Showing papers in "IEEE Computer Applications in Power in 1999"
TL;DR: In this article, the authors focus on some technical aspects, but not on the impact on the quality of supply and on tariff signals, and they focus on the technical aspects only.
Abstract: The insertion of dispersed generation into existing electric power systems has a great impact on real-time operation and planning. Several uncertainties characterize the ability of the existing power system to integrate this form of generation, Hence, dispersed generation must be taken into consideration in power system performance so that operation and security are not disturbed. Dispersed generation increases the complexity of controlling, protecting and maintaining power distribution systems. This article focuses on some technical aspects, but not on the impact on the quality of supply and on tariff signals.
459 citations
TL;DR: In this paper, the authors describe how the Electric Power Research Institute (EPRI) commissioned an implementation and commercialization of a nonintrusive appliance load monitoring system (NIALMS) based on EPRI-developed intellectual property.
Abstract: The authors describe how the Electric Power Research Institute (EPRI) commissioned an implementation and commercialization of a nonintrusive appliance load monitoring system (NIALMS) based on EPRI-developed intellectual property. The system determines the energy consumption of individual appliances being turned on and off within a whole building's electric load.
213 citations
TL;DR: The locational marginal pricing (LMP) system is in use in the Pennsylvania, New Jersey, Maryland (PJM) Interconnection ISO and is proposed for the New York ISO, which is expected to be in operation in 1999.
Abstract: Deregulation is intended to encourage competition among utilities and power marketers to reduce energy prices. The pricing system is very critical in restructuring the electrical industry and depends upon market rules and the function of the independent system operator (ISO). The locational marginal pricing (LMP) system is in use in the Pennsylvania, New Jersey, Maryland (PJM) Interconnection ISO and is proposed for the New York ISO, which is expected to be in operation in 1999. This article provides fundamental concepts of the LMP and outlines the basic requirements for a computer simulation tool to accurately forecast prices in an LMP-based market. Examples are used to demonstrate the concepts, and some preliminary results for the Eastern Interconnection are presented.
170 citations
TL;DR: The author presents an introduction to game theory as well as its application to electric power market allocation problems as a generalization of decision theory.
Abstract: Game theory is a discipline that is used to analyze problems of conflict among interacting decision makers. It may be considered as a generalization of decision theory to include multiple players or decision makers. Here, the author presents an introduction to game theory as well as its application to electric power market allocation problems.
96 citations
TL;DR: It is shown that intelligent systems are able to learn and interpret several variations of the same conditions, thus helping in predicting iron losses with increased accuracy.
Abstract: Methods for iron loss reduction during manufacturing of wound-core distribution transformers are presented. More specifically, measurements taken at the first stages of core construction are effectively used, in order to minimize iron losses of transformer (final product). To optimally exploit the measurements (feedback), artificial intelligence methods are applied. It is shown that intelligent systems are able to learn and interpret several variations of the same conditions, thus helping in predicting iron losses with increased accuracy.
53 citations
TL;DR: In this article, the authors present an analysis of the components of the emerging deregulated electricity industry which provides a basis for structural classification, with a view toward defining the required support tools.
Abstract: In this paper, the authors present an analysis of the components of the emerging deregulated electricity industry which provides a basis for structural classification, with a view toward defining the required support tools.
48 citations
TL;DR: In this article, a free-flowing exploration of issues that seem to the authors to be significant in the post-restructuring era of the electricity supply industry is presented.
Abstract: Protective devices (relays) are the first line of defense against faults and other disturbances that could do extensive damage to power equipment as well as to power systems. They are the most important self-healing mechanisms of power systems. Modern protective systems have evolved into a highly reliable system over many years. As most of the evolution took place during the era of vertically integrated power companies (i.e., where the generation-transmission-distribution-load in a region were all under direct control of a single company), it is natural that protection philosophies in existence today have an in-built character that is well suited to such utility company structures. This paper is a free-flowing exploration of issues that seem to the authors to be significant in the post-restructuring era of the electricity supply industry. They raise many questions from the point of view of power system protection engineers.
