4,338 research outputs found
Evaluation of Time-Critical Communications for IEC 61850-Substation Network Architecture
Present-day developments, in electrical power transmission and distribution,
require considerations of the status quo. In other meaning, international
regulations enforce increasing of reliability and reducing of environment
impact, correspondingly they motivate developing of dependable systems. Power
grids especially intelligent (smart grids) ones become industrial solutions
that follow standardized development. The International standardization, in the
field of power transmission and distribution, improve technology influences.
The rise of dedicated standards for SAS (Substation Automation Systems)
communications, such as the leading International Electro-technical Commission
standard IEC 61850, enforces modern technological trends in this field. Within
this standard, a constraint of low ETE (End-to-End) latency should be
respected, and time-critical status transmission must be achieved. This
experimental study emphasis on IEC 61850 SAS communication standard, e.g. IEC
61850 GOOSE (Generic Object Oriented Substation Events), to implement an
investigational method to determine the protection communication delay. This
method observes GOOSE behaviour by adopting monitoring and analysis
capabilities. It is observed by using network test equipment, i.e. SPAN (Switch
Port Analyser) and TAP (Test Access Point) devices, with on-the-shelf available
hardware and software solutions
Ethernet - a survey on its fields of application
During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application fieldâs requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal
Simulation of Mixed Critical In-vehicular Networks
Future automotive applications ranging from advanced driver assistance to
autonomous driving will largely increase demands on in-vehicular networks. Data
flows of high bandwidth or low latency requirements, but in particular many
additional communication relations will introduce a new level of complexity to
the in-car communication system. It is expected that future communication
backbones which interconnect sensors and actuators with ECU in cars will be
built on Ethernet technologies. However, signalling from different application
domains demands for network services of tailored attributes, including
real-time transmission protocols as defined in the TSN Ethernet extensions.
These QoS constraints will increase network complexity even further.
Event-based simulation is a key technology to master the challenges of an
in-car network design. This chapter introduces the domain-specific aspects and
simulation models for in-vehicular networks and presents an overview of the
car-centric network design process. Starting from a domain specific description
language, we cover the corresponding simulation models with their workflows and
apply our approach to a related case study for an in-car network of a premium
car
A multiprocessor based packet-switch: performance analysis of the communication infrastructure
The intra-chip communication infrastructures are receiving always more attention since they are becoming a crucial part in the development of current SoCs. Due to the high availability of pre-characterized hard-IP, the complexity of the design is moving toward global interconnections which are introducing always more constraints at each technology node. Power consumption, timing closure, bandwidth requirements, time to market, are some of the factors that are leading to the proposal of new solutions for next generation multi-million SoCs. The need of high programmable systems and the high gate-count availability is moving always more attention on multiprocessors systems (MP-SoC) and so an adequate solution must be found for the communication infrastructure. One of the most promising technologies is the Network-On-Chip (NoC) architecture, which seems to better fit with the new demanding complexity of such systems. Before starting to develop new solutions, it is crucial to fully understand if and when current bus architectures introduce strong limitations in the development of high speed systems. This article describes a case study of a multiprocessor based ethernet packet-switch application with a shared-bus communication infrastructure. This system aims to depict all the bottlenecks which a shared-bus introduces under heavy load. What emerges from this analysis is that, as expected, a shared-bus is not scalable and it strongly limits whole system performances. These results strengthen the hypothesis that new communication architectures (like the NoC) must be found
Data Acquisition and Control System of Hydroelectric Power Plant Using Internet Techniques
