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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Processjämförelse : Byte av kommunikationsutrustning i elnätet

Jonsson, Jakob January 2016 (has links)
Denna rapport behandlar olika typer av tillvägagångssätt som används vid byte utav kommunikationsutrustning. Arbetet som gjorts innefattar en jämförelse mellan två olika bytesprojekt och deras olika organisationer. En beskrivning utav kommunikationsenheten (Remote Terminal Unit) som används i de olika projekten görs, för att ge läsaren en uppfattning av enheten och dess funktion i det svenska elnätet. När läsaren bildat sig en uppfattning utav enheten så påbörjas själva organisationsjämförelsen. De två projektens olika organisationsuppbyggnader presenteras och granskas, för att sedan kunna analyseras på ett djupare plan. Utifrån granskning och analysering utav de två projekten så lyfts mina egna tankar och idéer fram i en diskussionsdel. Detta för att sedan, helt opartiskt kunna ta fram vad som anses vara ett optimerat tillvägagångssätt vid denna typ utav projekt.
2

Study on Fault Restoration Strategy of Distribution Feeders and Main Transformers

Chen, I-Tsung 07 July 2007 (has links)
The demand for electric load in recent years has been growing consistently in Taiwan. Besides supplying the load demand, the electricity service of distribution systems has to be reliable to meet the power quality of high tech industry. For a fault contingency in distribution systems, the fault location has to be identified and isolated by operating the boundary line switches. The electricity service for the un-faulted but outaged area has to be restored by transfering the loading to the neighboring feeders. The service reliability of distribution systems, a comprehensive distribution automation system DAS is implemented by integrating the computer master station, the communication system and the remote controlling equipments. The master station of DAS system to perform the function of fault detection, isolation and restoration (FDIR) can accelerate the process of service restoration for fault contingency. To support the topology process of distribution system network, the outage management system (OMS), which has also been installed in all Taipower districts to store the attributes of distribution components, has been applied in this study. The operating mapping system is created to support distribution system operation by retrieving the static data from the OMS system and the dynamic data of line switch status from the real time database (RTDB). By this way, the distribution system network is updated by executing the network topology processor according to the operation of line switches. In this thesis, a rule-based expert system is developed for fault restoration of distribution systems. To assure the proposed switch operation plan for fault restoration can comply with the distribution system operation regulation in Taipower, all of the feeders with open the switch to each feeder are formulated as a supporting group. The reserve capacity of each supporting feeders is used to compare the loading of unfaulted but outaged sections for downstream restoration. Based on the embeded rule base in the application program, the op line switch plan for fault restoration can therefore be derived for dispatchers engineers to restore the service in a short time period. Besides the FDIR function, the application software can also be used to derive the optimal switching operation for loading balance of distribution feeders to enhance the operation efficiency of distribution systems.
3

A Multi-Agent Approach for Fault Restoration of Distribution Systems

Su, Chao-ting 08 July 2008 (has links)
With the application of high tech equipments in the industrial, commercial, and residential areas, the enhancement of power quality has become a very critical issue for power utilities. Distribution automation and customer automation will be the most important functions to be implemented. Distribution automation consists of control center, communication system, remote terminal units, and feeder terminal units. The currents, voltages, phase angles, and switch status will be collected by the real time SCADA system. Based on the switch status and connectivity analysis, the distribution network configuration can be identified by executing the topology process. The distribution system planning and optimal operation strategy can be achieved by various application software functions. A multiagent-based distribution automation system is developed for fault detection, isolation, and restoration (FDIR) of distribution systems with JADE platform in this thesis. Remote terminal unit (RTU) agents, main transformer (MTR) agents, feeder circuit breaker (FCB) agents, and feeder terminal unit (FTU) agents of the multiagent system (MAS) are proposed to derive a proper restoration plan after a faulted location has been identified and isolated. To ensure the fault restoration plan can comply with the operation regulation, heuristic rules based on the standard operation procedures of Taipower distribution system are included in the best first search of the MAS. For the fault contingency during summer peak season, the load shedding may be executed and the MAS are designed to restore service to as many key customers and loads as possible. The priority indices of each feeder and service zone are determined according to the key customers within the service territory. A Taipower distribution system with 43 feeders is selected for computer simulation to demonstrate the effectiveness of the proposed methodology in this thesis. It is found that the service restoration of distribution system can be obtained very efficiently by applying the proposed multiagent-based MAS.
4

Jämförande analys av driftsäkerhet medRTU och PLC / Comparative analysis of the operation safety of the RTU and PLC