47 citations
Journal Article•
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TL;DR: This tutorial presents the concept of data mining and aims at providing an understanding of the overall process and tools involved: how the process turns out, what can be done with it, what are the main techniques behind it, and which are the operational aspects.
Abstract: Data mining (DM) is a folkloric denomination of a complex activity that aims at extracting synthesized and previously unknown information from large databases. It denotes also a multidisciplinary field of research and development of algorithms and software environments to support this activity in the context of real-life problems where often huge amounts of data are available for mining. There is a lot of publicity in this field and also different ways to see the things. Hence, depending on the viewpoints, DM is sometimes considered as just a step in a broader overall process called knowledge discovery in databases (KDD), or as a synonym of the latter. This tutorial presents the concept of data mining and aims at providing an understanding of the overall process and tools involved: how the process turns out, what can be done with it, what are the main techniques behind it, and which are the operational aspects. The tutorial also describes a few examples of data mining applications, so as to motivate the power system field as a very opportune data mining application.
46 citations
TL;DR: In this article, the authors introduce the basics of wavelet analysis and propose how this new mathematical tool may be applied in power engineering, and present a tutorial to grasp the rudiments and begin investigating the use of this powerful tool in a variety of applications related to power engineering.
Abstract: The purpose of this tutorial is to introduce the basics of wavelet analysis and propose how this new mathematical tool may be applied in power engineering. Frequently, newcomers to wavelet analysis become discouraged due to the oftentimes elusive mathematical rigor of the subject and the variety of nomenclatures that are used in various arenas. This tutorial presents wavelet analysis in such a way that the reader can easily grasp the rudiments and begin investigating the use of this powerful tool in a variety of applications related to power engineering.
35 citations
TL;DR: The next generation of intelligent electronic devices (IEDs) based on UCA are coming to the market and are focused on networking in the substation and are based on an MMS/Ethernet profile with one of two networking layers in between.
Abstract: The trend toward electric utility deregulation is moving full speed ahead throughout the world. As a result, the integration, consolidation, and dissemination of information both inter- and intra-utility has become a critical piece of the deregulation picture. Information traditionally used only within a given utility now becomes desired by many players. The general trend in the industry has been toward the use of the Internet for the transfer of data. The Electric Power Research Institute (EPRI) launched a concept in 1990 known as the Utility Communication Architecture (UCA). The goal behind UCA was to identify a suite of existing communication protocols that could be easily mixed and matched, provide the foundation for the functionality required to solve the utility enterprise communication issues, and be extensible for the future. UCA provides a network solution to the interconnection of data sources, similar to the Web solution used throughout the world to interconnect computers. At this time, the next generation of intelligent electronic devices (IEDs) based on UCA are coming to the market. These devices are focused on networking in the substation and are based on an MMS/Ethernet profile with one of two networking layers in between.
32 citations
TL;DR: The authors describe the California independent system operator (ISO) which uses a metering data acquisition system, scheduling infrastructure, scheduling applications, balance of business systems and a power management system.
Abstract: The authors describe the California independent system operator (ISO) which uses a metering data acquisition system, scheduling infrastructure, scheduling applications, balance of business systems and a power management system.
TL;DR: In this article, an advanced system for power system automated fault analysis, accurate fault location and extensive power quality monitoring based on a digital fault recorder (DFR) infrastructure is presented.
Abstract: This article introduces an advanced system for power system automated fault analysis, accurate fault location and extensive power quality monitoring based on a digital fault recorder (DFR) infrastructure. Existing DFRs can be modified to provide the required data acquisition features. The existing communication network and processing power can be extended to accommodate the required data acquisition, processing and analysis. New software can be developed to accomplish the automated analysis.
TL;DR: In this paper, the authors examined the relationship between low frequency oscillations and weak interconnections in the transmission system network, and showed that generators in specific areas of a power system behave coherently in low-frequency oscillations.
