Vehicles charging stations in power systems. The paper starts with choosing IEEE34 node test feeder as the distribution system, building electric vehicle level two charging battery model and other four different testing scenarios: overhead transmission line and underground cable, industrial area, transformer and photovoltaic (PV) system. Then the statistic method is used to analyze different characteristics of THD in the plug-in transient, plug-out transient and steady-state charging conditions associated with these four scenarios are taken into the analysis. Finally, the factors influencing the THD in different scenarios are found. The analyzing results lead the conclusion of this paper to have constructive suggestions for both Electric Vehicle charging station construction and customers' charging habits.

75 FR 56471 - Revisions to the Requirements for Authority To Manufacture and Distribute Postage Evidencing Systems

Science.gov (United States)

2010-09-16

... evidencing systems (``Company or Companies'') engage a qualified, independent audit firm to perform an... Distribute Postage Evidencing Systems AGENCY: Postal Service TM . ACTION: Final rule. SUMMARY: The Postal..., at 202-268-7613. SUPPLEMENTARY INFORMATION: Postage Evidencing Systems are devices or systems of...

Optimizing queries in distributed systems

Directory of Open Access Journals (Sweden)

Ion LUNGU

2006-01-01

Full Text Available This research presents the main elements of query optimizations in distributed systems. First, data architecture according with system level architecture in a distributed environment is presented. Then the architecture of a distributed database management system (DDBMS is described on conceptual level followed by the presentation of the distributed query execution steps on these information systems. The research ends with presentation of some aspects of distributed database query optimization and strategies used for that.

The institutional structure and political economy of food distribution systems: A comparative analysis of six Eastern European countries

DEFF Research Database (Denmark)

Esbjerg, Lars; Skytte, Hans

This paper discusses the food distribution systems of six Eastern European countries. It considers the macro and task environments of distribution systems, discussing the constraints and opportunities the environments present to companies. The institutional structure of retailing and wholesaling...... are analysed and important developments in the institutional structure are noted. The internal political economy of distribution channels in Eastern Europe is analysed and the modernisation of distribution systems discussed. Finally, some conclusions are offered and areas for future research suggested....

Distributed Secure Coordinated Control for Multiagent Systems Under Strategic Attacks.

Science.gov (United States)

Feng, Zhi; Wen, Guanghui; Hu, Guoqiang

2017-05-01

This paper studies a distributed secure consensus tracking control problem for multiagent systems subject to strategic cyber attacks modeled by a random Markov process. A hybrid stochastic secure control framework is established for designing a distributed secure control law such that mean-square exponential consensus tracking is achieved. A connectivity restoration mechanism is considered and the properties on attack frequency and attack length rate are investigated, respectively. Based on the solutions of an algebraic Riccati equation and an algebraic Riccati inequality, a procedure to select the control gains is provided and stability analysis is studied by using Lyapunov's method.. The effect of strategic attacks on discrete-time systems is also investigated. Finally, numerical examples are provided to illustrate the effectiveness of theoretical analysis.

Energy Management of Smart Distribution Systems

Science.gov (United States)

Ansari, Bananeh

Electric power distribution systems interface the end-users of electricity with the power grid. Traditional distribution systems are operated in a centralized fashion with the distribution system owner or operator being the only decision maker. The management and control architecture of distribution systems needs to gradually transform to accommodate the emerging smart grid technologies, distributed energy resources, and active electricity end-users or prosumers. The content of this document concerns with developing multi-task multi-objective energy management schemes for: 1) commercial/large residential prosumers, and 2) distribution system operator of a smart distribution system. The first part of this document describes a method of distributed energy management of multiple commercial/ large residential prosumers. These prosumers not only consume electricity, but also generate electricity using their roof-top solar photovoltaics systems. When photovoltaics generation is larger than local consumption, excess electricity will be fed into the distribution system, creating a voltage rise along the feeder. Distribution system operator cannot tolerate a significant voltage rise. ES can help the prosumers manage their electricity exchanges with the distribution system such that minimal voltage fluctuation occurs. The proposed distributed energy management scheme sizes and schedules each prosumer's ES to reduce the electricity bill and mitigate voltage rise along the feeder. The second part of this document focuses on emergency energy management and resilience assessment of a distribution system. The developed emergency energy management system uses available resources and redundancy to restore the distribution system's functionality fully or partially. The success of the restoration maneuver depends on how resilient the distribution system is. Engineering resilience terminology is used to evaluate the resilience of distribution system. The proposed emergency energy

Thermal Distribution System | Energy Systems Integration Facility | NREL

Science.gov (United States)

Thermal Distribution System Thermal Distribution System The Energy Systems Integration Facility's . Photo of the roof of the Energy Systems Integration Facility. The thermal distribution bus allows low as 10% of its full load level). The 60-ton chiller cools water with continuous thermal control

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Helm, R.; Irwin, J.

1992-08-01

Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We will outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We will discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread, bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, will be described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC will be given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC)

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Helm, R.; Irwing, J.

1992-01-01

Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread , bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, are described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC are given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC). (Author) 16 refs., 4 tabs., 6 figs

A Multi-Agent Traffic Control Model Based on Distributed System

Directory of Open Access Journals (Sweden)

Qian WU

2014-06-01

Full Text Available With the development of urbanization construction, urban travel has become a quite thorny and imminent problem. Some previous researches on the large urban traffic systems easily change into NPC problems. We purpose a multi-agent inductive control model based on the distributed approach. To describe the real traffic scene, this model designs four different types of intelligent agents, i.e. we regard each lane, route, intersection and traffic region as different types of intelligent agents. Each agent can achieve the real-time traffic data from its neighbor agents, and decision-making agents establish real-time traffic signal plans through the communication between local agents and their neighbor agents. To evaluate the traffic system, this paper takes the average delay, the stopped time and the average speed as performance parameters. Finally, the distributed multi-agent is simulated on the VISSIM simulation platform, the simulation results show that the multi-agent system is more effective than the adaptive control system in solving the traffic congestion.

Research on distributed virtual reality system in electronic commerce

Science.gov (United States)

Xue, Qiang; Wang, Jiening; Sun, Jizhou

2004-03-01

In this paper, Distributed Virtual Reality (DVR) technology applied in Electronical Commerce (EC) is discussed. DVR has the capability of providing a new means for human being to recognize, analyze and resolve the large scale, complex problems, which makes it develop quickly in EC fields. The technology of CSCW (Computer Supported Cooperative Work) and middleware is introduced into the development of EC-DVR system to meet the need of a platform which can provide the necessary cooperation and communication services to avoid developing the basic module repeatedly. Finally, the paper gives a platform structure of EC-DVR system.

Distributed systems

CERN Document Server

Van Steen, Maarten

2017-01-01

For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A separation has been made between basic material and more specific subjects. The latter have been organized into boxed sections, which may be skipped on first reading. To assist in understanding the more algorithmic parts, example programs in Python have been included. The examples in the book leave out many details for readability, but the complete code is available through the book's Website, hosted at www.distributed-systems.net.

Drinking Water Distribution Systems

Science.gov (United States)

Learn about an overview of drinking water distribution systems, the factors that degrade water quality in the distribution system, assessments of risk, future research about these risks, and how to reduce cross-connection control risk.

Estimating the transmission potential of supercritical processes based on the final size distribution of minor outbreaks.

Science.gov (United States)

Nishiura, Hiroshi; Yan, Ping; Sleeman, Candace K; Mode, Charles J

2012-02-07

Use of the final size distribution of minor outbreaks for the estimation of the reproduction numbers of supercritical epidemic processes has yet to be considered. We used a branching process model to derive the final size distribution of minor outbreaks, assuming a reproduction number above unity, and applying the method to final size data for pneumonic plague. Pneumonic plague is a rare disease with only one documented major epidemic in a spatially limited setting. Because the final size distribution of a minor outbreak needs to be normalized by the probability of extinction, we assume that the dispersion parameter (k) of the negative-binomial offspring distribution is known, and examine the sensitivity of the reproduction number to variation in dispersion. Assuming a geometric offspring distribution with k=1, the reproduction number was estimated at 1.16 (95% confidence interval: 0.97-1.38). When less dispersed with k=2, the maximum likelihood estimate of the reproduction number was 1.14. These estimates agreed with those published from transmission network analysis, indicating that the human-to-human transmission potential of the pneumonic plague is not very high. Given only minor outbreaks, transmission potential is not sufficiently assessed by directly counting the number of offspring. Since the absence of a major epidemic does not guarantee a subcritical process, the proposed method allows us to conservatively regard epidemic data from minor outbreaks as supercritical, and yield estimates of threshold values above unity. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Distribution system modeling and analysis

CERN Document Server

Kersting, William H

2001-01-01

For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures. Distribution System Modeling and Analysis helps prevent those errors. It gives readers a basic understanding of the modeling and operating characteristics of the major components of a distribution system. One by one, the author develops and analyzes each component as a stand-alone element, then puts them all together to analyze a distribution system comprising the various shunt and series devices for power-flow and short-circuit studies. He includes the derivation of all models and includes many num...

A distribution management system

Energy Technology Data Exchange (ETDEWEB)

Jaerventausta, P; Verho, P; Kaerenlampi, M; Pitkaenen, M [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

1998-08-01

The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion to the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. Nowadays the SCADA is the main computer system (and often the only) in the control center. However, the information displayed by the SCADA is often inadequate, and several tasks cannot be solved by a conventional SCADA system. A need for new computer applications in control center arises from the insufficiency of the SCADA and some other trends. The latter means that the overall importance of the distribution networks is increasing. The slowing down of load-growth has often made network reinforcements unprofitable. Thus the existing network must be operated more efficiently. At the same time larger distribution areas are for economical reasons being monitored at one control center and the size of the operation staff is decreasing. The quality of supply requirements are also becoming stricter. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the

TECHNOLOGY FORMING PRICE DISTRIBUTION OF FINISHED GOODS OF LOGISTICS SYSTEM

Directory of Open Access Journals (Sweden)

Novikova T. V.

2015-12-01

Full Text Available Modern economics has developed a number of areas of the system for controlling the distribution of finished products. However, in domestic and foreign economic literature the mechanisms of logistics approach are not sufficient to provide higher sales of enterprise-producers, that have sales in remote areas. In this study, first, the importance of company-producers and end-users the methods of rational delivery of finished products is considered, and secondly, the approaches to defining the essence and content of the concept of «distribution» are given, in the third, the logistics processes of the distribution system ready products of a particular company-producer are described, fourthly, the technology of one price product delivery was developed and it was shown the economic efficiency (the possible results of the solution of the problem of distribution logistics of its application in the target company. The study showed that there is an opportunity, based on the development and implementation of technologies to reduce the final price of the goods, to develop the company and increase its competitiveness by minimizing costs and increasing return on investment. The results of research extend the knowledge of methodology of system logistics management in the enterprise.

Distributed Adaptive Fuzzy Control for Nonlinear Multiagent Systems Via Sliding Mode Observers.

Science.gov (United States)

Shen, Qikun; Shi, Peng; Shi, Yan

2016-12-01

In this paper, the problem of distributed adaptive fuzzy control is investigated for high-order uncertain nonlinear multiagent systems on directed graph with a fixed topology. It is assumed that only the outputs of each follower and its neighbors are available in the design of its distributed controllers. Equivalent output injection sliding mode observers are proposed for each follower to estimate the states of itself and its neighbors, and an observer-based distributed adaptive controller is designed for each follower to guarantee that it asymptotically synchronizes to a leader with tracking errors being semi-globally uniform ultimate bounded, in which fuzzy logic systems are utilized to approximate unknown functions. Based on algebraic graph theory and Lyapunov function approach, using Filippov-framework, the closed-loop system stability analysis is conducted. Finally, numerical simulations are provided to illustrate the effectiveness and potential of the developed design techniques.

Development, Demonstration, and Field Testing of Enterprise-Wide Distributed Generation Energy Management System: Final Report

Energy Technology Data Exchange (ETDEWEB)

Greenberg, S.; Cooley, C.

2005-01-01

This report details progress on subcontract NAD-1-30605-1 between the National Renewable Energy Laboratory and RealEnergy (RE), the purpose of which is to describe RE's approach to the challenges it faces in the implementation of a nationwide fleet of clean cogeneration systems to serve contemporary energy markets. The Phase 2 report covers: utility tariff risk and its impact on market development; the effect on incentives on distributed energy markets; the regulatory effectiveness of interconnection in California; a survey of practical field interconnection issues; trend analysis for on-site generation; performance of dispatch systems; and information design hierarchy for combined heat and power.

Cooling water distribution system

Science.gov (United States)

Orr, Richard

1994-01-01

A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

Coordinated Volt/Var Control in Distribution Systems with Distributed Generations Based on Joint Active and Reactive Powers Dispatch

Directory of Open Access Journals (Sweden)

Abouzar Samimi

2016-01-01

Full Text Available One of the most significant control schemes in optimal operation of distribution networks is Volt/Var control (VVC. Owing to the radial structure of distribution systems and distribution lines with a small X/R ratio, the active power scheduling affects the VVC issue. A Distribution System Operator (DSO procures its active and reactive power requirements from Distributed Generations (DGs along with the wholesale electricity market. This paper proposes a new operational scheduling method based on a joint day-ahead active/reactive power market at the distribution level. To this end, based on the capability curve, a generic reactive power cost model for DGs is developed. The joint active/reactive power dispatch model presented in this paper motivates DGs to actively participate not only in the energy markets, but also in the VVC scheme through a competitive market. The proposed method which will be performed in an offline manner aims to optimally determine (i the scheduled active and reactive power values of generation units; (ii reactive power values of switched capacitor banks; and (iii tap positions of transformers for the next day. The joint active/reactive power dispatch model for daily VVC is modeled in GAMS and solved with the DICOPT solver. Finally, the plausibility of the proposed scheduling framework is examined on a typical 22-bus distribution test network over a 24-h period.

High Voltage Distribution System (HVDS) as a better system compared to Low Voltage Distribution System (LVDS) applied at Medan city power network

Science.gov (United States)

Dinzi, R.; Hamonangan, TS; Fahmi, F.

2018-02-01

In the current distribution system, a large-capacity distribution transformer supplies loads to remote locations. The use of 220/380 V network is nowadays less common compared to 20 kV network. This results in losses due to the non-optimal distribution transformer, which neglected the load location, poor consumer profile, and large power losses along the carrier. This paper discusses how high voltage distribution systems (HVDS) can be a better system used in distribution networks than the currently used distribution system (Low Voltage Distribution System, LVDS). The proposed change of the system into the new configuration is done by replacing a large-capacity distribution transformer with some smaller-capacity distribution transformers and installed them in positions that closest to the load. The use of high voltage distribution systems will result in better voltage profiles and fewer power losses. From the non-technical side, the annual savings and payback periods on high voltage distribution systems will also be the advantage.

Optimal Operation of Radial Distribution Systems Using Extended Dynamic Programming

DEFF Research Database (Denmark)

Lopez, Juan Camilo; Vergara, Pedro P.; Lyra, Christiano

2018-01-01

An extended dynamic programming (EDP) approach is developed to optimize the ac steady-state operation of radial electrical distribution systems (EDS). Based on the optimality principle of the recursive Hamilton-Jacobi-Bellman equations, the proposed EDP approach determines the optimal operation o...... approach is illustrated using real-scale systems and comparisons with commercial programming solvers. Finally, generalizations to consider other EDS operation problems are also discussed.......An extended dynamic programming (EDP) approach is developed to optimize the ac steady-state operation of radial electrical distribution systems (EDS). Based on the optimality principle of the recursive Hamilton-Jacobi-Bellman equations, the proposed EDP approach determines the optimal operation...... of the EDS by setting the values of the controllable variables at each time period. A suitable definition for the stages of the problem makes it possible to represent the optimal ac power flow of radial EDS as a dynamic programming problem, wherein the 'curse of dimensionality' is a minor concern, since...

Optimal Coordination of Automatic Line Switches for Distribution Systems

Directory of Open Access Journals (Sweden)

Jyh-Cherng Gu

2012-04-01

Full Text Available For the Taiwan Power Company (Taipower, the margins of coordination times between the lateral circuit breakers (LCB of underground 4-way automatic line switches and the protection equipment of high voltage customers are often too small. This could lead to sympathy tripping by the feeder circuit breaker (FCB of the distribution feeder and create difficulties in protection coordination between upstream and downstream protection equipment, identification of faults, and restoration operations. In order to solve the problem, it is necessary to reexamine the protection coordination between LCBs and high voltage customers’ protection equipment, and between LCBs and FCBs, in order to bring forth new proposals for settings and operations. This paper applies linear programming to optimize the protection coordination of protection devices, and proposes new time current curves (TCCs for the overcurrent (CO and low-energy overcurrent (LCO relays used in normally open distribution systems by performing simulations in the Electrical Transient Analyzer Program (ETAP environment. The simulation results show that the new TCCs solve the coordination problems among high voltage customer, lateral, feeder, bus-interconnection, and distribution transformer. The new proposals also satisfy the requirements of Taipower on protection coordination of the distribution feeder automation system (DFAS. Finally, the authors believe that the system configuration, operation experience, and relevant criteria mentioned in this paper may serve as valuable references for other companies or utilities when building DFAS of their own.

MACHINE LEARNING FOR THE SELF-ORGANIZATION OF DISTRIBUTED SYSTEMS IN ECONOMIC APPLICATIONS

Directory of Open Access Journals (Sweden)

Jerzy Balicki

2017-03-01

Full Text Available In this paper, an application of machine learning to the problem of self-organization of distributed systems has been discussed with regard to economic applications, with particular emphasis on supervised neural network learning to predict stock investments and some ratings of companies. In addition, genetic programming can play an important role in the preparation and testing of several financial information systems. For this reason, machine learning applications have been discussed because some software applications can be automatically constructed by genetic programming. To obtain a competitive advantage, machine learning can be used for the management of self-organizing cloud computing systems performing calculations for business. Also the use of selected economic self-organizing distributed systems has been described, including some testing methods of predicting borrower reliability. Finally, some conclusions and directions for further research have been proposed.

Improved control of distributed parameter systems using wireless sensor and actuator networks: An observer-based method

International Nuclear Information System (INIS)

Jiang Zheng-Xian; Cui Bao-Tong; Lou Xu-Yang; Zhuang Bo

2017-01-01

In this paper, the control problem of distributed parameter systems is investigated by using wireless sensor and actuator networks with the observer-based method. Firstly, a centralized observer which makes use of the measurement information provided by the fixed sensors is designed to estimate the distributed parameter systems. The mobile agents, each of which is affixed with a controller and an actuator, can provide the observer-based control for the target systems. By using Lyapunov stability arguments, the stability for the estimation error system and distributed parameter control system is proved, meanwhile a guidance scheme for each mobile actuator is provided to improve the control performance. A numerical example is finally used to demonstrate the effectiveness and the advantages of the proposed approaches. (paper)

Quality monitored distributed voting system

Science.gov (United States)

Skogmo, David

1997-01-01

A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system.

Experiences with the new ATLAS Distributed Data Management System

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00214543; The ATLAS collaboration

2016-01-01

The ATLAS Distributed Data Management (DDM) system has evolved drastically in the last two years with the Rucio software fully replacing the previous system before the start of LHC Run-2. The ATLAS DDM system manages now more than 200 petabytes spread on 130 storage sites and can handle file transfer rates of up to 30Hz. In this talk, we discuss our experience acquired in developing, commissioning, running and maintaining such a large system. First, we describe the general architecture of the system, our integration with external services like the WLCG File Transfer Service and the evolution of the system over its first year of production. Then, we show the performance of the system, describe the integration of new technologies such as object stores, and outline future developments which mainly focus on performance and automation. Finally we discuss the long term evolution of ATLAS data management.

A distribution management system

Energy Technology Data Exchange (ETDEWEB)

Verho, P.; Jaerventausta, P.; Kaerenlampi, M.; Paulasaari, H. [Tampere Univ. of Technology (Finland); Partanen, J. [Lappeenranta Univ. of Technology (Finland)

1996-12-31

The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

A distribution management system

Energy Technology Data Exchange (ETDEWEB)

Verho, P; Jaerventausta, P; Kaerenlampi, M; Paulasaari, H [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

1997-12-31

The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

RBAC Administration in Distributed Systems

NARCIS (Netherlands)

Dekker, M.A.C.; Crampton, J.; Etalle, Sandro

2007-01-01

Despite a large body of literature on the administration of RBAC policies in centralized systems, the problem of the administration of a distributed system has hardly been addressed. We present a formal system for modelling a distributed RBAC system and its administration. We define two basic

Design of distributed systems of hydrolithosphere processes management. A synthesis of distributed management systems

Science.gov (United States)

Pershin, I. M.; Pervukhin, D. A.; Ilyushin, Y. V.; Afanaseva, O. V.

2017-10-01

The paper considers an important problem of designing distributed systems of hydrolithosphere processes management. The control actions on the hydrolithosphere processes under consideration are implemented by a set of extractive wells. The article shows the method of defining the approximation links for description of the dynamic characteristics of hydrolithosphere processes. The structure of distributed regulators, used in the management systems by the considered processes, is presented. The paper analyses the results of the synthesis of the distributed management system and the results of modelling the closed-loop control system by the parameters of the hydrolithosphere process.

Practical reliability and uncertainty quantification in complex systems : final report.

Energy Technology Data Exchange (ETDEWEB)

Grace, Matthew D.; Ringland, James T.; Marzouk, Youssef M. (Massachusetts Institute of Technology, Cambridge, MA); Boggs, Paul T.; Zurn, Rena M.; Diegert, Kathleen V. (Sandia National Laboratories, Albuquerque, NM); Pebay, Philippe Pierre; Red-Horse, John Robert (Sandia National Laboratories, Albuquerque, NM)

2009-09-01

The purpose of this project was to investigate the use of Bayesian methods for the estimation of the reliability of complex systems. The goals were to find methods for dealing with continuous data, rather than simple pass/fail data; to avoid assumptions of specific probability distributions, especially Gaussian, or normal, distributions; to compute not only an estimate of the reliability of the system, but also a measure of the confidence in that estimate; to develop procedures to address time-dependent or aging aspects in such systems, and to use these models and results to derive optimal testing strategies. The system is assumed to be a system of systems, i.e., a system with discrete components that are themselves systems. Furthermore, the system is 'engineered' in the sense that each node is designed to do something and that we have a mathematical description of that process. In the time-dependent case, the assumption is that we have a general, nonlinear, time-dependent function describing the process. The major results of the project are described in this report. In summary, we developed a sophisticated mathematical framework based on modern probability theory and Bayesian analysis. This framework encompasses all aspects of epistemic uncertainty and easily incorporates steady-state and time-dependent systems. Based on Markov chain, Monte Carlo methods, we devised a computational strategy for general probability density estimation in the steady-state case. This enabled us to compute a distribution of the reliability from which many questions, including confidence, could be addressed. We then extended this to the time domain and implemented procedures to estimate the reliability over time, including the use of the method to predict the reliability at a future time. Finally, we used certain aspects of Bayesian decision analysis to create a novel method for determining an optimal testing strategy, e.g., we can estimate the 'best' location to

Communication Facilities for Distributed Systems

Directory of Open Access Journals (Sweden)

V. Barladeanu

1997-01-01

Full Text Available The design of physical networks and communication protocols in Distributed Systems can have a direct impact on system efficiency and reliability. This paper tries to identify efficient mechanisms and paradigms for communication in distributed systems.

Supervisor Localization: A Top-Down Approach to Distributed Control of Discrete-Event Systems

International Nuclear Information System (INIS)

Cai, K.; Wonham, W. M.

2009-01-01

A purely distributed control paradigm is proposed for discrete-event systems (DES). In contrast to control by one or more external supervisors, distributed control aims to design built-in strategies for individual agents. First a distributed optimal nonblocking control problem is formulated. To solve it, a top-down localization procedure is developed which systematically decomposes an external supervisor into local controllers while preserving optimality and nonblockingness. An efficient localization algorithm is provided to carry out the computation, and an automated guided vehicles (AGV) example presented for illustration. Finally, the 'easiest' and 'hardest' boundary cases of localization are discussed.

Control and operation of distributed generation in distribution systems

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2011-01-01

Many distribution systems nowadays have significant penetration of distributed generation (DG)and thus, islanding operation of these distribution systems is becoming a viable option for economical and technical reasons. The DG should operate optimally during both grid-connected and island...... algorithm, which uses average rate of change off requency (Af5) and real power shift RPS), in the islanded mode. RPS will increase or decrease the power set point of the generator with increasing or decreasing system frequency, respectively. Simulation results show that the proposed method can operate...

Underfrequency Load Shedding for an Islanded Distribution System With Distributed Generators

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2010-01-01

Significant penetration of distributed generation in many distribution systems has opened an option of operating distribution systems in island mode for economical and technical reasons. However, balancing frequency of the islanded system is still an issue to be solved, especially when the demand...

Loss Allocation in a Distribution System with Distributed Generation Units

DEFF Research Database (Denmark)

Lund, Torsten; Nielsen, Arne Hejde; Sørensen, Poul Ejnar

2007-01-01

In Denmark, a large part of the electricity is produced by wind turbines and combined heat and power plants (CHPs). Most of them are connected to the network through distribution systems. This paper presents a new algorithm for allocation of the losses in a distribution system with distributed...... generation. The algorithm is based on a reduced impedance matrix of the network and current injections from loads and production units. With the algorithm, the effect of the covariance between production and consumption can be evaluated. To verify the theoretical results, a model of the distribution system...

Plug and Play Robust Distributed Control with Ellipsoidal Parametric Uncertainty System

Directory of Open Access Journals (Sweden)

Hong Wang-jian

2016-01-01

Full Text Available We consider a continuous linear time invariant system with ellipsoidal parametric uncertainty structured into subsystems. Since the design of a local controller uses only information on a subsystem and its neighbours, we combine the plug and play idea and robust distributed control to propose one distributed control strategy for linear system with ellipsoidal parametric uncertainty. Firstly for linear system with ellipsoidal parametric uncertainty, a necessary and sufficient condition for robust state feedback control is proposed by means of linear matrix inequality. If this necessary and sufficient condition is satisfied, this robust state feedback gain matrix can be easily derived to guarantee robust stability and prescribed closed loop performance. Secondly the plug and play idea is introduced in the design process. Finally by one example of aircraft flutter model parameter identification, the efficiency of the proposed control strategy can be easily realized.

Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems

OpenAIRE

Herrera, Manuel; Meniconi, Silvia; Alvisi, Stefano; Izquierdo, Joaquin

2018-01-01

This document is intended to be a presentation of the Special Issue “Advanced Hydroinformatic Techniques for the Simulation and Analysis of Water Supply and Distribution Systems”. The final aim of this Special Issue is to propose a suitable framework supporting insightful hydraulic mechanisms to aid the decision-making processes of water utility managers and practitioners. Its 18 peer-reviewed articles present as varied topics as: water distribution system design, optimization of network perf...

A risk assessment model based on fuzzy logic for electricity distribution system asset management

Directory of Open Access Journals (Sweden)

Alireza Yazdani

2014-06-01

Full Text Available Electricity distribution systems are considered as the most critical sectors in countries because of the essentiality of power supplement security, socioeconomic security, and way of life. According to the central role of electricity distribution systems, risk analysis helps decision maker determine the most serious risk items to allocate the optimal amount of resources and time. Probability-impact (PI matrix is one of the most popular methods for assessment of the risks involved in the system. However, the traditional PI matrix is criticized for its inability to take into account the inherent uncertainty imposed by real-world systems. On the other hand, fuzzy sets are capable of handling the uncertainty. Thus, in this paper, fuzzy risk assessment model is developed in order to assess risk and management for electricity distribution system asset protection. Finally, a comparison analysis is conducted to show the effectiveness and the capability of the new risk assessment model.

Distributed systems status and control

Science.gov (United States)

Kreidler, David; Vickers, David

1990-01-01

Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

Load Distribution of Semi-Central Evaporative Cooling Air-Conditioning System Based on the TRNSYS Platform

Directory of Open Access Journals (Sweden)

Ji Li

2018-05-01

Full Text Available Evaporative cooling is a green, energy-efficient cooling technology adopted in hot and dry regions, which has wider application in the field of air-conditioning systems. Outdoor meteorological parameters have a great influence on the operation mode and control strategy of evaporative cooling air-conditioning systems, and the system load distribution and system configuration will be affected. This paper aims at investigating the load distribution of semi-central evaporative cooling air-conditioning systems under the condition of hourly outdoor meteorological parameters. Firstly, this paper introduced the design partition, operation mode, controlling strategy and load distribution method on semi-central evaporative cooling air-conditioning system. Then, taking an office building in Lanzhou (China as an example, the evaporative cooling air-conditioning system was divided into five regions and the load distribution was simulated by TRNSYS (The Transient Energy System Simulation Tool under the condition of hourly outdoor meteorological parameters. Finally, the results have shown that the evaporative cooling air-conditioning system can provide 25.46% of the building loads, which was of great significance to reduce the energy consumption of air-conditioning system.

Analysis of distribution systems with a high penetration of distributed generation

DEFF Research Database (Denmark)

Lund, Torsten

Since the mid eighties, a large number of wind turbines and distributed combined heat and power plants (CHPs) have been connected to the Danish power system. Especially in the Western part, comprising Jutland and Funen, the penetration is high compared to the load demand. In some periods the wind...... power alone can cover the entire load demand. The objective of the work is to investigate the influence of wind power and distributed combined heat and power production on the operation of the distribution systems. Where other projects have focused on the modeling and control of the generators and prime...... movers, the focus of this project is on the operation of an entire distribution system with several wind farms and CHPs. Firstly, the subject of allocation of power system losses in a distribution system with distributed generation is treated. A new approach to loss allocation based on current injections...

Analysis of Mesh Distribution Systems Considering Load Models and Load Growth Impact with Loops on System Performance

Science.gov (United States)

Kumar Sharma, A.; Murty, V. V. S. N.

2014-12-01

The distribution system is the final link between bulk power system and consumer end. A distinctive load flow solution method is used for analysis of the load flow of radial and weakly meshed network based on Kirchhoff's Current Law (KCL) and KVL. This method has excellent convergence characteristics for both radial as well as weakly meshed structure and is based on bus injection to branch current and branch-current to bus-voltage matrix. The main contribution of the paper is: (i) an analysis has been carried out for a weekly mesh network considering number of loops addition and its impact on the losses, kW and kVAr requirements from a system, and voltage profile, (ii) different load models, realistic ZIP load model and load growth impact on losses, voltage profile, kVA and kVAr requirements, (iii) impact of addition of loops on losses, voltage profile, kVA and kVAr requirements from substation, and (iv) comparison of system performance with radial distribution system. Voltage stability is a major concern in planning and operation of power systems. This paper also includes identifying the closeness critical bus which is the most sensitive to the voltage collapse in radial distribution networks. Node having minimum value of voltage stability index is the most sensitive node. Voltage stability index values are computed for meshed network with number of loops added in the system. The results have been obtained for IEEE 33 and 69 bus test system. The results have also been obtained for radial distribution system for comparison.

Distributed Role Selection With ANC and TDBC Protocols in Two-Way Relaying Systems

KAUST Repository

Ding, Haiyang

2015-09-28

This paper advocates a distributed role selection strategy to coordinate two-way relaying transmissions among three cooperative nodes. For such, the local channel state information comparison and decision feedback mechanism are merged into classical analog network coding (ANC) and time division broadcast (TDBC) protocols such that the cooperative role of each node can be designated in a distributed fashion. We refer to this distributed role selection rule as d-ROSE. In both ANC-based and TDBC-based two-way relaying scenarios, strict proof for the equivalence of d-ROSE and optimal ROSE is given, which indicates that albeit the different form, their final role decision is essentially the same. Outage analysis for the d-ROSE strategy is carried out and the scaling law of the system outage behavior at high signal-to-noise ratio (SNR) is characterized, which manifests that d-ROSE can enhance the system diversity gain to one-order higher relative to the ANC and TDBC protocols. It is also shown that d-ROSE can reduce the signaling overhead upto 60% to perform the outage-optimal role selection. Finally, the impacts of node placement on the outage performance as well as the average signaling overhead of d-ROSE are numerically evaluated and some useful conclusions are drawn. © 2015 IEEE.

A Simple Adaptive Overcurrent Protection of Distribution Systems With Distributed Generation

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2011-01-01

current when the system is connected to the grid and when it is islanded. This paper proposes the use of adaptive protection, using local information, to overcome the challenges of the overcurrent protection in distribution systems with distributed generation. The trip characteristics of the relays...... are updated by detecting operating states (grid connected or island) and the faulted section. The paper also proposes faulted section detection using the time over-current characteristics of the protective relays. Simulation results show that the operating state and faulted section can be correctly identified......A significant increase in the penetration of distributed generation has resulted in a possibility of operating distribution systems with distributed generation in islanded mode. However, over-current protection of an islanded distribution system is still an issue due to the difference in fault...

Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

Directory of Open Access Journals (Sweden)

Wenjie Peng

2014-01-01

Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

Distributed Treatment Systems.

Science.gov (United States)

Zgonc, David; Plante, Luke

2017-10-01

This section presents a review of the literature published in 2016 on topics relating to distributed treatment systems. This review is divided into the following sections with multiple subsections under each: constituent removal; treatment technologies; and planning and treatment system management.

A New Approach to Optimal Allocation of Reactive Power Ancillary Service in Distribution Systems in the Presence of Distributed Energy Resources

Directory of Open Access Journals (Sweden)

Abouzar Samimi

2015-11-01

Full Text Available One of the most important Distribution System Operators (DSO schemes addresses the Volt/Var control (VVC problem. Developing a cost-based reactive power dispatch model for distribution systems, in which the reactive powers are appropriately priced, can motivate Distributed Energy Resources (DERs to participate actively in VVC. In this paper, new reactive power cost models for DERs, including synchronous machine-based DGs and wind turbines (WTs, are formulated based on their capability curves. To address VVC in the context of competitive electricity markets in distribution systems, first, in a day-ahead active power market, the initial active power dispatch of generation units is estimated considering environmental and economic aspects. Based on the results of the initial active power dispatch, the proposed VVC model is executed to optimally allocate reactive power support among all providers. Another novelty of this paper lies in the pricing scheme that rewards transformers and capacitors for tap and step changing, respectively, while incorporating the reactive power dispatch model. A Benders decomposition algorithm is employed as a solution method to solve the proposed reactive power dispatch, which is a mixed integer non-linear programming (MINLP problem. Finally, a typical 22-bus distribution network is used to verify the efficiency of the proposed method.

The Impact of Connecting Distributed Generation to the Distribution System

Directory of Open Access Journals (Sweden)

E. V. Mgaya

2007-01-01

Full Text Available This paper deals with the general problem of utilizing of renewable energy sources to generate electric energy. Recent advances in renewable energy power generation technologies, e.g., wind and photovoltaic (PV technologies, have led to increased interest in the application of these generation devices as distributed generation (DG units. This paper presents the results of an investigation into possible improvements in the system voltage profile and reduction of system losses when adding wind power DG (wind-DG to a distribution system. Simulation results are given for a case study, and these show that properly sized wind DGs, placed at carefully selected sites near key distribution substations, could be very effective in improving the distribution system voltage profile and reducing power losses, and hence could  improve the effective capacity of the system. 

Final design of a free-piston hydraulic advanced Stirling conversion system

Science.gov (United States)

Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

1991-01-01

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

Final design of a free-piston hydraulic advanced Stirling conversion system

Science.gov (United States)

Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

RELIABILITY ANALYSIS OF POWER DISTRIBUTION SYSTEMS

Directory of Open Access Journals (Sweden)

Popescu V.S.

2012-04-01

Full Text Available Power distribution systems are basic parts of power systems and reliability of these systems at present is a key issue for power engineering development and requires special attention. Operation of distribution systems is accompanied by a number of factors that produce random data a large number of unplanned interruptions. Research has shown that the predominant factors that have a significant influence on the reliability of distribution systems are: weather conditions (39.7%, defects in equipment(25% and unknown random factors (20.1%. In the article is studied the influence of random behavior and are presented estimations of reliability of predominantly rural electrical distribution systems.

Output Feedback Distributed Containment Control for High-Order Nonlinear Multiagent Systems.

Science.gov (United States)

Li, Yafeng; Hua, Changchun; Wu, Shuangshuang; Guan, Xinping

2017-01-31

In this paper, we study the problem of output feedback distributed containment control for a class of high-order nonlinear multiagent systems under a fixed undirected graph and a fixed directed graph, respectively. Only the output signals of the systems can be measured. The novel reduced order dynamic gain observer is constructed to estimate the unmeasured state variables of the system with the less conservative condition on nonlinear terms than traditional Lipschitz one. Via the backstepping method, output feedback distributed nonlinear controllers for the followers are designed. By means of the novel first virtual controllers, we separate the estimated state variables of different agents from each other. Consequently, the designed controllers show independence on the estimated state variables of neighbors except outputs information, and the dynamics of each agent can be greatly different, which make the design method have a wider class of applications. Finally, a numerical simulation is presented to illustrate the effectiveness of the proposed method.

Synchronous Design and Test of Distributed Passive Radar Systems Based on Digital Broadcasting and Television

Directory of Open Access Journals (Sweden)

Wan Xianrong

2017-02-01

Full Text Available Digital broadcasting and television are important classes of illuminators of opportunity for passive radars. Distributed and multistatic structure are the development trends for passive radars. Most modern digital broadcasting and television systems work on a network, which not only provides a natural condition to distributed passive radar but also puts forward higher requirements on the design of passive radar systems. Among those requirements, precise synchronization among the receivers and transmitters as well as among multiple receiving stations, which mainly involves frequency and time synchronization, is the first to be solved. To satisfy the synchronization requirements of distributed passive radars, a synchronization scheme based on GPS is presented in this paper. Moreover, an effective scheme based on the China Mobile Multimedia Broadcasting signal is proposed to test the system synchronization performance. Finally, the reliability of the synchronization design is verified via the distributed multistatic passive radar experiments.

Final Report: MaRSPlus Sensor System Electrical Cable Management and Distributed Motor Control Computer Interface

Science.gov (United States)

Reil, Robin

2011-01-01

The success of JPL's Next Generation Imaging Spectrometer (NGIS) in Earth remote sensing has inspired a follow-on instrument project, the MaRSPlus Sensor System (MSS). One of JPL's responsibilities in the MSS project involves updating the documentation from the previous JPL airborne imagers to provide all the information necessary for an outside customer to operate the instrument independently. As part of this documentation update, I created detailed electrical cabling diagrams to provide JPL technicians with clear and concise build instructions and a database to track the status of cables from order to build to delivery. Simultaneously, a distributed motor control system is being developed for potential use on the proposed 2018 Mars rover mission. This system would significantly reduce the mass necessary for rover motor control, making more mass space available to other important spacecraft systems. The current stage of the project consists of a desktop computer talking to a single "cold box" unit containing the electronics to drive a motor. In order to test the electronics, I developed a graphical user interface (GUI) using MATLAB to allow a user to send simple commands to the cold box and display the responses received in a user-friendly format.

A FPGA-based identity authority method in quantum key distribution system

International Nuclear Information System (INIS)

Cui Ke; Luo Chunli; Zhang Hongfei; Lin Shengzhao; Jin Ge; Wang Jian

2012-01-01

In this article, an identity authority method realized in hardware is developed which is used in quantum key distribution (QKD) systems. This method is based on LFSR-Teoplitz hashing matrix. Its benefits relay on its easy implementation in hardware and high secure coefficient. It can gain very high security by means of splitting part of the final key generated from QKD systems as the seed where it is required in the identity authority method. We propose an specific flow of the identity authority method according to the problems and features of the hardware. The proposed method can satisfy many kinds of QKD systems. (authors)

A New Wind Turbine Generating System Model for Balanced and Unbalanced Distribution Systems Load Flow Analysis

Directory of Open Access Journals (Sweden)

Ahmet Koksoy

2018-03-01

Full Text Available Wind turbine generating systems (WTGSs, which are conventionally connected to high voltage transmission networks, have frequently been employed as distributed generation units in today’s distribution networks. In practice, the distribution networks always have unbalanced bus voltages and line currents due to uneven distribution of single or double phase loads over three phases and asymmetry of the lines, etc. Accordingly, in this study, for the load flow analysis of the distribution networks, Conventional Fixed speed Induction Generator (CFIG based WTGS, one of the most widely used WTGS types, is modelled under unbalanced voltage conditions. The Developed model has active and reactive power expressions in terms of induction machine impedance parameters, terminal voltages and input power. The validity of the Developed model is confirmed with the experimental results obtained in a test system. The results of the slip calculation based phase-domain model (SCP Model, which was previously proposed in the literature for CFIG based WTGSs under unbalanced voltages, are also given for the comparison. Finally, the Developed model and the SCP model are implemented in the load flow analysis of the IEEE 34 bus test system with the CFIG based WTGSs and unbalanced loads. Thus, it is clearly pointed out that the results of the load flow analysis implemented with both models are very close to each other, and the Developed model is computationally more efficient than the SCP model.

Distributed optimal coordination for distributed energy resources in power systems

DEFF Research Database (Denmark)

Wu, Di; Yang, Tao; Stoorvogel, A.

2017-01-01

Driven by smart grid technologies, distributed energy resources (DERs) have been rapidly developing in recent years for improving reliability and efficiency of distribution systems. Emerging DERs require effective and efficient coordination in order to reap their potential benefits. In this paper......, we consider an optimal DER coordination problem over multiple time periods subject to constraints at both system and device levels. Fully distributed algorithms are proposed to dynamically and automatically coordinate distributed generators with multiple/single storages. With the proposed algorithms...

Research in Distributed Real-Time Systems

Science.gov (United States)

Mukkamala, R.

1997-01-01

This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

Evolution of the ATLAS distributed computing system during the LHC long shutdown

Science.gov (United States)

Campana, S.; Atlas Collaboration

2014-06-01

The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the Worldwide LHC Computing Grid (WLCG) distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1 PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileup. We will describe the evolution of the ADC software foreseen during this period. This includes consolidating the existing Production and Distributed Analysis framework (PanDA) and ATLAS Grid Information System (AGIS), together with the development and commissioning of next generation systems for distributed data management (DDM/Rucio) and production (Prodsys-2). We will explain how new technologies such as Cloud Computing and NoSQL databases, which ATLAS investigated as R&D projects in past years, will be integrated in production. Finally, we will describe more fundamental developments such as breaking job-to-data locality by exploiting storage federations and caches, and event level (rather than file or dataset level) workload engines.

Evolution of the ATLAS distributed computing system during the LHC long shutdown

International Nuclear Information System (INIS)

Campana, S

2014-01-01

The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the Worldwide LHC Computing Grid (WLCG) distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1 PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileup. We will describe the evolution of the ADC software foreseen during this period. This includes consolidating the existing Production and Distributed Analysis framework (PanDA) and ATLAS Grid Information System (AGIS), together with the development and commissioning of next generation systems for distributed data management (DDM/Rucio) and production (Prodsys-2). We will explain how new technologies such as Cloud Computing and NoSQL databases, which ATLAS investigated as R and D projects in past years, will be integrated in production. Finally, we will describe more fundamental developments such as breaking job-to-data locality by exploiting storage federations and caches, and event level (rather than file or dataset level) workload engines.

A Distribution-class Locational Marginal Price (DLMP) Index for Enhanced Distribution Systems

Science.gov (United States)

Akinbode, Oluwaseyi Wemimo

The smart grid initiative is the impetus behind changes that are expected to culminate into an enhanced distribution system with the communication and control infrastructure to support advanced distribution system applications and resources such as distributed generation, energy storage systems, and price responsive loads. This research proposes a distribution-class analog of the transmission LMP (DLMP) as an enabler of the advanced applications of the enhanced distribution system. The DLMP is envisioned as a control signal that can incentivize distribution system resources to behave optimally in a manner that benefits economic efficiency and system reliability and that can optimally couple the transmission and the distribution systems. The DLMP is calculated from a two-stage optimization problem; a transmission system OPF and a distribution system OPF. An iterative framework that ensures accurate representation of the distribution system's price sensitive resources for the transmission system problem and vice versa is developed and its convergence problem is discussed. As part of the DLMP calculation framework, a DCOPF formulation that endogenously captures the effect of real power losses is discussed. The formulation uses piecewise linear functions to approximate losses. This thesis explores, with theoretical proofs, the breakdown of the loss approximation technique when non-positive DLMPs/LMPs occur and discusses a mixed integer linear programming formulation that corrects the breakdown. The DLMP is numerically illustrated in traditional and enhanced distribution systems and its superiority to contemporary pricing mechanisms is demonstrated using price responsive loads. Results show that the impact of the inaccuracy of contemporary pricing schemes becomes significant as flexible resources increase. At high elasticity, aggregate load consumption deviated from the optimal consumption by up to about 45 percent when using a flat or time-of-use rate. Individual load

State Electricity Regulatory Policy and Distributed Resources: Distributed Resources and Electric System Reliability

Energy Technology Data Exchange (ETDEWEB)

Cowart, R.; Harrington, C.; Moskovitz, D.; Shirley, W.; Weston, F.; Sedano, R.

2002-10-01

Designing and implementing credit-based pilot programs for distributed resources distribution is a low-cost, low-risk opportunity to find out how these resources can help defer or avoid costly electric power system (utility grid) distribution upgrades. This report describes implementation options for deaveraged distribution credits and distributed resource development zones. Developing workable programs implementing these policies can dramatically increase the deployment of distributed resources in ways that benefit distributed resource vendors, users, and distribution utilities. This report is one in the State Electricity Regulatory Policy and Distributed Resources series developed under contract to NREL (see Annual Technical Status Report of the Regulatory Assistance Project: September 2000-September 2001, NREL/SR-560-32733). Other titles in this series are: (1) Accommodating Distributed Resources in Wholesale Markets, NREL/SR-560-32497; (2) Distributed Resources and Electric System Re liability, NREL/SR-560-32498; (3) Distribution System Cost Methodologies for Distributed Generation, NREL/SR-560-32500; (4) Distribution System Cost Methodologies for Distributed Generation Appendices, NREL/SR-560-32501.

Reliability Evaluation of Distribution System Considering Sequential Characteristics of Distributed Generation

Directory of Open Access Journals (Sweden)

Sheng Wanxing

2016-01-01

Full Text Available In allusion to the randomness of output power of distributed generation (DG, a reliability evaluation model based on sequential Monte Carlo simulation (SMCS for distribution system with DG is proposed. Operating states of the distribution system can be sampled by SMCS in chronological order thus the corresponding output power of DG can be generated. The proposed method has been tested on feeder F4 of IEEE-RBTS Bus 6. The results show that reliability evaluation of distribution system considering the uncertainty of output power of DG can be effectively implemented by SMCS.

Grid-connected distributed solar power systems

Science.gov (United States)

Moyle, R.; Chernoff, H.; Schweizer, T.

This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

A Westinghouse designed distributed mircroprocessor based protection and control system

International Nuclear Information System (INIS)

Bruno, J.; Reid, J.B.

1980-01-01

For approximately five years, Westinghouse has been involved in the design and licensing of a distributed microprocessor based system for the protection and control of a pressurized water reactor nuclear steam supply system. A 'top-down' design methodology was used, in which the system global performance objectives were specified, followed by increasingly more detailed design specifications which ultimately decomposed the system into its basic hardware and software elements. The design process and design decisions were influenced by the recognition that the final product would have to be verified to ensure its capability to perform the safety-related functions of a class 1E protection system. The verification process mirrored the design process except that it was 'bottom-up' and thus started with the basic elements and worked upwards through the system in increasingly complex blocks. A number of areas which are of interest in a distributed system are disucssed, with emphasis on two systems. The first, the Integrated Protection System is primarily responsible for processing signals from field mounted sensors to provide for reactor trips and the initiation of the Engineered Safety Features. The Integrated Control System, which is organized in a parallel manner, processes other sensor signals and generates the necessary analog and on-off signals to maintain the plant parameters within specified limits. Points covered include system structure, systems partitioning strategies, communications techniques, software design concepts, reliability and maintainability, commercial component availability, interference susceptibility, licensing issues, and applicability. (LL)

Analysis and forecast of electrical distribution system materials. Final report. Volume III. Appendix

Energy Technology Data Exchange (ETDEWEB)

Love, C G

1976-08-23

These appendixes are referenced in Volume II of this report. They contain the detailed electrical distribution equipment requirements and input material requirements forecasts. Forecasts are given for three electric energy usage scenarios. Also included are data on worldwide reserves and demand for 30 raw materials required for the manufacture of electrical distribution equipment.

Islanding Operation of Distribution System with Distributed Generations

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2010-01-01

The growing interest in distributed generations (DGs) due to environmental concern and various other reasons have resulted in significant penetration of DGs in many distribution system worldwide. DGs come with many benefits. One of the benefits is improved reliability by supplying load during power...

Analysis to Inform CA Grid Integration Rules for PV: Final Report on Inverter Settings for Transmission and Distribution System Performance

Energy Technology Data Exchange (ETDEWEB)

Smith, Jeff [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Rylander, Matthew [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Boemer, Jens [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Broderick, Robert Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reno, Matthew J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mather, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

The fourth solicitation of the California Solar Initiative (CSI) Research, Development, Demonstration and Deployment (RD&D) Program established by the California Public Utilities Commission (CPUC) supported the Electric Power Research Institute (EPRI), National Renewable Energy Laboratory (NREL), and Sandia National Laboratories (SNL) with data provided from Pacific Gas and Electric (PG&E), Southern California Edison (SCE), and San Diego Gas and Electric (SDG&E) conducted research to determine optimal default settings for distributed energy resource advanced inverter controls. The inverter functions studied are aligned with those developed by the California Smart Inverter Working Group (SIWG) and those being considered by the IEEE 1547 Working Group. The advanced inverter controls examined to improve the distribution system response included power factor, volt-var, and volt-watt. The advanced inverter controls examined to improve the transmission system response included frequency and voltage ride-through as well as Dynamic Voltage Support. This CSI RD&D project accomplished the task of developing methods to derive distribution focused advanced inverter control settings, selecting a diverse set of feeders to evaluate the methods through detailed analysis, and evaluating the effectiveness of each method developed. Inverter settings focused on the transmission system performance were also evaluated and verified. Based on the findings of this work, the suggested advanced inverter settings and methods to determine settings can be used to improve the accommodation of distributed energy resources (PV specifically). The voltage impact from PV can be mitigated using power factor, volt-var, or volt-watt control, while the bulk system impact can be improved with frequency/voltage ride-through.

Evaluation of higher distribution and/or utilization voltages. Final report

Energy Technology Data Exchange (ETDEWEB)

Hazelrigg, Jr, George A.

1981-01-01

An electric energy distribution/utilization system cost analysis model is presented for exploring cost tradeoffs (capital innvestment, operation and maintenance and cost of losses) and optimizing system configuration. The model focuses on the treatment of residential and light commercial service areas with time-varying load characteristics, including customer load profile changes, per customer load growth and service area population growth. Applications of the model are discussed. These include providing insight on: the selection of primary and secondary voltages; conductor sizing; distribution transformer sizing, change out policies and copper-to-core-loss ratio; and limits on allowable voltage variation at the service entrance. Examples are provided to illustrate model capabilities.

Advanced Distribution Management System

OpenAIRE

Avazov, Artur; Sobinova, Lubov Anatolievna

2016-01-01

This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

Advanced Distribution Management System

Science.gov (United States)

Avazov, Artur R.; Sobinova, Liubov A.

2016-02-01

This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

In core system mapping reactor power distribution

International Nuclear Information System (INIS)

Yoriyaz, H.; Moreira, J.M.L.

1989-01-01

Based on the signals of SPND'S (Self Powered Neutron Detectors) distributed inside of a core, the spatial power distribution is obtained using the MAP program, developed in this work. The methodology applied in MAP program uses a least mean square technique to calculate expansion coefficients that depend on the SPND'S signals. The final power or neutron flux distribution is obtained by a combination of certains functions or expansion modes that are provided from diffusion calculation with the CITATION code. The MAP program is written in PASCAL language and will be used in IEA-R1 reactor for assisting its operation. (author) [pt

Final Technical Report: Integrated Distribution-Transmission Analysis for Very High Penetration Solar PV

Energy Technology Data Exchange (ETDEWEB)

Palmintier, Bryan [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Hale, Elaine [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Hansen, Timothy M. [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Jones, Wesley [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Biagioni, David [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Baker, Kyri [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Wu, Hongyu [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Giraldez, Julieta [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Sorensen, Harry [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Lunacek, Monte [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Merket, Noel [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Jorgenson, Jennie [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)); Hodge, Bri-Mathias [NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))

2016-01-29

Transmission and distribution simulations have historically been conducted separately, echoing their division in grid operations and planning while avoiding inherent computational challenges. Today, however, rapid growth in distributed energy resources (DERs)--including distributed generation from solar photovoltaics (DGPV)--requires understanding the unprecedented interactions between distribution and transmission. To capture these interactions, especially for high-penetration DGPV scenarios, this research project developed a first-of-its-kind, high performance computer (HPC) based, integrated transmission-distribution tool, the Integrated Grid Modeling System (IGMS). The tool was then used in initial explorations of system-wide operational interactions of high-penetration DGPV.