Albadri, Rand January 2015 (has links)
Examensarbetet kommer att göra en jämförande analys av driftsäkerhet med trådade signaler till en Remote Terminal Unit (RTU) och en Programmable Logic Controller (PLC) med busstyrning. Rapporten genomfördes som ett uppdrag av Skellefteå Kraft AB för att se om det möjligt att byta till PLC- med busstyrning. Rapporten redogör för grundläggande beskrivning för skillnaden mellan de här två system och kommer att undersöka vilken som är driftsäkrare och lönsammare med hänsyn till krav enligt Svenska Kraftföretagens riktlinjer för dammsäkerhet (Ridas).Med hjälp av kurslitteratur, ABB handboken, internet websidor samt intervjuar med Skellefteå Kraft AB:s personal har arbetets resultat visat att busstyrning med PLC kommer att fungera driftsäkert samt kommer att bli lönsamt jämfört med trådade signaler till RTU. Resultat visat även att det finns ingenting som hindrar att installera busstyrning enligt Ridas men vissa funktioner bör installeras. Rapporten är avgränsat genom att inte ta upp eventuella krav från miljöbalken. / This thesis will make a comparative analysis of the operation safety of the wire connection to Remote Terminal Unit (RTU) and Programmable Logic Controller (PLC) with bus-controller. The report describes the basic description of the difference between these two systems and will explore which is safer and more economic with consideration to qualification according to Swedish energy companies' guidelines for dam safety (Ridas).Through course literature, ABB Bok, internet web sits and interviews with Skellefteå Kraft AB staff the result of this report have been created.The report results prove that PLC with bus-controller will operate operationally safe and profitable compared to wire connection to RTU. Results also showed that there is nothing which prevents to install bus-controller according to RIDAS but certain features should be installed.
5

Vývoj patra u pacientů s orofaciálními rozštěpy po primární sutuře rtu / Development of maxilla in patients with orofacial clefts after the primary cheiloplasty.

Hoffmannová, Eva January 2013 (has links)
The present study is concerned with development of maxilla, or moreprecisely palate,in course of first year of life in patients with unilateral cleft lip and palate (UCLP), before and after cheiloplasty. The metodology has it's center in processing of dental plaster casts of UCLP patients via classical and geometric morphometry. All the patients have been operated following same protocol in the neonatal period. The operation was conducted by the same surgeon Jiří Borský, M.D. in the teaching hospital Motol in Prague. In the trackedThe results suggest that the variability of shape was larger in cUCLP patients than in UCLP+M patients. Statistically significant differences in the palate shape were observed in both age categories within both defect categories. The variability of form (size and shape) was followed within each defect category and statistically significant differences between both age category was proven. In the light of average changes intha palate morphology, we tracked both anterior and posterior growth of both segments with increasing age in both defect categories. More distinctive aproximation of both segments, due to the pressure after the cheiloplasty and growth of both segments, was observed in cUCLP patients. Essencial influence of increasing gravity of the defect on changes...
6

Método para locação de medidores e UTRs para efeito de estimação de estados em sistemas elétricos de potência / not available

Brito, George Lauro Ribeiro de 15 October 2003 (has links)
Desenvolveu-se neste trabalho um método para projeto e fortalecimento de planos de medição, para efeito de estimação de estados. O método proposto permite a obtenção de planos de medição que além de isentos de medidas críticas e de conjuntos críticos de medidas, garantem a observabilidade do sistema, mesmo com a perda simultânea de 1 ou 2 medidas quaisquer, ou, até mesmo, com a perda de 1 UTR. É um método numérico simples, de fácil implantação, que se baseia na análise da estrutura da matriz resultante da decomposição LDU, que é obtida através da fatoração triangular da matriz Jacobiana. Para comprovar a sua eficiência, vários testes foram realizados, utilizando os sistemas de 14 e 30 barras do IEEE, o sistema de 121 barras da ELETROSUL e o sistema de 383 barras da CHESF. / In this work a method to design and to upgrade Measurements Placement Plan for state estimation is proposed. The proposed method allows the obtention of measurements placement plans that, besides free of both critical measurements and critical sets, maintain the system observability when 1 or 2 measurements are lost, at same time, or even when a Remote Terminal Unit (RTU) is lost. It is a simple numerical method, easy to implement and based on the analysis of the structure of the resultant matrix of the decomposition LDU, that it is obtained through a triangular factorization of the Jacobian matrix. To prove the efficiency of the proposed method, several tests were made using the IEEE 14 and 30-bus systems, a 121-bus system from ELETROSUL and a 383-bus system from CHESF.
7

