| Name | Author | Date | Size | Type | ID |
A Virtual Environment for Interactive Visualization of Power System Economic and Security Information
Abstract - Simulation and analysis of power systems often involves modeling extremely complex systems. This is particularly true when the model involves not just the electrical power system, but also other networks layered on top of the power system, such as the accompanying financial transactions. Such layered networks can often involve interactions that are not at all obvious. Interactive visualization can be a very effective means for determining otherwise hidden relationships between various elements in the network. This paper describes a 3D virtual environment developed to allow users to interactively visualize such information and relationships. The paper describes the architecture used to develop this environment, and then provides several examples of how the environment is used to provide an interactive visualization of power system economic and security information.
Uploaded: March 30, 1999.
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Thomas J Overbye, Raymond P. Klump, Jamie D. Weber
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03/30/99
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430.09 KB
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PDF
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99-01
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The Impact of Generation Mix on Placement of Static VAR Compensators
Abstract - This paper looks at the problem of placing Static Var Compensators to provide maximum transfer capability for all possible generation mixes. The margin to low voltage limit is one of the quantities used to determine power system transfer capability. A fast method for finding the location of SVC systems that will have the greatest impact on the low voltage margin will be shown. The IEEE 24 bus system will be used to demonstrate this method over a wide range of generation patterns.
Uploaded: May 21, 1999.
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Robert H. Lasseter, Ronghai Wang
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05/21/99
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98.87 KB
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PDF
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99-02
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Optimal Power Flow Formulation in Market of Retail Wheeling
Abstract - Power system deregulation along with retail wheeling was proposed in legislation for the future power system operation. Retail wheeling implies customers have more choices. One important option is the power supplier providing cheaper power. In this paper we introduce new concepts of generation sets and load sets to model the behavior of power supply and load distribution in the new retail wheeling market. Formation of optimal power flow (OPF) problem, in which the public interests are maximized, is demonstrated.. IEEE-14 bus system is used as an example.
Uploaded: May 21, 1999.
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Taiyou Yong, Robert Lasseter
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05/21/99
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35.40 KB
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PDF
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99-03
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Coordination of Excitation and Governing Control Based on Fuzzy Logic
Abstract - In deregulated power systems, competition could push the system near its security limit. The issue of power system stability is becoming more crucial. The excitation and governing controls of generator play an important role in improving the dynamic and transient stability of power system. Typically the excitation control and governing control are designed independently. In this paper, we present a fuzzy logic based method for the excitation control and governing control. Fuzzy logic is applied to generate two compensating signals to modify the controls during system disturbances. A single machine to infinite bus system is applied in simulation. The oscillation of internal generator angles is observed to indicate the good performance of proposed control scheme.
Uploaded: May 21, 1999.
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Taiyou Yong, Robert H. Lasseter, Wenjin Cui
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05/21/99
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101.59 KB
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PDF
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99-04
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Designing Cost Effective Demand Management Contracts using Game Theory
Abstract - Demand relief from customers can help a utility solve a variety of problems. There exist all sorts of different demand management programs that utilities use. A critical issue is the incentive paid to the customer to participate in demand management programs and provide load relief. The utility has to design cost effective yet attractive demand management contracts. The main goal is to get load relief when needed. If the contracts are designed to be cost effective they can help the utility reduce costs. Customers sign up for programs when the benefits they derive in the form of up front payments and interruption payments exceed their cost of interruption. In order to design such contracts, mechanism design with revelation principle is adopted from Game Theory and applied to the interaction between a utility and its customers.The idea behind mechanism design is to design an incentive structure that encourages customers to sign up for the right contract and reveal their true value of power (and thus, the value of power interruptibility).
Uploaded: June 8, 1999.
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Murat Fahrioglu and Fernando L. Alvarado
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06/08/99
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108.97 KB
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PDF
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99-05
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Using Utility Information to Calibrate Customer Demand Management Behavior Models
Abstract - In times of stress customers can help a utility by means of voluntary demand management programs if they are offered the right incentives. The incentives offered can be optimized if the utility can estimate the outage or substitution costs of its customers. This report illustrates how existing utility data can be used to predict customer demand management behavior. More specifically, it shows how estimated customer cost functions can be calibrated to help in designing efficient demand management contracts.