The completed design of the SLC Final Focus System

International Nuclear Information System (INIS)

Murray, J.J.; Brown, K.L.; Fieguth, T.

1987-02-01

The design of the SLC Final Focus System has evolved from its initial conceptual design into its final form. This final design is described including a review of the critical decisions influencing the adoption of particular features. The creation of a feasible design has required that these decisions be tempered by practical considerations such as site constraints, correction of optical errors caused by imperfections, and accommodations requested by engineers and particle detector physicists. As this is the first such system to be built, it is hoped that the experience gained will be useful for the design of future systems

Control and Operation of Islanded Distribution System

DEFF Research Database (Denmark)

Mahat, Pukar

deviation and real power shift. When a distribution system, with all its generators operating at maximum power, is islanded, the frequency will go down if the total load is more than the total generation. An under-frequency load shedding procedure for islanded distribution systems with DG unit(s) based...... states. Short circuit power also changes when some of the generators in the distribution system are disconnected. This may result in elongation of fault clearing time and hence disconnection of equipments (including generators) in the distribution system or unnecessary operation of protective devices...... operational challenges. But, on the other hand, it has also opened up some opportunities. One opportunity/challenge is an islanded operation of a distribution system with DG unit(s). Islanding is a situation in which a distribution system becomes electrically isolated from the remainder of the power system...

Water Treatment Technology - Distribution Systems.

Science.gov (United States)

Ross-Harrington, Melinda; Kincaid, G. David

One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

Integrating photovoltaics into utility distribution systems

International Nuclear Information System (INIS)

Zaininger, H.W.; Barnes, P.R.

1995-01-01

Electric utility distribution system impacts associated with the integration of distributed photovoltaic (PV) energy sources vary from site to site and utility to utility. The objective of this paper is to examine several utility- and site-specific conditions which may affect economic viability of distributed PV applications to utility systems. Assessment methodology compatible with technical and economic assessment techniques employed by utility engineers and planners is employed to determine PV benefits for seven different utility systems. The seven case studies are performed using utility system characteristics and assumptions obtained from appropriate utility personnel. The resulting site-specific distributed PV benefits increase nonsite-specific generation system benefits available to central station PV plants as much as 46%, for one utility located in the Southwest

Planning and Optimization Methods for Active Distribution Systems

DEFF Research Database (Denmark)

Abbey, Chad; Baitch, Alex; Bak-Jensen, Birgitte

distribution planning. Active distribution networks (ADNs) have systems in place to control a combination of distributed energy resources (DERs), defined as generators, loads and storage. With these systems in place, the AND becomes an Active Distribution System (ADS). Distribution system operators (DSOs) have...

Study of Power Flow Algorithm of AC/DC Distribution System including VSC-MTDC

Directory of Open Access Journals (Sweden)

Haifeng Liang

2015-08-01

Full Text Available In recent years, distributed generation and a large number of sensitive AC and DC loads have been connected to distribution networks, which introduce a series of challenges to distribution network operators (DNOs. In addition, the advantages of DC distribution networks, such as the energy conservation and emission reduction, mean that the voltage source converter based multi-terminal direct current (VSC-MTDC for AC/DC distribution systems demonstrates a great potential, hence drawing growing research interest. In this paper, considering losses of the reactor, the filter and the converter, a mathematical model of VSC-HVDC for the load flow analysis is derived. An AC/DC distribution network architecture has been built, based on which the differences in modified equations of the VSC-MTDC-based network under different control modes are analyzed. In addition, corresponding interface functions under five control modes are provided, and a back/forward iterative algorithm which is applied to power flow calculation of the AC/DC distribution system including VSC-MTDC is proposed. Finally, by calculating the power flow of the modified IEEE14 AC/DC distribution network, the efficiency and validity of the model and algorithm are evaluated. With various distributed generations connected to the network at appropriate locations, power flow results show that network losses and utilization of transmission networks are effectively reduced.

Coordination control of distributed systems

CERN Document Server

Villa, Tiziano

2015-01-01

This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized control,  control with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

Advanced Distribution Management System

Directory of Open Access Journals (Sweden)

Avazov Artur R.

2016-01-01

Full Text Available This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

Development of Final Running Test System for Digital Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed.

Development of Final Running Test System for Digital Systems

International Nuclear Information System (INIS)

Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok

2016-01-01

In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed

Optimizing electrical distribution systems

International Nuclear Information System (INIS)

Scott, W.G.

1990-01-01

Electrical utility distribution systems are in the middle of an unprecedented technological revolution in planning, design, maintenance and operation. The prime movers of the revolution are the major economic shifts that affect decision making. The major economic influence on the revolution is the cost of losses (technical and nontechnical). The vehicle of the revolution is the computer, which enables decision makers to examine alternatives in greater depth and detail than their predecessors could. The more important elements of the technological revolution are: system planning, computers, load forecasting, analytical systems (primary systems, transformers and secondary systems), system losses and coming technology. The paper is directed towards the rather unique problems encountered by engineers of utilities in developing countries - problems that are being solved through high technology, such as the recent World Bank-financed engineering computer system for Sri Lanka. This system includes a DEC computer, digitizer, plotter and engineering software to model the distribution system via a digitizer, analyse the system and plot single-line diagrams. (author). 1 ref., 4 tabs., 6 figs

Design of distributed PID-type dynamic matrix controller for fractional-order systems

Science.gov (United States)

Wang, Dawei; Zhang, Ridong

2018-01-01

With the continuous requirements for product quality and safety operation in industrial production, it is difficult to describe the complex large-scale processes with integer-order differential equations. However, the fractional differential equations may precisely represent the intrinsic characteristics of such systems. In this paper, a distributed PID-type dynamic matrix control method based on fractional-order systems is proposed. First, the high-order approximate model of integer order is obtained by utilising the Oustaloup method. Then, the step response model vectors of the plant is obtained on the basis of the high-order model, and the online optimisation for multivariable processes is transformed into the optimisation of each small-scale subsystem that is regarded as a sub-plant controlled in the distributed framework. Furthermore, the PID operator is introduced into the performance index of each subsystem and the fractional-order PID-type dynamic matrix controller is designed based on Nash optimisation strategy. The information exchange among the subsystems is realised through the distributed control structure so as to complete the optimisation task of the whole large-scale system. Finally, the control performance of the designed controller in this paper is verified by an example.

Solar heating system installed at Telex Communications, Inc. , Blue Earth, Minnesota. Final report

Energy Technology Data Exchange (ETDEWEB)

McEver, William S.

1979-10-26

The final results are summarized of a contract for space heating a 97,000 square foot building which houses administrative offices, assembly areas and warehouse space. Information is also provided on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature, and as-built drawings. The system began delivering space heating in February 1978. The Telex solar system is composed of four main subsystems; they are the solar collectors, controls, thermal storage and heat distribution. The ITC/Solar Mark III collector was used. The collector array consists of 10 rows of 36 collectors each. The control subsystem controls the operation of the system pumps and control valves. Thermal storage for the system is provided by a 20,000 gallon water storage tank located inside the building. Heating is accomplished by water-to-air heat exchangers and controlled by thermostats.

A scheme for a future distribution automation system in Finnish utilities

Energy Technology Data Exchange (ETDEWEB)

Lehtonen, M.; Kaerkkaeinen, S. [VTT Energy, Espoo (Finland); Partanen, J. [Lappeenranta Univ. of Technology (Finland)

1996-12-31

This presentation summarizes the results of a project, the aim of which was to define the optimal set of functions for the future distribution automation (DA) systems in Finland. The general factors. which affect the automation needs, are first discussed. The benefits of various functions of DA and demand side management (DSM) are then studied. Next a computer model for a DA feasibility analysis is presented, and some computation results are given. From these. the proposed automation scheme is finally concluded

A scheme for a future distribution automation system in Finnish utilities

Energy Technology Data Exchange (ETDEWEB)

Lehtonen, M; Kaerkkaeinen, S [VTT Energy, Espoo (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

1998-08-01

This presentation summarizes the results of a project, the aim of which was to define the optimal set of functions for the future distribution automation (DA) systems in Finland. The general factors, which affect the automation needs, are first discussed. The benefits of various functions of DA and demand side management (DSM) are then studied. Next a computer model for a DA feasibility analysis is presented, and some computation results are given. From these, the proposed automation scheme is finally concluded

A scheme for a future distribution automation system in Finnish utilities

Energy Technology Data Exchange (ETDEWEB)

Lehtonen, M; Kaerkkaeinen, S [VTT Energy, Espoo (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

1997-12-31

This presentation summarizes the results of a project, the aim of which was to define the optimal set of functions for the future distribution automation (DA) systems in Finland. The general factors. which affect the automation needs, are first discussed. The benefits of various functions of DA and demand side management (DSM) are then studied. Next a computer model for a DA feasibility analysis is presented, and some computation results are given. From these. the proposed automation scheme is finally concluded

Reliability assessment of distribution power systems including distributed generations

International Nuclear Information System (INIS)

Megdiche, M.

2004-12-01

Nowadays, power systems have reached a good level of reliability. Nevertheless, considering the modifications induced by the connections of small independent producers to distribution networks, there's a need to assess the reliability of these new systems. Distribution networks present several functional characteristics, highlighted by the qualitative study of the failures, as dispersed loads at several places, variable topology and some electrotechnical phenomena which must be taken into account to model the events that can occur. The adopted reliability calculations method is Monte Carlo simulations, the probabilistic method most powerful and most flexible to model complex operating of the distribution system. We devoted a first part on the case of a 20 kV feeder to which a cogeneration unit is connected. The method was applied to a software of stochastic Petri nets simulations. Then a second part related to the study of a low voltage power system supplied by dispersed generations. Here, the complexity of the events required to code the method in an environment of programming allowing the use of power system calculations (load flow, short-circuit, load shedding, management of units powers) in order to analyse the system state for each new event. (author)

Energy efficient distributed computing systems

CERN Document Server

Lee, Young-Choon

2012-01-01

The energy consumption issue in distributed computing systems raises various monetary, environmental and system performance concerns. Electricity consumption in the US doubled from 2000 to 2005.  From a financial and environmental standpoint, reducing the consumption of electricity is important, yet these reforms must not lead to performance degradation of the computing systems.  These contradicting constraints create a suite of complex problems that need to be resolved in order to lead to 'greener' distributed computing systems.  This book brings together a group of outsta

Bluetooth-based distributed measurement system

International Nuclear Information System (INIS)

Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng

2007-01-01

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit

Bluetooth-based distributed measurement system

Science.gov (United States)

Tang, Baoping; Chen, Zhuo; Wei, Yuguo; Qin, Xiaofeng

2007-07-01

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

Bluetooth-based distributed measurement system

Energy Technology Data Exchange (ETDEWEB)

Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng [Department of Mechatronics, College of Mechanical Engineering, Chongqing University, Chongqing, 400030 (China)

2007-07-15

A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

Large scale network-centric distributed systems

CERN Document Server

Sarbazi-Azad, Hamid

2014-01-01

A highly accessible reference offering a broad range of topics and insights on large scale network-centric distributed systems Evolving from the fields of high-performance computing and networking, large scale network-centric distributed systems continues to grow as one of the most important topics in computing and communication and many interdisciplinary areas. Dealing with both wired and wireless networks, this book focuses on the design and performance issues of such systems. Large Scale Network-Centric Distributed Systems provides in-depth coverage ranging from ground-level hardware issu

Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of 234U

International Nuclear Information System (INIS)

Montoya, M.; Rojas, J.; Lobato, I.

2008-01-01

The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

Distribution network strengthens sales systems

International Nuclear Information System (INIS)

Janoska, J.

2003-01-01

Liberalisation of the electricity market pushes Slovak distribution companies to upgrade their sale technologies. The first one to invest into a complex electronic sales system will be Stredoslovenska energetika, a.s., Zilina. The system worth 200 million Sk (4,83 million Euro) will be supplied by Polish software company Winuel. The company should also supply a software that would allow forecasting and planning of sales. The system should be fully operational by 2006. TREND has not managed to obtain information regarding plans Zapadoslovenska energetika - the largest and most active distribution company - might have in this area. In eastern Slovakia distribution company Vychodoslovenska energetika, a.s., Kosice has also started addressing this issue. (Author)

Final Report for File System Support for Burst Buffers on HPC Systems

Energy Technology Data Exchange (ETDEWEB)

Yu, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mohror, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-11-27

Distributed burst buffers are a promising storage architecture for handling I/O workloads for exascale computing. As they are being deployed on more supercomputers, a file system that efficiently manages these burst buffers for fast I/O operations carries great consequence. Over the past year, FSU team has undertaken several efforts to design, prototype and evaluate distributed file systems for burst buffers on HPC systems. These include MetaKV: a Key-Value Store for Metadata Management of Distributed Burst Buffers, a user-level file system with multiple backends, and a specialized file system for large datasets of deep neural networks. Our progress for these respective efforts are elaborated further in this report.

Phase-remapping attack in practical quantum-key-distribution systems

International Nuclear Information System (INIS)

Fung, Chi-Hang Fred; Qi, Bing; Lo, Hoi-Kwong; Tamaki, Kiyoshi

2007-01-01

Quantum key distribution (QKD) can be used to generate secret keys between two distant parties. Even though QKD has been proven unconditionally secure against eavesdroppers with unlimited computation power, practical implementations of QKD may contain loopholes that may lead to the generated secret keys being compromised. In this paper, we propose a phase-remapping attack targeting two practical bidirectional QKD systems (the 'plug-and-play' system and the Sagnac system). We showed that if the users of the systems are unaware of our attack, the final key shared between them can be compromised in some situations. Specifically, we showed that, in the case of the Bennett-Brassard 1984 (BB84) protocol with ideal single-photon sources, when the quantum bit error rate (QBER) is between 14.6% and 20%, our attack renders the final key insecure, whereas the same range of QBER values has been proved secure if the two users are unaware of our attack; also, we demonstrated three situations with realistic devices where positive key rates are obtained without the consideration of Trojan horse attacks but in fact no key can be distilled. We remark that our attack is feasible with only current technology. Therefore, it is very important to be aware of our attack in order to ensure absolute security. In finding our attack, we minimize the QBER over individual measurements described by a general POVM, which has some similarity with the standard quantum state discrimination problem

Probabilistic analysis in normal operation of distribution system with distributed generation

DEFF Research Database (Denmark)

Villafafila-Robles, R.; Sumper, A.; Bak-Jensen, B.

2011-01-01

Nowadays, the incorporation of high levels of small-scale non-dispatchable distributed generation is leading to the transition from the traditional 'vertical' power system structure to a 'horizontally-operated' power system, where the distribution networks contain both stochastic generation...... and load. This fact increases the number of stochastic inputs and dependence structures between them need to be considered. The deterministic analysis is not enough to cope with these issues and a new approach is needed. Probabilistic analysis provides a better approach. Moreover, as distribution systems...

The THUDSOS Distributed Operating System

Institute of Scientific and Technical Information of China (English)

廖先Zhi; 刘旭峰; 等

1991-01-01

The THUDSOS is a distributed operating system modeled as an abstract machine which provides decentralized control,transparency,availability,and reliability,as welol as a good degree of autonomy at each node,that makes our distributed system usable.Our operating system supports transparent access to data through network wide filesystem.The simultaneous access to any device is discussed for the case when the peripherals are treated as files.This operating system allows spawning of parallel application programs to solve problems in the fields,such as numerical analysis and artificial intelligence.

Distributed Control of Battery Energy Storage Systems for Voltage Regulation in Distribution Networks with High PV Penetration

DEFF Research Database (Denmark)

Zeraati, Mehdi; Golshan, Mohamad Esmaeil Hamedani; Guerrero, Josep M.

2018-01-01

of their installed capacity whereas the second one modifies the BESs performance in terms of their state of charge (SoC) to prevent the excessive saturation or depletion of batteries. The proposed controller enables the effective use of storage capacity in different conditions. Finally, the simulation results based...... issues of distribution networks. In this paper, the battery energy storage (BES) systems are used in order to solve the voltage rise during the peak PV generation as well as the voltage drop while meeting the peak load. A coordinated control strategy is proposed to regulate the charge/discharge of BESs...

Strategy Guideline. Compact Air Distribution Systems

Energy Technology Data Exchange (ETDEWEB)

Burdick, Arlan [IBACOS, Inc., Pittsburgh, PA (United States)

2013-06-01

This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

Electrical power systems for distributed generation

Energy Technology Data Exchange (ETDEWEB)

Robertson, T.A.; Huval, S.J. [Stewart & Stevenson Services, Inc., Houston, TX (United States)

1996-12-31

{open_quotes}Distributed Generation{close_quotes} has become the {open_quotes}buzz{close_quotes} word of an electric utility industry facing deregulation. Many industrial facilities utilize equipment in distributed installations to serve the needs of a thermal host through the capture of exhaust energy in a heat recovery steam generator. The electrical power generated is then sold as a {open_quotes}side benefit{close_quotes} to the cost-effective supply of high quality thermal energy. Distributed generation is desirable for many different reasons, each with unique characteristics of the product. Many years of experience in the distributed generation market has helped Stewart & Stevenson to define a range of product features that are crucial to most any application. The following paper will highlight a few of these applications. The paper will also examine the range of products currently available and in development. Finally, we will survey the additional services offered by Stewart & Stevenson to meet the needs of a rapidly changing power generation industry.

Coordinated Optimization of Distributed Energy Resources and Smart Loads in Distribution Systems: Preprint

Energy Technology Data Exchange (ETDEWEB)

Yang, Rui; Zhang, Yingchen

2016-08-01

Distributed energy resources (DERs) and smart loads have the potential to provide flexibility to the distribution system operation. A coordinated optimization approach is proposed in this paper to actively manage DERs and smart loads in distribution systems to achieve the optimal operation status. A three-phase unbalanced Optimal Power Flow (OPF) problem is developed to determine the output from DERs and smart loads with respect to the system operator's control objective. This paper focuses on coordinating PV systems and smart loads to improve the overall voltage profile in distribution systems. Simulations have been carried out in a 12-bus distribution feeder and results illustrate the superior control performance of the proposed approach.

Equilibrium distribution function in collisionless systems

International Nuclear Information System (INIS)

Pergamenshchik, V.M.

1988-01-01

Collisionless systems of a large number of N particles interacting by Coulomb forces are widely spread in cosmic and laboratory plasma. A statistical theory of equilibrium state of collisionless Coulomb systems which evolution obeys Vlasov equation is proposed. The developed formalism permits a sequential consideration of such distributed in one-particle six-dimensional phase space of a system and to obtain a simple result: equilibrium distribution function has the form of Fermi-Dirac distribution and doesn't depend on initial state factors

On Distributed Port-Hamiltonian Process Systems

NARCIS (Netherlands)

Lopezlena, Ricardo; Scherpen, Jacquelien M.A.

2004-01-01

In this paper we use the term distributed port-Hamiltonian Process Systems (DPHPS) to refer to the result of merging the theory of distributed Port-Hamiltonian systems (DPHS) with the theory of process systems (PS). Such concept is useful for combining the systematic interconnection of PHS with the

A Heuristic Approach to Distributed Generation Source Allocation for Electrical Power Distribution Systems

Directory of Open Access Journals (Sweden)

M. Sharma

2010-12-01

Full Text Available The recent trends in electrical power distribution system operation and management are aimed at improving system conditions in order to render good service to the customer. The reforms in distribution sector have given major scope for employment of distributed generation (DG resources which will boost the system performance. This paper proposes a heuristic technique for allocation of distribution generation source in a distribution system. The allocation is determined based on overall improvement in network performance parameters like reduction in system losses, improvement in voltage stability, improvement in voltage profile. The proposed Network Performance Enhancement Index (NPEI along with the heuristic rules facilitate determination of feasible location and corresponding capacity of DG source. The developed approach is tested with different test systems to ascertain its effectiveness.

Review on Islanding Operation of Distribution System with Distributed Generation

DEFF Research Database (Denmark)

Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

2011-01-01

The growing environmental concern and various benefits of distributed generation (DG) have resulted in significant penetration of DG in many distribution systems worldwide. One of the major expected benefits of DG is the improvement in the reliability of power supply by supplying load during power...... outage by operating in an island mode. However, there are many challenges to overcome before islanding operation of a distribution system with DG can become a viable solution in future. This paper reviews some of the major challenges with islanding operation and explores some possible solutions...

General method for final focus system design for circular colliders

Directory of Open Access Journals (Sweden)

Riccardo de Maria

2008-03-01

Full Text Available Colliders use final focus systems to reduce the transverse beam sizes at the interaction point in order to increase collision event rates. The maximum focal strength (gradient of the quadrupoles, and the maximum beam size in them, together limit the beam size reduction that is possible. The goal of a final focus system design is to find the best compromise between quadrupole aperture and quadrupole gradient, for the magnet technology that is used. This paper develops a design method that identifies the intrinsic limitations of a final focus system, validates the results of the method against realistic designs, and reports its application to the upgrade of the Large Hadron Collider final focus.

Galileo spacecraft power management and distribution system

International Nuclear Information System (INIS)

Detwiler, R.C.; Smith, R.L.

1990-01-01

It has been twelve years since two Voyager spacecraft began the direct route to the outer planets. In October 1989 a single Galileo spacecraft started the return to Jupiter. Conceived as a simple Voyager look-alike, the Galileo power management and distribution (PMAD) system has undergone many iterations in configuration. Major changes to the PMAD resulted from dual spun slip ring limitations, variations in launch vehicle thrust capabilities, and launch delays. Lack of an adequate launch vehicle for an interplanetary mission of Galileo's size has resulted in an extremely long flight duration. A Venus-Earth-Earth Gravity Assist (VEEGA) tour, vital to attain the required energy, results in a 6 year trip to Jupiter and its moons. This paper provides a description of the Galileo PMAD and documents the design drivers that established the final as-built hardware

Distributed Fault Detection for a Class of Nonlinear Stochastic Systems

Directory of Open Access Journals (Sweden)

Bingyong Yan

2014-01-01

Full Text Available A novel distributed fault detection strategy for a class of nonlinear stochastic systems is presented. Different from the existing design procedures for fault detection, a novel fault detection observer, which consists of a nonlinear fault detection filter and a consensus filter, is proposed to detect the nonlinear stochastic systems faults. Firstly, the outputs of the nonlinear stochastic systems act as inputs of a consensus filter. Secondly, a nonlinear fault detection filter is constructed to provide estimation of unmeasurable system states and residual signals using outputs of the consensus filter. Stability analysis of the consensus filter is rigorously investigated. Meanwhile, the design procedures of the nonlinear fault detection filter are given in terms of linear matrix inequalities (LMIs. Taking the influence of the system stochastic noises into consideration, an outstanding feature of the proposed scheme is that false alarms can be reduced dramatically. Finally, simulation results are provided to show the feasibility and effectiveness of the proposed fault detection approach.

Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

KAUST Repository

Eleiwi, Fadi; N'Doye, Ibrahima; Laleg-Kirati, Taous-Meriem

2015-01-01

In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

KAUST Repository

Eleiwi, Fadi

2015-09-21

In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

Light distribution system comprising spectral conversion means

DEFF Research Database (Denmark)

2012-01-01

, longer wavelength,a spectral conversion characteristics of the spectral conversion fibre being essentially determined by the spectral absorption and emission properties of the photoluminescent agent, the amount of photo- luminescent agent,and the distribution of the photoluminescent agent in the spectral......System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side...... of providing a light distribution system and a method of correcting the spectral transmission characteristics of a light distribution system are disclosed....

Cathode power distribution system and method of using the same for power distribution

Science.gov (United States)

Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

2014-11-11

Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

Advanced smartgrids for distribution system operators

CERN Document Server

Boillot, Marc

2014-01-01

The dynamic of the Energy Transition is engaged in many region of the World. This is a real challenge for electric systems and a paradigm shift for existing distribution networks. With the help of "advanced" smart technologies, the Distribution System Operators will have a central role to integrate massively renewable generation, electric vehicle and demand response programs. Many projects are on-going to develop and assess advanced smart grids solutions, with already some lessons learnt. In the end, the Smart Grid is a mean for Distribution System Operators to ensure the quality and the secu

47 CFR 73.6023 - Distributed transmission systems.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Distributed transmission systems. 73.6023... distributed transmission system. [73 FR 74064, Dec. 5, 2008] ... RADIO BROADCAST SERVICES Class A Television Broadcast Stations § 73.6023 Distributed transmission...

Reliability assessment of distribution system with the integration of renewable distributed generation

International Nuclear Information System (INIS)

Adefarati, T.; Bansal, R.C.

2017-01-01

Highlights: • Addresses impacts of renewable DG on the reliability of the distribution system. • Multi-objective formulation for maximizing the cost saving with integration of DG. • Uses Markov model to study the stochastic characteristics of the major components. • The investigation is done using modified RBTS bus test distribution system. • Proposed approach is useful for electric utilities to enhance the reliability. - Abstract: Recent studies have shown that renewable energy resources will contribute substantially to future energy generation owing to the rapid depletion of fossil fuels. Wind and solar energy resources are major sources of renewable energy that have the ability to reduce the energy crisis and the greenhouse gases emitted by the conventional power plants. Reliability assessment is one of the key indicators to measure the impact of the renewable distributed generation (DG) units in the distribution networks and to minimize the cost that is associated with power outage. This paper presents a comprehensive reliability assessment of the distribution system that satisfies the consumer load requirements with the penetration of wind turbine generator (WTG), electric storage system (ESS) and photovoltaic (PV). A Markov model is proposed to access the stochastic characteristics of the major components of the renewable DG resources as well as their influence on the reliability of a conventional distribution system. The results obtained from the case studies have demonstrated the effectiveness of using WTG, ESS and PV to enhance the reliability of the conventional distribution system.

