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Mahajan, Nikhil R. "System Protection for Power Electronic Building Block Based DC Distribution Systems." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-12052004-233822/.
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The purpose of this research has been to develop an agent based protection and reconfiguration scheme for power electronic building block based (PEBB) DC distribution systems. One of the foremost applications would be in the new zonal DC distribution on naval ships. The research involves the design of an agent based protection scheme which uses the PEBBs for current limiting and circuit breaking purposes. Considerations are given to reduce the system downtime under fault conditions, allow proper coordination and provide backup protection. The research also involves the design of a reconfiguration management scheme based on collaborative agents. The collaboration ensures that the reconfiguration is achieved at a global level, enhancing the system survivability under the conditions of multiple faults and damages. The coordination ensures that only the faulted part of the system is isolated and the reconfiguration makes sure that the power to the healthy part of the system is supplied continuously. The reconfiguration management also performs load shedding if the generation does not meet the load demand of the reconfigured system due to a fault or damage in the generator.
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Thompson, Jeffrey Craig. "An expert system for protection system design of interconnected electrical distribution circuits." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-170345/.
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Mao, Yiming Mui Karen. "Protection system design for power distribution systems in the presence of distributed generation /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/501.
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Tetteh, Bright. "Implementation of wide area protection system (WAPS) for electrical power system smart transmission grids." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33993.
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The planning, operation and control of the power system has been evolving since its inception. These changes are due to the advancement in science and technology, and changes in energy policy and customer demands. The envisioned power system - smart grid (SG) - is expected to have functional and operational capabilities that maximize the reliability, minimize generation deficit, and cost issues in the power system. However, many power systems in the world today still operate traditionally, with one-way communication and one-way power flow. Transitioning to a smart grid influences the protection schemes of the power system, as the smart grid is to leverage distributed energy resources (DERs) using distributed generation (DG) units and allow for bi-directional flow of power and information. Therefore, there is a need for advanced protection schemes. Wide-area protection (WAP) techniques are proposed as one of the solutions to solve the protection challenges in the smart grid due to their reliance on wide-area information instead of local information. This dissertation considered three WAP techniques which are differentiated based on the data used for faulted zone detection: (A) Positive sequence voltage magnitude (PSVM), (B) Gain in momentum (GIM) and (C) Sum of positive and zero sequence currents (SPZSC). The dissertation investigated their performances in terms of accuracy in detecting the faulted zones and the faulted lines, and fault clearing time. The investigation was done using three simulation platforms: MATLAB/Simulink, Real-Time (Software in the Loop (SIL)) and Hardware-in-the-Loop (HIL) implementation using Opal-RT and SEL-351A relay. The results show that, in terms of detecting the faulted zones, all the techniques investigated have 100% accuracy in all the 36 tested fault cases. However, in terms of identifying the faulted line in the faulted zone, the algorithms were not able to detect all the 36 tested cases accurately. In some cases, the adjacent line was detected instead of the actual faulted line. In those scenarios, the detected line and the faulted line present similar characteristics making the algorithms to detect the wrong line. For the faulted line detection accuracy, the algorithm (A) has an accuracy of 86%, (B) has an accuracy of 94% and (C) has an accuracy of 92%. The fault clearing times of the algorithms were similar for both the MATLAB/Simulink and realtime simulation without the actual control hardware which was the SEL-351A relay. When the simulation was done with the control hardware through Hardware-in-the-loop, a communication delay was introduced which increased the fault clearing times. The maximum fault clearing time for the techniques investigated through the HIL simulation are 404 ms, 256 ms, and 150 ms for the techniques (A), (B) and (C) respectively and this variation is due to the different fault detection methods used in the three algorithms. The fault clearing time includes communication between the Opal-RT real-time simulator and SEL-351A relay using RJ45 ethernet cable, these fault clearing times can change if a different communication medium is used. From the performance data presented, it is evident that these algorithms will perform better when used as backup protection since the common timer settings for backup protection schemes range from 1200 ms to 1800 ms, while primary protection is expected to respond almost instantaneously, that is, with no initial time delay.
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Meadowcroft, Brian K. "Hidden Failures in Shipboard Electrical Integrated Propulsion Plants." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/42754.
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The differences between shipboard and land based power systems are explored to support the main focus of this work. A model was developed for simulating hidden failures on shipboard integrated propulsion plants, IPP. The model was then used to evaluate the segregation of the IPP high voltage, HV, buses in a similar fashion as a shipboard firemain. The HV buses were segregated when loss of propulsion power would put the ship as risk. This new treatment reduces the region of vulnerability by providing a high impedance boundary that limits the effects of a hidden failure of a current magnitude or differential based protective element, without the installation of any additional hardware or software. It is shown that this protection could be further improved through the use of a simple adaptive protection scheme that disarms unneeded protective elements in certain configurations.Master of Science
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Lao, Man I. "Simulation on I-V feature of protection system for superconducting cable." Thesis, University of Macau, 2008. http://umaclib3.umac.mo/record=b1795645.
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Van, Eyssen Juanita. "An investigation into the importance of considering protection performance during power system out-of-step conditions." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/18229.
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The performance of power system protection is affected by out-of-step conditions in that system. Protection relays such as distance relays may detect an out-of-step condition and consequently operate to trip unfaulted lines. The tripping of unfaulted lines interrupts supply to loads and exacerbates an already existing stability problem. To prevent distance-relay operation during out-of-step conditions, distance protection can incorporate out-of-step blocking protection. The purpose of the out-of-step blocking protection is to detect an out-of-step condition and, upon detection, block distance-relay operation. In the research the following were investigated: 1) The effect of out-of-step conditions on distance-protection performance 2) The performance of distance protection incorporating out-of-step blocking protection, during out-of-step conditions. A nine-bus IEEE benchmark network was chosen for the purposes of the research. The nine-bus network is representative, simple and small. It is a benchmark which is often used in comparative studies in the power system field. The nine-bus network data taken from reference [22] (see Table 3.1 in Chapter 3) were consistently used for every study done. Mathematical protection models representing the behaviour of distance protection incorporating out-of-step blocking protection were modelled in such a way as to simulate the protection of every line in the nine-bus network. These models were included in the power system model representing the nine-bus network. Two types of stability studies were done to investigate protection performance: a dynamic-stability study and a transient-stability study. IV In modelling the protection in the stability studies, it was found that a cascade effect of switching unfaulted lines can occur due to relay operation. Results also show that distance-protection performance improves with the application of out-of-step blocking protection. The research covers the following topics: 1) Dynamic stability 2) Transient stability 3) Distance protection 4) Out-of-step blocking protection results are discussed. An important conclusion reached is the need to take protection performance into account in routine stability studies. It will be shown that this may change the outcome of a stability study. For the sake of completeness, suggestions are made for further research.
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Haj-ahmed, Mohammed A. "Protection and Automation of Microgrids for Flexible Distribution of Energy and Storage Resources." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1430694499.
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Escalante, De Leon Lazaro Samuel. "Protection and communication for a 230 kV transmission line using a pilot overreaching transfer tripping (POTT) scheme." Kansas State University, 2013. http://hdl.handle.net/2097/16899.
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Master of ScienceDepartment of Electrical and Computer Engineering
Noel Schulz
New applications are continuously emerging in the ever-changing field of power systems in the United States and throughout the world, consequently causing new pressures on grid performance. Because power system protection is a fundamental aspect of the system, their operation must be addressed when a system is under high stress or when a high demand of energy is required. An extreme example is the transmission protection of a system because it transports large amounts of power. Transmission lines in a power system are frequently exposed to faults and generally protected by distance relays. If a faulted segment of transmission lines is not cleared in a short period of time, the system becomes unstable. The basic function of distance protection is to detect faults in buses, transmission lines, or substations and isolate them based on voltage and current measurements. Power system protection has previously focused on matching automation and control technologies to system performance needs. This report focuses on project activities that run simulations to determine settings for a protective relay for pilot overreaching transfer tripping and then test the settings using hardware equipment for various scenarios. The first set of scenarios consists of five faults in the system; two faults are in the protected line, and the remaining faults are outside the protective line. The second set of scenarios consists of instrument transformer failures in which the current transformer (CT) of one relay fails to operate while the other relay is fully operational. The second scenario consists of a failure of the voltage transformer (VT) of one relay while the other relay remains fully operational. Finally, the third and fourth scenarios consist of the failure of both CTs and VTs for each relay.
