Showing papers on "Smart grid published in 2006"
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09 Jul 2006TL;DR: In this paper, the authors discuss the possibilities of the distributed power generation systems (DPGS) to deliver power when grid disturbances are present in the utility network, and the focus is set more on the control strategies for active power generation, and mainly on the creation of the reference currents which fulfill the demanded output power.
Abstract: The distributed power generation based on renewable energy sources such as wind and sun experiences a high penetration in the power systems around the world, having in some countries a large contribution to the total energy production. In order to protect the distribution and transmission systems, the grid operators are more and more talking about the ability of the distribution systems (mainly wind turbines WT systems) to behave as a conventional power plant. This paper discusses the possibilities of the distributed power generation systems (DPGS) to deliver power when grid disturbances are present in the utility network. The focus is set more on the control strategies for active power generation, and mainly on the creation of the reference currents which fulfill the demanded output power. Considerations about reactive power are also stated. Experimental results are presented in order to validate the theory behind the proposed control strategies on faulty grid.
91 citations
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01 Sep 2006TL;DR: In this article, the integration of new sources of renewable energy into the power systems in Europe challenges and possible solutions, application of wind power prediction tools for power system operation, new tasks that create new solutions for communication in distribution systems, wind power in Greece, integration of dispersed generation in Denmark, EdF and distributed energy resources in France, and new renewable sources in Italy.
Abstract: This paper examines the integration of new sources of renewable energy into the power systems in Europe challenges and possible solutions, application of wind power prediction tools for power system operation, new tasks that create new solutions for communication in distribution systems, wind power in Greece, integration of dispersed generation in Denmark, EdF and distributed energy resources in France, and new renewable sources in Italy, The paper also examines the European Commission Technology Platform's vision paper on Electricity Networks of the Future that was published in January 2006. In this respect, drivers towards Smart Grids, Grids today, and key challenges for Smart Grids of the Future are critically assessed.
69 citations
01 Jan 2006
TL;DR: The interaction between grid-coupled full hybrid electric vehicles (HEV) and the grid allows the hybrid vehicle to travel a significant part of the time in all-electric mode and enables a lower energy cost and a reduction in environmental pollution, on condition that the electric energy production itself is environmently friendly.
Abstract: The paper examines the interaction between grid-coupled full hybrid electric vehicles (HEV) and the grid. The interaction allows the hybrid vehicle to travel a significant part of the time in all-electric mode. On the other hand, the grid coupling allows the grid to use the hybrid car as a controllable load and energy storage facility, enabling a higher penetration of variable generation units, such as renewable sources based on wind and photovoltaic cells. Experiments with a battery, grid connection and induction machine prove the feasibility of these grid-coupled hybrid electric vehicles. 1 Introduction The batteries currently used in HEVs are expensive and heavy, leading to a low specific energy content. Through the rapid development of batteries the cost per kWh diminishes while the specific energy content rises. As a consequence, larger amounts of energy can be stored in an economic way for the electric propulsion of HEVs and larger distances can be travelled in an all-electric “emission free” mode. An estimated 85 % of fuel (not energy) savings can be achieved if the vehicle has an all-electric driving range of 100 km [6]. In order to achieve this kind of fuel savings, the battery needs to be charged with electrical energy from the grid, as opposed to the current practice where a combustion engine powers an on-board electric generator to produce electric energy. The only requirement to make this happen is a grid coupling. This grid coupling makes a variety of interactions possible between a fleet of HEVs and the grid [1,5]. From the perspective of the hybrid fleet, the grid coupling enables a lower energy cost and a reduction in environmental pollution, on condition that the electric energy production itself is environmently friendly. From the perspective of the grid the fleet of hybrid electric vehicles can act as a controllable load to smooth grid load. Power electronics for the grid coupling, can provide reactive power to enhance the power factor of the installation and can be used as an active filter to eliminate harmonics. By injecting electrical energy in the grid, the HEV can be used as reserve power unit to set off the loss of a power plant, as replacement for peak power units, as part of a microgrid or as stand-alone mobile generator. Other possibilities such as peak-shaving are possible from a technical point of view, but lack the necessary economical feasibility.
