Showing papers on "Blackout published in 2000"

Initial evidence for self-organized criticality in electric power system blackouts

Abstract: We examine correlations in a time series of electric power system blackout sizes using scaled window variance analysis and R/S statistics. The data shows some evidence of long time correlations and has Hurst exponent near 0.7. Large blackouts tend to correlate with further large blackouts after a long time interval. Similar effects are also observed in many other complex systems exhibiting self-organized criticality. We discuss this initial evidence and possible explanations for self-organized criticality in power systems blackouts. Self-organized criticality, if fully confirmed in power systems, would suggest new approaches to understanding and possibly controlling blackouts.

Should NFL blackouts be banned

Abstract: In this paper, the authors examine the economic and policy implications of the National Football League (NFL) ‘blackout rule,’ a league rule that prohibits local television broadcast of games that are not sold out at least 72 hours prior to game time. The foundation for understanding and assessing the impact of the blackout rule is an analysis of attendance using data on games during the 1996–1997 National Football League season. Expanding on previous research, three separate components of attendance (season ticket sales, game day ticket sales, and game day noshows) are examined in detail. Accounting for the endogeneity of key variables, Tobit and Probit analyses are used to estimate and predict individual game attendance. These empirical estimates are then used as a vehicle to assess the implications of game day blackouts and the potential for public policy intervention. More specifically, the authors begin by estimating the impact of the blackout on game day attendance. Using these estimates, they asses...

A remedial control scheme protects against transient instabilities based on phasor measurement units (PMUs)-a case study

Abstract: This paper proposes a fast remedial control scheme to prevent power system blackout due to the severe fault at the major EHV transmission line, which transfers large power between areas. The authors use PMUs to monitor the generators and the major EHV transmission lines of a power system, and apply fault detection/location system to precisely detect/locate fault for initiating remedial control actions to avoid a sequence of relay trip events whenever necessary. Real-time phasor measurements are then use to estimate the parameters of OMIB. The remedial control actions consist of load shedding and fast-valve control of turbines. The strategy for determining the timing and amount of remedial control actions is a proposed line-based equal area criterion. The proposed scheme is tested with the Taipower system, which experienced a severe fault at a major EHV tie-line which carried more than 1500 MW and caused successive relay trips resulting in power system blackout. Almost total 83% consumers had an interruption in 729-event. The authors simulate the scenario of 7a 29-event and the proposed scheme using the PSS/E-24 simulator program. Encouraging results are obtained.

Emergency power control device for elevator

Abstract: PROBLEM TO BE SOLVED: To secure the operation of an elevator in case of traveling with the power of a blackout storage battery, and to prevent a stop of a car between stories due to the reduction of the storage power of the storage battery. SOLUTION: In case of the regenerative running of an electric motor 5 for driving a car 7, the regenerative power is generated in a direct current side of an inverter 4. A storage battery 13 stores the regenerative power through a two-way power converting device 14, and discharges the power in case of the power running to supply the power to the inverter 14. In case of blackout, the car 7 travels with the power of the storage battery 13. A charge and discharge control device 15 controls so that the storage power of the storage battery 13 becomes larger than the power for making the car 7 travels in case of blackout. COPYRIGHT: (C)2002,JPO

Summary of System Restoration Plan for the Pacific Northwest Power System

Abstract: This chapter contains sections titled: History and Characteristics of the BPA Grid Blackout Scenario Restoration of BPA Base System Power Grid Conclusion ]]>

Random adaptive optimizer restores distribution service

Abstract: Power network faults may lead to blackouts in some areas. Dispatchers should accurately diagnose faulted elements as soon as possible and restore those areas to their normal state. The restoration of the blackout area in a distribution network is a complex nonlinear combinatorial optimization problem, which is to restore as much of the blacked out area as possible and not to lead to overload in the normal area. In view of the limitation of the conventional expert system (ES) based on rules for restoring a blacked out area, a new random adaptive optimizing method based on a genetic algorithm (GA) is applied to the restoration system of the distribution network.