VodnĂ energie se nynĂ stala nejlepĆĄĂm zdrojem elektrickĂ© energie na zemi. VyrĂĄbĂ se pomocĂ energie poskytovanĂ© pohybem nebo pĂĄdem vody. Historie dokazuje, ĆŸe nĂĄklady na tuto elektrickou energii zĆŻstĂĄvajĂ konstantnĂ v prĆŻbÄhu celĂ©ho roku. Vzhledem k mnoha vĂœhodĂĄm, vÄtĆĄina zemĂ nynĂ vyuĆŸĂvĂĄ vodnĂ energie jako hlavnĂ zdroj pro vĂœrobu elektrickĂ© energie.NejdĆŻleĆŸitÄjĆĄĂ vĂœhodou je, ĆŸe vodnĂ energie je zelenĂĄ energie, coĆŸ znamenĂĄ, ĆŸe ĆŸĂĄdnĂ© vzduĆĄnĂ© nebo vodnĂ zneÄiĆĄĆ„ujĂcĂ lĂĄtky nejsou vyrĂĄbÄny, takĂ© ĆŸĂĄdnĂ© sklenĂkovĂ© plyny jako oxid uhliÄitĂœ nejsou vyrĂĄbÄny, coĆŸ ÄinĂ tento zdroj energie ĆĄetrnĂœ k ĆŸivotnĂmu prostĆedĂ. A tak brĂĄnĂ nebezpeÄĂ globĂĄlnĂho oteplovĂĄnĂ. PouĆŸitĂ internetovĂ© techniky k ovladĂĄnĂ nÄkolika vodnĂch elektrĂĄren mĂĄ velmi vĂœznamnĂ© vĂœhody, jako snĂĆŸenĂ provoznĂch nĂĄkladĆŻ a flexibilitu uspokojenĂ zmÄny poptĂĄvky po energii na stranÄ spotĆeby. TakĂ© velmi efektivnÄ ÄelĂ velkĂœm naruĆĄenĂm elektrickĂ© sĂtÄ, jako je napĆĂklad pĆidĂĄnĂ nebo odebrĂĄnĂ velkĂ© zĂĄtÄĆŸe, a poruch. Na druhou stranu, systĂ©m zĂskĂĄvĂĄnĂ dat poskytuje velmi uĆŸiteÄnĂ© informace pro typickĂ© i vÄdeckĂ© analĂœzy, jako jsou ekonomickĂ© nĂĄklady, predikce poruchy systĂ©mĆŻ, predikce poptĂĄvky, plĂĄny ĂșdrĆŸby, systĂ©mĆŻ pro podporu rozhodovĂĄnĂ a mnoho dalĆĄĂch vĂœhod. Tato prĂĄce popisuje vĆĄeobecnĂœ model, kterĂœ mĆŻĆŸe bĂœt pouĆŸit k simulaci pro sbÄr dat a kontrolnĂ systĂ©my pro vodnĂ elektrĂĄrny v prostĆedĂ Matlab / Simulink a TrueTime Simulink knihovnu. UvaĆŸovanĂĄ elektrĂĄrna sestĂĄvĂĄ z vodnĂ turbĂny pĆipojenĂ© k synchronnĂmu generĂĄtoru s budicĂ soustavou, generĂĄtor je pĆipojen k veĆejnĂ© elektrickĂ© sĂti. SimulacĂ vodnĂ turbĂny a synchronnĂho generĂĄtoru lze provĂ©st pomocĂ rĆŻznĂœch simulaÄnĂch nĂĄstrojĆŻ. V tĂ©to prĂĄci je upĆednostĆovĂĄn SIMULINK / MATLAB pĆed jinĂœmi nĂĄstroji k modelovĂĄnĂ dynamik vodnĂ turbĂny a synchronnĂho stroje. Program s prostĆedĂm MATLAB SIMULINK vyuĆŸĂvĂĄ k ĆeĆĄenĂ schematickĂœ model vodnĂ elektrĂĄrny sestavenĂœ ze zĂĄkladnĂch funkÄnĂch blokĆŻ. Tento pĆĂstup je pedagogicky lepĆĄĂ neĆŸ komplikovanĂ© kĂłdy jinĂœch softwarovĂœch programĆŻ. Knihovna programu Simulink obsahuje funkÄnĂ bloky, kterĂ© mohou bĂœt spojovĂĄny, upravovĂĄny a modelovĂĄny. K vytvoĆenĂ a simulovĂĄnĂ internetovĂœch a Real Time systĂ©mĆŻ je moĆŸnĂ© pouĆŸĂt budâ knihovnu simulinku Real-Time nebo TRUETIME, v prĂĄci byla pouĆŸita knihovna TRUETIME.Hydropower has now become the best source of electricity on earth. It is produced due to the energy provided by moving or falling water. History proves that the cost of this electricity remains constant over the year. Because of the many advantages, most of the countries now have hydropower as the source of major electricity producer. The most important advantage of hydropower is that it is green energy, which mean that no air or water pollutants are produced, also no greenhouse gases like carbon dioxide are produced which makes this source of energy environment-friendly. It prevents us from the danger of global warming. Using internet techniques to control several hydroelectric plants has very important advantages, as reducing operating costs and the flexibility of meeting changes of energy demand occurred in consumption side. Also it is very effective to confront large disturbances of electrical grid, such as adding or removing large loads, and faults. In the other hand, data acquisition systems provides very useful information for both typical and scientific analysis, such as economical costs reducing, fault prediction systems, demand prediction, maintenance schedules, decision support systems and many other benefits. This thesis describes a generalized model which can be used to simulate a data acquisition and control system of hydroelectric power plant using MATLAB/SIMULINK and TrueTime simulink library. The plant considered consists of hydro turbine connected to synchronous generator with excitation system, and the generator is connected to public grid. Simulation of hydro turbine and synchronous generator can be done using various simulation tools, In this work, SIMULINK/MATLAB is favored over other tools in modeling the dynamics of a hydro turbine and synchronous machine. The SIMULINK program in MATLAB is used to obtain a schematic model of the hydro plant by means of basic function blocks. This approach is pedagogically better than using a compilation of program code as in other software programs .The library of SIMULINK software programs includes function blocks which can be linked and edited to model. Either Simulink Real-Time library or TrueTime library can be used to build and simulate internet and real time systems, in this thesis the TrueTime library was used.
Position paper on time and event-triggered communication services in the context of e-manufacturing
Modern factories are complex systems where
advances in networking and information technologies are
opening new ways towards higher efficiency. Such move
is being driven by market rules with ever-increasing
competition levels, in search for faster time-to-market,
improved process yield, non-stop operations, flexible
manufacturing and tighter supply-chain coupling. All
these aims present a common requirement, i.e. a realtime
flow of information, from the plant-floor up to the
management, maintenance, suppliers and clients, to
support accurate monitoring and control of the factory.
This stresses the importance achieved by the communication
infrastructure in modern manufacturing industry.
This paper presents the authors view concerning the
current trends in modern factory communication systems.
It addresses the problems of seamlessly integrating
different information flows with diverse requirements,
mainly in terms of timeliness. In this aspect, the debate
between event-triggered and time-triggered communication
is revisited as well as the joint support for both types
of traffic. Finally, a view of where factory communication
systems are moving to is also presented, showing the
impact of open and widely available technologies.FCT. ComissĂŁo Europeia(ARTIST,IST-2001-34820
- âŠ