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Ma, Tan. "Hybrid Power System Intelligent Operation and Protection Involving Plug-in Electric Vehicles." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/1760.
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Two key solutions to reduce the greenhouse gas emissions and increase the overall energy efficiency are to maximize the utilization of renewable energy resources (RERs) to generate energy for load consumption and to shift to low or zero emission plug-in electric vehicles (PEVs) for transportation. The present U.S. aging and overburdened power grid infrastructure is under a tremendous pressure to handle the issues involved in penetration of RERS and PEVs. The future power grid should be designed with for the effective utilization of distributed RERs and distributed generations to intelligently respond to varying customer demand including PEVs with high level of security, stability and reliability. This dissertation develops and verifies such a hybrid AC-DC power system. The system will operate in a distributed manner incorporating multiple components in both AC and DC styles and work in both grid-connected and islanding modes.
The verification was performed on a laboratory-based hybrid AC-DC power system testbed as hardware/software platform. In this system, RERs emulators together with their maximum power point tracking technology and power electronics converters were designed to test different energy harvesting algorithms. The Energy storage devices including lithium-ion batteries and ultra-capacitors were used to optimize the performance of the hybrid power system. A lithium-ion battery smart energy management system with thermal and state of charge self-balancing was proposed to protect the energy storage system. A grid connected DC PEVs parking garage emulator, with five lithium-ion batteries was also designed with the smart charging functions that can emulate the future vehicle-to-grid (V2G), vehicle-to-vehicle (V2V) and vehicle-to-house (V2H) services. This includes grid voltage and frequency regulations, spinning reserves, micro grid islanding detection and energy resource support.
The results show successful integration of the developed techniques for control and energy management of future hybrid AC-DC power systems with high penetration of RERs and PEVs.
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Alanzi, Sultan. "Analysis of a Major Electric Grid – Stability and Adaptive Protection." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365969976.
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Sakr, Ziad. "Designed system for the composition and protection of MPEG-4 and SMIL scenes and their multimedia content." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/29257.
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For the past decade, there have been numerous research works focusing on the protection of digital images, audio, video, 3D virtual scenes, and software data from unauthorized use and distribution. With the emerging technology of the MPEG-4 standard, many different media objects, such as images, video, audio, and 3D virtual objects, may be combined together to compose a given MPEG-4 scene. A MPEG-4 scene can be composed using the MPEG-4 XMT textual-based format or the MPEG-4 BIFS compressed binary format. Using the MPEG-4 XMT standard, MPEG-4 scenes can easily be constructed. XMT allows content authors to exchange their content with other authors, tools, or service providers and facilitates interoperability with MPEG-4, X3D and SMIL. In order for owners and designers to protect and/or authenticate their work, some form of security needs to be applied to the MPEG-4 scenes and its media content.
This thesis presents the design of an MPEG-4 player that is able to compose or open a scene whether it is in the MPEG-4 BIFS format or the MPEG-4 XMT format. The scene can also be edited and modified with nodes or parts of the scene added, deleted, or translated in position with respect to the rest of the scene. All updates and modifications to the scene are viewed on the display scene graph. The MPEG-4 scene can also be saved in any of the desired formats whether the MPEG-4 BIFS for enhanced compression or the MPEG-4 XMT for ease of editing and modification.
The thesis also presents the design and implementation of a novel robust algorithm for the authentication and protection of MPEG-4 scenes and their media content. The algorithm is applied on the MPEG-4 XMT-A scenes. Even though the XMT structure lacks the noise components, which are considered a vital part for information hiding in media objects such as image, audio and video scenes, the designed and developed algorithm still proved to be robust against many forms of scene structure modifications and tampering attacks. Even if a given scene is in the MPEG-4 BIFS format, it can be converted to the MPEG-4 XMT format and then checked for authenticity and any located copyrighted material.
The design and implementation of a new algorithm for SMIL scene authentication and media content location and copyright protection is also presented in this thesis. The test results shown proved the algorithm to be robust against different scene structural modifications and tampering attacks.
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Iftakhar, Mohammad M. "Thevenin Equivalent Circuit Estimation and Application for Power System Monitoring and Protection." UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_theses/583.
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The Estimation of Thevenin Equivalent Parameters is useful for System Monitoring and Protection. We studied a method for estimating the Thevenin equivalent circuits. We then studied two applications including voltage stability and fault location. A study of the concepts of Voltage Stability is done in the initial part of this thesis. A Six Bus Power System Model was simulated using MATLAB SIMULINK®. Subsequently, the Thevenin Parameters were calculated. The results were then used for two purposes, to calculate the Maximum Power that can be delivered and for Fault Location.
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Gullipalli, Raashita, and Kiran Kumar Golla. "Arduino-Based Radio Technology System for Bird Protection : Wind Farm Application Approach." Thesis, Blekinge Tekniska Högskola, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-20056.
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Piesciorovsky, Emilio C. "Relay in the loop test procedures for adaptive overcurrent protection." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/20537.
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Doctor of PhilosophyElectrical and Computer Engineering
Anil Pahwa
Noel N. Schulz
Microgrids with distributed generators have changed how protection and control systems are designed. Protection systems in conventional U.S. distribution systems are radial with the assumption that current flows always from the utility source to the end user. However, in a microgrid with distributed generators, currents along power lines do not always flow in one direction. Therefore, protection systems must be adapted to different circuit paths depending on distributed generator sites in the microgrid and maximum fuse ampere ratings on busses. Adaptive overcurrent protection focuses on objectives and constraints based on operation, maximum load demand, equipment, and utility service limitations. Adaptive overcurrent protection was designed to protect the power lines and bus feeders of the microgrid with distributed generators by coordinating fuses and relays in the microgrid. Adaptive overcurrent protection was based on the relay setting group and protection logic methods. Non-real-time simulator (NRTS) and real-time simulator (RTS) experiments were performed with computer-based simulators. Tests with two relays in the loop proved that primary relays tripped faster than backup relays for selectivity coordination in the adaptive overcurrent protection system. Relay test results from tripping and non-tripping tests showed that adaptive inverse time overcurrent protection achieved selectivity, speed, and reliability. The RTS and NRTS with two relays in the loop techniques were described and compared in this work. The author was the first graduate student to implement real-time simulation with two relays in the loop at the Burns & McDonnell - K-State Smart Grid Laboratory. The RTS experimental circuit and project are detailed in this work so other graduate students can apply this technique with relays in the loop in smart grid research areas such as phasor measurement units, adaptive protection, communication, and cyber security applications.
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Hossan, Md Shakawat. "Prediction Model to Estimate the Zero Crossing Point for Faulted Waveforms." UKnowledge, 2014. http://uknowledge.uky.edu/ece_etds/53.
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In any power system, fault means abnormal flow of current. Insulation breakdown is the cause of fault generation. Different factors can cause the breakdown: Wires drifting together in the wind, Lightning ionizing air, wires with contacts of animals and plants, Salt spray or pollution on insulators. The common type of faults on a three phase system are single line-to-ground (SLG), Line-to-line faults (LL), double line-to-ground (DLG) faults, and balanced three phase faults. And these faults can be symmetrical (balanced) or Unsymmetrical (imbalanced).In this Study, a technique to predict the zero crossing point has been discussed and simulated. Zero crossing point prediction for reliable transmission and distribution plays a significant role. Electrical power control switching works in zero crossing point when a fault occurs. The precision of measuring zero crossing point for syncing power system control and instrumentation requires a thoughtful approach to minimize noise and external signals from the corrupted waveforms A faulted current waveform with estimated faulted phase/s, the technique is capable of identifying the time of zero crossing point. Proper Simulation has been organized on MATLAB R2012a.