Abstract: Electromechanical oscillations are inherent to interconnected power systems. However, the frequency of the oscillations and the number of generators that oscillate in any electromechanical oscillatory mode depend on the structure of the power system network. Low frequency electromechanical oscillations occur when existing generation/load areas are connected to other similar areas by relatively weak transmission lines. Weak interconnections are obvious in many interconnected systems, for example, when two independent electric grids are interconnected for the first time through one or two tie lines. However, in systems that have been interconnected for some time, such as the US/Canadian interconnected systems, and that are being stressed by increased load, weak links are less obvious. Often, the first signs of trouble are low frequency oscillations becoming unstable. The connection between loading and stability is not always obvious. It is also unclear which contingencies may lead to oscillatory instability. This tutorial examines in detail the relationship between low frequency oscillations and weak interconnections in the transmission system network. The basis of the analysis is the observation that generators in specific areas of a power system behave coherently in low frequency oscillations and that groups of coherent generators are separated from other groups of coherent generators by weak interconnections. This observation is also the starting point for dynamic system reduction.
TL;DR: In this paper, computer-based integrated substation protection and control monitoring systems, partial discharge measurement systems, and distributed temperature sensing systems are discussed in the Singapore transmission network at voltages up to 400 kV.
Abstract: Designed and operated as a totally underground system for environmental and aesthetic reasons, underground cables are exclusively used in the Singapore transmission network at voltages up to 400 kV. Fully metal-clad sulphur hexaflouride (SF/sub 6/) gas insulated switchgear (GIS) is used at all transmission levels to circumvent land scarcity in the siting of substations. To maintain and ensure reliability and availability of transmission facilities, technologically advanced systems for protection, control, supervision, and online diagnostics are employed. These are: computer-based integrated substation protection and control monitoring systems, partial discharge measurement systems, and distributed temperature sensing systems. These systems are discussed in this paper.
TL;DR: What is required to introduce information management technology to the substation and how to turn a substation into a distributed database server are examined.
Abstract: Information management technology has undergone tremendous change over the course of the last decade. Exponential advances in hardware, software and communication equipment allow the transportation, storage and manipulation of vast quantities of data at blinding speed relative to just a few years ago. The phenomenal growth of the Internet has delivered unprecedented access to data virtually independent of distance or location. Although these enabling technologies have reached far into work and home environments, they have as yet been little utilized within substations. This article examines what is required to introduce information management technology to the substation and how to turn a substation into a distributed database server.
TL;DR: This article is a summary of technology that has been developed, or is in the process of being developed, that would be useful in improving real-time data modeling exchange for security applications and online security applications that use this technology.
Abstract: With increased energy use, very little new transmission, and open access, the electric power system is experiencing much greater levels of regional transfers. These new requirements push the system to its limits for maximum economic benefit, while maintaining adequate security margins requires online real-time network analysis. An interconnected system can collapse due to a number of different limits being exceeded: thermal, voltage stability, transient stability, and dynamic stability. EPRI has been developing the infrastructure to extract data from proprietary EMS systems, tools to collect and manage large amounts of modeling data, and advanced security applications. These applications will significantly improve the security and efficiency of the operation of the electric power grid for the benefit of all users. EPRI's Grid Operations and Planning department has been working with its members and with the North American Reliability Council to develop technology to: improve data exchange and data communication for security applications; develop transactions systems for tracking transmission reservations and energy schedules; and develop advanced security and reliability applications that use this technology. This article is a summary of technology that has been developed, or is in the process of being developed, that would be useful in improving real-time data modeling exchange for security applications and online security applications that use this technology.
TL;DR: A fuzzy logic based closed loop control system which controls the armature voltage of a generator by varying its field current in real-time in order to solve power system control problems.
Abstract: Fuzzy logic controllers are rapidly becoming a viable alternative for classical controllers. The reason for this is that a fuzzy controller can imitate human control processes closely. Fuzzy logic technology enables the use of engineering experience and experimental results in designing an embedded system. In many applications, this circumvents the use of rigorous mathematical modeling to derive a control solution. Another advantage of fuzzy logic control is that it allows for a model-free estimation of the system. In other words, the designer does not need to state how the outputs depend mathematically upon the inputs. A fuzzy controller can be developed by encoding the structured knowledge of the system, which will allow faster control algorithms to be developed in less time and at less cost. With the advance of microprocessors and digital signal processors (DSPs), fuzzy logic control techniques are becoming more attractive for real-time control problems. It is expected that it will be implemented in many power system control applications in the near future. The paper describes a fuzzy logic based closed loop control system which controls the armature voltage of a generator by varying its field current in real-time.