49 citations
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18 Jun 2006TL;DR: An analysis of compatibility levels for voltages and currents in the PCC for different control strategies of the grid side converter in large wind turbine applications is presented, based on the existing recommendation within the grid codes.
Abstract: Until recently, there were no specific requirements in the grid codes for connecting the wind turbines/farms to the electrical network. Nowadays the power system operators e.g. in Denmark, Germany and Spain, have started to issue new grid codes addressed to wind turbines/farms. The grid connection requirements are addressed both at distribution and transmission level and can be applied to on-shore units as well as to off-shore ones. The focus in these grid codes is on the power quality, grid stability, control capabilities and on the performances of the wind turbines/farms under fault conditions as well. These requirements can vary considerably from one specific grid code to another and one of the major goals for the wind turbine industry is to meet them without major changes in the control algorithms as well as in the hardware. The grid side converter is a key element in achieving the grid code requirements regarding the compatibility levels for voltages and currents in the Point of Common Coupling (PCC). An analysis of these compatibility levels for voltages and currents in the PCC for different control strategies of the grid side converter in large wind turbine applications is presented in this paper. Different grid conditions as well as different connection method to PCC are considered. The analysis is based on the existing recommendation within the grid codes.
42 citations
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04 Apr 2006TL;DR: In this paper, the interaction between grid-coupled full hybrid electric vehicles (HEV) and the grid is examined, which allows the hybrid vehicle to travel a significant part of the time in all-electric mode, enabling a higher penetration of variable generation units based on wind and photovoltaic cells.
Abstract: The paper examines the interaction between grid-coupled full hybrid electric vehicles (HEV) and the grid. The interaction allows the hybrid vehicle to travel a significant part of the time in all-electric mode. On the other hand, the grid coupling allows the grid to use the hybrid car as a controllable load and energy storage facility, enabling a higher penetration of variable generation units, such as renewable sources based on wind and photovoltaic cells. Experiments with a battery, grid connection and induction machine prove the feasibility of these grid-coupled hybrid electric vehicles.
39 citations
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01 Aug 2006TL;DR: In this article, the authors presented a new look at the way a smart grid can be implemented based on using highly interconnected meshed networks, which can be used in high density urban areas for many years.
Abstract: The power grid is aging and under stress. Unlike other modern networked systems, the grid lacks intelligence and automation. This paper has presented a new look at the way a Smart Grid can be implemented. The conventional approach has been to first obtain real time information on critical parameters, and then by controlling VAR resources, tap changers, and FACTS devices to achieve the desired control. A simpler approach is presented here based on using highly interconnected meshed networks. Such networks have been used in high density urban areas for many years for the high reliability achievable, but suffer from poor line utilization and lack of flexibility under contingency or load growth conditions. The use of a large number of Current Limiting Conductor or CLiC modules provides a simple and cost-effective approach for realizing a controllable meshed network, maximizing network capacity under diverse contingencies and load growth scenarios. Using a low-tech approach, it is seen that basic network performance and reliability are dramatically increased. It is also seen that the distributed nature and inherent redundancy in the deployment of large numbers of CLiC modules, results in high system reliability.
37 citations
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16 Oct 2006TL;DR: Preliminary results show that RSA-grid can provide the comprehensive assessment results for real power systems efficiently and economically.
Abstract: Grid computing is an emerging technology for providing the high performance computing capability and collaboration mechanism for solving the collaborated and complex problems while using the existing resources. In this paper, a grid computing based framework is proposed for the probabilistic based power system reliability and security analysis. The suggested name of this computing grid is reliability and security grid (RSA-grid). Then the architecture of this grid is presented. A prototype system has been built for further development of grid-based services for power systems reliability and security assessment based on probabilistic techniques, which require high performance computing and large amount of memory. Preliminary results based on prototype of this grid show that RSA-grid can provide the comprehensive assessment results for real power systems efficiently and economically.