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Farhadi, Mustafa. "Hybrid Energy Storage Implementation in DC and AC Power System for Efficiency, Power Quality and Reliability Improvements." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2471.
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Battery storage devices have been widely utilized for different applications. However, for high power applications, battery storage systems come with several challenges, such as the thermal issue, low power density, low life span and high cost. Compared with batteries, supercapacitors have a lower energy density but their power density is very high, and they offer higher cyclic life and efficiency even during fast charge and discharge processes. In this dissertation, new techniques for the control and energy management of the hybrid battery-supercapacitor storage system are developed to improve the performance of the system in terms of efficiency, power quality and reliability.
To evaluate the findings of this dissertation, a laboratory-scale DC microgrid system is designed and implemented. The developed microgrid utilizes a hybrid lead-acid battery and supercapacitor energy storage system and is loaded under various grid conditions. The developed microgrid has also real-time monitoring, control and energy management capabilities.
A new control scheme and real-time energy management algorithm for an actively controlled hybrid DC microgrid is developed to reduce the adverse impacts of pulsed power loads. The developed control scheme is an adaptive current-voltage controller that is based on the moving average measurement technique and an adaptive proportional compensator. Unlike conventional energy control methods, the developed controller has the advantages of controlling both current and voltage of the system. This development is experimentally tested and verified. The results show significant improvements achieved in terms of enhancing the system efficiency, reducing the AC grid voltage drop and mitigating frequency fluctuation.
Moreover, a novel event-based protection scheme for a multi-terminal DC power system has been developed and evaluated. In this technique, fault identification and classifications are performed based on the current derivative method and employing an artificial inductive line impedance. The developed scheme does not require high speed communication and synchronization and it transfers much less data when compared with the traditional method such as the differential protection approach. Moreover, this scheme utilizes less measurement equipment since only the DC bus data is required.
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Ouahdi, Driss. "Mining electrical supply protection systems." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328432.
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Liu, Yaqing. "Transient Response of Grounding Systems Caused by Lightning: Modelling and Experiments." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4556.
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Junior, Eloi Rufato. "Viabilidade técnica e econômica da modernização do sistema de proteção da distribuição." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-11122006-143845/.
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O objetivo do desenvolvimento deste trabalho é tecer uma análise da viabilidade técnica - econômica da modernização do sistema de Proteção da Distribuição, comparando a utilização dos relés digitais aos quais foram incorporadas novas funções, em relação aos relés eletromecânicos e estáticos. As informações apresentadas nesse trabalho mostram que os relés digitais oferecem uma significante economia quanto ao custo de aquisição e implantação, no desenvolvimento dos projetos de aplicação e na manutenção destes equipamentos após instalados em campo. Os relés eletromecânicos tem sido largamente utilizados nos esquemas de proteção de consumidores industriais e residencias de grande porte e nos sistemas de proteção das companhias de eletricidade. Devido a quantidade de peças móveis e freqüentes re-ajustes que estes tipos de equipamentos necessitam, os mesmos demandam muitas horas dispendidas pelo pessoal de calibração e manutenção das empresas de eletricidade. A realização de Estudos de Proteção, com a parametrização destes relés muitas vezes torna-se inviável, sob o ponto de vista de sensibilidade e da coordenação das proteções, devido ao fato de que estes equipamentos possuem ajustes limitados tanto de valores de corrente de partida como na seleção de curvas tempo x corrente utilizadas para temporização das proteções, no caso de relés eletromecânicos de sobrecorrente. Durante os últimos anos, com o advento da evolução da indústria, da micro eletrônica e do desenvolvimento de softwares, os relés digitais veêm substituíndo os relés eletromecânicos e estáticos, tanto em instalações novas como também nas remodelações das instalações mais antigas, nos sistemas elétricos de proteção industrial e de empresas de eletricidade. Realizou-se uma análise quanto ao histórico dos relés de proteção, mostrando o seu desenvolvimento desde os relés mais antigos, tipos eletromecânicos, após os relés estáticos, que foram a evolução dos anteriores e finalmente estudando os relés digitais. Os relés digitais oferecem muitas vantagens se comparados com os relés eletromecânicos e estáticos, as quais serão abordandos em items específicos da revisão de literatura neste trabalho. O trabalho é finalizado com uma análise de casos, onde foram computados e analisados casos, como índices de fornecimento, custos de instalação de relés digitais em substituição à relés e sistemas eletromecânicos e estáticos, utilizados convencionalmente para a proteção em alimentadores de Subestações da Copel - Companhia Paranaense de Energia, com o objetivo de coletar-se e analisar-se, ao longo de 12 meses as reais vantagens e desvantagens da utilização destes equipamentos nos sistemas elétricos de proteção dos circuitos de distribuição de energia.The purpose of this study is to carry out a technical and economic feasibility assessment of the updating of the Distribution Protection system, comparing the use of digital relays, to which new functions have been integrated, with electromechanical and static relays. Information hereby presented shows that digital relays are significantly cost-effective in terms of acquisition and implementation for developing application projects and in maintaining that equipment after it has been set up in the field. Electromechanical relays have been largely used in protection schemes for large-scale industrial and residential consumers, as well as in security schemes for power plant companies. Because of the large number of moving parts and frequent readjustments required by that type of equipment, many manhours must be put in by calibration and maintenance staff employed by power plant companies. Carrying out a Protection Study that establishes parameters for those relays is often unfeasible given the sensitivity and coordination of the protections, in that the equipment in question has limited adjustments, both in terms of pick-up currents values and of the selection of time curve vs. current used in the protection timer, in the case of overcurrent electromechanical relays. During the last years, with the rise of industrial evolution, microelectronics and software development, digital relays are replacing electromechanical and static relays in electrical security systems used by industrial and power plant company protection, both in new facilities and in refurbished facilities. A study was carried out on the history of protection relays showing how they developed from the older, electromechanical type after the static relays, which evolved form the former, and was concluded with the study of digital relay models. Digital relays provide significant advantages compared to electromechanical and static relays, which will be covered under specific revision items of the references provided herein. The study is concluded by assessing case studies that were accounted for and assessed, such as supply rates, installation costs of digital relays to replace electromechanical and static systems used traditionally to provide protection for COPEL´s (Power Company of the State of Paraná) Substations. The purpose was to collect and analyze, over a 12-month period, the actual advantages and disadvantages of using that type of equipment in electrical systems that provide circuit protection for power distribution.
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Moghadasiriseh, Amirhasan. "Analysis and Modeling of Advanced Power Control and Protection Requirements for Integrating Renewable Energy Sources in Smart Grid." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2469.
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Attempts to reduce greenhouse gas emissions are promising with the recent dramatic increase of installed renewable energy sources (RES) capacity. Integration of large intermittent renewable resources affects smart grid systems in several significant ways, such as transient and voltage stability, existing protection scheme, and power leveling and energy balancing. To protect the grid from threats related to these issues, utilities impose rigorous technical requirements, more importantly, focusing on fault ride through requirements and active/reactive power responses following disturbances. This dissertation is aimed at developing and verifying the advanced and algorithmic methods for specification of protection schemes, reactive power capability and power control requirements for interconnection of the RESs to the smart grid systems. The first findings of this dissertation verified that the integration of large RESs become more promising from the energy-saving, and downsizing perspective by introducing a resistive superconducting fault current limiter (SFCL) as a self-healing equipment. The proposed SFCL decreased the activation of the conventional control scheme for the wind power plant (WPP), such as dc braking chopper and fast pitch angle control systems, thereby increased the reliability of the system.