Blackout restoration techniques for Saudi Electric Company-Central Branch

Abstract: This paper describes the concepts and techniques inserted into the blackout restoration procedure for the complete restoration of the SEC C network (Saudi Electric Company-Central Branch). It addresses (a) the criteria established to ensure satisfactory steady state conditions of frequency, voltage and generator's MVAr loading, (b) the studies made to ensure that transient and steady state conditions will be within limits under the worst conditions, (c) the concepts of the restoration arrangement, (d) the standard switching procedures for load pickup, (e) the partial load restoration to speed up the energization of all substations, (f) the rules on spinning reserve and redundant network element to warrant against contingencies that could recollapse the network, and finally, (g) the support group to provide technical expertise to the dispatchers during the process.

Blackout History Project

Abstract: The WARC file must be opened using a program like Webrecorder.io. The ZIP contains a static version of the website.

Time-delay blackout energy saving switch

Abstract: The utility model relates to a time-delay blackout energy saving switch, which is composed of a light touch switch SB, a charge and discharge circuit of a capacitor C3, a triode Q, a solid relay J, a power supply circuit thereof, a fuse FU, a light-emitting diode LED, diodes D3 and D4, a manual switch S, etc. The utility model which is provided with a continuous lighting switch has the advantages of small size, high reliability of assembly and adjustable delay time; the utility model can be started by current limiting, and the service life of a lamp can be prolonged. The utility model is a time delay switch which is used for lighting for stairs, hallways, etc.

Nodal-price dependent, dual-mode transmission line protection strategy

Abstract: It is argued that the Independent System Operator (ISO) should be able to adjust the security and dependability of the power protection system in response to system and market conditions. However the existing protection philosophy's multiple, overlapping schemes tend to favor individual elements over the security of the wide-area. We revisit the rare-probability, hidden failures embedded within the individual relays but this time include the failure to trip when a fault needs to be cleared along with the unnecessary tripping of a transmission line. We devise a relaying concept to reduce the probability of cascading outages by decreasing incorrect relay operations through a dual-mode or the security-dependability mode (S-D Mode) scheme. It is our contention that during periods of high nodal prices which may even predict a cascading event, we can reduce the probability of a blackout by changing to a secure mode over the dependable region of operation.

Operation control method of refrigerator at the time of resetting power source after blackout

Abstract: PROBLEM TO BE SOLVED: To keep a cooling capacity of a refrigerator at a certain level after reset of a power source, by performing re-operation on the basis of the operational information of the preoccurrence of a blackout, in the case where power source is re-applied after the blackout. SOLUTION: When resetting power source after a blackout, a control unit 100 confirms operational information which has been stored in an EEPROM 42 of an information storage 40 to check the presence of data which has been stored in respect of a refrigerator temperature setting value. If determined YES, an operational mode which copes with the temperature setting value is automatically set. Thereafter, a determination is made as to the presence of integrated information on an operating time of a compressor 60. When determined that the integrated information is present, and that re-operation of the refrigerator caused by the blackout is to be executed, the temperature of the inside of the refrigerator and the temperature of the surface of an evaporator are detected, followed by comparison thereof with each of standard temperatures. When either one of the two kinds of determination requirements is satisfied, judgement is made that a short blackout has occurred, and then, as a cooling operation is conducted to comply with the set operational mode, the integrated information on the operating time of the compressor 60 is multiplied with the operating time of the compressor 60.

Electricity: Lifeline or Bottom Line?