Report dated June 10, 1999. Uploaded: June 10, 1999.
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Murat Fahrioglu, and Fernando L. Alvarado
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06/10/99
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123.89 KB
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PDF
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99-06
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Detecting and Improving the Vulnerable Links in the Power Network: Part I
Abstract - We simulate, via a variance reduction scheme called importance sampling, rare events involving generator trips and incorrect zone three relay operations while monitoring the frequency, generation, and load deviation. We have studied the significance of reducing the probability of a false relay operations in the weak links to determine its effect on the rest of the network and prove that reducing the probability of hidden failures does not pose negative side effects on the system security. Given a system and economic conditions, it is useful to know where investments such as microprocessor relays will be most effective. It is our contention that the improvements in protection in these weak links will allow the ISO to make better future financial investments.
Uploaded: June 16, 1999.
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Koeunyi Bae and James S. Thorp
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06/16/99
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207.67 KB
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PDF
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99-07
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Suggested Analytic Approach to TransmissionReliability Margin; Draft Report June 1999
Transmission Reliability Margin (TRM) is the component of available transfer capability that accounts for uncertainties and safety margins. We suggest an analytic framework for TRM calculation using transfer capability sensitivity formulas and a probabilistic characterization of the various uncertainties. Preliminary results on a simple example show how we plan to test the TRM calculation and validate it with a Monte Carlo method. This draft report is produced in order to seek comment from PSerc members on the practicality and usefulness of this approach to TRM.
Draft Report: June 22, 1999. Uploaded: July 5, 1999.
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Jianfeng Zhang, Ian Dobson, Fernando L. Alvarado
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07/05/99
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102.60 KB
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PDF
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99-08
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Fast Determination of Simultaneous Available Transfer Capability (ATC)
Abstract - This paper proposes a novel fast computational method to determine the simultaneous power available transfer capability (ATC) in a power system. This method consists of a fast estimation algorithm and a constrained power flow iteration. The ATC limiting factors considered in the method are: line thermal limits, bus voltage limits, and generator reactive power limits. When combined with the first line contingency considerations, this method will give the fastest ATC computing. The feature of this method is that it uses only one steady state power flow result for the fast estimation algorithm. Without further time consuming power flow iterations, it is the fastest estimation algorithm available.
Based on the fast estimation, with a few more constrained power flow iterations, precise ATC value can be obtained. This method can be used to improve the speed of many available ATC programs. Especially, it may be used in addition to the widely used DC power flow program or simply replace it to provide additional voltage and var information, since DC power flow generally ignore voltage or var problems. This method can help the independent system operator (ISO) to determine the validity of the bidding results in an open access deregulated electricity market when timely ATC information is very important. It can also help the power market participants to place bids strategically when congestion happens.
Uploaded: July 23, 1999.
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Ronghai Wang, Robert H. Lasseter, Jiangping Meng, Fernando L. Alvarado
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07/23/99
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60.10 KB
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PDF
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99-09
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Application of Optimal Multiplier Method in Weighted Least-Squares State Estimation: Part I - THEORY
Abstract - Standard algorithms for state estimation may be viewed as quasi-Newton's methods applied to the first order optimality conditions of a least squares minimization problem. Previous work in the literature has documented the (somewhat surprising) fact that when a full Newton's method is applied to the same formulation, convergence properties are far worse than the quasi-Newton's method, until the iterates reach an EXTREMELY small neighborhood of the solution. Motivated by these results, and by availability of efficient algorithms to compute higher order derivatives necessary in an exact Newton formulation, this paper proposes several Newton's method variants to improve state estimator convergence. Benchmarks for the IEEE 118 and 300 bus test systems are provided, with comparisons against classical normal equation method, Hatchel's method, and QR algorithms. In these benchmark examples, the new algorithms developed show more reliable convergence for ill-conditioned cases, while making minimal sacrifices in computational efficiency for well-conditioned cases.
Uploaded: July 23, 1999.