A static synchronous compensator (STATCOM) has been proposed to assist with the uninterrupted operation of the doubly-fed induction generators (DFIGs)-based WTs during grid disturbances. The key motivation of this study was to design a new computational intelligence technique based on a multi-objective optimization problem (MOP), for the online coordinated reactive power control between the DFIG and the STATCOM in order to improve the low voltage ride-through (LVRT) capability of the WT during the fault, and to smooth low-frequency oscillations of the active power during the recovery. Furthermore, the application of a three-phase single-stage module-integrated converter (MIC) incorporated into a grid-tied photovoltaic (PV) system was investigated in this dissertation. A new current control scheme based on multivariable PI controller, with a faster dynamic and superior axis decoupling capability compared with the conventional PI control method, was developed and experimentally evaluated for three-phase PV MIC system. Finally, a study was conducted based on the framework of stochastic game theory to enable a power system to dynamically survive concurrent severe multi-failure events, before such failures turn into a full blown cascading failure. This effort provides reliable strategies in the form of insightful guidelines on how to deploy limited budgets for protecting critical components of the smart grid systems.
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Wistedt, Johan. "Digital secondary substations with auto-configuration of station monitoring through IEC 61850 and CIM." Thesis, Uppsala universitet, Elektricitetslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-360513.
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This thesis explore the possibility to automate a process for configuration of secondary substations monitoring and control. By using a network information system (NIS), information of secondary substations can be extracted, such as feeder naming, primary equipment type, rating and model. From this information an automated process of configuring the secondary substation is possible, which open up the possibility to cost-efficiently digitalise the distribution grid. In the project, the standard IEC 61850 for configuration of communications of intelligent electrical devices was used to automate and standardize the process. The process starts with a extracted IEC 61970 CIM file from the NIS. The IEC 61970 CIM file is converted into a IEC 61850 SCL file through an system engineering tool. The configuration is based of information from the NIS, where the models and types of the equipments decides what type of functionality that is needed for the secondary substation. With help of the created SCL file hardware and human-machine interface (HMI) was configured, creating a full functional system for the secondary substation monitoring and control equipment. The usage of 400V capable input module together with bus couplers, configured in IEC 61850, lowers the configuration needed for the hardware. The usage of SCL files also helps automate the creation of HMI for the secondary substation through IEC 61850 based tools in SCADA software. Creating views of both single-line diagrams as well as digital representation of the secondary substation outgoing feeders with measured values on display. The result of the project helps show NIS information is sufficient and standards mature enough to allow an almost fully automated system. Lowering the total time spent on each stations configuration to around two hours. Leading the way for future development of automating software for configurations of the secondary substations.
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Qadri, Syed Saadat. "A systematic approach to setting underfrequency relays in electric power systems /." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116022.
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Generation loss contingencies in electric power systems result in a deviation of system frequency from nominal, a condition which must be corrected promptly in order to prevent further degradation of the power system. Automatic load-shedding using underfrequency relays is one of the techniques used to correct abnormal frequency deviations and prevent the risk of uncontrolled outages. If sufficient load is shed following a contingency to preserve interconnections and keep generators on-line, the system can be restored with relative speed and ease. On the other hand, if a declining frequency condition is not dealt with adequately, a cascading disconnection of generating units may develop, leading to a possible total system blackout.This thesis develops and tests a new systematic method for setting underfrequency relays offering a number of advantages over conventional methods. A discretized swing equation model is used to evaluate the system frequency following a contingency, and the operational logic of an underfrequency relay is modeled using mixed integer linear programming (MILP) techniques. The proposed approach computes relay settings with respect to a subset of all plausible contingencies for a given system. A method for selecting the subset of contingencies for inclusion in the MILP is presented. The goal of this thesis is to demonstrate that given certain types of degrees of freedom in the relay setting problem, it is possible to obtain a set of relay settings that limits damage or disconnection of generating units for each and every possible generation loss outage in a given system, while attempting to shed the least amount of load for each contingency.
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Uddin, Salman. "A novel approach to detect CT saturation using standalone CT measurements." Thesis, KTH, Elkraftteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214076.
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The requirement for reliability and security in power system is increasing every passingday with the increase in complexity of the power system. To ensure highest level ofreliability, protection relays have to receive correct measurements. One of the most importantmeasurement that is needed by a relay as an input is current. However, currentmeasurements received from current transformer (CT) can become inaccurate due to aphenomenon called CT saturation. This Master's thesis objective is to build a novel algorithmfor the protection relays to detect CT saturation. The algorithm should be basedon a stand-alone method that is able to detect CT saturation within 1-2 ms for a samplingfrequency of 4 kHz.This project comprises a study of the background about CTs and CT saturation. Therelated work done to detect CT saturation is also studied. Later, major existing methodsused in the industry to deal with CT saturation are investigated in detail and modelledin Simulink. A novel method is proposed to exclusively detect CT saturation, keeping inmind the strict requirements, set in the beginning of the project. The proposed methodis implemented in Simulink and HiDraw(in-house software in ABB to create C code forprotection functions). Lastly, the proposed method and the existing methods are testedin Simulink for more than 1300 test cases based on dierent power system conditions,IEC-60255-187-1 and real current recordings from relays.The results of the tests showed that the proposed method successfully detect CT saturationand was better than the existing methods in terms of speed and accuracy. It was concludedthat the proposed method successfully detects CT saturation and hence, can be used withany protection function in a relay where there is a need to detect CT saturation.Kraven pa tillforlitlighet och sakerhet i kraftsystem okar varje dag i samband med allthogre komplexitet i kraftsystemet. For att uppna den hogsta nivan av tillforlitlighetbehover relaskydden ta emot korrekta matvarden fran kraftsystemet. Ett av de mest viktigamatvardena som behovs for ett relaskydd ar strom. Emellertid, kan matvarden franen stromtransformator bli felaktiga pagrund av ett fenomen som kallas stromtransformatormattning. Malet for detta examensarbete ar att skapa en ny algoritm for relaskydd somdetekterar stromtransformatormattning. Algoritmen ska baseras pa en fristaende metodsom klarar av att detektera stromtransformatormattning inom 1-2 ms for en samplingsfrekvenspa 4 kHz.Detta projekt omfattar, forutom en studie av hur stromtransformatormattning kan detekteras,aven en bakgrundsstudie om stromtransformatorer och stromtransformatormattning.Viktigare existerande metoder, som anvands i industrin for att detektera stromtransformatormattning, undersoks i detalj och modelleras i Simulink. En ny metod foreslas foratt exklusivt detektera stromtransformatormattning med hansyn till de strikta krav somfaststalldes i borjan av projektet. Den foreslagna metoden ar implementerad i Simulinkoch i HiDraw (en intern ABB mjukvara for att skapa C-kod for skyddsfunktioner). Slutligenar den nya foreslagna metoden och de existerande metoderna testade i Simulinkmed er an 1300 testfall baserade paolika forhallanden i kraftsystemet, IEC-60255-187-1standarden och med verkliga inspelningar av strom gjorda av relaskydd i drift.Resultatet av testerna visar att den nya foreslagna metoden framgangsrikt detekterarstromtransformatormattning och gor det battre an existerande metoder med avseende pasnabbhet och noggrannhet. Det konstaterades att den nya foreslagna metoden framgangsriktdetekterar stromtransformatormattning och darfor kan anvandas for vilken relaskyddsfunktionsom helst i ett relaskydd dar behovet av att detektera stromtransformatormattningnns.
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Dunn, Ian. "Computer aided design of protection systems for electrical drives." Thesis, University of South Wales, 1994. https://pure.southwales.ac.uk/en/studentthesis/computer-aided-design-of-protection-systems-for-electrical-drives(083070e9-5cde-45e7-8bbd-e25f8f9c4742).html.