Strategy Guideline: Compact Air Distribution Systems

Energy Technology Data Exchange (ETDEWEB)

Burdick, A.

2013-06-01

This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

Communication Systems and Study Method for Active Distribution Power systems

DEFF Research Database (Denmark)

Wei, Mu; Chen, Zhe

Due to the involvement and evolvement of communication technologies in contemporary power systems, the applications of modern communication technologies in distribution power system are becoming increasingly important. In this paper, the International Organization for Standardization (ISO......) reference seven-layer model of communication systems, and the main communication technologies and protocols on each corresponding layer are introduced. Some newly developed communication techniques, like Ethernet, are discussed with reference to the possible applications in distributed power system....... The suitability of the communication technology to the distribution power system with active renewable energy based generation units is discussed. Subsequently the typical possible communication systems are studied by simulation. In this paper, a novel method of integrating communication system impact into power...

The stabilisation of final focus system

Indian Academy of Sciences (India)

The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative ... quadrupole magnets will be the most demanding application, where mutual and beam- ... interferometers to measure lines of a geodetic network to record relative motion between two beam ... coupled interferometer design.

Distributed Cognition and Distributed Morality: Agency, Artifacts and Systems.

Science.gov (United States)

Heersmink, Richard

2017-04-01

There are various philosophical approaches and theories describing the intimate relation people have to artifacts. In this paper, I explore the relation between two such theories, namely distributed cognition and distributed morality theory. I point out a number of similarities and differences in these views regarding the ontological status they attribute to artifacts and the larger systems they are part of. Having evaluated and compared these views, I continue by focussing on the way cognitive artifacts are used in moral practice. I specifically conceptualise how such artifacts (a) scaffold and extend moral reasoning and decision-making processes, (b) have a certain moral status which is contingent on their cognitive status, and (c) whether responsibility can be attributed to distributed systems. This paper is primarily written for those interested in the intersection of cognitive and moral theory as it relates to artifacts, but also for those independently interested in philosophical debates in extended and distributed cognition and ethics of (cognitive) technology.

Man-systems distributed system for Space Station Freedom

Science.gov (United States)

Lewis, J. L.

1990-01-01

Viewgraphs on man-systems distributed system for Space Station Freedom are presented. Topics addressed include: description of man-systems (definition, requirements, scope, subsystems, and topologies); implementation (approach, tools); man-systems interfaces (system to element and system to system); prime/supporting development relationship; selected accomplishments; and technical challenges.

Distributed systems for protecting nuclear power stations

International Nuclear Information System (INIS)

Jover, P.

1980-05-01

The advantages of distributed control systems for the control of nuclear power stations are obviously of great interest. Some years ago, EPRI, (Electric Power Research Institute) showed that multiplexing the signals is technically feasible, that it enables the availability specifications to be met and costs to be reduced. Since then, many distributed control systems have been proposed by the manufacturers. This note offers some comments on the application of the distribution concept to protection systems -what should be distributed- and ends with a brief description of a protection system based on microprocessors for the pressurized power stations now being built in France [fr

Differences Between Distributed and Parallel Systems

Energy Technology Data Exchange (ETDEWEB)

Brightwell, R.; Maccabe, A.B.; Rissen, R.

1998-10-01

Distributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma.

Distributed Cooperative Control of Multi Flywheel Energy Storage System for Electrical Vehicle Fast Charging Stations

DEFF Research Database (Denmark)

Sun, Bo; Dragicevic, Tomislav; Quintero, Juan Carlos Vasquez

2015-01-01

Plug-in electrical vehicles will play a critical role in future smart grid and sudden connection of electrical vehicles chargers may cause huge power-peaks with high slew-rates on grid. In order to cope with this issue, this paper applies a distributed cooperative control for fast charging station...... with dedicated paralleled flywheel-based energy storage system. The distributed DC-bus signaling method is employed in the power coordination of grid and flywheel converters, and a distributed secondary controller generates DC voltage correction term to adjust the local voltage set-point through a dynamic...... consensus based voltage observer by communicating with its neighbors. The control system can realize the power balancing and DC voltage regulation with low reliance on communications. Finally, real-time hardware-in-the-loop results have been reported in order to verify the feasibility of proposed approach....

Progress on Protection Strategies to Mitigate the Impact of Renewable Distributed Generation on Distribution Systems

Directory of Open Access Journals (Sweden)

Mohamad Norshahrani

2017-11-01

Full Text Available The benefits of distributed generation (DG based on renewable energy sources leads to its high integration in the distribution network (DN. Despite its well-known benefits, mainly in improving the distribution system reliability and security, there are challenges encountered from a protection system perspective. Traditionally, the design and operation of the protection system are based on a unidirectional power flow in the distribution network. However, the integration of distributed generation causes multidirectional power flows in the system. Therefore, the existing protection systems require some improvement or modification to address this new feature. Various protection strategies for distribution system have been proposed so that the benefits of distributed generation can be fully utilized. This paper reviews the current progress in protection strategies to mitigate the impact of distributed generation in the distribution network. In general, the reviewed strategies in this paper are divided into: (1 conventional protection systems and (2 modifications of the protection systems. A comparative study is presented in terms of the respective benefits, shortcomings and implementation cost. Future directions for research in this area are also presented.

Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of {sup 234}U

Energy Technology Data Exchange (ETDEWEB)

Montoya, M.; Rojas, J. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, Lima 41 (Peru); Lobato, I. [Facultad de Ciencias, Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Apartado Postal 31-139, Lima (Peru)]. e-mail: mmontoya@ipen.gob.pe

2008-07-01

The standard deviation of the final kinetic energy distribution ({sigma}{sub e}) as a function of mass of final fragments (m) from low energy fission of {sup 234}U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution ({sigma}{sub E}) as a function of primary fragment mass (A). The second peak is attributed to a real peak on {sigma}{sub E}(A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on {sigma}{sub E}(A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on {sigma}{sub e} (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the {sigma}{sub E} (A) curve, and the observed peaks on {sigma}{sub e} (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

Distributed Optimization System

Science.gov (United States)

Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

2004-11-30

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

National Renewable Energy Laboratory (NREL) Topic 2 Final Report: End-to-End Communication and Control System to Support Clean Energy Technologies

Energy Technology Data Exchange (ETDEWEB)

Hudgins, Andrew P. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Carrillo, Ismael M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Jin, Xin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Simmins, John [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States)

2018-02-21

This document is the final report of a two-year development, test, and demonstration project, 'Cohesive Application of Standards- Based Connected Devices to Enable Clean Energy Technologies.' The project was part of the National Renewable Energy Laboratory's (NREL's) Integrated Network Testbed for Energy Grid Research and Technology (INTEGRATE) initiative hosted at Energy Systems Integration Facility (ESIF). This project demonstrated techniques to control distribution grid events using the coordination of traditional distribution grid devices and high-penetration renewable resources and demand response. Using standard communication protocols and semantic standards, the project examined the use cases of high/low distribution voltage, requests for volt-ampere-reactive (VAR) power support, and transactive energy strategies using Volttron. Open source software, written by EPRI to control distributed energy resources (DER) and demand response (DR), was used by an advanced distribution management system (ADMS) to abstract the resources reporting to a collection of capabilities rather than needing to know specific resource types. This architecture allows for scaling both horizontally and vertically. Several new technologies were developed and tested. Messages from the ADMS based on the common information model (CIM) were developed to control the DER and DR management systems. The OpenADR standard was used to help manage grid events by turning loads off and on. Volttron technology was used to simulate a homeowner choosing the price at which to enter the demand response market. Finally, the ADMS used newly developed algorithms to coordinate these resources with a capacitor bank and voltage regulator to respond to grid events.

Distributed computer systems theory and practice

CERN Document Server

Zedan, H S M

2014-01-01

Distributed Computer Systems: Theory and Practice is a collection of papers dealing with the design and implementation of operating systems, including distributed systems, such as the amoeba system, argus, Andrew, and grapevine. One paper discusses the concepts and notations for concurrent programming, particularly language notation used in computer programming, synchronization methods, and also compares three classes of languages. Another paper explains load balancing or load redistribution to improve system performance, namely, static balancing and adaptive load balancing. For program effici

Stability analysis of distributed order fractional chen system.

Science.gov (United States)

Aminikhah, H; Refahi Sheikhani, A; Rezazadeh, H

2013-01-01

We first investigate sufficient and necessary conditions of stability of nonlinear distributed order fractional system and then we generalize the integer-order Chen system into the distributed order fractional domain. Based on the asymptotic stability theory of nonlinear distributed order fractional systems, the stability of distributed order fractional Chen system is discussed. In addition, we have found that chaos exists in the double fractional order Chen system. Numerical solutions are used to verify the analytical results.

Stability Analysis of Distributed Order Fractional Chen System

Science.gov (United States)

Aminikhah, H.; Refahi Sheikhani, A.; Rezazadeh, H.

2013-01-01

We first investigate sufficient and necessary conditions of stability of nonlinear distributed order fractional system and then we generalize the integer-order Chen system into the distributed order fractional domain. Based on the asymptotic stability theory of nonlinear distributed order fractional systems, the stability of distributed order fractional Chen system is discussed. In addition, we have found that chaos exists in the double fractional order Chen system. Numerical solutions are used to verify the analytical results. PMID:24489508

BIOFILMS IN DRINKING WATER DISTRIBUTION SYSTEMS

Science.gov (United States)

Virtually anywhere a surface comes into contact with the water in a distribution system, one can find biofilms. Biofilms are formed in distribution system pipelines when microbial cells attach to pipe surfaces and multiply to form a film or slime layer on the pipe. Probably withi...

Workflow management in large distributed systems

International Nuclear Information System (INIS)

Legrand, I; Newman, H; Voicu, R; Dobre, C; Grigoras, C

2011-01-01

The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

Workflow management in large distributed systems

Science.gov (United States)

Legrand, I.; Newman, H.; Voicu, R.; Dobre, C.; Grigoras, C.

2011-12-01

The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

Advanced Propulsion Power Distribution System for Next Generation Electric/Hybrid Vehicle. Phase 1; Preliminary System Studies

Science.gov (United States)

Bose, Bimal K.; Kim, Min-Huei

1995-01-01

The report essentially summarizes the work performed in order to satisfy the above project objective. In the beginning, different energy storage devices, such as battery, flywheel and ultra capacitor are reviewed and compared, establishing the superiority of the battery. Then, the possible power sources, such as IC engine, diesel engine, gas turbine and fuel cell are reviewed and compared, and the superiority of IC engine has been established. Different types of machines for drive motor/engine generator, such as induction machine, PM synchronous machine and switched reluctance machine are compared, and the induction machine is established as the superior candidate. Similar discussion was made for power converters and devices. The Insulated Gate Bipolar Transistor (IGBT) appears to be the most superior device although Mercury Cadmium Telluride (MCT) shows future promise. Different types of candidate distribution systems with the possible combinations of power and energy sources have been discussed and the most viable system consisting of battery, IC engine and induction machine has been identified. Then, HFAC system has been compared with the DC system establishing the superiority of the former. The detailed component sizing calculations of HFAC and DC systems reinforce the superiority of the former. A preliminary control strategy has been developed for the candidate HFAC system. Finally, modeling and simulation study have been made to validate the system performance. The study in the report demonstrates the superiority of HFAC distribution system for next generation electric/hybrid vehicle.

Island Partition of Distribution System with Distributed Generators Considering Protection of Vulnerable Nodes

Directory of Open Access Journals (Sweden)

Gang Xu

2017-10-01

Full Text Available To improve the reliability of power supply in the case of the fault of distribution system with multiple distributed generators (DGs and reduce the influence of node voltage fluctuation on the stability of distribution system operation in power restoration, this paper proposes an island partition strategy of the distribution system considering the protection of vulnerable nodes. First of all, the electrical coupling coefficient of neighboring nodes is put forward according to distribution system topology and equivalent electrical impedance, and the power-dependence relationship between neighboring nodes is calculated based on the direction and level of the power flow between nodes. Then, the bidirectional transmission of the coupling features of neighboring nodes is realized through the modified PageRank algorithm, thus identifying the vulnerable nodes that have a large influence on the stability of distribution system operation. Next, combining the index of node vulnerability, an island partition model is constructed with the restoration of important loads as the primary goal. In addition, the mutually exclusive firefly algorithm (MEFA is also proposed to realize the interaction of learning and competition among fireflies, thus enhancing the globally optimal solution search ability of the algorithm proposed. The proposed island partition method is verified with a Pacific Gas and Electric Company (PG and E 60-node test system. Comparison with other methods demonstrates that the new method is feasible for the distribution system with multiple types of distributed generations and valid to enhance the stability and safety of the grid with a relatively power restoration ratio.

Checkpointing for graceful degradation in distributed embedded systems

Science.gov (United States)

Sababha, Belal Hussein

Graceful degradation is an approach to developing dependable safety-critical embedded applications, where redundant active or standby resources are used to cope with faults through a system reconfiguration at run-time. Compared to traditional hardware and software redundancy, it is a promising technique that may achieve dependability with a significant reduction in cost, size, weight, and power requirements. Reconfiguration at run-time necessitates using proper checkpointing protocols to support state reservation to ensure correct task restarts after a system reconfiguration. One of the most common checkpointing protocols are communication induced checkpointing (CIC) protocols, which are well developed and understood for large parallel and information systems, but not much has been done for resource limited embedded systems. This work implements and evaluates some of the most common CIC protocols in a periodic resource constrained distributed embedded system for graceful degradation purposes. A test-bed has been developed and used for the evaluation of the various protocols. The implemented protocols are thoroughly studied and performances are contrasted. Specifically the periodicity property and how it benefits checkpointing in embedded systems is investigated. This work introduces a unique effort of CIC protocol implementation and evaluation in the field of distributed embedded systems. Other than providing a test-bed for graceful degradation support, this work shows that some checkpointing protocols that are not efficient in large information systems and supercomputers perform well in embedded systems. We show that a simple index-based CIC protocol, such as the BCS protocol, is more appropriate in embedded system applications compared to other protocols that piggyback a significant amount of information to reduce the number of forced checkpoints. Finally, this work proposes a whole graceful degradation approach to achieve fault tolerance in resource constrained

A high spatial resolution distributed optical fiber grating sensing system based on OFDR

Science.gov (United States)

Dong, Ke; Xiong, Yuchuan; Wen, Hongqiao; Tong, Xinlin; Zhang, Cui; Deng, Chengwei

2017-10-01

A distributed optical fiber grating sensing system with large capacity and high spatial resolution is presented. Since highdensity identical weak grating array was utilized as sensing fiber, the multiplexing number was greatly increased, meanwhile, optical frequency domain reflectometry (OFDR) technology was used to implement high resolution distributed sensing system. In order to eliminate the nonlinear effect of tunable light source, a windowed FFT algorithm based on cubic spline interpolation was applied. The feasibility of the algorithm was experimentally testified, ultimately, the spatial resolution of system can reach mm-level. The influence of the crosstalk signal in the grating array on the OFDR system was analyzed. A method that a long enough delay fiber was added before the first FBG to remove crosstalk signal was proposed. The experiment was verified using an optical fiber with 113 uniform Bragg gratings at an interval of 10cm whose reflectivity are less than 1%. It demonstrates that crosstalk signal and measurement signal can be completely separated in the distance domain after adding a long enough delay fiber. Finally, the temperature experiment of distributed grating sensing system was carried out. The results display that each raster's center wavelength in the fiber link is independent of each other and the center wavelength drift has a good linear relationship with the temperature. The sensitivity of linear fitting is equal to 11.1pm/°C.

Formal Specification of Distributed Information Systems

NARCIS (Netherlands)

Vis, J.; Brinksma, Hendrik; de By, R.A.; de By, R.A.

The design of distributed information systems tends to be complex and therefore error-prone. However, in the field of monolithic, i.e. non-distributed, information systems much has already been achieved, and by now, the principles of their design seem to be fairly well-understood. The past decade

Distribution system protection with communication technologies

DEFF Research Database (Denmark)

Wei, Mu; Chen, Zhe

2010-01-01

Due to the communication technologies’ involvement in the distribution power system, the time-critical protection function may be implemented more accurately, therefore distribution power systems’ stability, reliability and security could be improved. This paper presents an active distribution...

Efficient string similarity join in multi-core and distributed systems.

Directory of Open Access Journals (Sweden)

Cairong Yan

Full Text Available In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

Software Quality Measurement for Distributed Systems. Volume 3. Distributed Computing Systems: Impact on Software Quality.

Science.gov (United States)

1983-07-01

Distributed Computing Systems impact DrnwrR - aehR on Sotwar Quaity. PERFORMING 010. REPORT NUMBER 7. AUTNOW) S. CONTRACT OR GRANT "UMBER(*)IS ThomasY...C31 Application", "Space Systems Network", "Need for Distributed Database Management", and "Adaptive Routing". This is discussed in the last para ...data reduction, buffering, encryption, and error detection and correction functions. Examples of such data streams include imagery data, video

Smart-DS: Synthetic Models for Advanced, Realistic Testing: Distribution Systems and Scenarios

Energy Technology Data Exchange (ETDEWEB)

Krishnan, Venkat K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Palmintier, Bryan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hale, Elaine T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elgindy, Tarek [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bugbee, Bruce [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rossol, Michael N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lopez, Anthony J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnamurthy, Dheepak [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vergara, Claudio [MIT; Domingo, Carlos Mateo [IIT Comillas; Postigo, Fernando [IIT Comillas; de Cuadra, Fernando [IIT Comillas; Gomez, Tomas [IIT Comillas; Duenas, Pablo [MIT; Luke, Max [MIT; Li, Vivian [MIT; Vinoth, Mohan [GE Grid Solutions; Kadankodu, Sree [GE Grid Solutions

2017-08-09

The National Renewable Energy Laboratory (NREL) in collaboration with Massachusetts Institute of Technology (MIT), Universidad Pontificia Comillas (Comillas-IIT, Spain) and GE Grid Solutions, is working on an ARPA-E GRID DATA project, titled Smart-DS, to create: 1) High-quality, realistic, synthetic distribution network models, and 2) Advanced tools for automated scenario generation based on high-resolution weather data and generation growth projections. Through these advancements, the Smart-DS project is envisioned to accelerate the development, testing, and adoption of advanced algorithms, approaches, and technologies for sustainable and resilient electric power systems, especially in the realm of U.S. distribution systems. This talk will present the goals and overall approach of the Smart-DS project, including the process of creating the synthetic distribution datasets using reference network model (RNM) and the comprehensive validation process to ensure network realism, feasibility, and applicability to advanced use cases. The talk will provide demonstrations of early versions of synthetic models, along with the lessons learnt from expert engagements to enhance future iterations. Finally, the scenario generation framework, its development plans, and co-ordination with GRID DATA repository teams to house these datasets for public access will also be discussed.

Distributed Cooperative Optimal Control for Multiagent Systems on Directed Graphs: An Inverse Optimal Approach.

Science.gov (United States)

Zhang, Huaguang; Feng, Tao; Yang, Guang-Hong; Liang, Hongjing

2015-07-01

In this paper, the inverse optimal approach is employed to design distributed consensus protocols that guarantee consensus and global optimality with respect to some quadratic performance indexes for identical linear systems on a directed graph. The inverse optimal theory is developed by introducing the notion of partial stability. As a result, the necessary and sufficient conditions for inverse optimality are proposed. By means of the developed inverse optimal theory, the necessary and sufficient conditions are established for globally optimal cooperative control problems on directed graphs. Basic optimal cooperative design procedures are given based on asymptotic properties of the resulting optimal distributed consensus protocols, and the multiagent systems can reach desired consensus performance (convergence rate and damping rate) asymptotically. Finally, two examples are given to illustrate the effectiveness of the proposed methods.

Designing and Implementing a Distributed System Architecture for the Mars Rover Mission Planning Software (Maestro)

Science.gov (United States)

Goldgof, Gregory M.

2005-01-01

Distributed systems allow scientists from around the world to plan missions concurrently, while being updated on the revisions of their colleagues in real time. However, permitting multiple clients to simultaneously modify a single data repository can quickly lead to data corruption or inconsistent states between users. Since our message broker, the Java Message Service, does not ensure that messages will be received in the order they were published, we must implement our own numbering scheme to guarantee that changes to mission plans are performed in the correct sequence. Furthermore, distributed architectures must ensure that as new users connect to the system, they synchronize with the database without missing any messages or falling into an inconsistent state. Robust systems must also guarantee that all clients will remain synchronized with the database even in the case of multiple client failure, which can occur at any time due to lost network connections or a user's own system instability. The final design for the distributed system behind the Mars rover mission planning software fulfills all of these requirements and upon completion will be deployed to MER at the end of 2005 as well as Phoenix (2007) and MSL (2009).

Quantum distribution function of nonequilibrium system

International Nuclear Information System (INIS)

Sogo, Kiyoshi; Fujimoto, Yasushi.

1990-03-01

A path integral representation is derived for the Wigner distribution function of a nonequilibrium system coupled with heat bath. Under appropriate conditions, the Wigner distribution function approaches an equilibrium distribution, which manifests shifting and broadening of spectral lines due to the interaction with heat bath. It is shown that the equilibrium distribution becomes the quantum canonical distribution in the vanishing coupling constant limit. (author)

Water-storage-tube systems. Final report

Energy Technology Data Exchange (ETDEWEB)

Hemker, P.

1981-12-24

Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

Recommendation System Based On Association Rules For Distributed E-Learning Management Systems

Science.gov (United States)

Mihai, Gabroveanu

2015-09-01

Traditional Learning Management Systems are installed on a single server where learning materials and user data are kept. To increase its performance, the Learning Management System can be installed on multiple servers; learning materials and user data could be distributed across these servers obtaining a Distributed Learning Management System. In this paper is proposed the prototype of a recommendation system based on association rules for Distributed Learning Management System. Information from LMS databases is analyzed using distributed data mining algorithms in order to extract the association rules. Then the extracted rules are used as inference rules to provide personalized recommendations. The quality of provided recommendations is improved because the rules used to make the inferences are more accurate, since these rules aggregate knowledge from all e-Learning systems included in Distributed Learning Management System.

Dealing with distributed intelligence in monitoring and control systems

International Nuclear Information System (INIS)

McLaren, R.A.

1981-01-01

The Euorpean Hybrid Spectrometer is built up of many individual detectors, each having widely varying monitoring and control requirements. With the advent of cheap microprocessor systems a shift from the concept of a single monitoring and control computer of that of distributed intelligent controllers has been economically feasible. A detector designer can now thoroughly test and debug a complete monitoring and control system on a local, dedicated micro-computer, while during operation, the central computer can be relieved of many simple repetitive tasks. Rapidly, however, it has become obvious that the designers of these systems have to take into account the final operational environment and build into both the hardware and software, features allowing easy integration into a central monitoring and control chain. In addition, the problems of maintenance and enventual modification have to be taken into consideration early in the development. Examples of currently operational systems will be briefly described to demonstrate how a set of basic guidelines plus standardisation of hardware/software can minimise the problems of integration and maintenance. Based on practical experience gained in the European Hybrid Spectrometer, investigations are proceeding on various possible alternatives for future micro-computer based monitoring and control systems. (orig.)

Combined operation of AC and DC distribution system with distributed generation units

International Nuclear Information System (INIS)

Noroozian, R.; Abedi, M.; Gharehpetian, G.

2010-01-01

This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system. (authors)

An Architecture for a Wide Area Distributed System

NARCIS (Netherlands)

Homburg, P.; Steen, M.R. van; Tanenbaum, A.S.

1996-01-01

Distributed systems provide sharing of resources and information over a computer network. A key design issue that makes these systems attractive is that all aspects related to distribution are transparent to users. Unfortunately, general-purpose wide area distributed systems that allow users to

Distributed computer control system for reactor optimization

International Nuclear Information System (INIS)

Williams, A.H.

1983-01-01

At the Oldbury power station a prototype distributed computer control system has been installed. This system is designed to support research and development into improved reactor temperature control methods. This work will lead to the development and demonstration of new optimal control systems for improvement of plant efficiency and increase of generated output. The system can collect plant data from special test instrumentation connected to dedicated scanners and from the station's existing data processing system. The system can also, via distributed microprocessor-based interface units, make adjustments to the desired reactor channel gas exit temperatures. The existing control equipment will then adjust the height of control rods to maintain operation at these temperatures. The design of the distributed system is based on extensive experience with distributed systems for direct digital control, operator display and plant monitoring. The paper describes various aspects of this system, with particular emphasis on: (1) the hierarchal system structure; (2) the modular construction of the system to facilitate installation, commissioning and testing, and to reduce maintenance to module replacement; (3) the integration of the system into the station's existing data processing system; (4) distributed microprocessor-based interfaces to the reactor controls, with extensive security facilities implemented by hardware and software; (5) data transfer using point-to-point and bussed data links; (6) man-machine communication based on VDUs with computer input push-buttons and touch-sensitive screens; and (7) the use of a software system supporting a high-level engineer-orientated programming language, at all levels in the system, together with comprehensive data link management

Distributed Large Data-Object Environments: End-to-End Performance Analysis of High Speed Distributed Storage Systems in Wide Area ATM Networks

Science.gov (United States)

Johnston, William; Tierney, Brian; Lee, Jason; Hoo, Gary; Thompson, Mary

1996-01-01

We have developed and deployed a distributed-parallel storage system (DPSS) in several high speed asynchronous transfer mode (ATM) wide area networks (WAN) testbeds to support several different types of data-intensive applications. Architecturally, the DPSS is a network striped disk array, but is fairly unique in that its implementation allows applications complete freedom to determine optimal data layout, replication and/or coding redundancy strategy, security policy, and dynamic reconfiguration. In conjunction with the DPSS, we have developed a 'top-to-bottom, end-to-end' performance monitoring and analysis methodology that has allowed us to characterize all aspects of the DPSS operating in high speed ATM networks. In particular, we have run a variety of performance monitoring experiments involving the DPSS in the MAGIC testbed, which is a large scale, high speed, ATM network and we describe our experience using the monitoring methodology to identify and correct problems that limit the performance of high speed distributed applications. Finally, the DPSS is part of an overall architecture for using high speed, WAN's for enabling the routine, location independent use of large data-objects. Since this is part of the motivation for a distributed storage system, we describe this architecture.

