84 research outputs found

    GNSS Related Threats to Power Grid Applications

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    As power grid environments are moving towards the smart grid vision of the future, the traditional schemes for power grid protection and control are making way for new applications. The advancements in this field have made the requirements for power grid’s time synchronization accuracy and precision considerably more demanding. So far, the signals provided by Global Navigation Satellite Systems have generally addressed the need for highly accurate and stable reference time in power grid applications. These signals however are highly susceptible to tampering as they are being transmitted. Since electrical power transmission and distribution are critical functions for any modern society, the risks and impacts affiliated with satellite-based time synchronization in power grids ought to be examined. This thesis aims to address the matter. The objective is to examine how Global Navigation Satellite Systems are utilized in the power grids, how different attacks would potentially be carried out by employing interference and disturbance to GNSS signals and receivers and how the potential threats can be mitigated. A major part of the research is done through literature review, and the core concepts and different implementations of Global Navigation Satellite Systems are firstly introduced. The literature review also involves the introduction of different power grid components and subsystems, that utilize Global Positioning System for time synchronization. Threat modeling techniques traditionally practiced in software development are applied to power grid components and subsystems to gain insight about the possible threats and their impacts. The threats recognized through this process are evaluated and potential techniques for mitigating the most notable threats are presented.Sähköverkot ovat siirtymässä kohti tulevaisuuden älykkäitä sähköverkkoja ja perinteiset sähköverkon suojaus- ja ohjausmenetelmät tekevät tilaa uusille sovelluksille. Alan kehitys on tehnyt aikasynkronoinnin tarkkuusvaatimuksista huomattavasti aikaisempaa vaativampia. Tarkka aikareferenssi sähköverkoissa on tähän saakka saavutettu satelliittinavigointijärjestelmien tarjoamien signaalien avulla. Nämä signaalit ovat kuitenkin erittäin alttiita erilaisille hyökkäyksille. Sähkönjakelujärjestelmät ovat kriittinen osa nykyaikaista yhteiskuntaa ja riskejä sekä seuraamuksia, jotka liittyvät satelliittipohjaisten aikasynkronointimenetelmien hyödyntämiseen sähköverkoissa, tulisi tarkastella. Tämä tutkielma pyrkii vastaamaan tähän tarpeeseen. Päämääränä on selvittää, miten satelliittinavigointijärjestelmiä hyödynnetään sähköverkoissa, kuinka erilaisia hyökkäyksiä voidaan toteuttaa satelliittisignaaleja häiritsemällä ja satelliittisignaalivastaanottimia harhauttamalla ja kuinka näiden muodostamia uhkia voidaan lieventää. Valtaosa tästä tutkimuksesta on toteutettu kirjallisuuskatselmoinnin pohjalta. Työ kattaa satelliittinavigointijärjestelmien perusteet ja esittelee erilaisia tapoja, kuinka satelliittisignaaleja hyödynnetään sähköverkoissa erityisesti aikasynkronoinnin näkökulmasta. Työssä hyödynnettiin perinteisesti ohjelmistokehityksessä käytettyjä uhkamallinnusmenetelmiä mahdollisten uhkien ja seurausten analysointiin. Lopputuloksena esitellään riskiarviot uhkamallinnuksen pohjalta tunnistetuista uhkista, sekä esitellään erilaisia menettelytapoja uhkien lieventämiseksi

    Sensor-based ICT Systems for Smart Societies

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Open-Source TIG-Based Metal 3D-Printing

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    Metal 3-D printing has been relegated to high-cost proprietary high-resolution systems and low-resolution low-cost metal inert gas (MIG) systems. In order to provide a path to high-resolution, low-cost, metal 3-D printing, this manuscript proposes a new open source metal 3-D printer design based around a low-cost tungsten inert gas (TIG) welder coupled to a commercial open source self replicating rapid prototyper. Optimal printing parameters for the machine are acquired using a novel computational intelligence software. TIG has many advantages over MIG, such as having a low heat input, clean beads, and the potential for both high-resolution prints as well as insitu alloying of complex geometries. The design can be adapted to most RepRap-class systems and has a basic yet powerful free and open source software (FOSS) package for the characterization of the 3-D printer. This system can be used for fabricating custom metal scientific components and tools, near net-shape structural metal component rapid prototyping, adapting and depositing on existing metal structures, and is deployable for in-field prototyping for appropriate technology applications