30 citations
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TL;DR: Takao Shinji Member (Tokyo University of Agriculture & Technology, y3701203@gc.tuat.ac.jp) Tuyoshi Sekine Non-member (Tok Tokyo University of agriculture & technology, y3255511@ug.co.nz)
Abstract: Takao Shinji Member (Tokyo University of Agriculture & Technology, y3701203@gc.tuat.ac.jp) Tuyoshi Sekine Non-member (Tokyo University of Agriculture & Technology, y3255511@ug.tuat.ac.jp) Takao Kashiwagi Non-member (Tokyo University of Agriculture & Technology, kasiwagi@cc.tuat.ac.jp) Atsushi Akisawa Member (Tokyo University of Agriculture & Technology, akisawa@cc.tuat.ac.jp) Goro Fujita Member (Shibaura Institute of Technology, gfujita@sic.shibaura-it.ac.jp) Masayoshi Matsubara Student Member (Shibaura Institute of Technology, e00093@sic.shibaura-it.ac.jp)
27 citations
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11 May 2006
TL;DR: Superconductivity offers powerful new opportunities for restoring the reliability of the power grid and increasing its capacity and efficiency as discussed by the authors, which is the most complex artificial system ever built and may be the greatest engineering achievement of the 20th century.
Abstract: As an energy carrier, electricity has no rival with regard to its environmental cleanliness, flexibility in interfacing with multiple production sources and end uses, and efficiency of delivery. In fact, the electric power grid was named ?the greatest engineering achievement of the 20th century? by the National Academy of Engineering. This grid, a technological marvel ingeniously knitted together from local networks growing out from cities and rural centers, may be the biggest and most complex artificial system ever built. However, the growing demand for electricity will soon challenge the grid beyond its capability, compromising its reliability through voltage fluctuations that crash digital electronics, brownouts that disable industrial processes and harm electrical equipment, and power failures like the North American blackout in 2003 and subsequent blackouts in London, Scandinavia, and Italy in the same year. The North American blackout affected 50 million people and caused approximately $6 billion in economic damage over the four days of its duration. Superconductivity offers powerful new opportunities for restoring the reliability of the power grid and increasing its capacity and efficiency. Superconductors are capable of carrying current without loss, making the parts of the grid they replace dramatically more efficient. Superconducting wires carry up tomore » five times the current carried by copper wires that have the same cross section, thereby providing ample capacity for future expansion while requiring no increase in the number of overhead access lines or underground conduits. Their use is especially attractive in urban areas, where replacing copper with superconductors in power-saturated underground conduits avoids expensive new underground construction. Superconducting transformers cut the volume, weight, and losses of conventional transformers by a factor of two and do not require the contaminating and flammable transformer oils that violate urban safety codes. Unlike traditional grid technology, superconducting fault current limiters are smart. They increase their resistance abruptly in response to overcurrents from faults in the system, thus limiting the overcurrents and protecting the grid from damage. They react fast in both triggering and automatically resetting after the overload is cleared, providing a new, self-healing feature that enhances grid reliability. Superconducting reactive power regulators further enhance reliability by instantaneously adjusting reactive power for maximum efficiency and stability in a compact and economic package that is easily sited in urban grids. Not only do superconducting motors and generators cut losses, weight, and volume by a factor of two, but they are also much more tolerant of voltage sag, frequency instabilities, and reactive power fluctuations than their conventional counterparts. The challenge facing the electricity grid to provide abundant, reliable power will soon grow to crisis proportions. Continuing urbanization remains the dominant historic demographic trend in the United States and in the world. By 2030, nearly 90% of the U.S. population will reside in cities and suburbs, where increasingly strict permitting requirements preclude bringing in additional overhead access lines, underground cables are saturated, and growth in power demand is highest. The power grid has never faced a challenge so great or so critical to our future productivity, economic growth, and quality of life. Incremental advances in existing grid technology are not capable of solving the urban power bottleneck. Revolutionary new solutions are needed ? the kind that come only from superconductivity.« less
18 citations
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04 Oct 2006
TL;DR: The trends and challenges described here will contribute to this change by building a new electricity model that makes the existing one obsolete while recognising today's reality.