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The contents of this thesis describe the results of an investigation into the means by which computer aided design (CAD) may be applied to the protection systems of electrical drives, removing much of the repetitive procedures presently used in determining relay settings. To further this aim, a series of algorithms have been devised which allow exploitation of the concept. The areas chosen for demonstration are, direct-on-line started induction motors and transformer fed variable speed drives. In both cases "standard settings' cannot be implemented as the field of application varies enormously. The text discusses an algorithm which utilises several databases containing motor, fuse and cable parameters. Chapter three uses a program derived from this algorithm which allows data to be extracted from the databases and manipulated in order to determine the optimum circuit components. Subsequent chapters examine the implementation of two types of motor protection relay and discusses the algorithms used in modelling them. The text is supported by applications which demonstrate the effectiveness of the derived programs. Chapter six discusses in depth the application of overcurrent relays for the protection of transformers used on variable speed drive installations. The possibility of using overcurrent elements in two or three phases is examined together with the attendant difficulties which may arise. The algorithms are further expanded to incorporate applications which involve the protection of multi-transformer installations supplied from a common point.
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Orji, Uzoma A. "Condition based monitoring and protection in electrical distribution systems." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/87933.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 354-362).
The U.S. Department of Energy has identified "sensing and measurement" as one of the "five fundamental technologies" essential for driving the creation of a "Smart Grid". Consumers will need "simple, accessible..., rich, useful information" to help manage their electrical consumption without interference in their lives. There is a need for flexible, inexpensive metering technologies that can be deployed in many different monitoring scenarios. Individual loads may be expected to compute information about their power consumption. New utility meters will need to communicate bidirectionally, and may need to compute parameters of power flow not commonly assessed by most current meters. These meters may be called upon to perform not only energy score-keeping, but also assist with condition-based maintenance. They may potentially serve as part of the utility protection gear. And they may be called upon to operate in new environments, e.g., non-radial distribution systems as might be found on microgrids or warships. This thesis makes contributions in three areas of condition-based maintenance and protection in electric distribution systems. First, this thesis presents a diagnostic tool for tracking non-integer harmonics on the utility. The tool employs a modified algorithm to enhance the capability of the Fast Fourier Transform (FFT) to determine the precise frequency of a newly detected harmonic. The efficacy of the tool is demonstrated with field applications detecting principal slot harmonics for speed estimation and diagnostics. Second, data from nonintrusive monitors have been shown to be valuable for power systems design. This thesis presents a new behavioral modeling framework developed for microgrid-style shipboard power system design using power observations from the ship's electrical distribution service. Metering can be used to inform new designs or update maintenance parameters on existing ship power systems. Finally, nonintrusive metering allows for new possibilities for adaptive fault protection. Adaptive thresholding of voltage magnitude, angle and harmonic content will be demonstrated for improving protection schemes currently used in ship electrical distribution systems.
by Uzoma Orji.
Ph. D.
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Ibrahem, Amr. "Leakage Current Detection and Protection for Electrical Railway Systems." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1501106215129042.
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Alvarez, Rogelio E. "Interdicting electrical power grids." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FAlvarez.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2004.Thesis advisor(s): Javier Salmeron, R. Kevin Wood. Includes bibliographical references (p. 69-70). Also available online.
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Harris, Raymond Trevor. "Replacement of seven 132/66 kv distance protection schemes by means of a generic relay implemented as a strategic spare." Thesis, Port Elizabeth Technikon, 2000. http://hdl.handle.net/10948/34.
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Eskom is experiencing problems in the field of protection maintenance and in-service breakdowns which negatively influence the quality of electrical supply to the consumer, an integral component of the utility business. These facts initiated the research into the further development of a generic relay to be implemented as a strategic spare for the replacement of several schemes operating within Eskom’s southern region. These include the electromechanical, solid state and numerical distance protection relay and scheme failures on the 132 / 66 kV feeder network. Hence, the primary objective of the research is to develop, test and configure the strategic spare in terms of software and peripheral hardware for the input and output terminal connections, generic equations and settings for the purpose of the scheme replacements. The various schemes are assessed for stepped distance and permissive intertripping for three or single pole operation. This is done in conjunction with the internal and external circuit diagrams in order to understand the detailed operation of the scheme and to ensure the effective implementation of the strategic spare. The generic relay is configured for the emergency replacement of the various schemes during in-service breakdowns. This constitutes a temporary installation and therefore the downtime in essence, of all the distance protection schemes that require replacement, is limited to a minimum. This dissertation therefore explores the implementation of the strategic spare.
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Ramadan, Asmaiel. "Permanent magnet fault current limiters for electrical power protection systems." Thesis, Sheffield Hallam University, 2018. http://shura.shu.ac.uk/22433/.
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The main aim of this work is to design and test a permanent magnet fault current limiter (PMFCL) to limit the fault current in electrical power system network. The (fit and forget) device presented in this thesis is based on two important aspects; the best selection of the state of the art soft and hard magnetic materials and the design topology of PMFCL. Rare earth material is used as a permanent magnet, which is the main source of excitation to keep the non-oriented silicon steel iron core in magnetic saturation state. During the normal operation of the device the saturated core offers low impedance to the grid and during the fault state the core inherently rushed to high impedance state that limits the high short circuit current. A commercial Finite Element software (FEM) was used in the device modelling techniques from the commencement till the end of the final design. The work commenced with the verifications and investigations of a recently reported model in 2D (FEM). Then, a prototype of small scale, in two design configurations of the same PMFCL specifications, was built and tested at the electrical laboratory of Sheffield Hallam University to verify the simulation results and to access the design of the PMFCL device. After that, the 11-kV PMFCL for substation distribution transformer was designed. Finally, the low voltage toroidal core PMFCL was proposed for the existing renewable energy and future wind-photovoltaic (wind-PV) step-up transformer. The dry type PMFCL current-inductance profiles were obtained by 3D (FEM) magneto static solver to predict the behaviour of the devices in the abnormal condition. The calculated RMS current, using 3D (FEM) time saving inductance-current approach, agreed with the peak transient currents obtained by the lengthy computation process time-step solver. The current limitation capability has been calculated in comparison with the air-cored of similar specifications as the PMFCL device and a useful reduction in the fault current has been achieved. The simulation results proved that the proposed PMFCL topologies (toroidal and square-shaped) can protect the renewable energy generator-transformer and real power grids from the fault current. Both the toroidal and full scale PMFCL devices initial and energy cost over an expected service of life have been evaluated. The merit of the PMFCL device is that it reduces downtime during power system’s outages by mitigating the severe fault current in the first half cycle.
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Raghuvanshi, Anurag. "Characterization of Airborne Antenna Group Delay as a Function of Arrival Angle and its Impact on Accuracy and Integrity of the Global Positioning System." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1533314646617932.
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Marek, Michal. "Tester vlakového zabezpečovače." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318161.
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The Master´s thesis describes continuous automatic train protection system and its functional properties, principally the transmission of special encoded signal between stationary part and rail vehicle. There is also summarized some important information about the gear rotational speed sensors and its communication with other onboard peripherals. Depends by analysed parameters of electrical signals, the general suggestion of portable electronic device is outlined. Portable electronic device or TESTER will be used to in phase of testing mobile part of automatic train protection system mounted onboard of rail vehicle. Tester will generate equivalent electrical signals to signals in system automatic train protection and the real system response will be possible to evaluate. The generator block allows to model real electrical signals in automatic train protection technology type LS or type EVM and signals rail vehicle odometry.
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Latzo, Curtis Thomas. "Approaches to Arc Flash Hazard Mitigation in 600 Volt Power Systems." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3198.
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ABSTRACT
Federal regulations have recognized that arc flash hazards are a critical source of potential injury. As a consequence, in order to work on some electrical equipment, the energy source must be completely shut-down. However, power distribution systems in mission critical facilities such as hospitals and data centers must sometimes remain energized while being maintained. In recent years the Arc Flash Hazard Analysis has emerged as a power system tool that informs the qualified technician of the incident energy at the equipment to be maintained and recommends the proper protective equipment to wear. Due to codes, standards and historically acceptable design methods, the Arc Flash Hazard is often higher and more dangerous than necessary.