Abstract: If we're not careful, the benefits of competition may be overshadowed by a loss of reliability On a blistering day last July, two large cables at a Chicago substation failed, triggering a local blackout that sent hundreds of air-conditioning deprived residents to hospitals and a few, tragically, to cemeteries At its worst, the blackout left more than 100,000 people without electricity, and thousands remained that way for the better part of three days This was only one in a string of blackouts during the summer of 1999 that afflicted hundreds of thousands in New York City, Long Island, New Jersey, the Delmarva Peninsula, and four Gulf states And the problems were not confined to local power companies; several high-voltage transmission systems--designed to deliver vast amounts of power over great distances in all sorts of weather-- strained to keep up with demand Over the course of five tense weeks, two other blackouts hit Chicago while other electric systems suffered with voltage problems and a few teetered on the brink of collapse What's happening here? Why is the world's strongest, most reliable electric grid scrambling to keep up with hot, but not unprecedented, summer weather? And why is it hard for some transmission operators to make eye contact when asked about the prospects for this summer? The reasons are complex, and agreement is lacking, but many point to the pressures competition is placing on an industry still learning how to compete In short, the move to restructure the electric utility industry has the industry sprinting toward competition before it can walk As a consequence, the long-sacred focus on reliability is beginning to blur Instead of filling its traditional role as a lifeline, electricity is in danger of becoming just a bottom line Lights Out Blackouts--small or large--are nothing new; but the reasons for some of last summer's blackouts and near misses are disturbing For example, the US Department of Energy cited Chicago's Commonwealth Edison for scrimping on its substation maintenance budget--which went from a high of $47 million in 1991 to just $15 million in 1998--as it shifted money into its nuclear program and preparations for competition [1] Other systems, including TVA's, were threatened when operators were unable to predict the massive amounts of power flowing across their systems from eager new sellers on one side to eager new buyers on the other Unless transmission operators understand exactly where and when power will flow across their systems, lines that are already overburdened by severe weather can fail, triggering widespread disruptions Looking at the blackouts of 1999, DOE concluded that " the necessary operating practices, regulatory policies and technological tools for dealing with the changes [resulting from a restructured environment] are not yet in place to assure an acceptable level of reliability" [2] Energy Secretary Bill Richardson and Federal Energy Regulatory Commission Chairman James Hoecker have warned of more blackouts this summer, and Richardson criticized policymakers who "haven't kept pace with the rapid changes in the electric utility industry" [3] While many would welcome legislation to ensure reliability, the industry desperately needs something more--time Unless the industry has time to strengthen the grid, time to understand the new pressures that competitive pricing brings, and time to develop the complex computer modeling and analytical tools needed to safely manage the phenomenal increase in electricity transactions, many fear the grid may be headed for the most severe outages since the New York blackout of 1965 The Electric Power Research Institute estimates that power failures in the United States cost the economy approximately $50 billion per year The World's Largest Machine Someone once called the North American electric grid--the massive conglomeration of generators, wires, switches, breakers, and related equipment that produces and moves electricity to almost every point on the continent--the world's largest machine …

Improving voltage stability of transmission line limits

Abstract: An approach is described which can allow the development an arrangement for automatically dealing with the threat to system voltage stability. The approach utilises pattern recognition to provide adaptive and timely responses throughout the entire grid. Pattern recognition offers an intrinsically simple (minimal computation) and reliable method, an essential for a practical protection which must function whenever it is needed. To allow an affordable solution against multiple contingencies to the grid, load shedding is proposed, as it avoids the inordinate expense of redundant equipment for withstanding unpredictable situations. This offers a modest cost protection at only a tiny fraction of the tens of millions of dollar costs incurred by the 2nd July and 10th August 1996 US power blackout incidents.

Evaluating a Restoration Tool Using Consolidated Edison's Training Simulator

Abstract: To facilitate the implementation of restoration procedures in the event of a blackout, Consolidated Edison is considering the implementation of a knowledge-based restoration tool. This tool would not only guide operators through the execution of predefined procedures, but would also have the ability to adapt and modify these procedures if needed. These requirements can be met if the tool is built on top of a model of the power system and if it decomposes the procedure into components with an explicit or easily identifiable purpose. This tool has been developed and integrated with ConEd's Operator Training Simulator so that it can be used to train the operators in the restoration procedures. After evaluation it may be enhanced to become an on-line tool for use during an actual restoration.