Abstract: We are moving towards a sustainable internal electricity market in the European Union with a more diversified generation structure in which small units will seek integration into the electricity grids. The most distinguishing feature of future electricity grids in Europe will be the ability for the users to play an active role in the supply chain. In this transition, new markets will emerge to cover generating capacity, reserve capacity and ancillary services. Some of them are already currently handled by informal trading systems; others will be based on the fully potential that smart energy devices can provide when they are assembled together in a system. The trends and challenges described here will contribute to this change by building a new electricity model that makes the existing one obsolete while recognising today's reality. To my wife and my son, to whom I promised this a few years ago. They fully supported me to conclude it during weekends and holidays. I promise I will not do anything like this again! To my parents, who would have liked to see it finished.
14 citations
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26 Mar 2006
TL;DR: In this article, the authors define the key attributes of the Multipurpose BPL Network down to the silicon level, highlight emerging Smart Grid applications, and showcase how progressive utilities worldwide are leveraging the latest innovation in the BPL technology.
Abstract: Momentum around Broadband over Powerline continues to accelerate. The transformation of the entire electric distribution network into a broadband-enabled communications network is no longer just an industry vision. The Multipurpose BPL Network today is a commercially available reality. BPL not only is proving as a viable commercial broadband alternative, but also is central to the emergence of new Smart Grid Applications, which are designed to significantly enhance the utility core business. This keynote will define the key attributes of the Multipurpose BPL Network down to the silicon level, highlight emerging Smart Grid applications, and showcase how progressive utilities worldwide are leveraging the latest innovation in the BPL technology.
01 Jan 2006
TL;DR: A brief introduction of the current control centers, and a design for the grid service-based future control centers is discussed, and the challenges it is being confronted with.
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TL;DR: The main objective of this paper is to develop a distributed model using grid environment through which on-line monitoring of multi-area power systems can be carried out continuously and has inherent features of scalability and reliability implicitly.
Abstract: The main objective of this paper is to develop a distributed model using grid environment through which on-line monitoring of multi-area power systems can be carried out continuously. Grid computing is a viable solution in order to exploit the enormous amount of computing power available across Internet to solve large interconnected power system problems. A grid service model is proposed for on-line monitoring of multi-area power systems, which provides solutions at specific intervals of time. The proposed model is designed in such a way that any node in the grid can provide the service, which can obtain the power system data from other client grid nodes and responds with solution. Hence the proposed model is highly distributed and has inherent features of scalability and reliability implicitly.
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01 Jan 2006TL;DR: In this article, a study of the current policies, regulations and models that give priority to wind power in the European power system is carried out, where a model for the optimal solution is found as each country chooses its own procedure according to its own conditions, intensions and peculiarities.
Abstract: Wind power has reached an average market growth of 40% in Europe over the last decade. The wind power capacity attained in 2005 the European commission's 40 GW target for 2010, live years in advance. The continuous rise of fuel prices and the commitment to the Kyoto agreement push this growth constantly further. But this phenomenon is not accidental. Policies and grid codes have been redesigned in the last years in almost all the European countries in order to match this increasing amount of intermittent generation. Different economic incentives were offered to wind power and changing grid requirements were asked from these technologies. Industry, government and power market had to develop a system with no precedents. Currently, no optimal solution is found as each country chooses its own procedure according to its own conditions, intensions and peculiarities. Here, a study of the current policies, regulations and models that give priority to wind power in the European power system is carried out
01 Jan 2006
TL;DR: In this paper, the advantages of using both ACand/or HVDC transmission will be compared from technical and economical aspects, and the basic arrangements of different technical solutions, which can be used to interconnect and transport the electrical energy from far remote located wind parks to the local consumer's at large industrial or residential areas.