    Process Monitoring of Demolition Waste Recycling Crushing: Feasibility study

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    Demolition waste is produced when buildings or other infrastructure approach the end of their life and are demolished. To support the objectives of circular economy and financial interests, demolition waste can be processed to produce recycled aggregates and by-products using crushing and screening equipment. Due to the nature and components of the demolition waste, the crushing and screening process is subject to different disturbances, which can compromise the efficiency of operation along with other negative effects. Directions for future development of the machinery for processing demolition waste have sparked the need to research the possibility of the equipment achieving a level of awareness on the state of the process. Ultimately, the crushing and screening plant could detect the problematic process state in an early phase and avoid serious consequences that might result from for example a total blockage of the machine. This thesis researches the subject with several methods. A literature review was done to collect information on the subject and to get familiar with different approaches used elsewhere in the industry. An interview study was conducted to gather existing knowledge about the demolition waste crushing process and different failure types that may occur during the process. Information from these two phases were used to build understanding on monitoring the crushing and screening process. Finally, an empirical part of the study was carried out, consisting of a measurement campaign on a real-world process, and a failure case -based analysis for the measurement data. As a result from the interview study and follow-up analysis, an overview of the demolition waste crushing process and its possible failure modes was formed. The scope of the thesis was limited to track-driven impactor crushing plants, and the results and analysis maintained this focus as well. A total of 11 failure modes were identified, along with their possible causes, root causes and effects on the process. The measurement campaign was planned with objectives derived from the scope of this thesis as well as interests within a wider scope. Three working days of plant operation were captured using data acquisition equipment and microphones, accelerometers, existing signals on the control system of the plant, as well as additional mechanical sensors. The data was analysed on a failure case -based approach, utilizing all information gathered in the previous phases. Results of the analysis indicate that detecting anomalies from the crushing process can be done using data from audio-, vibration-, and other domains, but performance greatly depends on the type of process failure and the nature of associated phenomena, also being dependent on correct sensor selection and placement. Different data types were demonstrated to be useful in the analysis, but the overall picture is governed by variability in the process and possible ways it can fail. In the literature, modern deep learning -based methods were suggested as a solution to combat the complexity, but they could not be included in the scope of this work

    Performance Improvement of Wide-Area-Monitoring-System (WAMS) and Applications Development

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    Wide area monitoring system (WAMS), as an application of situation awareness, provides essential information for power system monitoring, planning, operation, and control. To fully utilize WAMS in smart grid, it is important to investigate and improve its performance, and develop advanced applications based on the data from WAMS. In this dissertation, the work on improving the WAMS performance and developing advanced applications are introduced.To improve the performance of WAMS, the work includes investigation of the impacts of measurement error and the requirements of system based on WAMS, and the solutions. PMU is one of the main sensors for WAMS. The phasor and frequency estimation algorithms implemented highly influence the performance of PMUs, and therefore the WAMS. The algorithms of PMUs are reviewed in Chapter 2. To understand how the errors impact WAMS application, different applications are investigated in Chapter 3, and their requirements of accuracy are given. In chapter 4, the error model of PMUs are developed, regarding different parameters of input signals and PMU operation conditions. The factors influence of accuracy of PMUs are analyzed in Chapter 5, including both internal and external error sources. Specifically, the impacts of increase renewables are analyzed. Based on the analysis above, a novel PMU is developed in Chapter 6, including algorithm and realization. This PMU is able to provide high accurate and fast responding measurements during both steady and dynamic state. It is potential to improve the performance of WAMS. To improve the interoperability, the C37.118.2 based data communication protocol is curtailed and realized for single-phase distribution-level PMUs, which are presented in Chapter 7.WAMS-based applications are developed and introduced in Chapter 8-10. The first application is to use the spatial and temporal characterization of power system frequency for data authentication, location estimation and the detection of cyber-attack. The second application is to detect the GPS attack on the synchronized time interval. The third application is to detect the geomagnetically induced currents (GIC) resulted from GMD and EMP-E3. These applications, benefited from the novel PMU proposed in Chapter 6, can be used to enhance the security and robust of power system

    Advanced Radio Frequency Identification Design and Applications

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    Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. This book focuses on the advances in RFID tag antenna and ASIC design, novel chipless RFID tag design, security protocol enhancements along with some novel applications of RFID

    Research and Technology 1996: Innovation in Time and Space

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    As the NASA Center responsible for assembly, checkout, servicing, launch, recovery, and operational support of Space Transportation System elements and payloads, the John F. Kennedy Space Center is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the Engineering Development Directorate laboratories, most of the KSC operations contractors, academia, and selected commercial industries - all working in a team effort within their own areas of expertise. This edition of the Kennedy Space Center Research and Technology 1996 Annual Report covers efforts of all these contributors to the KSC advanced technology development program, as well as our technology transfer activities
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