TL;DR: The article discusses the user-interface design of the program, integration of network analysis engines with the spreadsheet, experiences on utilizing various spreadsheet features to facilitate case studies and the pros and cons of spreadsheet-based power system analysis software.
Abstract: This article presents an Excel add-on program for power system load flow, fault and harmonic analysis that has been used to solve real engineering problems as well as to teach university students. The objective is to share the authors' experiences on using spreadsheet-based power system analysis programs. The article discusses the user-interface design of the program, integration of network analysis engines with the spreadsheet, experiences on utilizing various spreadsheet features to facilitate case studies and the pros and cons of spreadsheet-based power system analysis software.
TL;DR: In this paper, the authors describe a data analysis tool that allows electric utility personnel to automatically and accurately compute the location of faults on power transmission lines and analyze fault data without cumbersome manual data retrieval and calculation procedures.
Abstract: This article describes a data analysis tool that allows electric utility personnel to automatically and accurately compute the location of faults on power transmission lines and analyze fault data without cumbersome manual data retrieval and calculation procedures. When a fault is detected anywhere on the power network, an operator needs only to identify the faulted line, and the data analysis tool will compute the location of the fault as accurately as possible using the information available.
TL;DR: A new method is described for establishing the advance time, which is the most important parameter of an automatic generator synchronizer, and focuses on computer simulations used to test the results.
Abstract: In today's electric power systems, generation relies almost exclusively on many AC generating units operating in parallel. When a new generating unit is being connected to the system, a variety of conditions must be precisely satisfied, including the amplitude, frequency, and phase conditions. This article describes a new method for establishing the advance time, which is the most important parameter of an automatic generator synchronizer, and focuses on computer simulations used to test the results.
TL;DR: RemoteX, which is an infrastructure to deliver power engineering laboratory experiments as objects over the Internet, enables instructors, researchers and students to conduct and control actual experiments remotely through the Internet.
Abstract: This article features RemoteX, which is an infrastructure to deliver power engineering laboratory experiments as objects over the Internet. It enables instructors, researchers and students to conduct and control actual experiments remotely through the Internet. Real-time relevant waveforms can be shown right in front of students so instructors can explain technical subjects and concepts better. In other words, equipment and instrumentation located elsewhere can be used to assist the classroom teaching of technical courses that are offered at other universities or teaching institutions.
TL;DR: The danger signs of technological illiteracy are subtle and largely ignored as mentioned in this paper, which is reflected in consumer discomfort with electronic appliances, like computers and V C R s, and it surfaces in public discussion about the development and use of certain technologies.
Abstract: Technology has transformed virtually every aspect of American life. People rely on technology every day in countless ways, including for transportation, communication, medical care, entertainment, the food they eat, the clothing they wear, and the buildings in which they live and work. Yet, most Americans do not understand how technology works, how it is c rea ted , how it impacts their daily lives, or its potential for changing the future. The nation's collective ignorance about technology is reflected in such seemingly trivial things as consumer discomfort with electronic appliances , like computers and V C R s . More worrisome, it surfaces in public discussion about the development and use of certain technologies. Informed, reasoned debate about such issues as nuclear power and cloning, for example, is nearly impossible today, although both technologies will likely play critical roles in our future. For the most part, the danger signs of technological illiteracy are subtle and largely ignored. Since becoming president of the National Academy of Engineering (NAE), I have spoken out forcefully and often about the need for greater technological literacy in the United States. I firmly believe that our continued success as a nation depends on all Americans having a firmer grasp of technological issues. This is especially true for our children, who are inheriting a world driven by, and by no small measure dependent on, technology. By technological literacy, I mean the ability to understand, use, and make sound decisions about technology. I do not mean simply the use of computers is a potent tool, when used intelligently, but it is only one ele ment of the vision I want to promote.
TL;DR: An overview of an easily accessible software tool which allows engineers to integrate, compare and manipulate power system data from various sources and the program's structure and methodology for data import and processing is presented.