Abstract: Large wind turbine/ wind park Installations are developing to an important alternative of renewable energy resources. Wind park installations with a rated capacity of several hundred Megawatts up to more than 1000 MW installations for future offshore applications are under investigation in different countries. This paper will give an overview on planning and applications studying such large applications. Both the transmission technologies and the Grid Code requirements are in discussion with the Power Grid Utilities to find the most economical and reliable technical solutions. Long distance underground and sea cable transmission may be used either in HVDC or HVAC technology for some of these applications: Also Power Quality and Reactive Power Compensation / FACTS devices may be used to improve transmission capacity and dynamic stability of such transmission systems. The presentation will provide a summary on the present technologies available and the necessary planning/design steps. The advantages of using both ACand/or HVDC transmission will be compared from technical and economical aspects. The presentation will include some examples to demonstrate some specific design principles, the basic arrangements of different technical solutions, which can be used to interconnect and transport the electrical energy from far remote located wind parks to the local consumer’s at large industrial or residential areas.
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TL;DR: The paper analyzes the characteristic of grid technology and discusses the principle and possibility of information resources integration using grid technology, and the sharing principle of information Resources and work style in the power information grid.
Abstract: The paper analyzes the characteristic of grid technology and discusses the principle and possibility of information resources integration using grid technology. The framework of power information grid platform consists of four parts, i.e. grid system management node, grid public service node, local servers and user grid application services. The former two provide grid fundamental services, while the latter two provide grid application services. The sharing principle of information resources and work style in the power information grid are also discussed.
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01 Dec 2006
TL;DR: In this article, the benefits of using the telecommunication line for monitoring and controlling the system devices is discussed, as an alternative method, autonomous distribution control that enables local power supply and demand control is also required in design and operational stage.
Abstract: Recently, solar energy generation and wind power generation have been introduced to electric power system. But, as for this natural energy, influence such as frequency fluctuation is exerted on electric power system, which is a fundamental problem in operation of a small grid system such as micro-grid. These systems should provide appropriate power quality compared to a large grid. However, using the telecommunication line for monitoring and controlling the system devices is costly, as an alternative method, autonomous distribution control that enables local power supply and demand control is also required in design and operational stage. This paper discusses benefits of these methods conducting cost evaluation.
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TL;DR: In this paper, the main factors influencing the maximum acceptable wind power capacity by Jiangsu Power Grid and the grids of coastal area are analyzed, and suggestions on the voltage degrees at which the large wind power field could be connected to the power system and problems that may occur in operation management of Jiangsu power grid with wind power connected and the countermeasures that should be adopted are put forward.
Abstract: According to the status quo and the "Eleventh Five-Year" Plan of Jiangsu Power Grid,the main factors influencing the maximum acceptable wind power capacity by Jiangsu Power Grid and the grids of coastal area are analyzed.Suggestions on the voltage degrees at which the large wind power field could be connected to the power system and problems that may occur in operation management of Jiangsu Power Grid with wind power connected and the countermeasures that should be adopted are put forward.
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TL;DR: The GridWise™ Testbed Demonstration as discussed by the authors has been used in the Pacific Northwest region of the United States to test and speed adoption of new smart grid technologies that can make the power grid more resilient and efficient.
Abstract: Imagine you’re at home one Saturday morning on the computer, as your son takes a shower, your daughter is watching TV, and a load of laundry is in your washer and dryer. Meanwhile, the fragrance of fresh-brewed coffee fills the house. You hear a momentary beep from the dryer that tells you that if you were to look, a high-energy price indicator would be displayed on the front panels of some of your favorite appliances. This tells you that you could save money right now by using less energy. (You’ve agreed to this arrangement to help your utility avoid a substation upgrade. In return, you get a lower rate most of the time.) So you turn off some of the unneeded lights in your home and opt to wait until evening to run the dishwasher. Meanwhile, some of your largest appliances have automatically responded to this signal and have already reduced your home’s energy consumption, saving you money. On January 11, 2006, demonstration projects were launched in 200 homes in the Pacific Northwest region of the United States to test and speed adoption of new smart grid technologies that can make the power grid more resilient and efficient. Pacific Northwest more » National Laboratory, a U.S. Department of Energy national laboratory in Richland, Washington, is managing the yearlong study called the Pacific Northwest GridWise™ Testbed Demonstration, a project funded primarily by DOE. Through the GridWise™ Demonstration projects, researchers are gaining insight into energy consumers’ behavior while testing new technologies designed to bring the electric transmission system into the information age. Northwest utilities, appliance manufacturers and technology companies are also supporting this effort to demonstrate the devices and assess the resulting consumer response. A combination of devices, software and advanced analytical tools will give homeowners more information about their energy use and cost, and we want to know if this will modify their behavior. Approximately 100 homes on the Olympic Peninsula in Washington State receive energy price information through a broadband Internet connection and have received automated demand-response thermostats and water heaters that can adjust energy use based on price. Fifty of those homes and an additional 50 homes in Yakima, Washington, and 50 homes in Gresham, Oregon, have computer chips helping control their dryers. These chips sense when the power transmission system is under stress and automatically turn off certain functions briefly until the grid can be stabilized by power operators. « less
01 Jan 2006
TL;DR: The required complexity or quality of research of student theses may vary by program, and the required minimum minimum study period may vary in duration as discussed by the authors. But the grade received is not published on the document as presented in the repository.