Comparing Multicomponent Erlang Distribution and Lévy Distribution of Particle Transverse Momentums

International Nuclear Information System (INIS)

Wei, Hua-Rong; Chen, Ya-Hui; Gao, Li-Na; Liu, Fu-Hu

2014-01-01

The transverse momentum spectrums of final-state products produced in nucleus-nucleus and proton-proton collisions at different center-of-mass energies are analyzed by using a multicomponent Erlang distribution and the Lévy distribution. The results calculated by the two models are found in most cases to be in agreement with experimental data from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The multicomponent Erlang distribution that resulted from a multisource thermal model seems to give a better description as compared with the Lévy distribution. The temperature parameters of interacting system corresponding to different types of final-state products are obtained. Light particles correspond to a low temperature emission, and heavy particles correspond to a high temperature emission. Extracted temperature from central collisions is higher than that from peripheral collisions

Distribution System Pricing with Distributed Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Hledik, Ryan [The Brattle Group, Cambridge, MA (United States); Lazar, Jim [The Regulatory Assistance Project, Montpelier, VT (United States); Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-08-16

Technological changes in the electric utility industry bring tremendous opportunities and significant challenges. Customers are installing clean sources of on-site generation such as rooftop solar photovoltaic (PV) systems. At the same time, smart appliances and control systems that can communicate with the grid are entering the retail market. Among the opportunities these changes create are a cleaner and more diverse power system, the ability to improve system reliability and system resilience, and the potential for lower total costs. Challenges include integrating these new resources in a way that maintains system reliability, provides an equitable sharing of system costs, and avoids unbalanced impacts on different groups of customers, including those who install distributed energy resources (DERs) and low-income households who may be the least able to afford the transition.

Final design of thermal diagnostic system in SPIDER ion source

Energy Technology Data Exchange (ETDEWEB)

Brombin, M., E-mail: matteo.brombin@igi.cnr.it; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N. [Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova (Italy)

2016-11-15

The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H{sup −} production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

Final design of thermal diagnostic system in SPIDER ion source

International Nuclear Information System (INIS)

Brombin, M.; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N.

2016-01-01

The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H"− production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

Supervisory Control and Diagnostics System Distributed Operating System

International Nuclear Information System (INIS)

McGoldrick, P.R.

1979-01-01

This paper contains a description of the Supervisory Control and Diagnostics System (SCDS) Distributed Operating System. The SCDS consists of nine 32-bit minicomputers with shared memory. The system's main purpose is to control a large Mirror Fusion Test Facility

47 CFR 73.626 - DTV distributed transmission systems.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false DTV distributed transmission systems. 73.626... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.626 DTV distributed transmission systems. (a... distributed transmission system (DTS). Except as expressly provided in this section, DTV stations operating a...

Evaluation of two typical distributed energy systems

Science.gov (United States)

Han, Miaomiao; Tan, Xiu

2018-03-01

According to the two-natural gas distributed energy system driven by gas engine driven and gas turbine, in this paper, the first and second laws of thermodynamics are used to measure the distributed energy system from the two parties of “quantity” and “quality”. The calculation results show that the internal combustion engine driven distributed energy station has a higher energy efficiency, but the energy efficiency is low; the gas turbine driven distributed energy station energy efficiency is high, but the primary energy utilization rate is relatively low. When configuring the system, we should determine the applicable natural gas distributed energy system technology plan and unit configuration plan according to the actual load factors of the project and the actual factors such as the location, background and environmental requirements of the project. “quality” measure, the utilization of waste heat energy efficiency index is proposed.

The design of distributed database system for HIRFL

International Nuclear Information System (INIS)

Wang Hong; Huang Xinmin

2004-01-01

This paper is focused on a kind of distributed database system used in HIRFL distributed control system. The database of this distributed database system is established by SQL Server 2000, and its application system adopts the Client/Server model. Visual C ++ is used to develop the applications, and the application uses ODBC to access the database. (authors)

Maintaining consistency in distributed systems

Science.gov (United States)

Birman, Kenneth P.

1991-01-01

In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

Enhanced distributed energy resource system

Science.gov (United States)

Atcitty, Stanley [Albuquerque, NM; Clark, Nancy H [Corrales, NM; Boyes, John D [Albuquerque, NM; Ranade, Satishkumar J [Las Cruces, NM

2007-07-03

A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

Distributed Optimal Consensus Control for Multiagent Systems With Input Delay.

Science.gov (United States)

Zhang, Huaipin; Yue, Dong; Zhao, Wei; Hu, Songlin; Dou, Chunxia; Huaipin Zhang; Dong Yue; Wei Zhao; Songlin Hu; Chunxia Dou; Hu, Songlin; Zhang, Huaipin; Dou, Chunxia; Yue, Dong; Zhao, Wei

2018-06-01

This paper addresses the problem of distributed optimal consensus control for a continuous-time heterogeneous linear multiagent system subject to time varying input delays. First, by discretization and model transformation, the continuous-time input-delayed system is converted into a discrete-time delay-free system. Two delicate performance index functions are defined for these two systems. It is shown that the performance index functions are equivalent and the optimal consensus control problem of the input-delayed system can be cast into that of the delay-free system. Second, by virtue of the Hamilton-Jacobi-Bellman (HJB) equations, an optimal control policy for each agent is designed based on the delay-free system and a novel value iteration algorithm is proposed to learn the solutions to the HJB equations online. The proposed adaptive dynamic programming algorithm is implemented on the basis of a critic-action neural network (NN) structure. Third, it is proved that local consensus errors of the two systems and weight estimation errors of the critic-action NNs are uniformly ultimately bounded while the approximated control policies converge to their target values. Finally, two simulation examples are presented to illustrate the effectiveness of the developed method.

PanDA: distributed production and distributed analysis system for ATLAS

International Nuclear Information System (INIS)

Maeno, T

2008-01-01

A new distributed software system was developed in the fall of 2005 for the ATLAS experiment at the LHC. This system, called PANDA, provides an integrated service architecture with late binding of jobs, maximal automation through layered services, tight binding with ATLAS Distributed Data Management system [1], advanced error discovery and recovery procedures, and other features. In this talk, we will describe the PANDA software system. Special emphasis will be placed on the evolution of PANDA based on one and half year of real experience in carrying out Computer System Commissioning data production [2] for ATLAS. The architecture of PANDA is well suited for the computing needs of the ATLAS experiment, which is expected to be one of the first HEP experiments to operate at the petabyte scale

Comparison between Different Air Distribution Systems

DEFF Research Database (Denmark)

Nielsen, Peter V.

The aim of an air conditioning system is to remove excess heat in a room and replace room air with fresh air to obtain a high air quality. It is not sufficient to remove heat and contaminated air, it is also necessary to distribute and control the air movement in the room to create thermal comfort...... in the occupied zone. Most air distribution systems are based on mixing ventilation with ceiling or wall-mounted diffusers or on displacement ventilation with wall-mounted low velocity diffusers. New principles for room air distribution were introduced during the last decades, as the textile terminals mounted...... in the ceiling and radial diffusers with swirling flow also mounted in the ceiling. This paper addresses five air distribution systems in all, namely mixing ventilation from a wallmounted terminal, mixing ventilation from a ceiling-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser...

Finite Time Control for Fractional Order Nonlinear Hydroturbine Governing System via Frequency Distributed Model

Directory of Open Access Journals (Sweden)

Bin Wang

2016-01-01

Full Text Available This paper studies the application of frequency distributed model for finite time control of a fractional order nonlinear hydroturbine governing system (HGS. Firstly, the mathematical model of HGS with external random disturbances is introduced. Secondly, a novel terminal sliding surface is proposed and its stability to origin is proved based on the frequency distributed model and Lyapunov stability theory. Furthermore, based on finite time stability and sliding mode control theory, a robust control law to ensure the occurrence of the sliding motion in a finite time is designed for stabilization of the fractional order HGS. Finally, simulation results show the effectiveness and robustness of the proposed scheme.

Support for User Interfaces for Distributed Systems

Science.gov (United States)

Eychaner, Glenn; Niessner, Albert

2005-01-01

An extensible Java(TradeMark) software framework supports the construction and operation of graphical user interfaces (GUIs) for distributed computing systems typified by ground control systems that send commands to, and receive telemetric data from, spacecraft. Heretofore, such GUIs have been custom built for each new system at considerable expense. In contrast, the present framework affords generic capabilities that can be shared by different distributed systems. Dynamic class loading, reflection, and other run-time capabilities of the Java language and JavaBeans component architecture enable the creation of a GUI for each new distributed computing system with a minimum of custom effort. By use of this framework, GUI components in control panels and menus can send commands to a particular distributed system with a minimum of system-specific code. The framework receives, decodes, processes, and displays telemetry data; custom telemetry data handling can be added for a particular system. The framework supports saving and later restoration of users configurations of control panels and telemetry displays with a minimum of effort in writing system-specific code. GUIs constructed within this framework can be deployed in any operating system with a Java run-time environment, without recompilation or code changes.

EGSNRC distributed systems on commercial network

International Nuclear Information System (INIS)

McCormack, J.M.

2001-01-01

Full text: EGSnrc is a Monte Carlo based simulation program for determining radiation dose distribution within a body. Computational times are large as each individual photon path must be calculated and every energy absorption event stored. This means that EGSnrc lends itself to distributed processing, as each photon is independent of the next, and code is included within the package to enable this. EGSnrc is currently only supported on Unix based computer systems, whilst the department has ∼45 Pentium II and III class workstations all operating under Windows NT within a Novell network. This investigation demonstrates the capability of a windows based system to perform distributed computation of EGSnrc. All Unix scripts were modified to work as one single Windows NT batch file. The source code was then compiled using the gcc C compiler (a Windows NT version of the Unix compiler) without modification of the underlying source code. A small Visual Basic program was used as a trigger to start the simulation as a Windows NT service, with Novell Z.E.N. Works to distribute the trigger code to each system. When a trigger was received, the computer began a simulation as a low priority task in such a way that the user did not see anything on the screen, and so the simulation did not slow down the general running of the computer. The results were then transferred to the network, and collated on a central computer. As an unattended system, a calculation can start within 15 minutes of any desired time, calculate the desired results, and return the results for collation. This demonstrated effectively a distributed Windows NT TM EGSnrc system. Simulations must be chosen carefully to ensure that each photon can be considered independent, as photon histories do not get distributed. Each system that was used for EGSnrc was required to be capable of running the full EGSnrc simulation on its own EGSnrc stored the entire result array locally, so a large, high-resolution body required

Distributed System Design Checklist

Science.gov (United States)

Hall, Brendan; Driscoll, Kevin

2014-01-01

This report describes a design checklist targeted to fault-tolerant distributed electronic systems. Many of the questions and discussions in this checklist may be generally applicable to the development of any safety-critical system. However, the primary focus of this report covers the issues relating to distributed electronic system design. The questions that comprise this design checklist were created with the intent to stimulate system designers' thought processes in a way that hopefully helps them to establish a broader perspective from which they can assess the system's dependability and fault-tolerance mechanisms. While best effort was expended to make this checklist as comprehensive as possible, it is not (and cannot be) complete. Instead, we expect that this list of questions and the associated rationale for the questions will continue to evolve as lessons are learned and further knowledge is established. In this regard, it is our intent to post the questions of this checklist on a suitable public web-forum, such as the NASA DASHLink AFCS repository. From there, we hope that it can be updated, extended, and maintained after our initial research has been completed.

Silver disinfection in water distribution systems

Science.gov (United States)

Silvestry Rodriguez, Nadia

Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

Final report on the FMIT Control System

International Nuclear Information System (INIS)

Johnson, J.A.

1985-01-01

The computer control system for the Fusion Materials Irradiation Test Facility (FMIT) prototype accelerator was designed using distributed intelligence driven by a distributed database. The system consists of two minicomputers in the central control room and four microcomputers residing in CAMAC crates located near appropriate subsystems of the accelerator. The system uses single vendor hardware as much as practical in an attempt to minimize the maintenance problems. Local control consoles are an integral part of each node computer to provide subsystem check-out. The main console is located in the central control room and permits one-point operation of the complete control system. Automatic surveillance is provided for each data channel by the node computer with out-of-bounds alarms sent to the main console. Report by exception is used for data logging. This control system has been operational for two years. The computers are too heavily loaded and the operator response is slower than desired. A system upgrade to a faster local-area network has been undertaken and is scheduled to be operational by conference time

Synchronization in Quantum Key Distribution Systems

Directory of Open Access Journals (Sweden)

Anton Pljonkin

2017-10-01

Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.

Archtecture of distributed real-time systems

OpenAIRE

Wing Leung, Cheuk

2013-01-01

CRAFTERS (Constraint and Application Driven Framework for Tailoring Embedded Real-time System) project aims to address the problem of uncertainty and heterogeneity in a distributed system by providing seamless, portable connectivity and middleware. This thesis contributes to the project by investigating the techniques that can be used in a distributed real-time embedded system. The conclusion is that, there is a list of specifications to be meet in order to provide a transparent and real-time...

Protection of Distribution Systems with Distributed Energy Resources

DEFF Research Database (Denmark)

Bak-Jensen, Birgitte; Browne, Matthew; Calone, Roberto

of 17 months of work of the Joint Working Group B5/C6.26/CIRED “Protection of Distribution Systems with Distributed Energy Resources”. The working group used the CIGRE report TB421 “The impact of Renewable Energy Sources and Distributed Generation on Substation Protection and Automation”, published...... by WG B5.34 as the entry document for the work on this report. In doing so, the group aligned the content and the scope of this report, the network structures considered, possible islanding, standardized communication and adaptive protection, interface protection, connection schemes and protection...... are listed (chapter 3). The first main part of the report starts with a summary of the backgrounds on DER and current practices in protection at the distribution level (chapter 4). This chapter contains an analysis of CIGRE TB421, protection relevant characteristics of DER, a review of current practices...

Architectural transformations in network services and distributed systems

CERN Document Server

Luntovskyy, Andriy

2017-01-01

With the given work we decided to help not only the readers but ourselves, as the professionals who actively involved in the networking branch, with understanding the trends that have developed in recent two decades in distributed systems and networks. Important architecture transformations of distributed systems have been examined. The examples of new architectural solutions are discussed. Content Periodization of service development Energy efficiency Architectural transformations in Distributed Systems Clustering and Parallel Computing, performance models Cloud Computing, RAICs, Virtualization, SDN Smart Grid, Internet of Things, Fog Computing Mobile Communication from LTE to 5G, DIDO, SAT-based systems Data Security Guaranteeing Distributed Systems Target Groups Students in EE and IT of universities and (dual) technical high schools Graduated engineers as well as teaching staff About the Authors Andriy Luntovskyy provides classes on networks, mobile communication, software technology, distributed systems, ...

Optimizing Client Latency in a Distributed System by Using the “Remote Façade” Design Pattern

Directory of Open Access Journals (Sweden)

Cosmin RABLOU

2010-01-01

Full Text Available In this paper we investigate the role of the Remote Façade pattern in the optimization of dis-tributed systems. The intent of this pattern is to wrap fine-grained remote objects in a coarse-grained interface and thus greatly reduce the total number of calls executed over the network. The measurement of the performance gain achieved by implementing this pattern is done through testing with a distributed application written in C# and using the latest Microsoft framework for distributed systems (Windows Communication Framework. Furthermore, we will be presenting the scenarios in which the implementation of the Remote Façade pattern brings a significant performance gain. Finally we show further scenarios in which the per-formance brought by this pattern can be investigated.

Distributed Computerized Catalog System

Science.gov (United States)

Borgen, Richard L.; Wagner, David A.

1995-01-01

DarkStar Distributed Catalog System describes arbitrary data objects in unified manner, providing end users with versatile, yet simple search mechanism for locating and identifying objects. Provides built-in generic and dynamic graphical user interfaces. Design of system avoids some of problems of standard DBMS, and system provides more flexibility than do conventional relational data bases, or object-oriented data bases. Data-collection lattice partly hierarchical representation of relationships among collections, subcollections, and data objects.

Laser spark distribution and ignition system

Science.gov (United States)

Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

2008-09-02

A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

Distributed synchronization of networked drive-response systems: A nonlinear fixed-time protocol.

Science.gov (United States)

Zhao, Wen; Liu, Gang; Ma, Xi; He, Bing; Dong, Yunfeng

2017-11-01

The distributed synchronization of networked drive-response systems is investigated in this paper. A novel nonlinear protocol is proposed to ensure that the tracking errors converge to zeros in a fixed-time. By comparison with previous synchronization methods, the present method considers more practical conditions and the synchronization time is not dependent of arbitrary initial conditions but can be offline pre-assign according to the task assignment. Finally, the feasibility and validity of the presented protocol have been illustrated by a numerical simulation. Copyright © 2017. Published by Elsevier Ltd.

Evaluation of Laser Stabilization and Imaging Systems for LCLS-II - Final Paper

Energy Technology Data Exchange (ETDEWEB)

Barry, Matthew [Auburn Univ., AL (United States)

2015-08-20

By combining the top performing commercial laser beam stabilization system with the most ideal optical imaging configuration, the beamline for the Linear Accelerator Coherent Light Source II (LCLS-II) will deliver the highest quality and most stable beam to the cathode. To determine the optimal combination, LCLS-II beamline conditions were replicated and the systems tested with a He-Ne laser. The Guidestar-II and MRC active laser beam stabilization systems were evaluated for their ideal positioning and stability. Both a two and four lens optical imaging configuration was then evaluated for beam imaging quality, magnification properties, and natural stability. In their best performances when tested over fifteen hours, Guidestar-II kept the beam stable over approximately 70-110um while the MRC system kept it stable over approximately 90-100um. During short periods of time, Guidestar-II kept the beam stable between 10-20um, but was more susceptible to drift over time, while the MRC system maintained the beam between 30-50um with less overall drift. The best optical imaging configuration proved to be a four lens system that images to the iris located in the cathode room and from there, imaged to the cathode. The magnification from the iris to the cathode was 2:1, within an acceptable tolerance to the expected 2.1:1 magnification. The two lens configuration was slightly more stable in small periods of time (less than 10 minutes) without the assistance of a stability system, approximately 55um compared to approximately 70um, but the four lens configurations beam image had a significantly flatter intensity distribution compared to the two lens configuration which had a Gaussian distribution. A final test still needs to be run with both stability systems running at the same time through the four lens system. With this data, the optimal laser beam stabilization system can be determined for the beamline of LCLS-II.

Modelling transient temperature distribution for injecting hot water through a well to an aquifer thermal energy storage system

Science.gov (United States)

Yang, Shaw-Yang; Yeh, Hund-Der; Li, Kuang-Yi

2010-10-01

Heat storage systems are usually used to store waste heat and solar energy. In this study, a mathematical model is developed to predict both the steady-state and transient temperature distributions of an aquifer thermal energy storage (ATES) system after hot water is injected through a well into a confined aquifer. The ATES has a confined aquifer bounded by aquicludes with different thermomechanical properties and geothermal gradients along the depth. Consider that the heat is transferred by conduction and forced convection within the aquifer and by conduction within the aquicludes. The dimensionless semi-analytical solutions of temperature distributions of the ATES system are developed using Laplace and Fourier transforms and their corresponding time-domain results are evaluated numerically by the modified Crump method. The steady-state solution is obtained from the transient solution through the final-value theorem. The effect of the heat transfer coefficient on aquiclude temperature distribution is appreciable only near the outer boundaries of the aquicludes. The present solutions are useful for estimating the temperature distribution of heat injection and the aquifer thermal capacity of ATES systems.

modeling workflow management in a distributed computing system

African Journals Online (AJOL)

Dr Obe

communication system, which allows for computerized support. ... Keywords: Distributed computing system; Petri nets;Workflow management. 1. ... A distributed operating system usually .... the questionnaire is returned with invalid data,.

Detection of contamination of municipal water distribution systems

Science.gov (United States)

Cooper, John F [Oakland, CA

2012-01-17

A system for the detection of contaminates of a fluid in a conduit. The conduit is part of a fluid distribution system. A chemical or biological sensor array is connected to the conduit. The sensor array produces an acoustic signal burst in the fluid upon detection of contaminates in the fluid. A supervisory control system connected to the fluid and operatively connected to the fluid distribution system signals the fluid distribution system upon detection of contaminates in the fluid.

Distributed systems for the protection of nuclear stations

International Nuclear Information System (INIS)

Jover, P.

1980-01-01

The advantages of distributed control systems usually mentioned are improved exploitation, cost reduction, and adaptation to changes in technology. These advantages are obviously very interesting for nuclear power plant applications, and many such systems have been proposed. This note comments on the application of the distributed system concept to protection systems - what should be distributed - and closes with a brief description of a protection system based on microprocessors for pressurized water stations being built in France. (auth) [fr

District heating and cooling systems for communities through power plant retrofit and distribution network. Final report. Volume I. Text

Energy Technology Data Exchange (ETDEWEB)

None

1979-09-15

An analysis was performed investigating the potential of retrofitting Detroit Edison's Conners Creek power plant to supply district heating and cooling to an area surrounding the plant and within the City of Detroit. A detailed analysis was made of the types and ages of the buildings in the service area as a basis for establishing loads. The analysis of the power plant established possible modifications to the turbines to serve the load in the area. Based upon the service area data and plant retrofit schemes, a distribution system was developed incrementally over a 20-y period. An economic analysis of the system was performed to provide cash flows and payback periods for a variety of energy costs, system costs, and escalation rates to determine the economic viability of the system analyzed. The legal and regulatory requirements required of the district heating and cooling system owner in Michigan were also analyzed to determine what conditions must be met to own and operate the system.

Applying Distributed Object Technology to Distributed Embedded Control Systems

DEFF Research Database (Denmark)

Jørgensen, Bo Nørregaard; Dalgaard, Lars

2012-01-01

In this paper, we describe our Java RMI inspired Object Request Broker architecture MicroRMI for use with networked embedded devices. MicroRMI relieves the software developer from the tedious and error-prone job of writing communication protocols for interacting with such embedded devices. MicroR...... in developing control systems for distributed embedded platforms possessing severe resource restrictions.......RMI supports easy integration of high-level application specific control logic with low-level device specific control logic. Our experience from applying MicroRMI in the context of a distributed robotics control application, clearly demonstrates that it is feasible to use distributed object technology...

The TDF System for Thermonuclear Plasma Reaction Rates, Mean Energies and Two-Body Final State Particle Spectra

International Nuclear Information System (INIS)

Warshaw, S I

2001-01-01

The rate of thermonuclear reactions in hot plasmas as a function of local plasma temperature determines the way in which thermonuclear ignition and burning proceeds in the plasma. The conventional model approach to calculating these rates is to assume that the reacting nuclei in the plasma are in Maxwellian equilibrium at some well-defined plasma temperature, over which the statistical average of the reaction rate quantity σv is calculated, where σ is the cross-section for the reaction to proceed at the relative velocity v between the reacting particles. This approach is well-understood and is the basis for much nuclear fusion and astrophysical nuclear reaction rate data. The Thermonuclear Data File (TDF) system developed at the Lawrence Livermore National Laboratory (Warshaw 1991), which is the topic of this report, contains data on the Maxwellian-averaged thermonuclear reaction rates for various light nuclear reactions and the correspondingly Maxwellian-averaged energy spectra of the particles in the final state of those reactions as well. This spectral information closely models the output particle and energy distributions in a burning plasma, and therefore leads to more accurate computational treatments of thermonuclear burn, output particle energy deposition and diagnostics, in various contexts. In this report we review and derive the theoretical basis for calculating Maxwellian-averaged thermonuclear reaction rates, mean particle energies, and output particle spectral energy distributions for these reactions in the TDF system. The treatment of the kinematics is non-relativistic. The current version of the TDF system provides exit particle energy spectrum distributions for two-body final state reactions only. In a future report we will discuss and describe how output particle energy spectra for three- and four-body final states can be developed for the TDF system. We also include in this report a description of the algorithmic implementation of the TDF

Design of a distributed control system

Energy Technology Data Exchange (ETDEWEB)

Bilous, O [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

A digital computer is used to evaluate various pressure control systems for a gaseous diffusion cascade. This is an example of a distributed feedback control system. The paper gives a brief discussion of similar cases of distributed or stage wise control systems, which may occur in multiple temperature control of chemical processes. (author) [French] Une calculatrice digitale est utilisee pour evaluer divers systemes de controle de pression pour une cascade de diffusion gazeuse. C'est un exemple de systeme de controle a reaction distribue. Le rapport presente une breve discussion de cas semblables de systemes de controle distribues ou en etage, qui peuvent se presenter dans de nombreux controles de temperature de reactions chimiques. (auteur)

Predictive Analytics for Coordinated Optimization in Distribution Systems

Energy Technology Data Exchange (ETDEWEB)

Yang, Rui [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-13

This talk will present NREL's work on developing predictive analytics that enables the optimal coordination of all the available resources in distribution systems to achieve the control objectives of system operators. Two projects will be presented. One focuses on developing short-term state forecasting-based optimal voltage regulation in distribution systems; and the other one focuses on actively engaging electricity consumers to benefit distribution system operations.

A practical two-way system of quantum key distribution with untrusted source

International Nuclear Information System (INIS)

Chen Ming-Juan; Liu Xiang

2011-01-01

The most severe problem of a two-way 'plug-and-play' (p and p) quantum key distribution system is that the source can be controlled by the eavesdropper. This kind of source is defined as an “untrusted source . This paper discusses the effects of the fluctuation of internal transmittance on the final key generation rate and the transmission distance. The security of the standard BB84 protocol, one-decoy state protocol, and weak+vacuum decoy state protocol, with untrusted sources and the fluctuation of internal transmittance are studied. It is shown that the one-decoy state is sensitive to the statistical fluctuation but weak+vacuum decoy state is only slightly affected by the fluctuation. It is also shown that both the maximum secure transmission distance and final key generation rate are reduced when Alice's laboratory transmittance fluctuation is considered. (general)

A Multiagent System-Based Protection and Control Scheme for Distribution System With Distributed-Generation Integration

DEFF Research Database (Denmark)

Liu, Z.; Su, Chi; Hoidalen, Hans

2017-01-01

In this paper, a multi agent system (MAS) based protection and control scheme is proposed to deal with diverse operation conditions in distribution system due to distributed generation (DG) integration. Based on cooperation between DG controller and relays, an adaptive protection and control...... algorithm is designed on converter based wind turbine DG to limit the influence of infeed fault current. With the consideration of DG control modes, an adaptive relay setting strategy is developed to help protective relays adapt suitable settings to different operation conditions caused by the variations...