This dissertation presents detailed methodology and proposes alternative strategies to be implemented at the design stage of 600 volt facility power distribution systems which will decrease the Arc Flash Hazard Exposure when compared to widely used code acceptable design strategies. Software models have been developed for different locations throughout a power system. These software model simulations will analyze the Arc Flash Hazard in a system designed with typical mainstream code acceptable methods. The model will be changed to show implementation of arc flash mitigation techniques at the system design level. The computer simulations after the mitigation techniques will show significant lowering of the Arc Flash Hazard Exposure.
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Bernardes, Wellington Maycon Santos. "Algoritmo enxame de partículas discreto para coordenação de relés direcionais de sobrecorrente em sistemas elétricos de potência." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-14052013-094113/.
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Este trabalho propõe uma metodologia baseada em técnicas inteligentes capaz de fornecer uma coordenação otimizada de relés direcionais de sobrecorrente instalados em sistemas de energia elétrica. O problema é modelado como um caso de programação não linear inteira mista, em que os relés permitem ajustes discretizados de múltiplos de tempo e/ou múltiplos de corrente. A solução do problema de otimização correspondente é obtida através de uma metaheurística nomeada como Discrete Particle Swarm Optimization. Na literatura técnico-científica esse problema geralmente é linearizado e aplicam-se arredondamentos das variáveis discretas. Na metodologia proposta, as variáveis discretas são tratadas adequadamente para utilização na metaheurística e são apresentados os resultados que foram comparados com os obtidos pelo modelo clássico de otimização implementado no General Algebraic Modeling System (GAMS). Tendo em vista os aspectos observados, o método permite ao engenheiro de proteção ter um subsídio adicional na tarefa da coordenação dos relés direcionais de sobrecorrente, disponibilizando uma técnica eficaz e de fácil aplicabilidade ao sistema elétrico a ser protegido, independentemente da topologia e condição operacional.This work proposes a methodology that based on intelligent technique to obtain an optimized coordination of directional overcurrent relays in electric power systems. The problem is modeled as a mixed integer nonlinear problem, because the relays allows a discrete setting of time and/or current multipliers. The solution of the proposed optimization problem is obtained from the proposed metaheuristic named as Discrete Particle Swarm Optimization. In scientific and technical literature this problem is usually linearized and discrete variables are rounded off. In the proposed method, the discrete variables are modeled adequately in the metaheuristic and the results are compared to the classical optimization solvers implemented in General Algebraic Modeling System (GAMS). The method provides an important method for helping the engineers in to coordinate directional overcurrent relays in a very optimized way. It has high potential for the application to realistic systems, regardless of topology and operating condition.
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Yao, Xiu. "DC Arc Fault Detection and Protection in DC Based Electrical Power Systems." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1429857592.
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Bottura, Fernando Bambozzi. "Algoritmo de otimização híbrido para a coordenação de relés direcionais de sobrecorrente em um sistema elétrico malhado." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-07032014-143038/.
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Esta pesquisa tem como objetivo apresentar um método para a coordenação dos Relés Direcionais de Sobrecorrente (RDS) associados ao sistema de proteção de um Sistema Elétrico de Potência (SEP) malhado. O SEP malhado, referente a uma parte do sistema de subtransmissão da rede básica brasileira, em concessão da Companhia de Transmissão de Energia Elétrica Paulista (CTEEP), foi simulado via o software CAPE (Computer-Aided Protection Engineering) a partir da base de dados, para estudos de curtos-circuitos, disponibilizada pelo Operador Nacional do Sistema (ONS). Dada a topologia e a operação do SEP malhado em análise, um método de otimização híbrido foi implementado baseado na combinação e aplicação de Programação Linear (PL) e Algoritmo Genético (AG). O algoritmo desenvolvido permitiu a realização de diversos estudos de curtos-circuitos necessários para a obtenção e avaliação da coordenação dos pares de RDS, tanto para a topologia principal do SEP em análise, como para outras configurações de operação caracterizadas, principalmente, pela alteração topológica do SEP. Os resultados demonstram que o algoritmo foi capaz de fornecer uma coordenação adequada para os RDS, respeitando todas as restrições impostas pelo problema de coordenação.The aim of this work is to present a method for directional overcurrent relays coordination in a meshed power system which is part of the Brazilian power transmission system operated by São Paulo State Electric Power Transmission Company (CTEEP - Companhia de Transmissão de Energia Elétrica Paulista). This power system was simulated by CAPE (Computer-Aided Protection Engineering) software using the database of short circuits studies which is provided by the Electric System National Operator (ONS - Operador Nacional do Sistema). Given a specific power system topology and its operating conditions, the hybrid algorithm was developed based on the combination and execution of linear programming and genetic algorithm. Several short circuits scenarios were evaluated in order to obtain and assess the coordination between the pairs of directional overcurrent relays. In such scenarios, it was considered the main network topology, as well as other network operating conditions, mainly caused by certain topological variations. The results show that the hybrid algorithm provided a feasible coordination solution for the considered directional overcurrent relays.
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Bashour, Rami. "High voltage optical fibre sensor for use in wire relay electrical protection systems." Thesis, University of Derby, 2016. http://hdl.handle.net/10545/621343.
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The last few decades have a wide spread use of optical fibre sensors in many applications. Optical fibre sensors have significant benefits over existing conventional sensors such as; high immunity to electromagnetic interference, the ability to transmit signal over long distance at high bandwidth, high resolution, usage in hazardous environments and no need for isolation when working at high voltages. The measurement of high voltages is essential for electrical power systems as it is used as a source of electrical information for Relay Protection Systems (RPS) and load management systems. Electrical Power Systems need to be protected from faults. Faults can range from short circuits, voltage dips, surges, transients etc. The Optical High Voltage sensor developed is based on the principle that the Lead Zirconate Titanate (PZT) electrostriction displacement changes when a voltage is applied to it. The displacement causes the fibre (FBG) which is bonded to the PZT material to have a resultant change in the wavelength. An optical fibre sensor prototype has been developed and evaluated that measures up to 250 V DC. Simulation using ANSYS software has been used to demonstrate the operational capability of the sensor up to 300kV AC. This sensor overcomes some of the challenges of conventional sensors issues like electromagnetic interference, signal transmission, resolution etc. R BASHOUR 2 A novel optical fibre high voltage based on the Kerr effect has been demonstrated. The The Kerr effect was determined using Optsim (R-Soft) software and Maxwell software was used to model an optical Kerr Cell. Maxwell software is an electromagnetic/electric field software used for simulating, analysing, designing 2D and 3D electromagnetic materials and devices. It uses highly accurate Finite Element techniques to solve time varying, static, frequency domain electric and electromagnetic fields. A Relay Protection System on electrical networks was discussed in detail. Keywords: Fibre Bragg Grating, Fibre Optics Sensors, Piezoelectricity, Kerr effect, Relay Protection Systems.
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Sarawgi, Sanjoy Kumar. "A simulation tool for studying the effects of special protection systems and communications on power system stability." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Thesis/Summer2004/s%5Fsarawgi%5F072604.pdf.
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Mguzulwa, Ncedo Richard. "Investigation of interoperability of IEC 61850 protection functions." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2704.