Abstract: Disclaimer This document contains a student thesis (bachelor's or master's), as authored by a student at Eindhoven University of Technology. Student theses are made available in the TU/e repository upon obtaining the required degree. The grade received is not published on the document as presented in the repository. The required complexity or quality of research of student theses may vary by program, and the required minimum study period may vary in duration.
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01 Jan 2006
TL;DR: The recent developments in the emerging grid computing paradigm are presented and distributed systems structures for online transactions based on economic models are proposed.
Abstract: This paper presents the recent developments in the emerging grid computing paradigm. A background to grid technologies that try to provide dependable, consistent, pervasive and inexpensive on demand access to computer resources is introduced. Also, research issues and challenges of grids systems are presented. Finally, distributed systems structures for online transactions based on economic models are proposed
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TL;DR: In this article, a micro-grid is divided into multiple and optimized for the purpose of maximization of power generation efficiency, and the system proposed in this paper obtained results with high generation efficiency (from 21.1% to 27.6%) compared with the central system (20.6% to 24.8%).
Abstract: The fuel cell micro-grid is expected as a distributed power supply with little environmental impact. However, if a micro-grid is installed in an urban area, a generation efficiency of less than 21% on an all-year basis is expected. Generally, in planning an electric power network using a micro-grid, all the target buildings are connected and electric power is supplied. In this paper, a micro-grid is divided into multiple and each is optimized for the purpose of maximization of power generation efficiency. In the cooperation management of a micro-grid, large fluctuations in load, or increases and decreases in a building, can be followed with a grid using a system-interconnection device. The system proposed in this paper obtained results with high generation efficiency (from 21.1% to 27.6%) compared with the central system (generation efficiency is 20.6% to 24.8%) of a fuel cell micro-grid.
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TL;DR: This paper expounds on the main use of storage technology in grid environments and the state of its development.
Abstract: Grid computing is a new computing model and will become the core of the next generation Internet competitionThe storage is the foundation of grid computing and good solutions to storage are the key to achieving global data sharingThis paper expounds on the main use of storage technology in grid environments and the state of its development
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TL;DR: In this article, a wide area measurement system (WAMS) is built in Northeast Power Grid in China, in which the architecture containing analysis master station and phasor measurement (PMU) systems is adopted to catch dynamic processes and behavior features of power grid being disturbed.
Abstract: Along with the continual enlargement of power grid interconnection scale in China, the impact of load model on calculation results of system simulation cannot be neglected. To choose appropriate load model for simulation, according to the principles of accuracy, reliability, security and practicability and by means of integrating up-to-date technologies of phasor measurement, communication and computer, a wide area measurement system (WAMS) is built in Northeast Power Grid in China, in which the architecture containing analysis master station and phasor measurement (PMU) systems is adopted to catch dynamic processes and behavior features of power grid being disturbed. A powerful analysis master station of the WAMS is equipped in dispatching center of Northeast Power Grid, and different kinds of PMU devices provided by three manufacturers are equipped in twelve power plants and substations. The presented WAMS are tested by manifold ways in long period and by which a lot of dynamic processes of actual power grid are recorded, the recorded processes can offer the data for the check of simulation analysis, but also provide a brand-new dynamic monitoring measure for secure and stable operation of power grid.