Abstract: This paper presents an overview of an easily accessible software tool which allows engineers to integrate, compare and manipulate power system data from various sources. The program allows the visualisation of power system data from a variety of time and frequency domain simulation programs and measuring instruments. This article provides a detailed account of the program's structure and methodology for data import and processing. The following capabilities are discussed: data management; data display; data processing; data formatting; and data sharing.
TL;DR: The AC-DC Power System Analysis, a book published by the Institution of Electrical Engineers QEE, UK, as part of their Power and Energy Series, continues a fine tradition of textbooks on power system analysis from Canterbury, New Zealand as discussed by the authors.
Abstract: The power industry throughout the world is looking for ways to increase the capacity of transmission paths as well as means that allow better control of power flow on existing transmission equipment. One means that is becoming more prevalent is the use of d c transmission. AC-DC Power System Analysis, a book published by the Institution of Electrical Engineers QEE), UK, as part of their Power and Energy Series, continues a fine tradition of textbooks on power system analysis from Canterbury, New Zealand [ 1,2]. The text deals with analytical methods for the analysis of power systems that contain ac-dc converters and inverters. In particular, the book's main emphasis is on the use of these techniques for system studies where the power system contains or is influenced by ac-dc converters. The techniques covered include power flow (both conventional positive sequence and three phase power flow), harmonic analysis, analysis of the switching circuits using electromagnetic transient simulation software, and electromechanical stability analysis. In addition, the authors provide a complete set of appendices that cover the necessary numerical analysis background. The topics are all aimed at giving the reader an understanding of the methods necessary for the analysis of a c d c power system components. These methods are necessary if engineers are to properly design the a c d c converters, the necessary equipment that must be added outside the converters, and the effects of t h e s e converters on the remainder of the system. The first and second chapters start by introducing the reader to circuits with controlled \" valves \" that are drawn as diodes but have the important prop erty of having their \" firing \" controlled by an external signal. The second chapter C Power System Anc shows how the valves are connected and \" fired \" so as to effect either a rectifi-cation from acto dc or inversion from dc to ac. This is done for both balanced and unbalanced conditions. The reader is introduced t o the harmonic analysis problem that must be dealt with in any circuitry with switching elements. Chapter three begins the introduction of the numerical methods necessary to carry out the simulation of the a c d c converters within a conventional power flow. Common power flow numerical techniques such as Newton-Raphson and Decoupled Newton methods are used, but in quite different ways for analysis of voltages and currents …
TL;DR: In this article, the main objective of predictive reliability analysis is to quantify, predict and compare reliability indexes for various reliability improvement initiatives, which can be implemented without altering the fundamental system design or philosophy currently in place.
Abstract: The main objective of predictive reliability analysis is to quantify, predict and compare reliability indexes for various reliability improvement initiatives. This information helps engineers and managers at electric utility organizations decide how to spend reliability improvement dollars by identifying the most effective actions for improving reliability of distribution feeders. There are many types of system design and maintenance tasks that fall under the reliability improvement umbrella. The type of distribution reliability improvement software discussed here focuses on improvement initiatives that are both practical and economical to implement. Results can be implemented without altering the fundamental system design or philosophies currently in place. In other words, these are not radical departures from the current mode of business, but rather a fine-tuning of systems already in place to achieve a higher level of reliability.
TL;DR: Transmission users may benefit by analyzing their power transmission system using a suite of public domain tools that could provide insight into the calculations of the transmission provider.
Abstract: Transmission users may benefit by analyzing their power transmission system using a suite of public domain tools that could provide insight into the calculations of the transmission provider. The potential benefits of a hands on approach are detailed and the quality and consistency of the calculations should be of interest to all transmission users.
TL;DR: In this paper, the authors present a method for determining the number of feeders that is suitable for radial networks, and a simple optimization of these results is then carried out and discussed.
Abstract: It is not unusual for rural 11 kV distribution systems in the UK to be divided into four or five feeders associated with a single primary infeed. This is for a number of reasons concerning design standards, network constraints, costs, and performance. This article presents a method for determining the number of feeders that is suitable for radial networks. The input data for the model is crucial and is discussed before the results for losses, reliability, and network costs are presented. A simple optimization of these results is then carried out and discussed.