Measurement of fuel importance distribution in non-uniformly distributed fuel systems

International Nuclear Information System (INIS)

Yamane, Yoshihiro; Hirano, Yasushi; Yasui, Hazime; Izima, Kazunori; Shiroya, Seiji; Kobayashi, Keiji.

1995-01-01

A reactivity effect due to a spatial variation of nuclear fuel concentration is an important problem for nuclear criticality safety in a reprocessing plant. As a theory estimating this reactivity effect, the Goertzel and fuel importance theories are well known. It has been shown that the Goertzel's theory is valid in the range of our experiments based on measurements of reactivity effect and thermal neutron flux in non-uniformly distributed fuel systems. On the other hand, there have been no reports concerning systematic experimental studies on the flatness of fuel importance which is a more general index than the Goertzel's theory. It is derived from the perturbation theory that the fuel importance is proportional to the reactivity change resulting from a change of small amount of fuel mass. Using a uniform and three kinds of nonuniform fuel systems consisting of 93.2% enriched uranium plates and polyethylene plates, the fuel importance distributions were measured. As a result, it was found experimentally that the fuel importance distribution became flat, as its reactivity effect became large. Therefore it was concluded that the flatness of fuel importance distribution is the useful index for estimating reactivity effect of non-uniformly distributed fuel system. (author)

Distributed Optimal Consensus Control for Nonlinear Multiagent System With Unknown Dynamic.

Science.gov (United States)

Zhang, Jilie; Zhang, Huaguang; Feng, Tao

2017-08-01

This paper focuses on the distributed optimal cooperative control for continuous-time nonlinear multiagent systems (MASs) with completely unknown dynamics via adaptive dynamic programming (ADP) technology. By introducing predesigned extra compensators, the augmented neighborhood error systems are derived, which successfully circumvents the system knowledge requirement for ADP. It is revealed that the optimal consensus protocols actually work as the solutions of the MAS differential game. Policy iteration algorithm is adopted, and it is theoretically proved that the iterative value function sequence strictly converges to the solution of the coupled Hamilton-Jacobi-Bellman equation. Based on this point, a novel online iterative scheme is proposed, which runs based on the data sampled from the augmented system and the gradient of the value function. Neural networks are employed to implement the algorithm and the weights are updated, in the least-square sense, to the ideal value, which yields approximated optimal consensus protocols. Finally, a numerical example is given to illustrate the effectiveness of the proposed scheme.

Modeling of integrated environmental control systems for coal-fired power plants. Final report

Energy Technology Data Exchange (ETDEWEB)

Rubin, E.S.; Salmento, J.S.; Frey, H.C.; Abu-Baker, A.; Berkenpas, M.

1991-05-01

The Integrated Environmental Control Model (IECM) was designed to permit the systematic evaluation of environmental control options for pulverized coal-fired (PC) power plants. Of special interest was the ability to compare the performance and cost of advanced pollution control systems to ``conventional`` technologies for the control of particulate, SO{sub 2} and NO{sub x}. Of importance also was the ability to consider pre-combustion, combustion and post-combustion control methods employed alone or in combination to meet tough air pollution emission standards. Finally, the ability to conduct probabilistic analyses is a unique capability of the IECM. Key results are characterized as distribution functions rather than as single deterministic values. (VC)

Asymptotic work distributions in driven bistable systems

International Nuclear Information System (INIS)

Nickelsen, D; Engel, A

2012-01-01

The asymptotic tails of the probability distributions of thermodynamic quantities convey important information about the physics of nanoscopic systems driven out of equilibrium. We apply a recently proposed method to analytically determine the asymptotics of work distributions in Langevin systems to an one-dimensional model of single-molecule force spectroscopy. The results are in excellent agreement with numerical simulations, even in the centre of the distributions. We compare our findings with a recent proposal for an universal form of the asymptotics of work distributions in single-molecule experiments.

The design of a real-time distributed system

International Nuclear Information System (INIS)

Hertzberger, L.O.; Tuynman, F.; Mullender, S.J.; Poletiek, G.; Vermeulen, J.C.; Renesse, R. van; Tanenbaum, A.S.

1986-01-01

In modern physics experiments an increasing number and variety of programmable processors is used. As a consequence, a software environment is needed that provides an integrated approach to development, testing and use of real-time distributed software. This contribution is based on work being done in the AMOEBA Distributed Operating System Project and the FADOS Real-Time Distributed Operating System Project. A short description of both systems is presented as an example of how basic real-time operating system services can be organized. AMOEBA is the result of fundamental research in the field of distributed operating systems, while FADOS has been designed for applications as encountered in experimental high-energy physics. (Auth.)

Distribution system costs associated with the deployment of photovoltaic systems

Energy Technology Data Exchange (ETDEWEB)

Horowitz, Kelsey A. W.; Palmintier, Bryan; Mather, Barry; Denholm, Paul

2018-07-01

The broadening of our energy system to include increasing amounts of wind and solar has led to significant debate about the total costs and benefits associated with different types of generators - with potentially far-reaching policy implications. This has included debate about the cost associated with integrating these generators onto the electric grid. For photovoltaics (PV), this encompasses costs incurred on both the bulk power and distribution systems, as well as the value provided to them. These costs and benefits, in particular those associated with integrating PV onto the distribution system, are not well understood. We seek to advance the state of understanding of 'grid integration costs' for the distribution system by reviewing prior literature and outlining a transparent, bottom-up approach that can be used to calculate these costs. We provide a clear delineation of costs to integrate PV in to the distribution system within the larger context of total costs and benefits associated with PV generators. We emphasize that these costs are situationally dependent, and that a single 'cost of integration' cannot be obtained. We additionally emphasize that benefits must be considered when evaluating the competitiveness of the technology in a given situation.

Directional Overcurrent Relays Coordination Problems in Distributed Generation Systems

Directory of Open Access Journals (Sweden)

Jakub Ehrenberger

2017-09-01

Full Text Available This paper proposes a new approach to the distributed generation system protection coordination based on directional overcurrent protections with inverse-time characteristics. The key question of protection coordination is the determination of correct values of all inverse-time characteristics coefficients. The coefficients must be correctly chosen considering the sufficiently short tripping times and the sufficiently long selectivity times. In the paper a new approach to protection coordination is designed, in which not only some, but all the required types of short-circuit contributions are taken into account. In radial systems, if the pickup currents are correctly chosen, protection coordination for maximum contributions is enough to ensure selectivity times for all the required short-circuit types. In distributed generation systems, due to different contributions flowing through the primary and selective protections, coordination for maximum contributions is not enough, but all the short-circuit types must be taken into account, and the protection coordination becomes a complex problem. A possible solution to the problem, based on an appropriately designed optimization, has been proposed in the paper. By repeating a simple optimization considering only one short-circuit type, the protection coordination considering all the required short-circuit types has been achieved. To show the importance of considering all the types of short-circuit contributions, setting optimizations with one (the highest and all the types of short-circuit contributions have been performed. Finally, selectivity time values are explored throughout the entire protected section, and both the settings are compared.

Cyber Physical System Modelling of Distribution Power Systems for Dynamic Demand Response

Science.gov (United States)

Chu, Xiaodong; Zhang, Rongxiang; Tang, Maosen; Huang, Haoyi; Zhang, Lei

2018-01-01

Dynamic demand response (DDR) is a package of control methods to enhance power system security. A CPS modelling and simulation platform for DDR in distribution power systems is presented in this paper. CPS modelling requirements of distribution power systems are analyzed. A coupled CPS modelling platform is built for assessing DDR in the distribution power system, which combines seamlessly modelling tools of physical power networks and cyber communication networks. Simulations results of IEEE 13-node test system demonstrate the effectiveness of the modelling and simulation platform.

Economic Models and Algorithms for Distributed Systems

CERN Document Server

Neumann, Dirk; Altmann, Jorn; Rana, Omer F

2009-01-01

Distributed computing models for sharing resources such as Grids, Peer-to-Peer systems, or voluntary computing are becoming increasingly popular. This book intends to discover fresh avenues of research and amendments to existing technologies, aiming at the successful deployment of commercial distributed systems

Design a Fault Tolerance for Real Time Distributed System

OpenAIRE

Ban M. Khammas

2012-01-01

This paper designed a fault tolerance for soft real time distributed system (FTRTDS). This system is designed to be independently on specific mechanisms and facilities of the underlying real time distributed system. It is designed to be distributed on all the computers in the distributed system and controlled by a central unit.Besides gathering information about a target program spontaneously, it provides information about the target operating system and the target hardware in order to diagno...

Distributed simulation of large computer systems

International Nuclear Information System (INIS)

Marzolla, M.

2001-01-01

Sequential simulation of large complex physical systems is often regarded as a computationally expensive task. In order to speed-up complex discrete-event simulations, the paradigm of Parallel and Distributed Discrete Event Simulation (PDES) has been introduced since the late 70s. The authors analyze the applicability of PDES to the modeling and analysis of large computer system; such systems are increasingly common in the area of High Energy and Nuclear Physics, because many modern experiments make use of large 'compute farms'. Some feasibility tests have been performed on a prototype distributed simulator

Quantitative Vulnerability Assessment of Cyber Security for Distribution Automation Systems

Directory of Open Access Journals (Sweden)

Xiaming Ye

2015-06-01

Full Text Available The distribution automation system (DAS is vulnerable to cyber-attacks due to the widespread use of terminal devices and standard communication protocols. On account of the cost of defense, it is impossible to ensure the security of every device in the DAS. Given this background, a novel quantitative vulnerability assessment model of cyber security for DAS is developed in this paper. In the assessment model, the potential physical consequences of cyber-attacks are analyzed from two levels: terminal device level and control center server level. Then, the attack process is modeled based on game theory and the relationships among different vulnerabilities are analyzed by introducing a vulnerability adjacency matrix. Finally, the application process of the proposed methodology is illustrated through a case study based on bus 2 of the Roy Billinton Test System (RBTS. The results demonstrate the reasonability and effectiveness of the proposed methodology.

A DISTRIBUTED SMART HOME ARTIFICIAL INTELLIGENCE SYSTEM

DEFF Research Database (Denmark)

Lynggaard, Per

2013-01-01

A majority of the research performed today explore artificial intelligence in smart homes by using a centralized approach where a smart home server performs the necessary calculations. This approach has some disadvantages that can be overcome by shifting focus to a distributed approach where...... the artificial intelligence system is implemented as distributed as agents running parts of the artificial intelligence system. This paper presents a distributed smart home architecture that distributes artificial intelligence in smart homes and discusses the pros and cons of such a concept. The presented...... distributed model is a layered model. Each layer offers a different complexity level of the embedded distributed artificial intelligence. At the lowest layer smart objects exists, they are small cheap embedded microcontroller based smart devices that are powered by batteries. The next layer contains a more...

Research on intelligent power distribution system for spacecraft

Science.gov (United States)

Xia, Xiaodong; Wu, Jianju

2017-10-01

The power distribution system (PDS) mainly realizes the power distribution and management of the electrical load of the whole spacecraft, which is directly related to the success or failure of the mission, and hence is an important part of the spacecraft. In order to improve the reliability and intelligent degree of the PDS, and considering the function and composition of spacecraft power distribution system, this paper systematically expounds the design principle and method of the intelligent power distribution system based on SSPC, and provides the analysis and verification of the test data additionally.

A distributed model predictive control scheme for leader-follower multi-agent systems

Science.gov (United States)

Franzè, Giuseppe; Lucia, Walter; Tedesco, Francesco

2018-02-01

In this paper, we present a novel receding horizon control scheme for solving the formation problem of leader-follower configurations. The algorithm is based on set-theoretic ideas and is tuned for agents described by linear time-invariant (LTI) systems subject to input and state constraints. The novelty of the proposed framework relies on the capability to jointly use sequences of one-step controllable sets and polyhedral piecewise state-space partitions in order to online apply the 'better' control action in a distributed receding horizon fashion. Moreover, we prove that the design of both robust positively invariant sets and one-step-ahead controllable regions is achieved in a distributed sense. Simulations and numerical comparisons with respect to centralised and local-based strategies are finally performed on a group of mobile robots to demonstrate the effectiveness of the proposed control strategy.

A Metrics-Based Approach to Intrusion Detection System Evaluation for Distributed Real-Time Systems

Science.gov (United States)

2002-04-01

Based Approach to Intrusion Detection System Evaluation for Distributed Real - Time Systems Authors: G. A. Fink, B. L. Chappell, T. G. Turner, and...Distributed, Security. 1 Introduction Processing and cost requirements are driving future naval combat platforms to use distributed, real - time systems of...distributed, real - time systems . As these systems grow more complex, the timing requirements do not diminish; indeed, they may become more constrained

Distributed Supervisory Protection Interlock System

International Nuclear Information System (INIS)

Walz, H.V.; Agostini, R.C.; Barker, L.; Cherkassky, R.; Constant, T.; Matheson, R.

1989-03-01

The Distributed Supervisory Protection Interlock System, DSPI, is under development at the Stanford Linear Accelerator Center for requirements in the areas of personnel protection, beam containment and equipment protection interlocks. The DSPI system, distributed over the application site, consists of segments with microprocessor-based controller and I/O modules, local area networks for communication, and a global supervisor computer. Segments are implemented with commercially available controller and I/O modules arranged in local interlock clusters, and associated software. Segments provide local interlock data acquisition, processing and control. Local area networks provide the communication backbone between segments and a global supervisor processor. The supervisor processor monitors the overall system, reports detail status and provides human interfaces. Details of an R and D test system, which will implement the requirements for personnel protection of 4 typical linear accelerator sectors, will be described. 4 refs., 2 figs

The Distribution of Heavy Metal Pollutants in Suez Bay Using Geographic Information System (GIS)

International Nuclear Information System (INIS)

Hassan, H.B.; Mohamed, W.M.

2017-01-01

Suez city represents the southern entrance of the Suez Canal. As a result of the rapid development of industrialization and anthropogenic activities of Suez city may be entered containments such as heavy metals through Suez bay boundaries. The geographical information system (Arc GIS 9.1) is used to study the spatial distribution of heavy metals concentrations (Cd, Mn, Fe, Ni, Pb, Cu and Zn) of water samples which were collected in four different sampling sites (I, II, III and IV) from Suez bay. In this study, tabular data representation of the spatial distribution was developed using the inverse distance weighted (IDW) interpolation method. The GIS technique was applied to transfer the information into a final map illustrating the spatial distribution of heavy metals within the studied area. GIS models showed the high concentrations of heavy metals in some sites in the Suez city affecting by their activities. An overall distribution map of heavy metals is observed from GIS special analysis. Site (IV) in Suez City demonstrated the highest polluted are a in the overall distribution map

FINAL IMPLEMENTATION AND PERFORMANCE OF THE LHC COLLIMATOR CONTROL SYSTEM

CERN Document Server

Redaelli, S; Masi, A; Losito, R

2009-01-01

The 2008 collimation system of the CERN Large Hadron Collider (LHC) included 80 movable collimators for a total of 316 degrees of freedom. Before beam operation, the final controls implementation was deployed and commissioned. The control system enabled remote control and appropriate diagnostics of the relevant parameters. The collimator motion is driven with time-functions, synchronized with other accelerator systems, which allows controlling the collimator jaw positions with a micrometer accuracy during all machine phases. The machine protection functionality of the system, which also relies on function-based tolerance windows, was also fully validated. The collimator control challenges are reviewed and the final system architecture is presented. The results of the remote system commissioning and the overall performance are discussed.

Water sample-collection and distribution system

Science.gov (United States)

Brooks, R. R.

1978-01-01

Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

NNWSI project information management system concepts evaluation report. Final report

International Nuclear Information System (INIS)

1986-08-01

This report is intended as a first step in developing detailed information management system specifications for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The current state of information management at the NNWSI Project level is investigated and an information management system (IMS) is proposed. The IMS as it relates to aspects of Project and records management is discussed. Information management concepts and prospective IMS system components are investigated. Concepts and system components include: indexing, searching, retrieval, data base management system technology, computers, storage media, computer-assisted retrieval (CAR) of microfilm, electronic imaging-based systems, optical character recognition, and communications. Performance criteria and desirable system attributes applicable to the IMS are discussed. Six conceptual system approaches capable of satisfying the performance criteria are defined. System approaches include: fully centralized microfilm system based on CAR retrieval (Approach 1), partially distributed microfilm system based on CAR retrieval (Approach 2), fully distributed microfilm system based on CAR retrieval (Approach 3), fully centralized optical disk system based on electronic image and full-text retrieval (Approach 4), partially distributed optical system based on electron image and full-text retrieval (Approach 5), and fully distributed optical disk system based on electronic image and full-text retrieval (Approach 6). Technical and cost considerations associated with the six conceptual approaches are evaluated. Technical evaluation results indicate Approach 4 is the best conceptual approach, and cost evaluation results show no significant differences among approaches. On the basis of the evaluation, Approach 4 is recommended

A novel optimal distribution system planning framework implementing distributed generation in a deregulated electricity market

International Nuclear Information System (INIS)

Porkar, S.; Poure, P.; Abbaspour-Tehrani-fard, A.; Saadate, S.

2010-01-01

This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system conditions and three different scenarios depending on different planning alternatives and electrical market structures, have been considered. They have allowed validating the economical and electrical benefits of introducing DG by solving the distribution system planning problem and by improving power quality of distribution system. DG installation increases the feeders' lifetime by reducing their loading and adds the benefit of using the existing distribution system for further load growth without the need for feeders upgrading. More, by investing in DG, the DISCO can minimize its total planning cost and reduce its customers' bills. (author)

A novel optimal distribution system planning framework implementing distributed generation in a deregulated electricity market

Energy Technology Data Exchange (ETDEWEB)

Porkar, S. [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran); Groupe de Recherches en Electrotechnique et Electronique de Nancy, GREEN-UHP, Universite Henri Poincare de Nancy I, BP 239, 54506 Vandoeuvre les Nancy Cedex (France); Poure, P. [Laboratoire d' Instrumentation Electronique de Nancy, LIEN, EA 3440, Universite Henri Poincare de Nancy I, BP 239, 54506 Vandoeuvre les Nancy Cedex (France); Abbaspour-Tehrani-fard, A. [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran); Saadate, S. [Groupe de Recherches en Electrotechnique et Electronique de Nancy, GREEN-UHP, Universite Henri Poincare de Nancy I, BP 239, 54506 Vandoeuvre les Nancy Cedex (France)

2010-07-15

This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system conditions and three different scenarios depending on different planning alternatives and electrical market structures, have been considered. They have allowed validating the economical and electrical benefits of introducing DG by solving the distribution system planning problem and by improving power quality of distribution system. DG installation increases the feeders' lifetime by reducing their loading and adds the benefit of using the existing distribution system for further load growth without the need for feeders upgrading. More, by investing in DG, the DISCO can minimize its total planning cost and reduce its customers' bills. (author)

Hybrid solar lighting distribution systems and components

Science.gov (United States)

Muhs, Jeffrey D [Lenoir City, TN; Earl, Dennis D [Knoxville, TN; Beshears, David L [Knoxville, TN; Maxey, Lonnie C [Powell, TN; Jordan, John K [Oak Ridge, TN; Lind, Randall F [Lenoir City, TN

2011-07-05

A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

Programming a Distributed System Using Shared Objects

NARCIS (Netherlands)

Tanenbaum, A.S.; Bal, H.E.; Kaashoek, M.F.

1993-01-01

Building the hardware for a high-performance distributed computer system is a lot easier than building its software. The authors describe a model for programming distributed systems based on abstract data types that can be replicated on all machines that need them. Read operations are done locally,

FOCUS: a fire management planning system -- final report

Science.gov (United States)

Frederick W. Bratten; James B. Davis; George T. Flatman; Jerold W. Keith; Stanley R. Rapp; Theodore G. Storey

1981-01-01

FOCUS (Fire Operational Characteristics Using Simulation) is a computer simulation model for evaluating alternative fire management plans. This final report provides a broad overview of the FOCUS system, describes two major modules-fire suppression and cost, explains the role in the system of gaming large fires, and outlines the support programs and ways of...

A New Protection System for Islanding Detection in LV Distribution Systems

Directory of Open Access Journals (Sweden)

Anna Rita Di Fazio

2015-04-01

Full Text Available The growth of penetration of Distributed Generators (DGs is increasing the risk of unwanted islanded operation in Low Voltage (LV distribution systems. In this scenario, the existing anti-islanding protection systems, installed at the DG premises and based on classical voltage and frequency relays, are no longer effective, especially in the cases of islands characterized by a close match between generation and load. In this paper, a new protection system for islanding detection in LV distribution systems is proposed. The classical voltage and frequency relays in the DG interface protections are enriched with an innovative Smart Islanding Detector, which adopts a new passive islanding detection method. The aim is to keep the advantages of the classical relays while overcoming the problem of their limited sensitivity in detecting balanced islands. In the paper, to define the requirements of the anti-islanding protection system, the events causing the islanded operation of the LV distribution systems are firstly identified and classified. Then, referring to proposed protection system, its architecture and operation are described and, eventually, its performance is analyzed and validated by experimental laboratory tests, carried out with a hardware-in-the-loop technique.

RBAC administration in distributed systems

NARCIS (Netherlands)

Dekker, M.A.C.; Crampton, J.; Etalle, Sandro; Li, N.

Large and distributed access control systems are increasingly common, for example in health care. In such settings, access control policies may become very complex, thus complicating correct and efficient adminstration of the access control system. Despite being one of the most widely used access

Programming Languages for Distributed Computing Systems

NARCIS (Netherlands)

Bal, H.E.; Steiner, J.G.; Tanenbaum, A.S.

1989-01-01

When distributed systems first appeared, they were programmed in traditional sequential languages, usually with the addition of a few library procedures for sending and receiving messages. As distributed applications became more commonplace and more sophisticated, this ad hoc approach became less

Distributed redundancy and robustness in complex systems

KAUST Repository

Randles, Martin

2011-03-01

The uptake and increasing prevalence of Web 2.0 applications, promoting new large-scale and complex systems such as Cloud computing and the emerging Internet of Services/Things, requires tools and techniques to analyse and model methods to ensure the robustness of these new systems. This paper reports on assessing and improving complex system resilience using distributed redundancy, termed degeneracy in biological systems, to endow large-scale complicated computer systems with the same robustness that emerges in complex biological and natural systems. However, in order to promote an evolutionary approach, through emergent self-organisation, it is necessary to specify the systems in an \\'open-ended\\' manner where not all states of the system are prescribed at design-time. In particular an observer system is used to select robust topologies, within system components, based on a measurement of the first non-zero Eigen value in the Laplacian spectrum of the components\\' network graphs; also known as the algebraic connectivity. It is shown, through experimentation on a simulation, that increasing the average algebraic connectivity across the components, in a network, leads to an increase in the variety of individual components termed distributed redundancy; the capacity for structurally distinct components to perform an identical function in a particular context. The results are applied to a specific application where active clustering of like services is used to aid load balancing in a highly distributed network. Using the described procedure is shown to improve performance and distribute redundancy. © 2010 Elsevier Inc.

Smart intimation and location of faults in distribution system

Science.gov (United States)

Hari Krishna, K.; Srinivasa Rao, B.

2018-04-01

Location of faults in the distribution system is one of the most complicated problems that we are facing today. Identification of fault location and severity of fault within a short time is required to provide continuous power supply but fault identification and information transfer to the operator is the biggest challenge in the distribution network. This paper proposes a fault location method in the distribution system based on Arduino nano and GSM module with flame sensor. The main idea is to locate the fault in the distribution transformer by sensing the arc coming out from the fuse element. The biggest challenge in the distribution network is to identify the location and the severity of faults under different conditions. Well operated transmission and distribution systems will play a key role for uninterrupted power supply. Whenever fault occurs in the distribution system the time taken to locate and eliminate the fault has to be reduced. The proposed design was achieved with flame sensor and GSM module. Under faulty condition, the system will automatically send an alert message to the operator in the distribution system, about the abnormal conditions near the transformer, site code and its exact location for possible power restoration.

Economic impacts of power electronics on electricity distribution systems

International Nuclear Information System (INIS)

Duarte, Carlos Henrique; Schaeffer, Roberto

2010-01-01

To achieve more efficient energy use, power electronics (PEs) may be employed. However, these introduce nonlinear loads (NLLs) into the system by generating undesired frequencies that are harmonic in relation to (multiples of) the fundamental frequency (60 Hz in Brazil). Consequently, devices using PEs are more efficient but also contribute significantly to degradation of power quality. Besides this, both the conventional rules on design and operation of power systems and the usual premises followed in energy efficiency programs (without mentioning the electricity consumed by the devices themselves) consider the sinusoidal voltage and current waveforms at the fixed fundamental frequency of the power grid. Thus, analysis of electricity consumption reductions in energy efficiency programs that include the use of PEs considers the reduction of kWh to the final consumer but not the additional losses caused by the increase in harmonic distortion. This article contributes to a better understanding of this problem by reporting the results of a case study of the ownership and use of television sets (TV sets) to estimate the economic impacts of residential PEs on a mainly residential electricity distribution system. (author)

Foundations for Protecting Renewable-Rich Distribution Systems.

Energy Technology Data Exchange (ETDEWEB)

Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brahma, Sukumar [New Mexico State Univ., Las Cruces, NM (United States); Ranade, Satish [New Mexico State Univ., Las Cruces, NM (United States)

2016-11-01

High proliferation of Inverter Interfaced Distributed Energy Resources (IIDERs) into the electric distribution grid introduces new challenges to protection of such systems. This is because the existing protection systems are designed with two assumptions: 1) system is single-sourced, resulting in unidirectional fault current, and (2) fault currents are easily detectable due to much higher magnitudes compared to load currents. Due to the fact that most renewables interface with the grid though inverters, and inverters restrict their current output to levels close to the full load currents, both these assumptions are no longer valid - the system becomes multi-sourced, and overcurrent-based protection does not work. The primary scope of this study is to analyze the response of a grid-tied inverter to different faults in the grid, leading to new guidelines on protecting renewable-rich distribution systems.