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Thesis (Master of Engineering in Electrical Engineering)--Cape Peninsula University of Technology, [2018].Introduction of IEC 61850 standard defined substation automation system communication. The need of interoperability among the relevant devices coming from different vendors is a necessity to ensure utilities/municipalities obtain value for money. Vendors used their own proprietary tools to achieve communication in a substation. This caused an Intelligent Electronic Device (IED) from vendor A could not communicate with an IED from vendor B. Utilities/municipalities are forced to depend on single vendor solutions in a substation automation system. IEC 61850 systems tout Interoperability as a major gain in the Substation Automation System (SAS) environment. The implementation of interoperable systems in SAS environment requires extensive testing and careful selection of vendors. This involves extensive testing to meet the required requirements of a certain SAS. Interoperability implementation and testing methods need to be formulated and tested rigorously with various scenarios of interoperability in an SAS. GOOSE messages form the foundation of IEC 61850 standard as they are responsible for the copper-less connections for peer to peer communications. GOOSE messages are based on peer to peer communications to enable interoperability at the bay level which is called horizontal communication. IEDs need to be carefully selected to ensure GOOSE messaging interoperability is achieved. Test methods are equally important as methodology to achieve interoperability. The purpose of this research is to perform an investigation on interoperability of IEC 61850 conformant IEDs based on evaluation of their protection functions. The research looks at various vendors on how each has interpreted the IEC 61850 standard. Also an analysis on requirements to achieve interoperability is conducted. Investigation on various vendor independent system configuration tools to ease the implementation burden of a multivendor application is done. Evaluation into flexible object modelling and naming conventions in order to achieve interoperability is performed. Various tests using different tools to assess the integrity of interoperability are completed. The research delivers a methodology to evaluate and implement GOOSE message interoperability. The interoperability methodology can be used for improvement of interoperability applications. The methodology can also be implemented as procurement requirement to ensure interoperability. The evaluation/implementation of interoperability can be included in Factory Acceptance Test (FAT). The methodology to achieve interoperability is only usefully when requirements are clear with regard to what needs to achieved by SAS.
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Chaudhary, Arvind K. S. "Protection system representation in the Electromagnetic Transients Program." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-134541/.
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Amoda, Oluwaseun Adeyemi. "DEVELOPMENT OF AN ADAPTIVE PROTECTION SCHEME FOR SHIPBOARD POWER SYSTEMS." MSSTATE, 2007. http://sun.library.msstate.edu/ETD-db/theses/available/etd-06062007-133738/.
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Reconfiguration is needed to meet the fight-through and survivability requirements of a shipboard power system. Reconfiguration involves the re-arrangement of power system topology through the opening and switching of breakers, and adjusting of total generators and load values. When the power system is reconfigured, the protection system needs to be attuned to the new power system state. This thesis focuses on developing an adaptive protection scheme for shipboard power systems that will automatically update relay settings after changes in power system topology and operational state. The developed adaptive protection scheme employs four main algorithms to achieve its goal. A topology-recognition algorithm uses the statuses (open/close) of breakers to determine the topological-configuration of the system. A power-flow and a fault-analysis algorithm are used to determine the system?s normal and fault currents, respectively. A protection-setting algorithm is used to determine and set the operating parameters of all the relays in the system. The scheme was implemented in MATLAB m-files and tested on various configurations of a notional shipboard power system. The tests results were verified in CAPE.
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Nguyen, Huy Cuong. "Modélisation électrothermique de système électrique électronique automobile et pilotage de mosfet intelligents pour protéger les faisceaux, éviter les courts circuits aggravés et diminuer la masse de câblage." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR14776/document.
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Sur les différents calculateurs du véhicule, de plus en plus d'organes sont commandés par un interrupteur en silicium (circuit MOSFET) au lieu d'un relais. En plus de la fonction de commutation de puissance, le MOSFET peut comprendre un dispositif de mesure du courant afin de contrôler le pilotage de l'organe et/ou assurer une fonction de diagnostic. On appelle ce type de composant un commutateur intelligent de puissance ou Smart Switch. Il est aussi prévu dans le Smart Switch un dispositif de coupure du courant, en cas d'échauffement interne dû à une surintensité électrique. Avec les dernières avancées technologiques, ces composants peuvent aussi intégrer de la logique de pilotage et une interface de liaison numérique avec un microprocesseur. Cette dernière caractéristique motive lesujet de l'étude afin de définir des lois de protection améliorées contre les échauffements dus à une surintensité électrique.En effet, d’un point de vue de la protection électrique, le MOSFET a été conçu pour obtenir les mêmes caractéristiques qu’un fusible, avec la possibilité supplémentaire d’être réenclenché comme un disjoncteur. Le but est d’étudier les lois de pilotage qui pourraient permettre de mieux suivre les limites thermiques d’un conducteur électrique, en particulier dans les faibles surintensités, de façon à pouvoir diminuer le diamètre (donc le coût) des fils tout en assurant une meilleure protection face aux courts circuits impédants (courts-circuits sur une résistance un peu inférieure à la résistance nominale ducircuit, dans un rapport entre 1 et 3 par exemple)On various vehicles Electronic Control Unit (ECU), more and more members are controlled bya MOSFET circuits instead of a relay. In addition to the power switching function, the MOSFET maymeasure the current to the steering control of the body and / or to ensure that a diagnostic function. Wecall this type of component a smart power switch or Smart Switch. It is also provided in the SmartSwitch device power failure, if the internal heating caused by electrical current. With the latesttechnology, these components can also integrate control logic and an interface for connection to adigital microprocessor. This last characteristic motivates the subject of study in order to defineimproved protection laws against overheating caused by an electrical current.Indeed, from the point of view of electrical protection, the MOSFET has been designed toachieve the same characteristics as a fuse, with the additional possibility to be reset as a circuit breaker.The aim is to study the control laws that could lead to better monitor the thermal limits of an electricalconductor, especially in low current, so as to reduce the diameter (hence the cost) of son while ensuringbetter protection against short-circuit-impedance (short circuit resistance of a little less than thenominal resistance of the circuit, in a ratio between 1 and 3 for example)
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Naidoo, R. M. "A nonlinear adaptive filter for improved operation and protection of power systems." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5141.
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Includes abstract.Includes bibliographical references (leaves 161-171).
This thesis presents the application of a nonlinear adaptive filter to selected areas in power systems. The filter has demonstrated excellent performance against con-ventional methods in biomedical applications. The algorithm is robust in structure and highly immune to noise. Applications in this thesis include (1) sag detection, (2) symmetrical component estimation, (3) phase and frequency estimation, (4) sag analysis and (5) distributed generation synchronisation and protection. The appli-cations were chosen such that the amplitude, phase and frequency tracking ability are thoroughly tested.
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Liu, Bohan. "Advanced ROCOF protection of distribution systems." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/14344/.
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When islanding occurs, power supply from the main grid is interrupted which causes a problem when distributed generators continue to provide power into distributed networks. An islanding situation should be detected accurately soon after the island is formed. Because failure to trip the islanded distributed resource can lead to a number of problems for the resource and the connected load. Although ROCOF islanding detection method is the most commonly employed anti-islanding protection technique, it provides fast detection and easily implementation. It is sensitive to the system disturbance. Therefore, the application of the ROCOF relay to detect system islanding has been limited. This thesis proposes a solution to enhance the performance of the ROCOF relay by cooperation with rate of change of power or v2/p interlock function. During system load variation, the false operation of ROCOF relay can be blocked effectively. It is validated by applied in grid-connected synchronous generator, Doubly-fed Induction generator (both simulation and experiment) and microgrid. The principle of rate of change of power or v2/p interlock function are presented in this thesis. The new interlock function v2/p with ROCOF relays works well for different types of DGs within a short detection time without introducing perturbation into the system, which are the advantages over other active and hybrid islanding detection methods. The performances characteristics of ROCOF relays for DGs islanding detection (i.e. frequency measuring methods, measuring windows, generator inertia constant, relay settings and load power factor) are investigated. In addition, two other islanding detection methods (impedance measurement (active method) and the Total Harmonic Method) are applied to the grid-connected DFIG distributed system, the comparison and effectiveness of these two methods utilized in islanding and load changing conditions are also discussed.
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Yang, Jin. "Fault analysis and protection for wind power generation systems." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2420/.
