1,173 research outputs found
A test facility for assessing the performance of IEC61850 substation automation designs
Substation Automation Systems have undergone dramatic changes since the introduction of powerful micro-processing and digital communications devices over Ethernet based networks within the substation. Smart, multifunctional relays, known as Intelligent Electronic Devices, or IEDs, have replaced the traditional panels which contained multiple protection relays, control equipment, metering and status indicators.
ActewAGL Distribution, a power utility company servicing Canberra, Australia, has recently decided to undertake a review of its substation automation systems throughout its electrical network. As a result, ActewAGL Distribution has decided to investigate the IEC 61850 – Communication Networks and Systems in Substations standard, by constructing a test facility to assess its performance and capability with the view of implementing the standard into its 132/11kV zone substations network in the near future.
This report details the literature review, design, construction, and performance evaluation that was undertaken on the IEC 61850 substation automation designs developed with the use of the test facility.
The major achievement of this research project has been the successful development and evaluation of a substation automation system that utilised the IEC 61850 standard incorporated with multiple vendor devices
Tactical Military Communication Networks of the Future .
Military communication has the added dimension of mobility and bandwidth conservation. The paper deals with the necessity of advanced concepts of communicating images. data and fax in addition to voice as dictated by the command and control requirements. The Integrated services digital network as applied to tactical network of the future is presented. The topics of routing, encryption, mobile access, digital links are briefly covered. The importance of standards of CCITT and contemporary techniques like B-ISDN, cellular radios are discussed. The relevance of network management and its main features are brought out
Emerging technologies and future trends in substation automation systems for the protection, monitoring and control of electrical substations
Tese de Mestrado Integrado. Engenharia Electrotécnica e de Computadores (Automação). Faculdade de Engenharia. Universidade do Porto. 201
Design And Analysis Of a Multi-channel Optical Fibre Lan Based On Modified Csma/cd Protocol
Nowadays, optical communication is widely employed by telecommunication
providers in the whole world due to its ability to support high bit rate applications. The
urge to provide end-to-end fibre connectivity arises to overcome the bottleneck problem
that occurs when packets are transmitted on the slower speed medium such as copper. In
optical transmission, bandwidth utilisation can be improved further by using multiple
wavelengths or channels in a single fibre.
This thesis discusses the implementation of multiple wavelengths technique for
Local Area Network (LAN) environment. It proposes a new Ethernet-based protocol that
uses multiple wavelengths for transmission, which runs on a single fibre. Ethernet/IEEE
802.3 is chosen because of its widespread employment in today's network and the
ability of extending the transmission rate up to gigabit transmission. Even though light
does not collide with each other, receiver contention might occur if more than one signal
arrives at the receiver at the same time. Therefore, some arbitration mechanism is
needed to synchronise the transmission and the tuning time of the respective transmitter and receiver. The proposed design is based on the physical bus topology with n number
of connected nodes and m number of operating wavelengths. All nodes are able to listen
to all wavelengths. A fast control unit is used, which is responsible for packet
scheduling.
The packets are scheduled based on a pre-computed time. Both transmitter and
receiver will be asked to tune to the· allocated wavelength. The transmitter can start
transmitting and the receiver will start tuning at a specified time. Control packets are
used for handshaking purposes. The main operation is placed at the control unit so that
no added complexity is experienced by the receiver. Thus, this technique further reduces
the cost. A suitable range of channels is obtained from the result. The network
performance is evaluated against several design parameters by comparing the
performance of each channel. The result shows a significant improvement whereby the
throughput and efficiency are increased and average delay is minimised compared to the
conventional system
Automation, Protection and Control of Substation Based on IEC 61850
Reliability of power system protection system has been a key issue in the substation operation due to the use of multi-vendor equipment of proprietary features, environmental issues, and complex fault diagnosis. Failure to address these issues could have a significant effect on the performance of the entire electricity grid. With the introduction of IEC 61850 standard, substation automation system (SAS) has significantly altered the scenario in utilities and industries as indicated in this thesis
Ethernet goes real-time: a survey on research and technological developments
Ethernet is the most popular LAN technology. Its low price and robustness, resulting from its
wide acceptance and deployment, has created an eagerness to expand its responsibilities to
the factory-floor, where real-time requirements are to be fulfilled. However, it is difficult to
build a real-time control network using Ethernet, because its MAC protocol, the 1-persistent
CSMA/CD protocol with the BEB collision resolution algorithm, has unpredictable delay
characteristics. Many anticipate that the recent technological advances in Ethernet such as
the emerging Fast/Gigabit Ethernet, micro-segmentation and full-duplex operation using
switches will also enable it to support time-critical applications. This technical report provides
a comprehensive look at the unpredictability inherent to Ethernet and at recent technological
advances towards real-time operation
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