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Jianping Meng, Christopher L. DeMarco
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07/23/99
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134.63 KB
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PDF
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99-10
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Application of Optimal Multiplier Method in Weighted Least-Squares State Estimation: Part II - SIMULATION
Abstract - Standard algorithms for state estimation may be viewed as quasi-Newton's methods applied to the first order optimality conditions of a least squares minimization problem. Previous work in the literature has documented the (somewhat surprising) fact that when a full Newton's method is applied to the same formulation, convergence properties are far worse than the quasi-Newton's method, until the iterates reach an EXTREMELY small neighborhood of the solution. Motivated by these results, and by availability of efficient algorithms to compute higher order derivatives necessary in an exact Newton formulation, the companion paper proposes several Newton's method variants to improve state estimator convergence. In this paper Benchmarks for the IEEE 118 and 300 bus test systems are provided, with comparisons against classical normal equations, Hatchel's method, and QR algorithms. In these benchmark examples, the new algorithms developed show more reliable convergence for ill-conditioned cases, while making minimal sacrifices in computational efficiency for well-conditioned cases.
Uploaded: July 23, 1999.
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Jianping Meng, Christopher L. DeMarco
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07/23/99
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162.23 KB
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PDF
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99-11
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Visualization of Power System Data
Abstract - Effective power system operation requires power system engineers and operators to analyze vast amounts of information. In systems containing thousands of buses, a key challenge is to present this data in a form such that the user can assess the state of the system in an intuitive and quick man-ner. This is particularly true when trying to analyze relationships between actual network power flows, the scheduled power flows, and the capacity of the transmission system. With restructuring and the move towards having a single entity, such as an independent system operator or pool, operate a much larger system, this need has become more acute. This paper presents several power system visualization techniques to help in this task. These techniques include animation of power system flow values, contouring of bus and transmission line flow values, data aggregation techniques and virtual reality data visualization.
Uploaded: October 1, 1999.
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Thomas J. Overbye, Jamie D. Weber
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10/01/99
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429.48 KB
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PDF
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99-12
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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.
Copyright 2000 IEEE. Proceedings of the Hawaii International Conference on System Sciences, January 4-7, 2000, Maui, Hawaii. Uploaded: October 1, 1999.
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Ben A. Carreras, David E. Newman, Ian Dobson, A. Bruce Poole
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10/01/99
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71.26 KB
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PDF
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99-13
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Assessment of Transmission Constraint Costs: Northeast U.S. Case Study
Abstract - This paper provides a methodology to examine the impact of transmission constraints on the efficient operation of large scale power markets. The Northeast U.S. is presented as a case study. A system model was first constructed using the publicly available U.S. Federal Energy Regulatory Commission (FERC) Form 715 filings to provide a detailed representation of the transmission system. FERC Form 1 data and information from the U.S. Energy Information Administration's (EIA) National Energy Modeling System model were used to represent generator costs. An optimal power flow (OPF) was then used to optimally dispatch a large system consisting of the New England Region (NEPOOL), New York (NYPP), and the NERC MAAC and ECAR regions, both under base case and modified conditions. Using the OPF results, the costs associated with transmission constraints are determined. Finally, given the large amount of data generated by these studies, methods for the efficient visualization of the results are also discussed.
Uploaded: October 5, 1999.
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Thomas J. Overbye, Douglas R. Hale, Thomas Leckey, Jamie D. Weber
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10/05/99
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1.02 MB
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PDF
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99-14
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Sensitivity of transfer capability margins with a fast formula
Abstract - Bulk power transfers in electric power systems are limited by transmission network security. Transfer capability measures the maximum power transfer permissible under certain assumptions. Once a transfer capability has been computed for one set of assumptions, it is useful to quickly estimate the effect on the transfer capability of modifying those assumptions. This paper presents a computationally efficient formula for the first order sensitivity of the transfer capability with respect to the variation of any parameters. The sensitivity formula is very fast to evaluate. The approach is consistent with the current industrial practice of using DC load flow models and significantly generalizes that practice to more detailed AC power system models that include voltage and VAR limits. The computation is illustrated and tested on a 3357 bus power system. This paper is a preprint from the NSF ATC project.
Submitted to IEEE Transmission on Power Systems. Uploaded: December 30, 1999.