Fjärrkommunikation i elnätet : Funktionsbeskrivining och digital säkerhet av Netcontrol RTU

Kvist, Robin, Sjöberg, Victoria January 2018 (has links)
Detta arbete har undersökt vad en RTU är och vad den fyller för funktion. Med hjälp av SCADA-system kan flera RTUer kopplas samman för att få en övergripande bild av hur det ser ut i exempelvis ett ställverk eller en del av elnätet. Dock finns det många saker som gör att kommunikation över internet inte alltid är säker. Attacker som Stuxnet och NightDragon har visat att det går att göra stor skada för infrastruktur med hjälp av cyberattacker. Dock är det ännu ingen större prioritet att skydda sin RTU eller SCADA mot de mest sofistikerade attackerna eftersom den säkerhet som man redan byggt in skyddar mot de flesta hot. Ifall någon skulle ha tillräckliga kunskaper och resurser för att ta sig in kommer de att kunna göra det, oavsett förebyggande åtgärder.
8

Método para locação de medidores e UTRs para efeito de estimação de estados em sistemas elétricos de potência / not available

George Lauro Ribeiro de Brito 15 October 2003 (has links)
Desenvolveu-se neste trabalho um método para projeto e fortalecimento de planos de medição, para efeito de estimação de estados. O método proposto permite a obtenção de planos de medição que além de isentos de medidas críticas e de conjuntos críticos de medidas, garantem a observabilidade do sistema, mesmo com a perda simultânea de 1 ou 2 medidas quaisquer, ou, até mesmo, com a perda de 1 UTR. É um método numérico simples, de fácil implantação, que se baseia na análise da estrutura da matriz resultante da decomposição LDU, que é obtida através da fatoração triangular da matriz Jacobiana. Para comprovar a sua eficiência, vários testes foram realizados, utilizando os sistemas de 14 e 30 barras do IEEE, o sistema de 121 barras da ELETROSUL e o sistema de 383 barras da CHESF. / In this work a method to design and to upgrade Measurements Placement Plan for state estimation is proposed. The proposed method allows the obtention of measurements placement plans that, besides free of both critical measurements and critical sets, maintain the system observability when 1 or 2 measurements are lost, at same time, or even when a Remote Terminal Unit (RTU) is lost. It is a simple numerical method, easy to implement and based on the analysis of the structure of the resultant matrix of the decomposition LDU, that it is obtained through a triangular factorization of the Jacobian matrix. To prove the efficiency of the proposed method, several tests were made using the IEEE 14 and 30-bus systems, a 121-bus system from ELETROSUL and a 383-bus system from CHESF.
9

Převodník mezi protokoly Modbus-RTU a Modbus-TCP / Converter between Modbus-RTU and Modbus-TCP Protocols

Pitko, Erik January 2021 (has links)
The main objective of this work is to inform the reader of the communication protocols Modbus TCP and Modbus RTU and create an embedded device based on the microprocessor STM32 capable of conversion between Modbus RTU and Modbus TCP protocols. The device should be capable of simple first run configuration with simple user interface.
10

An intrusion detection system for supervisory control and data acquisition systems

Hansen, Sinclair D. January 2008 (has links)
Despite increased awareness of threats against Critical Infrastructure (CI), securing of Supervisory Control and Data Acquisition (SCADA) systems remains incomplete. The majority of research focuses on preventative measures such as improving communication protocols and implementing security policies. New attempts are being made to use commercial Intrusion Detection System (IDS) software to protect SCADA systems. These have limited effectiveness because the ability to detect specific threats requires the context of the SCADA system. SCADA context is defined as any information that can be used to characterise the current status and function of the SCADA system. In this thesis the standard IDS model will be used with the varying SCADA data sources to provide SCADA context to a signature and anomaly detection engine. A novel addition to enhance the IDS model will be to use the SCADA data sources to simulate the remote SCADA site. The data resulting from the simulation is used by the IDS to make behavioural comparison between the real and simulated SCADA site. To evaluate the enhanced IDS model the specific context of a water and wastewater system is used to develop a prototype. Using this context it was found that the inflow between sites has similar diurnal characteristic to network traffic. This introduced the idea of using inflow data to detect abnormal behaviour for a remote wastewater site. Several experiments are proposed to validate the prototype using data from a real SCADA site. Initial results show good promise for detecting abnormal behaviour and specific threats against water and wastewater SCADA systems.

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