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Wind power is growing rapidly around the world as a means of dealing with the world energy shortage and associated environmental problems. Ambitious plans concerning renewable energy applications around European countries require a reliable yet economic system to generate, collect and transmit electrical power from renewable resources. In populous Europe, collective offshore large-scale wind farms are efficient and have the potential to reach this sustainable goal. This means that an even more reliable collection and transmission system is sought. However, this relatively new area of offshore wind power generation lacks systematic fault transient analysis and operational experience to enhance further development. At the same time, appropriate fault protection schemes are required. This thesis focuses on the analysis of fault conditions and investigates effective fault ride-through and protection schemes in the electrical systems of wind farms, for both small-scale land and large-scale offshore systems. Two variable-speed generation systems are considered: doubly-fed induction generators (DFIGs) and permanent magnet synchronous generators (PMSGs) because of their popularity nowadays for wind turbines scaling to several-MW systems. The main content of the thesis is as follows. The protection issues of DFIGs are discussed, with a novel protection scheme proposed. Then the analysis of protection scheme options for the fully rated converter, direct-driven PMSGs are examined and performed with simulation comparisons. Further, the protection schemes for wind farm collection and transmission systems are studied in terms of voltage level, collection level wind farm collection grids and high-voltage transmission systems for multi-terminal DC connected transmission systems, the so-called “Supergrid”. Throughout the thesis, theoretical analyses of fault transient performances are detailed with PSCAD/EMTDC simulation results for verification. Finally, the economic aspect for possible redundant design of wind farm electrical systems is investigated based on operational and economic statistics from an example wind farm project.
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Ladendorff, Marlene Z. "The effect of North American Electric Reliability Corporation critical infrastructure protection standards on bulk electric system reliability." Thesis, Capella University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3640275.
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Compliance with regulations may not automatically produce a secure infrastructure. In the United States energy critical infrastructure sector, compliance with regulatory cyber security standards may not necessarily mean that an entity would be able to withstand a cyber attack on critical assets potentially supporting the reliability of the Bulk Electric System (BES). This qualitative exploratory inquiry study researched technical opinions of cyber security professionals in the energy critical infrastructure industry regarding the effect of the North American Electric Reliability Corporation (NERC) Critical Infrastructure Protection (CIP) standards on the reliability of the BES. NERC entities had been required to be compliant with the standards for several years at the time this study was undertaken. There has been speculation regarding the efficacy of the standards to impact the reliability of the BES. However, there was a lack of scholarly or professional literature confirming assumptions concerning BES reliability. In this study, data was gathered through interviews with individuals who were CIP implementation experts. The purpose of this study was to identify a theme or themes regarding changes in the reliability of the BES as a result of the NERC CIP standards implementation. Interview data from the study generated 9 themes including a theme for the research question indicating that reliability of the BES had improved as a result of the implementation and enforcement of the CIP standards. Some of the more prominent themes included NERC fines having influenced entities in the implementation of the standards; entities have been more concerned about CIP compliance than securing their equipment; and entities have removed equipment from their facilities in order to avoid the requirements, and the associated expense, the standards would demand.
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Manmek, Thip Electrical Engineering & Telecommunications Faculty of Engineering UNSW. "Real-time power system disturbance identification and its mitigation using an enhanced least squares algorithm." Awarded by:University of New South Wales. Electrical Engineering and Telecommunications, 2006. http://handle.unsw.edu.au/1959.4/26233.
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This thesis proposes, analyses and implements a fast and accurate real-time power system disturbances identification method based on an enhanced linear least squares algorithm for mitigation and monitoring of various power quality problems such as current harmonics, grid unbalances and voltage dips. The enhanced algorithm imposes less real-time computational burden on processing the system and is thus called ???efficient least squares algorithm???. The proposed efficient least squares algorithm does not require matrix inversion operation and contains only real numbers. The number of required real-time matrix multiplications is also reduced in the proposed method by pre-performing some of the matrix multiplications to form a constant matrix. The proposed efficient least squares algorithm extracts instantaneous sine and cosine terms of the fundamental and harmonic components by simply multiplying a set of sampled input data by the pre-calculated constant matrix. A power signal processing system based on the proposed efficient least squares algorithm is presented in this thesis. This power signal processing system derives various power system quantities that are used for real-time monitoring and disturbance mitigation. These power system quantities include constituent components, symmetrical components and various power measurements. The properties of the proposed power signal processing system was studied using modelling and practical implementation in a digital signal processor. These studies demonstrated that the proposed method is capable of extracting time varying power system quantities quickly and accurately. The dynamic response time of the proposed method was less than half that of a fundamental cycle. Moreover, the proposed method showed less sensitivity to noise pollution and small variations in fundamental frequency. The performance of the proposed power signal processing system was compared to that of the popular DFT/FFT methods using computer simulations. The simulation results confirmed the superior performance of the proposed method under both transient and steady-state conditions. In order to investigate the practicability of the method, the proposed power signal processing system was applied to two real-life disturbance mitigation applications namely, an active power filter (APF) and a distribution synchronous static compensator (D-STATCOM). The validity and performance of the proposed signal processing system in both disturbance mitigations applications were investigated by simulation and experimental studies. The extensive modelling and experimental studies confirmed that the proposed signal processing system can be used for practical real-time applications which require fast disturbance identification such as mitigation control and power quality monitoring of power systems
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Telford, Rory. "Novel methods for improving fault protection & health management within advanced aircraft electrical power systems." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27950.
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The more-electric aircraft (MEA) concept is widely viewed as the next evolutionary step towards enabling the industry goal of developing optimised, fuel efficient aircraft. MEA have an increased dependency on electrical energy for distribution to secondary systems and, in order to service this increased dependence, the electrical power systems (EPS) are more complex with increased voltage distribution levels, power conversion stages and safety critical components compared with their conventional counterparts. These complexities will only increase in future platforms as they further embrace the MEA concept - the migration to increasingly novel, critical and complex EPS will incur several development and integration challenges. This thesis considers the fundamental challenge of maintaining high reliability standards within future aircraft EPS through the development of accurate and discriminative real-time protection systems which will react during fault conditions. Specifically, the thesis researches novel methods that improve real-time aircraft EPS protection and health management systems by 1) accurately diagnosing degraded faults before their progression to critical failure and 2) diagnosing faults that are difficult to detect using only conventional protection methods â in particular, series arc faults are considered. Within future aircraft EPS, the volume of operational data is expected to significantly increase beyond that of the conventional systems; consequently, the thesis focuses on the use of data-driven, machine learning based methods, to enable these extended functionalities of the EPS protection and health management systems. The types of machine learning modelling techniques that were chosen are explained and justified. Conventional protection methods are described, including a discussion on the difficulties in using them to detect both degraded fault modes and arcing conditions. The necessity to detect these types of faults in an accurate and timely manner is also discussed. One of the main contributions of the thesis is the proposal of the EPSmart method that can autonomously diagnose and isolate a multitude of degraded faults within an aircraft representative EPS. These degraded faults include intermittent and incipient conditions, which, in comparison to overcurrent faults, often lack the energy to be detected by conventional means. Early, and accurate, detection of these conditions will improve overall system health management and reliability and ensure safe operation of the aircraft. Further contribution is the design of the IntelArc method that can detect series arc faults within direct current supplied systems. Accurate detection of series arc faults is extremely challenging as, despite their presence being a serious fire hazard, they result in a decrease of load current. Although methods do exist for diagnosis of series arcing, there remain challenges with regards to accurate detection across different system configurations and operating conditions. The thesis shows the potential for IntelArc to provide accurate detection across a variety of configurations and operating conditions. While the thesis only describes the initial development of these novel methods, the significant conclusions are that application testing has shown the potential for them to enhance real-time network protection, fault tolerance and health management of aircraft EPS through detection of degraded fault and arcing conditions.
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Xu, Ran. "Loss of field protection and its impact on power system stability." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/r_xu_120109.pdf.
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Thesis (M.S. in electrical engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 28, 2010). "School of Electrical Engineering and Computer Science." Includes bibliographical references (p. 99-101).
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Kumbale, Murali. "Bulk transmission system reliability analysis of protection and control groups." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/13840.
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