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Scott Greene, Ian Dobson, Fernando L. Alvarado
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12/30/99
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90.81 KB
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PDF
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99-15
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Reactive Power Market Power
Abstract - Market power refers to conditions where the providers of a service can consistently charge prices above those that would be established by a competitive market. There are many well known definitions of market power, including indices intended to quantify the degree of market concentration of energy supplies. This paper explores a method by which one of the standard indices in market power analysis (the Herfindahl-Hirschman Index) can be used to measure reactive power market concentration. The proposed method is illustrated by means of a simple example.
This paper was presented at the IEEE PES Winter Meeting. Uploaded: June 13, 1999.
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Fernando L. Alvarado, Thomas Overbye, and Peter Sauer
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06/13/99
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81.34 KB
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PDF
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99-16
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Solving Power Flow Problems with a Matlab Implementation of the Power System Applications Data Dictionary
This Word file uses a subset of the Power System Data Dictionary structures to implement a complete "vanilla" power flow along with a few more capabilities. It is designed so the examples can be executed by "cut and paste" from the Word document directly to Matlab. Abstract - This paper implements a power flow application and variations using the IEEE Power System Application Data Dictionary within a Matlab environment. It describes a number of useful data and implementation techniques for a variety of applications. The techniques include the use of very compact and efficient code for the computation of Power Transfer Distribution Factors. Power Transfer Distribution Factors are an important element of present and proposed congestion management strategies for power systems, particularly when these systems must operate in a deregulated environment.
Uploaded: January 20, 1999.
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Fernando L. Alvarado
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01/20/99
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84.50 KB
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DOC
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99-17
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A Web-Based Platform for Experimental Investigation of Electric Power Auctions
Abstract - This paper describes the architecture and uses of an Internet based software platform called PowerWeb. PowerWeb was designed and implemented as a simulation environment for evaluating various power exchange auction markets through experimental investigation. It is designed to host simulations of a competitive “day-ahead” electric energy market in which the participants interact by submitting bids or offers into a market via a web-based user interface. The PowerWeb environment is meant to be flexible so as to allow investigation of various market mechanisms. In this paper we describe its interactive, distributed and web-based character.
Decision Support Systems, vol. 24, nos. 3&4, January 1999. Uploaded: June 27, 2006.
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Ray Zimmerman, Robert J. Thomas, Deqiang Gan, Carlos E. Murillo-Sanchez
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06/27/06
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533.81 KB
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PDF
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99-18
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A Uniform Price Auction with Locational Price Adjustments for Competitive Electricity Markets
Competitive electricity markets which rely on centralized dispatch require a mechanism to solicit offers from competing generators. Ideally, such an auction mechanism provides incentives to submit offers equal to the marginal cost of generation for each generator. Economic theory suggests that the Uniform Price auction is an appropriate institution. However, an efficient implementation of this auction in an electricity context requires that the offers used in the auction reflect the appropriate locational price adjustments for transmission losses and congestion. This paper describes a uniform price auction that incorporates locational price adjustments on a Web-based platform suitable for experimentation. Preliminary results show dramatically different price and revenue results when compared with a simple continuous Discriminative auction.
q1998 Elsevier Science Ltd. All rights reserved. Electric Power and Energy Systems, vol. 21, pp. 103-110, 1999. Uploaded: June 27, 2006.
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Robert Ethier, Ray Zimmerman, Timothy Mount, William Schulze, Robert Thomas
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06/27/06
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533.11 KB
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PDF
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99-19
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Thermal Unit Commitment with Nonlinear Power Flow Constraints
Abstract - A formulation of the thermal unit commitment problem including nonlinear power flow constraints is presented, making the use of more realistic constraint models possible. It also allows potential VAr production to be sued as a criterion for the commitment of generators in strategic locations of the network. The Lagrangian Relaxation framework and a variable duplication technique are employed, permitting exploitation of the separation structure of the dual cost. Some results for small to medium-sized systems are reported.
IEEE Power Engineering Society Winter Meeting, vol. 1, pp. 484-489. Uploaded: June 27, 2006.
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Carlos E. Murillo-Sanchez, Robert J. Thomas
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06/27/06
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467.01 KB
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PDF
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99-20
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