Multi-target consensus circle pursuit for multi-agent systems via a distributed multi-flocking method

Science.gov (United States)

Pei, Huiqin; Chen, Shiming; Lai, Qiang

2016-12-01

This paper studies the multi-target consensus pursuit problem of multi-agent systems. For solving the problem, a distributed multi-flocking method is designed based on the partial information exchange, which is employed to realise the pursuit of multi-target and the uniform distribution of the number of pursuing agents with the dynamic target. Combining with the proposed circle formation control strategy, agents can adaptively choose the target to form the different circle formation groups accomplishing a multi-target pursuit. The speed state of pursuing agents in each group converges to the same value. A Lyapunov approach is utilised to analyse the stability of multi-agent systems. In addition, a sufficient condition is given for achieving the dynamic target consensus pursuit, and which is then analysed. Finally, simulation results verify the effectiveness of the proposed approaches.

Distributed Systems 3/e

NARCIS (Netherlands)

Tanenbaum, A.S.; van Steen, M.R.

2016-01-01

For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A

An Applet-based Anonymous Distributed Computing System.

Science.gov (United States)

Finkel, David; Wills, Craig E.; Ciaraldi, Michael J.; Amorin, Kevin; Covati, Adam; Lee, Michael

2001-01-01

Defines anonymous distributed computing systems and focuses on the specifics of a Java, applet-based approach for large-scale, anonymous, distributed computing on the Internet. Explains the possibility of a large number of computers participating in a single computation and describes a test of the functionality of the system. (Author/LRW)

Distributed generation and distribution market diversity in Europe

International Nuclear Information System (INIS)

Lopes Ferreira, H.; Costescu, A.; L'Abbate, A.; Minnebo, P.; Fulli, G.

2011-01-01

The unbundling of the electricity power system will play a key role on the deployment of distributed generation (DG) in European distribution systems evolving towards Smart Grids. The present paper firstly reviews the relevant European Union (EU) regulatory framework: specific attention is paid to the concept of unbundling of power distribution sector in Europe. Afterwards, the focus is on the current state of penetration of DG technologies in the EU Member States and the corresponding interrelations with distribution features. A comparison between the unbundling of the distribution and supply markets using econometric indicators such as the Herfindahl-Hirschmann (I HH ) and the Shannon-Wiener (I SW ) indices is then presented. Finally, a comparative analysis between these indices and the current level of penetration of distributed generation in most EU is shown; policy recommendations conclude the paper. - Highlights: →The EU regulatory framework and the concept of unbundling are addressed. →A comparison between the unbundling of the distribution and supply markets is shown. →The Herfindahl-Hirschmann and the Shannon-Wiener econometric indices are applied. →A comparison between the indices and the penetration level of DG in EU is presented. →A comparison between the indices and the penetration level of DG in EU is presented.

Distributed Processing System for Restoration of Electric Power Distribution Network Using Two-Layered Contract Net Protocol

Science.gov (United States)

Kodama, Yu; Hamagami, Tomoki

Distributed processing system for restoration of electric power distribution network using two-layered CNP is proposed. The goal of this study is to develop the restoration system which adjusts to the future power network with distributed generators. The state of the art of this study is that the two-layered CNP is applied for the distributed computing environment in practical use. The two-layered CNP has two classes of agents, named field agent and operating agent in the network. In order to avoid conflicts of tasks, operating agent controls privilege for managers to send the task announcement messages in CNP. This technique realizes the coordination between agents which work asynchronously in parallel with others. Moreover, this study implements the distributed processing system using a de-fact standard multi-agent framework, JADE(Java Agent DEvelopment framework). This study conducts the simulation experiments of power distribution network restoration and compares the proposed system with the previous system. We confirmed the results show effectiveness of the proposed system.

Intelligent decision support algorithm for distribution system restoration.

Science.gov (United States)

Singh, Reetu; Mehfuz, Shabana; Kumar, Parmod

2016-01-01

Distribution system is the means of revenue for electric utility. It needs to be restored at the earliest if any feeder or complete system is tripped out due to fault or any other cause. Further, uncertainty of the loads, result in variations in the distribution network's parameters. Thus, an intelligent algorithm incorporating hybrid fuzzy-grey relation, which can take into account the uncertainties and compare the sequences is discussed to analyse and restore the distribution system. The simulation studies are carried out to show the utility of the method by ranking the restoration plans for a typical distribution system. This algorithm also meets the smart grid requirements in terms of an automated restoration plan for the partial/full blackout of network.

Control of Networked Traffic Flow Distribution - A Stochastic Distribution System Perspective

Energy Technology Data Exchange (ETDEWEB)

Wang, Hong [Pacific Northwest National Laboratory (PNNL); Aziz, H M Abdul [ORNL; Young, Stan [National Renewable Energy Laboratory (NREL); Patil, Sagar [Pacific Northwest National Laboratory (PNNL)

2017-10-01

Networked traffic flow is a common scenario for urban transportation, where the distribution of vehicle queues either at controlled intersections or highway segments reflect the smoothness of the traffic flow in the network. At signalized intersections, the traffic queues are controlled by traffic signal control settings and effective traffic lights control would realize both smooth traffic flow and minimize fuel consumption. Funded by the Energy Efficient Mobility Systems (EEMS) program of the Vehicle Technologies Office of the US Department of Energy, we performed a preliminary investigation on the modelling and control framework in context of urban network of signalized intersections. In specific, we developed a recursive input-output traffic queueing models. The queue formation can be modeled as a stochastic process where the number of vehicles entering each intersection is a random number. Further, we proposed a preliminary B-Spline stochastic model for a one-way single-lane corridor traffic system based on theory of stochastic distribution control.. It has been shown that the developed stochastic model would provide the optimal probability density function (PDF) of the traffic queueing length as a dynamic function of the traffic signal setting parameters. Based upon such a stochastic distribution model, we have proposed a preliminary closed loop framework on stochastic distribution control for the traffic queueing system to make the traffic queueing length PDF follow a target PDF that potentially realizes the smooth traffic flow distribution in a concerned corridor.

Electric distribution systems and embedded generation capacity

International Nuclear Information System (INIS)

Calderaro, V.; Galdi, V.; Piccolo, A.; Siano, P.

2006-01-01

The main policy issues of European States are sustainable energy supply promotion and liberalization of energy markets, which introduced market competition in electricity production and created support mechanisms to encourage renewable electricity production and consumption. As a result of liberalization, any generator, including small-scale and renewable energy based units, can sell electricity on the free market. In order to meet future sustainability targets, connection of a higher number of Distributed Generation (DG) units to the electrical power system is expected, requiring changes in the design and operation of distribution electricity systems, as well as changes in electricity network regulation. In order to assist distribution system operators in planning and managing DG connections and in maximizing DG penetration and renewable sources exploitation, this paper proposed a reconfiguration methodology based on a Genetic Algorithm (GA), that was tested on a 70-bus system with DG units. The simulation results confirmed that the methodology represents a suitable tool for distribution system operators when dealing with DG capacity expansion and power loss issues, providing information regarding the potential penetration network-wide and allowing maximum exploitation of renewable generation. 35 refs., 4 tabs., 6 figs

Distributed ESO based cooperative tracking control for high-order nonlinear multiagent systems with lumped disturbance and application in multi flight simulators systems.

Science.gov (United States)

Cong, Zhang

2018-03-01

Based on extended state observer, a novel and practical design method is developed to solve the distributed cooperative tracking problem of higher-order nonlinear multiagent systems with lumped disturbance in a fixed communication topology directed graph. The proposed method is designed to guarantee all the follower nodes ultimately and uniformly converge to the leader node with bounded residual errors. The leader node, modeled as a higher-order non-autonomous nonlinear system, acts as a command generator giving commands only to a small portion of the networked follower nodes. Extended state observer is used to estimate the local states and lumped disturbance of each follower node. Moreover, each distributed controller can work independently only requiring the relative states and/or the estimated relative states information between itself and its neighbors. Finally an engineering application of multi flight simulators systems is demonstrated to test and verify the effectiveness of the proposed algorithm. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Distributed Administrative Management Information System (DAMIS).

Science.gov (United States)

Juckiewicz, Robert; Kroculick, Joseph

Columbia University's major program to distribute its central administrative data processing to its various schools and departments is described. The Distributed Administrative Management Information System (DAMIS) will link every department and school within the university via micrcomputers, terminals, and/or minicomputers to the central…

Interpretation of quasi-elastic barrier distributions for weakly bound systems

International Nuclear Information System (INIS)

Monteiro, D.S.; Gomes, P.R.S.; Lubian, J.

2009-01-01

Full text: We verify that quasi-elastic (elastic + inelastic) backscattering barrier distributions for weakly bound systems do not strictly correspond to fusion barrier distributions, but rather to reaction threshold distribution, as proposed by Zagrebaev in a recent paper concerning very heavy systems. In this work, we investigate whether Zagrebaevs interpretation is valid by comparing experimental results obtained in two very recent works with the 6 Li + 144 Sm system. Monteiro et al derived the quasi-elastic barrier distribution (or reaction threshold distribution, following Zagrebaevs interpretation) by adding elastic and inelastic backscattering for this system. Rath et al obtained fusion barrier distribution for the same system from the measured complete fusion cross section for the same system. We conclude that the quasi-elastic barrier distributions can be associated with fusion barrier distributions only in situations where there are no relevant reaction channels apart from fusion. This is not the situation for very heavy nor for weakly bound systems. (author)

Parallel and distributed processing: applications to power systems

Energy Technology Data Exchange (ETDEWEB)

Wu, Felix; Murphy, Liam [California Univ., Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences

1994-12-31

Applications of parallel and distributed processing to power systems problems are still in the early stages. Rapid progress in computing and communications promises a revolutionary increase in the capacity of distributed processing systems. In this paper, the state-of-the art in distributed processing technology and applications is reviewed and future trends are discussed. (author) 14 refs.,1 tab.

Intelligent distributed voltage control system for smart grid application

Energy Technology Data Exchange (ETDEWEB)

Sajadi, Amirhossein [Warsaw Univ. of Technology (Poland); Ariatabar, Mitra [RWTH Aachen Univ. (Germany)

2012-07-01

Increasing penetration of the renewable energy source (RES) units in distribution networks particularly due to nonlinear and unpredictable nature of renewable units brings up new challenges in different aspects of electricity network, which leads to more complex power systems. Multi-agent system is consisting of agents which are capable to perceive environment that they are located in and to reacts with each other by communication infrastructure in order to achieve overall goals. In this paper an approach to control the voltage based on in the power distribution system is proposed and discussed. Therefore, a multi-agent system has been integrated with artificial intelligence to come up with fuzzy multi-agent based system. The proposed control scheme is deployed to a smart distribution system consisting distribution generation units, modelled in MATLAB/Simulink, to evaluate its effectiveness. The simulation results show how proposed system can regulate voltage in smart distribution feeders. (orig.)

Distributed generation and centralized power system in Thailand

DEFF Research Database (Denmark)

Sukkumnoed, Decharut

2004-01-01

The paper examines and discusses conflicts between the development of distributed power and centralized power system.......The paper examines and discusses conflicts between the development of distributed power and centralized power system....

Rapid Prototyping of Formally Modelled Distributed Systems

OpenAIRE

Buchs, Didier; Buffo, Mathieu; Titsworth, Frances M.

1999-01-01

This paper presents various kinds of prototypes, used in the prototyping of formally modelled distributed systems. It presents the notions of prototyping techniques and prototype evolution, and shows how to relate them to the software life-cycle. It is illustrated through the use of the formal modelling language for distributed systems CO-OPN/2.

Integrating CLIPS applications into heterogeneous distributed systems

Science.gov (United States)

Adler, Richard M.

1991-01-01

SOCIAL is an advanced, object-oriented development tool for integrating intelligent and conventional applications across heterogeneous hardware and software platforms. SOCIAL defines a family of 'wrapper' objects called agents, which incorporate predefined capabilities for distributed communication and control. Developers embed applications within agents and establish interactions between distributed agents via non-intrusive message-based interfaces. This paper describes a predefined SOCIAL agent that is specialized for integrating C Language Integrated Production System (CLIPS)-based applications. The agent's high-level Application Programming Interface supports bidirectional flow of data, knowledge, and commands to other agents, enabling CLIPS applications to initiate interactions autonomously, and respond to requests and results from heterogeneous remote systems. The design and operation of CLIPS agents are illustrated with two distributed applications that integrate CLIPS-based expert systems with other intelligent systems for isolating and mapping problems in the Space Shuttle Launch Processing System at the NASA Kennedy Space Center.

Performance analysis of distributed beamforming in a spectrum sharing system

KAUST Repository

Yang, Liang

2013-05-01

In this paper, we consider a distributed beamforming scheme (DBF) in a spectrum sharing system where multiple secondary users share the spectrum with some licensed primary users under an interference temperature constraint. We assume that the DBF is applied at the secondary users. We first consider optimal beamforming and compare it with the user selection scheme in terms of the outage probability and bit error rate performance metrics. Since perfect feedback is difficult to obtain, we then investigate a limited feedback DBF scheme and develop an analysis for a random vector quantization design algorithm. Specifically, the approximate statistics functions of the squared inner product between the optimal and quantized vectors are derived. With these statistics, we analyze the outage performance. Furthermore, the effects of channel estimation error and number of primary users on the system performance are investigated. Finally, optimal power adaptation and cochannel interference are considered and analyzed. Numerical and simulation results are provided to illustrate our mathematical formalism and verify our analysis. © 2012 IEEE.

Distributed intelligence versus central laboratory

International Nuclear Information System (INIS)

Halling, H.

1983-01-01

After a discussion of the main tasks in a nuclear laboratory like overall experiment planning, sample production and management, performance of experiments, data processing and report generation the essential disadvantages of centralised systems are shown and the proper measures for overcoming those by distribution are discussed. Finally possible shortcomings due to improper design and management of distributed architectures are shown. (author)

A new HBMO algorithm for multiobjective daily Volt/Var control in distribution systems considering Distributed Generators

Energy Technology Data Exchange (ETDEWEB)

Niknam, Taher [Electrical and Electronics Engineering Department, Shiraz University of Technology, Modars Blvd. P.O. 71555-313, Shiraz (Iran, Islamic Republic of)

2011-03-15

In recent years, Distributed Generators (DGs) connected to the distribution network have received increasing attention. The connection of enormous DGs into existing distribution network changes the operation of distribution systems. Because of the small X/R ratio and radial structure of distribution systems, DGs affect the daily Volt/Var control. This paper presents a new algorithm for multiobjective daily Volt/Var control in distribution systems including Distributed Generators (DGs). The objectives are costs of energy generation by DGs and distribution companies, electrical energy losses and the voltage deviations for the next day. A new optimization algorithm based on a Chaotic Improved Honey Bee Mating Optimization (CIHBMO) is proposed to determine the active power values of DGs, reactive power values of capacitors and tap positions of transformers for the next day. Since objectives are not the same, a fuzzy system is used to calculate the best solution. The plausibility of the proposed algorithm is demonstrated and its performance is compared with other methods on a 69-bus distribution feeder. Simulation results illustrate that the proposed algorithm has better outperforms the other algorithms. (author)

A new HBMO algorithm for multiobjective daily Volt/Var control in distribution systems considering Distributed Generators

International Nuclear Information System (INIS)

Niknam, Taher

2011-01-01

In recent years, Distributed Generators (DGs) connected to the distribution network have received increasing attention. The connection of enormous DGs into existing distribution network changes the operation of distribution systems. Because of the small X/R ratio and radial structure of distribution systems, DGs affect the daily Volt/Var control. This paper presents a new algorithm for multiobjective daily Volt/Var control in distribution systems including Distributed Generators (DGs). The objectives are costs of energy generation by DGs and distribution companies, electrical energy losses and the voltage deviations for the next day. A new optimization algorithm based on a Chaotic Improved Honey Bee Mating Optimization (CIHBMO) is proposed to determine the active power values of DGs, reactive power values of capacitors and tap positions of transformers for the next day. Since objectives are not the same, a fuzzy system is used to calculate the best solution. The plausibility of the proposed algorithm is demonstrated and its performance is compared with other methods on a 69-bus distribution feeder. Simulation results illustrate that the proposed algorithm has better outperforms the other algorithms.

Analysis of residual chlorine in simple drinking water distribution system with intermittent water supply

Science.gov (United States)

Goyal, Roopali V.; Patel, H. M.

2015-09-01

Knowledge of residual chlorine concentration at various locations in drinking water distribution system is essential final check to the quality of water supplied to the consumers. This paper presents a methodology to find out the residual chlorine concentration at various locations in simple branch network by integrating the hydraulic and water quality model using first-order chlorine decay equation with booster chlorination nodes for intermittent water supply. The explicit equations are developed to compute the residual chlorine in network with a long distribution pipe line at critical nodes. These equations are applicable to Indian conditions where intermittent water supply is the most common system of water supply. It is observed that in intermittent water supply, the residual chlorine at farthest node is sensitive to water supply hours and travelling time of chlorine. Thus, the travelling time of chlorine can be considered to justify the requirement of booster chlorination for intermittent water supply.

Distribution System Reliability Analysis for Smart Grid Applications

Science.gov (United States)

Aljohani, Tawfiq Masad

Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. To address its reliability concerns, the power utilities and interested parties have spent extensive amount of time and effort to analyze and study the reliability of the generation and transmission sectors of the power grid. Only recently has attention shifted to be focused on improving the reliability of the distribution network, the connection joint between the power providers and the consumers where most of the electricity problems occur. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in conducting this thesis is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. The goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility's distribution system and measure the potential improvement of its reliability. The software used in this work is DISREL, which is intelligent power distribution software that is developed by General Reliability Co.

PROWAY - a standard for distributed control systems

International Nuclear Information System (INIS)

Gellie, R.W.

1980-01-01

The availability of cheap and powerful microcomputer and data communications equipment has led to a major revision of instrumentation and control systems. Intelligent devices can now be used and distributed about the control system in a systematic and economic manner. These sub-units are linked by a communications system to provide a total system capable of meeting the required plant objectives. PROWAY, an international standard process data highway for interconnecting processing units in distributed industrial process control systems, is currently being developed. This paper describes the salient features and current status of the PROWAY effort. (auth)

Online Scheduling in Distributed Message Converter Systems

NARCIS (Netherlands)

Risse, Thomas; Wombacher, Andreas; Surridge, Mike; Taylor, Steve; Aberer, Karl

The optimal distribution of jobs among hosts in distributed environments is an important factor to achieve high performance. The optimal strategy depends on the application. In this paper we present a new online scheduling strategy for distributed EDI converter system. The strategy is based on the

Support system for ATLAS distributed computing operations

CERN Document Server

Kishimoto, Tomoe; The ATLAS collaboration

2018-01-01

The ATLAS distributed computing system has allowed the experiment to successfully meet the challenges of LHC Run 2. In order for distributed computing to operate smoothly and efficiently, several support teams are organized in the ATLAS experiment. The ADCoS (ATLAS Distributed Computing Operation Shifts) is a dedicated group of shifters who follow and report failing jobs, failing data transfers between sites, degradation of ATLAS central computing services, and more. The DAST (Distributed Analysis Support Team) provides user support to resolve issues related to running distributed analysis on the grid. The CRC (Computing Run Coordinator) maintains a global view of the day-to-day operations. In this presentation, the status and operational experience of the support system for ATLAS distributed computing in LHC Run 2 will be reported. This report also includes operations experience from the grid site point of view, and an analysis of the errors that create the biggest waste of wallclock time. The report of oper...

Distributed photovoltaic system evaluation by Arizona Public Service Company

International Nuclear Information System (INIS)

Lambeth, R.; Lepley, T.

1993-01-01

Arizona Public Service Company (APS) has performed a study of the APS system to (1) determine whether APS has high-value distributed applications of photovoltaics (PV), (2) quantify the value of a distributed PV system, (3) compare the APS results with the earlier PG ampersand E results and (4) estimate whether there will be significant market for these applications at APS. The study confirmed that there is a value to distributing PV generation throughout the utility distribution system. The breakeven cost for a PV system in APS' best location is $3.44/watt, in 1996 dollars. Feeders which meet all the criteria and which will be eligible for full benefits are relatively rare. However, a PV system will usually have more value if it is distributed rather than installed at a central station site

Modeling and Control for Islanding Operation of Active Distribution Systems

DEFF Research Database (Denmark)

Cha, Seung-Tae; Wu, Qiuwei; Saleem, Arshad

2011-01-01

to stabilize the frequency. Different agents are defined to represent different resources in the distribution systems. A test platform with a real time digital simulator (RTDS), an OPen Connectivity (OPC) protocol server and the multi-agent based intelligent controller is established to test the proposed multi......Along with the increasing penetration of distributed generation (DG) in distribution systems, there are more resources for system operators to improve the operation and control of the whole system and enhance the reliability of electricity supply to customers. The distribution systems with DG...... are able to operate in is-landing operation mode intentionally or unintentionally. In order to smooth the transition from grid connected operation to islanding operation for distribution systems with DG, a multi-agent based controller is proposed to utilize different re-sources in the distribution systems...

THE FRANCHISE SYSTEM OF DISTRIBUTION.

Science.gov (United States)

The working relationships between franchise companies and their franchised dealers are analyzed. The benefits derived from the use of a franchisesise...system of distribution for both the franchisor and franchisee are determined. The principal problems encountered by the parties to the franchise ...agreement are isolated, and this method of distribution is evaluated from the standpoint of both the franchise company and franchised dealers and to assess its impact on the marketing economy of the nation.

SatisFactory Final System Evaluation Report

OpenAIRE

Sunlight SA

2018-01-01

The present document is a deliverable of the SatisFactory project, funded by the European Commission’s Directorate-General for Research and Innovation (DG RTD), under its Horizon 2020 Research and innovation programme (H2020). The main objective of this deliverable is to report on the SatisFactory Final System Evaluation, with regards to the industrial pilots at COMAU and SUNLIGHT. The evaluation of SatisFactory platform is based on the implementation of the business scenarios where each tool...

Response Time Analysis of Distributed Web Systems Using QPNs

Directory of Open Access Journals (Sweden)

Tomasz Rak

2015-01-01

Full Text Available A performance model is used for studying distributed Web systems. Performance evaluation is done by obtaining load test measurements. Queueing Petri Nets formalism supports modeling and performance analysis of distributed World Wide Web environments. The proposed distributed Web systems modeling and design methodology have been applied in the evaluation of several system architectures under different external loads. Furthermore, performance analysis is done to determine the system response time.

Risk based economic optimization of investment decisions of regulated power distribution system operators; Risikobasierte wirtschaftliche Optimierung von Investitionsentscheidungen regulierter Stromnetzbetreiber

Energy Technology Data Exchange (ETDEWEB)

John, Oliver

2012-07-01

The author of the contribution under consideration reports on risk-based economic optimization of investment decisions of regulated power distribution system operators. The focus is the economically rational decision behavior of operators under certain regulatory requirements. Investments in power distribution systems form the items subject to decisions. Starting from a description of theoretical and practical regulatory approaches, their financial implications are quantified at first. On this basis, optimization strategies are derived with respect to the investment behavior. For this purpose, an optimization algorithm is developed and applied to exemplary companies. Finally, effects of uncertainties in regulatory systems are investigated. In this context, Monte Carlo simulations are used in conjunction with real options analysis.

Future development of the electricity systems with distributed generation

Energy Technology Data Exchange (ETDEWEB)

Bayod-Rujula, Angel A. [Department of Electrical Engineering, Centro Politecnico Superior, University of Zaragoza, C/Maria de Luna, 3, 50018 Zaragoza (Spain)

2009-03-15

Electrical power systems have been traditionally designed taking energy from high-voltage levels, and distributing it to lower voltage level networks. There are large generation units connected to transmission networks. But in the future there will be a large number of small generators connected to the distribution networks. Efficient integration of this distributed generation requires network innovations. A development of active distribution network management, from centralised to more distributed system management, is needed. Information, communication, and control infrastructures will be needed with increasing complexity of system management. Some innovative concepts such as microgrids and virtual utilities will be presented. (author)

MicROS-drt: supporting real-time and scalable data distribution in distributed robotic systems.

Science.gov (United States)

Ding, Bo; Wang, Huaimin; Fan, Zedong; Zhang, Pengfei; Liu, Hui

A primary requirement in distributed robotic software systems is the dissemination of data to all interested collaborative entities in a timely and scalable manner. However, providing such a service in a highly dynamic and resource-limited robotic environment is a challenging task, and existing robot software infrastructure has limitations in this aspect. This paper presents a novel robot software infrastructure, micROS-drt, which supports real-time and scalable data distribution. The solution is based on a loosely coupled data publish-subscribe model with the ability to support various time-related constraints. And to realize this model, a mature data distribution standard, the data distribution service for real-time systems (DDS), is adopted as the foundation of the transport layer of this software infrastructure. By elaborately adapting and encapsulating the capability of the underlying DDS middleware, micROS-drt can meet the requirement of real-time and scalable data distribution in distributed robotic systems. Evaluation results in terms of scalability, latency jitter and transport priority as well as the experiment on real robots validate the effectiveness of this work.

RF phase distribution systems at the SLC

International Nuclear Information System (INIS)

Jobe, R.K.; Schwarz, H.D.

1989-04-01

Modern large linear accelerators require RF distribution systems with minimal phase drifts and errors. Through the use of existing RF coaxial waveguides, and additional installation of phase reference cables and monitoring equipment, stable RF distribution for the SLC has been achieved. This paper discusses the design and performance of SLAC systems, and some design considerations for future colliders. 6 refs., 4 figs

A Distributed Intelligent System for Emergency Convoy

Directory of Open Access Journals (Sweden)

Mohammed Benalla

2016-09-01

Full Text Available The general problem that guides this research is the ability to design a distributed intelligent system for guiding the emergency convoys; a solution that will be based on a group of agents and on the analysis of traffic in order to generate collective functional response. It fits into the broader issue of Distributed Artificial System (DAI, which is to operate a cooperatively computer agent into multi-agents system (MAS. This article describes conceptually two fundamental questions of emergency convoys. The first question is dedicated to find a response to the traffic situation (i.e. fluid way, while the second is devoted to the convoy orientation; while putting the point on the distributed and cooperative resolution for the general problem.

Transparent checkpointing and process migration in a distributed system

OpenAIRE

2004-01-01

A distributed system for creating a checkpoint for a plurality of processes running on the distributed system. The distributed system includes a plurality of compute nodes with an operating system executing on each compute node. A checkpoint library resides at the user level on each of the compute nodes, and the checkpoint library is transparent to the operating system residing on the same compute node and to the other compute nodes. Each checkpoint library uses a windowed messaging logging p...

OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

Science.gov (United States)

Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

Concurrency control in distributed database systems

CERN Document Server

Cellary, W; Gelenbe, E

1989-01-01

Distributed Database Systems (DDBS) may be defined as integrated database systems composed of autonomous local databases, geographically distributed and interconnected by a computer network.The purpose of this monograph is to present DDBS concurrency control algorithms and their related performance issues. The most recent results have been taken into consideration. A detailed analysis and selection of these results has been made so as to include those which will promote applications and progress in the field. The application of the methods and algorithms presented is not limited to DDBSs but a

Wireless distributed functional electrical stimulation system

Directory of Open Access Journals (Sweden)

Jovičić Nenad S

2012-08-01

Full Text Available Abstract Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers. One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

Wireless distributed functional electrical stimulation system.

Science.gov (United States)

Jovičić, Nenad S; Saranovac, Lazar V; Popović, Dejan B

2012-08-09

The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype's software. The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

Innovated feed water distributing system of VVER steam generators

International Nuclear Information System (INIS)

Matal, O.; Sousek, P.; Simo, T.; Lehota, M.; Lipka, J.; Slugen, V.

2000-01-01

Defects in feed water distributing system due to corrosion-erosion effects have been observed at many VVER 440 steam generators (SG). Therefore analysis of defects origin and consequently design development and testing of a new feed water distributing system were performed. System tests in-situ supported by calculations and comparison of measured and calculated data were focused on demonstration of long term reliable operation, definition of water flow and water chemical characteristics at the SG secondary side and their measurements and study of dynamic characteristics needed for the innovated feed water distributing system seismic features approval. The innovated feed water distributing system was installed in the SGs of two VVER units already. (author)

Operations-oriented performance measures for freeway management systems : final report.

Science.gov (United States)

2008-12-01

This report describes the second and final year activities of the project titled Using Operations-Oriented Performance Measures to Support Freeway Management Systems. Work activities included developing a prototype system architecture for testi...

Development of total medical material distribution management system.

Science.gov (United States)

Uto, Y; Kumamoto, I

1994-07-01

Since September 1992, attempts have been made at Kagoshima University Hospital to develop the Medical Material Distribution Management System which helps to realize optimal hospital management as a subsystem of the Total Hospital Information System of Kagoshima University (THINK). As this system has been established, it has become possible for us to have an accurate grasp of the flow and stock of medical materials at our hospital. Furthermore, since September 1993, the Medical Material Distribution Management System has been improved and the Total Medical Material Distribution Management System has been smoothly introduced into the site of clinical practice. This system enables automatic demands for fees for treatment with specific instruments and materials covered by health insurance. It was difficult to predict the effect of this system, because no similar system had been developed in Japan. However, more satisfactory results than expected have been obtained since its introduction.

A Distributed Approach to System-Level Prognostics

Science.gov (United States)

Daigle, Matthew J.; Bregon, Anibal; Roychoudhury, Indranil

2012-01-01

Prognostics, which deals with predicting remaining useful life of components, subsystems, and systems, is a key technology for systems health management that leads to improved safety and reliability with reduced costs. The prognostics problem is often approached from a component-centric view. However, in most cases, it is not specifically component lifetimes that are important, but, rather, the lifetimes of the systems in which these components reside. The system-level prognostics problem can be quite difficult due to the increased scale and scope of the prognostics problem and the relative Jack of scalability and efficiency of typical prognostics approaches. In order to address these is ues, we develop a distributed solution to the system-level prognostics problem, based on the concept of structural model decomposition. The system model is decomposed into independent submodels. Independent local prognostics subproblems are then formed based on these local submodels, resul ting in a scalable, efficient, and flexible distributed approach to the system-level prognostics problem. We provide a formulation of the system-level prognostics problem and demonstrate the approach on a four-wheeled rover simulation testbed. The results show that the system-level prognostics problem can be accurately and efficiently solved in a distributed fashion.

Research on fully distributed optical fiber sensing security system localization algorithm

Science.gov (United States)

Wu, Xu; Hou, Jiacheng; Liu, Kun; Liu, Tiegen

2013-12-01

A new fully distributed optical fiber sensing and location technology based on the Mach-Zehnder interferometers is studied. In this security system, a new climbing point locating algorithm based on short-time average zero-crossing rate is presented. By calculating the zero-crossing rates of the multiple grouped data separately, it not only utilizes the advantages of the frequency analysis method to determine the most effective data group more accurately, but also meets the requirement of the real-time monitoring system. Supplemented with short-term energy calculation group signal, the most effective data group can be quickly picked out. Finally, the accurate location of the climbing point can be effectively achieved through the cross-correlation localization algorithm. The experimental results show that the proposed algorithm can realize the accurate location of the climbing point and meanwhile the outside interference noise of the non-climbing behavior can be effectively filtered out.

Distributed expert systems for ground and space applications

Science.gov (United States)

Buckley, Brian; Wheatcraft, Louis

1992-01-01

Presented here is the Spacecraft Command Language (SCL) concept of the unification of ground and space operations using a distributed approach. SCL is a hybrid software environment borrowing from expert system technology, fifth generation language development, and multitasking operating system environments. Examples of potential uses for the system and current distributed applications of SCL are given.

The frequency characteristics of medium voltage distribution system impedances

Directory of Open Access Journals (Sweden)

Liviu Emil Petrean

2009-10-01

Full Text Available In this paper we present the frequency characteristics of impedances involved in the electrical equivalent circuit of a large medium voltage distribution system. These impedances influence harmonics distortions propagation occurring due to the nonsinusoidal loads. We analyse the case of a 10 kV large urban distribution system which supplies industrial, commercial and residential customers. The influence of various parameters of the distribution network on the frequency characteristics are presented, in order to assess the interaction of harmonic distortion and distribution system network.

Distributed operating system for NASA ground stations

Science.gov (United States)

Doyle, John F.

1987-01-01

NASA ground stations are characterized by ever changing support requirements, so application software is developed and modified on a continuing basis. A distributed operating system was designed to optimize the generation and maintenance of those applications. Unusual features include automatic program generation from detailed design graphs, on-line software modification in the testing phase, and the incorporation of a relational database within a real-time, distributed system.

The distribution of wind power forecast errors from operational systems

Energy Technology Data Exchange (ETDEWEB)

Hodge, Bri-Mathias; Ela, Erik; Milligan, Michael

2011-07-01

Wind power forecasting is one important tool in the integration of large amounts of renewable generation into the electricity system. Wind power forecasts from operational systems are not perfect, and thus, an understanding of the forecast error distributions can be important in system operations. In this work, we examine the errors from operational wind power forecasting systems, both for a single wind plant and for an entire interconnection. The resulting error distributions are compared with the normal distribution and the distribution obtained from the persistence forecasting model at multiple timescales. A model distribution is fit to the operational system forecast errors and the potential impact on system operations highlighted through the generation of forecast confidence intervals. (orig.)

11th International Symposium on Distributed Autonomous Robotic Systems

CERN Document Server

Chirikjian, Gregory

2014-01-01

Distributed robotics is a rapidly growing and maturing interdisciplinary research area lying at the intersection of computer science, network science, control theory, and electrical and mechanical engineering. The goal of the Symposium on Distributed Autonomous Robotic Systems (DARS) is to exchange and stimulate research ideas to realize advanced distributed robotic systems. This volume of proceedings includes 31 original contributions presented at the 2012 International Symposium on Distributed Autonomous Robotic Systems (DARS 2012) held in November 2012 at the Johns Hopkins University in Baltimore, MD USA. The selected papers in this volume are authored by leading researchers from Asia, Europa, and the Americas, thereby providing a broad coverage and perspective of the state-of-the-art technologies, algorithms, system architectures, and applications in distributed robotic systems. The book is organized into five parts, representative of critical long-term and emerging research thrusts in the multi-robot com...

A Case Study on Distributed Antenna Systems

DEFF Research Database (Denmark)

Sørensen, Troels Bundgaard

2007-01-01

Passive distributed antenna systems (DASs) consisting of distributed feeder lines or single point antennas are now often installed in large office buildings where they provide efficient coverage throughout the building. More sophisticated DASs with intelligent reuse and the ability to adapt...... is described in terms of algorithms for power allocation and access port assignment, as well as algorithms for (dynamic) channel assignment. After an outline of simulation assumptions, system capacity comparisons are given between the adaptive DAS and a system with fixed channel and access port assignment...

Evaluating system reliability and targeted hardening strategies of power distribution systems subjected to hurricanes

International Nuclear Information System (INIS)

Salman, Abdullahi M.; Li, Yue; Stewart, Mark G.

2015-01-01

Over the years, power distribution systems have been vulnerable to extensive damage from hurricanes which can cause power outage resulting in millions of dollars of economic losses and restoration costs. Most of the outage is as a result of failure of distribution support structures. Over the years, various methods of strengthening distribution systems have been proposed and studied. Some of these methods, such as undergrounding of the system, have been shown to be unjustified from an economic point of view. A potential cost-effective strategy is targeted hardening of the system. This, however, requires a method of determining critical parts of a system that when strengthened, will have greater impact on reliability. This paper presents a framework for studying the effectiveness of targeted hardening strategies on power distribution systems subjected to hurricanes. The framework includes a methodology for evaluating system reliability that relates failure of poles and power delivery, determination of critical parts of a system, hurricane hazard analysis, and consideration of decay of distribution poles. The framework also incorporates cost analysis that considers economic losses due to power outage. A notional power distribution system is used to demonstrate the framework by evaluating and comparing the effectiveness of three hardening measures. - Highlight: • Risk assessment of power distribution systems subjected to hurricanes is carried out. • Framework for studying effectiveness of targeted hardening strategies is presented. • A system reliability method is proposed. • Targeted hardening is cost effective for existing systems. • Economic losses due to power outage should be considered for cost analysis.

ASBESTOS PIPE-INSULATION REMOVAL ROBOT SYSTEM; FINAL

International Nuclear Information System (INIS)

Unknown

2000-01-01

This final topical report details the development, experimentation and field-testing activities for a robotic asbestos pipe-insulation removal robot system developed for use within the DOE's weapon complex as part of their ER and WM program, as well as in industrial abatement. The engineering development, regulatory compliance, cost-benefit and field-trial experiences gathered through this program are summarized

Plant systems/components modularization study. Final report

International Nuclear Information System (INIS)

1977-07-01

The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort

The Final Focus Test Beam laser referene system

International Nuclear Information System (INIS)

Bressler, V.E.; Ruland, R.E.

1993-05-01

The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented

On the Path to SunShot. Emerging Issues and Challenges in Integrating Solar with the Distribution System

Energy Technology Data Exchange (ETDEWEB)

Palmintier, Bryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Broderick, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mather, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States); Coddington, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baker, Kyri [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ding, Fei [National Renewable Energy Lab. (NREL), Golden, CO (United States); Reno, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lave, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bharatkumar, Ashwini [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2016-05-01

inverter functions. Finally, additional local and system-level value could be provided by integrating DGPV with energy storage and 'virtual storage,' which exploits improved management of electric vehicle charging, building energy systems, and other large loads. Together, continued innovation across this rich distribution landscape can enable the very-high deployment levels envisioned by SunShot.

2015 Plan. Project 6: urban and rural distribution systems

International Nuclear Information System (INIS)

1993-06-01

The main development trends of distribution systems in 2015 Plan is studied, with the data of market continuity, costs and evolution of the physique system. Some factors that will influence the evolution of the distribution systems are presented and the impacts of economic view are discussed. The strategic lines that will give direction for the distribution expansion, including the energy conservation are also shown. (C.G.C.)

Transverse momentum distributions of identified particles produced ...

Indian Academy of Sciences (India)

We assume that the transverse momentum distributions of identified particles measured in final state are contributed by a few energy sources which can be regarded as partons or quarks in the interacting system. The particle is contributed by each source with gluons which have transverse momentum distributions in an ...

Internet and redefining tourism distribution system

Directory of Open Access Journals (Sweden)

Đelić Tanja

2004-01-01

Full Text Available Since the introduction, computerized systems that manage reservation systems, rapidly became inevitable distribution channel for all service companies in tourist industry. GDS in reality using communication network connects service offer, selling personnel and air companies.

Data-Driven H∞ Control for Nonlinear Distributed Parameter Systems.

Science.gov (United States)

Luo, Biao; Huang, Tingwen; Wu, Huai-Ning; Yang, Xiong

2015-11-01

The data-driven H∞ control problem of nonlinear distributed parameter systems is considered in this paper. An off-policy learning method is developed to learn the H∞ control policy from real system data rather than the mathematical model. First, Karhunen-Loève decomposition is used to compute the empirical eigenfunctions, which are then employed to derive a reduced-order model (ROM) of slow subsystem based on the singular perturbation theory. The H∞ control problem is reformulated based on the ROM, which can be transformed to solve the Hamilton-Jacobi-Isaacs (HJI) equation, theoretically. To learn the solution of the HJI equation from real system data, a data-driven off-policy learning approach is proposed based on the simultaneous policy update algorithm and its convergence is proved. For implementation purpose, a neural network (NN)- based action-critic structure is developed, where a critic NN and two action NNs are employed to approximate the value function, control, and disturbance policies, respectively. Subsequently, a least-square NN weight-tuning rule is derived with the method of weighted residuals. Finally, the developed data-driven off-policy learning approach is applied to a nonlinear diffusion-reaction process, and the obtained results demonstrate its effectiveness.

DC Home Appliances for DC Distribution System

Directory of Open Access Journals (Sweden)

MUHAMMAD KAMRAN

2017-10-01

Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

Adaptive intelligent power systems: Active distribution networks

International Nuclear Information System (INIS)

McDonald, Jim

2008-01-01

Electricity networks are extensive and well established. They form a key part of the infrastructure that supports industrialised society. These networks are moving from a period of stability to a time of potentially major transition, driven by a need for old equipment to be replaced, by government policy commitments to cleaner and renewable sources of electricity generation, and by change in the power industry. This paper looks at moves towards active distribution networks. The novel transmission and distribution systems of the future will challenge today's system designs. They will cope with variable voltages and frequencies, and will offer more flexible, sustainable options. Intelligent power networks will need innovation in several key areas of information technology. Active control of flexible, large-scale electrical power systems is required. Protection and control systems will have to react to faults and unusual transient behaviour and ensure recovery after such events. Real-time network simulation and performance analysis will be needed to provide decision support for system operators, and the inputs to energy and distribution management systems. Advanced sensors and measurement will be used to achieve higher degrees of network automation and better system control, while pervasive communications will allow networks to be reconfigured by intelligent systems

Description of a 20 Kilohertz power distribution system

Science.gov (United States)

Hansen, I. G.

1986-01-01

A single phase, 440 VRMS, 20 kHz power distribution system with a regulated sinusoidal wave form is discussed. A single phase power system minimizes the wiring, sensing, and control complexities required in a multi-sourced redundantly distributed power system. The single phase addresses only the distribution link; mulitphase lower frequency inputs and outputs accommodation techniques are described. While the 440 V operating potential was initially selected for aircraft operating below 50,000 ft, this potential also appears suitable for space power systems. This voltage choice recognizes a reasonable upper limit for semiconductor ratings, yet will direct synthesis of 220 V, 3 power. A 20 kHz operating frequency was selected to be above the range of audibility, minimize the weight of reactive components, yet allow the construction of single power stages of 25 to 30 kW. The regulated sinusoidal distribution system has several advantages. With a regulated voltage, most ac/dc conversions involve rather simple transformer rectifier applications. A sinusoidal distribution system, when used in conjunction with zero crossing switching, represents a minimal source of EMI. The present state of 20 kHz power technology includes computer controls of voltage and/or frequency, low inductance cable, current limiting circuit protection, bi-directional power flow, and motor/generator operating using standard induction machines. A status update and description of each of these items and their significance is presented.

Architectural notes: a framework for distributed systems development

NARCIS (Netherlands)

Pires, L.F.; Ferreira Pires, Luis

1994-01-01

This thesis develops a framework of methods and techniques for distributed systems development. This framework consists of two related domains in which design concepts for distributed systems are defined: the entity domain and the behaviour domain. In the entity domain we consider structures of

Adjustable Parameter-Based Distributed Fault Estimation Observer Design for Multiagent Systems With Directed Graphs.

Science.gov (United States)

Zhang, Ke; Jiang, Bin; Shi, Peng

2017-02-01

In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.

Optimization scheduling in intelligent Energy Management System for the DC residential distribution system

DEFF Research Database (Denmark)

Yue, Jingpeng; Hu, Zhijian; Li, Chendan

2017-01-01

Smart DC residential distribution system(RDS) consisted by DC living homes will be a significant integral part in the future green transmission with demand flexibility. Meanwhile, the distributed generations will play an important role in the active demand response (DR). Energy Management System...... (EMS) with aid of the wireless communication and the smart meter is imperative in achieving ADR for DC residential community. This paper presents a framework of centralized management system integration and the key process of ADR in DC residential distribution system. The propose framework and methods...

System analysis and planning of a gas distribution network

Energy Technology Data Exchange (ETDEWEB)

Salas, Edwin F.M.; Farias, Helio Monteiro [AUTOMIND, Rio de Janeiro, RJ (Brazil); Costa, Carla V.R. [Universidade Salvador (UNIFACS), BA (Brazil)

2009-07-01

The increase in demand by gas consumers require that projects or improvements in gas distribution networks be made carefully and safely to ensure a continuous, efficient and economical supply. Gas distribution companies must ensure that the networks and equipment involved are defined and designed at the appropriate time to attend to the demands of the market. To do that a gas distribution network analysis and planning tool should use distribution networks and transmission models for the current situation and the future changes to be implemented. These models are used to evaluate project options and help in making appropriate decisions in order to minimize the capital investment in new components or simple changes in operational procedures. Gas demands are increasing and it is important that gas distribute design new distribution systems to ensure this growth, considering financial constraints of the company, as well as local legislation and regulation. In this study some steps of developing a flexible system that attends to those needs will be described. The analysis of distribution requires geographically referenced data for the models as well as an accurate connectivity and the attributes of the equipment. GIS systems are often used as a deposit center that holds the majority of this information. GIS systems are constantly updated as distribution network equipment is modified. The distribution network modeling gathered from this system ensures that the model represents the current network condition. The benefits of this architecture drastically reduce the creation and maintenance cost of the network models, because network components data are conveniently made available to populate the distribution network. This architecture ensures that the models are continually reflecting the reality of the distribution network. (author)

Agent-based distributed hierarchical control of dc microgrid systems

DEFF Research Database (Denmark)

Meng, Lexuan; Vasquez, Juan Carlos; Guerrero, Josep M.

2014-01-01

In order to enable distributed control and management for microgrids, this paper explores the application of information consensus and local decisionmaking methods formulating an agent based distributed hierarchical control system. A droop controlled paralleled DC/DC converter system is taken as ....... Standard genetic algorithm is applied in each local control system in order to search for a global optimum. Hardware-in-Loop simulation results are shown to demonstrate the effectiveness of the method.......In order to enable distributed control and management for microgrids, this paper explores the application of information consensus and local decisionmaking methods formulating an agent based distributed hierarchical control system. A droop controlled paralleled DC/DC converter system is taken...... as a case study. The objective is to enhance the system efficiency by finding the optimal sharing ratio of load current. Virtual resistances in local control systems are taken as decision variables. Consensus algorithms are applied for global information discovery and local control systems coordination...

Distributed systems design using separable communications

International Nuclear Information System (INIS)

Capel, A.C.; Yan, G.

1980-01-01

One of the promises of distributed systems is the ability to design each process function largely independently of the others, and in many cases locate the resulting hardware in close proximity to the application. The communications architecture for such systems should be approached in the same way, using separable communications facilities to meet individual sets of requirements while at the same time reducing the interactions between functions. Where complete physical separation is not feasible and hardware resource sharing is required, the protocols should be designed emphasizing the logical separation of communication paths. This paper discusses the different types of communications for process control applictions and the parameters which need to be characterized in designing separable communications for distributed systems. (auth)

Distributed expert systems for nuclear reactor control

International Nuclear Information System (INIS)

Otaduy, P.J.

1992-01-01

A network of distributed expert systems is the heart of a prototype supervisory control architecture developed at the Oak Ridge National Laboratory (ORNL) for an advanced multimodular reactor. Eight expert systems encode knowledge on signal acquisition, diagnostics, safeguards, and control strategies in a hybrid rule-based, multiprocessing and object-oriented distributed computing environment. An interactive simulation of a power block consisting of three reactors and one turbine provides a realistic, testbed for performance analysis of the integrated control system in real-time. Implementation details and representative reactor transients are discussed

Reflexive reasoning for distributed real-time systems

Science.gov (United States)

Goldstein, David

1994-01-01

This paper discusses the implementation and use of reflexive reasoning in real-time, distributed knowledge-based applications. Recently there has been a great deal of interest in agent-oriented systems. Implementing such systems implies a mechanism for sharing knowledge, goals and other state information among the agents. Our techniques facilitate an agent examining both state information about other agents and the parameters of the knowledge-based system shell implementing its reasoning algorithms. The shell implementing the reasoning is the Distributed Artificial Intelligence Toolkit, which is a derivative of CLIPS.

Electric Power Distribution System Model Simplification Using Segment Substitution

Energy Technology Data Exchange (ETDEWEB)

Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat; Reed, Gregory F.

2018-05-01

Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers model bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). In contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.

The effect of increasing levels of embedded generation on the distribution network. Final report

Energy Technology Data Exchange (ETDEWEB)

Collinson, A; Earp, G K; Howson, D; Owen, R D; Wright, A J

1999-10-01

This report was commissioned as part of the EA Technology Strategic Technology Programme under guidance of the Module 5 (Embedded Generation) Steering Group. This report aims to provide information related to the distribution and supply of electricity in the context of increasing levels of embedded generation. There is a brief description of the operating environment within which electricity companies in the UK must operate. Technical issues related to the connection of generation to the existing distribution infrastructure are highlighted and the design philosophy adopted by network designers in accommodating applications for the connection of embedded generation to the network is discussed. The effects embedded generation has on the network and the issues raised are presented as many of them present barriers to the connection of embedded generators. The final chapters cover the forecast of required connection to 2010 and solutions to restrictions preventing the connection of more embedded generation to the network. (author)

Integrating security in a group oriented distributed system

Science.gov (United States)

Reiter, Michael; Birman, Kenneth; Gong, LI

1992-01-01

A distributed security architecture is proposed for incorporation into group oriented distributed systems, and in particular, into the Isis distributed programming toolkit. The primary goal of the architecture is to make common group oriented abstractions robust in hostile settings, in order to facilitate the construction of high performance distributed applications that can tolerate both component failures and malicious attacks. These abstractions include process groups and causal group multicast. Moreover, a delegation and access control scheme is proposed for use in group oriented systems. The focus is the security architecture; particular cryptosystems and key exchange protocols are not emphasized.

Asymptotic Poisson distribution for the number of system failures of a monotone system

International Nuclear Information System (INIS)

Aven, Terje; Haukis, Harald

1997-01-01

It is well known that for highly available monotone systems, the time to the first system failure is approximately exponentially distributed. Various normalising factors can be used as the parameter of the exponential distribution to ensure the asymptotic exponentiality. More generally, it can be shown that the number of system failures is asymptotic Poisson distributed. In this paper we study the performance of some of the normalising factors by using Monte Carlo simulation. The results show that the exponential/Poisson distribution gives in general very good approximations for highly available components. The asymptotic failure rate of the system gives best results when the process is in steady state, whereas other normalising factors seem preferable when the process is not in steady state. From a computational point of view the asymptotic system failure rate is most attractive

Organization of the secure distributed computing based on multi-agent system

Science.gov (United States)

Khovanskov, Sergey; Rumyantsev, Konstantin; Khovanskova, Vera

2018-04-01

Nowadays developing methods for distributed computing is received much attention. One of the methods of distributed computing is using of multi-agent systems. The organization of distributed computing based on the conventional network computers can experience security threats performed by computational processes. Authors have developed the unified agent algorithm of control system of computing network nodes operation. Network PCs is used as computing nodes. The proposed multi-agent control system for the implementation of distributed computing allows in a short time to organize using of the processing power of computers any existing network to solve large-task by creating a distributed computing. Agents based on a computer network can: configure a distributed computing system; to distribute the computational load among computers operated agents; perform optimization distributed computing system according to the computing power of computers on the network. The number of computers connected to the network can be increased by connecting computers to the new computer system, which leads to an increase in overall processing power. Adding multi-agent system in the central agent increases the security of distributed computing. This organization of the distributed computing system reduces the problem solving time and increase fault tolerance (vitality) of computing processes in a changing computing environment (dynamic change of the number of computers on the network). Developed a multi-agent system detects cases of falsification of the results of a distributed system, which may lead to wrong decisions. In addition, the system checks and corrects wrong results.

Protection issues on microgrid/distributed generation based systems

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Angelo R. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil); Ribeiro, Paulo F. [Calvin College, Grand Rapids, MI (United States). Dept. of Electrical Engineering; Iung, Anderson M. [Geracao Paranapanema S.A., SP (Brazil). Duke Energy International. Market Analysis Dept.; Garcia, Paulo A.N. [Federal University of Juiz de Fora (UFJF), MG (Brazil). Dept. of Circuits

2009-07-01

This paper aims to discuss protection issues related to the presence of distributed generation (DG) in distribution systems. A case study is developed to show some impacts of transitions and operations with relay static settings to verify the reliability of systems in the presence of DG. (author)

Pull-Based Distributed Event-Triggered Consensus for Multiagent Systems With Directed Topologies.

Science.gov (United States)

Yi, Xinlei; Lu, Wenlian; Chen, Tianping

2017-01-01

This paper mainly investigates consensus problem with a pull-based event-triggered feedback control. For each agent, the diffusion coupling feedbacks are based on the states of its in-neighbors at its latest triggering time, and the next triggering time of this agent is determined by its in-neighbors' information. The general directed topologies, including irreducible and reducible cases, are investigated. The scenario of distributed continuous communication is considered first. It is proved that if the network topology has a spanning tree, then the event-triggered coupling algorithm can realize the consensus for the multiagent system. Then, the results are extended to discontinuous communication, i.e., self-triggered control, where each agent computes its next triggering time in advance without having to observe the system's states continuously. The effectiveness of the theoretical results is illustrated by a numerical example finally.