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TL;DR: In building campus grid system, there are many technologies to be studied and took shape, for example security mechanism, resource management, task management, communications technology.
Abstract: Grid computing is a new style of distributed computing technology.Grid,which can absorb various computing resources and translate them into convenient and reliable computer power,is a compositive environment of computing and resource.The characteristics and architecture of grid are put forward,then a difference between grid and traditional distributed computing is proposed.Finally analyze pivotal technologies in building campus grid environment.Building campus grid environment is an important work in grid gaining ground.In building campus grid system,there are many technologies to be studied and took shape,for example security mechanism,resource management,task management,communications technology.
01 Jan 2006
TL;DR: The 1996 outage, the most vivid and greatest disaster in power system reliability at that time, was the main focus of the paper and its research on the small world perspective started in 2002.
Abstract: The power grid which is designed to function as a network is vulnerable to physical and cyber disruption. The sources of vulnerability include natural disasters, equipment failures, human errors, or deliberate sabotage and attacks. As the power grids become heavily loaded with long distance transmission, the complex system become even more vulnerable as we have observed in several massive outages in the last decade. In a vulnerable system, a simple incident such as an equipment failure or a line touching a tree can lead to a cascaded sequence of events, leading to widespread blackouts. The power grid, unconcerned to most public most of the time when it is operating in normal condition, gets attention only when such outages occur. As shown in Table I, there were several major power outages in the US power grid in the last three decades [1, 2]. Additionally, in August 2003, even a greater outage occurred in the North-eastern United States. However, since our research on the small world perspective started in 2002, the 1996 outage, the most vivid and greatest disaster in power system reliability at that time, was the main focus of the paper. Actually, the 1996 outage occurred twice, apart by about a month. On July 2, 1996 a short circuit on a 345-kV line in Wyoming started a chain of events leading to a break-up of the western North America power grid which resulted in five islands with a blackout in southern Idaho with loss of 11,750MW of load. The August 10, 1996 failure resulted in break-up of the Western Systems Coordinating Council (WSCC) grid into four islands with loss of 30,390 MW of load affecting 7.49 million customers in western North America [3]. In general, generators in power systems are always subject to periodic disturbances, e.g., periodic load variations in steady state, swings of the other generators in transient state, and so on. The response of a power system to these impacts is oscillatory. If the oscillations are damped, so that after sufficient time has elapsed the deviation or the change in the state of the system due to the small impact is small (or less than some prescribed finite amount), the system is stable. If, on the other hand, the oscillations grow in magnitude or are sustained indefinitely, the system is unstable. When the stability of the system is investigated, it is often convenient to assume that the disturbances causing the changes disappear. Stability is then assured if the system returns to its original state.
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TL;DR: With the deepening of electric power industry restructuring and occurrence of blackouts in the world in recent years, the grid security holds a strategic position concerning national security and social stability.
Abstract: With the deepening of electric power industry restructuring and occurrence of blackouts in the world in recent years,the grid security holds a strategic position concerning national security and social stability.Consequently,the grid risk management ability is considered by grid enterprises as the core competence for subsistence,benefit creation,and future competition.The dispatch response system for grid risks is systematically discussed with emphasis on grid dispatching.
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TL;DR: In this paper, the authors summarized the works and safety measures of dispatching and operating control done by China Southern Power Grid Corp. to guarantee the safe and stable operation of hybrid AC/DC operation power network in China.
Abstract: Southern Power Grid is the first larger hybrid AC/DC operation power network in China, which is a power grid with complex structure, higher technology content and difficulty to operate and control. This paper elaborated the technical characteristics of Southern Power Grid, summarized the works and safety measures of dispatching and operating control done by China Southern Power Grid Corp. to guarantee the safe and stable operation of hybrid AC/DC Southern Power Grid, such as emphasizing power system stability analysis, strengthening construction and management of safe and stable control system, reinforcing PSS operation management, reasonable adjusting and control the distribution of AC/DC power.