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2003 Publications


Feeding our Profession
Power engineering education feeds the power engineering profession. If the profession is to continue to be a vital part of electrical engineering, something needs to be done about the educational stem. In some sense, power education is at a crossroads, and there is a need to take a positive growth path by moving the most pressing and difficult problems in power engineering to a viable 'high tech' power program. Such an educational program needs to center on systems, new materials, applications of advanced mathematics and physics, and integration of economic principles. One potential avenue is to appeal to national governments worldwide to support power engineering research through university based centers. A recent upsurge in student interest at the bachelors level, and the importance and complexity of typical power engineering problems are indicative of positive growth in the field; however vigilance and increased industry participation in all educational sectors are needed to insure vitality of the field.

Uploaded: March 6, 2003. IEEE Power and Energy Magazine, vol. 1, issue 1, pp. 38-45, January/February 2003.  
Gerald T. Heydt and Vijay Vittal 03/06/03 895.36 KB PDF 03-01
Fuel Parameter and Quality Constraints for Fuel Cell Distributed Generators
Distributed generation (DG) technologies are being discussed as the new paradigm for the electricity infrastructure, owing to growth in electric loads, deregulated markets, reliability constraints, emission control limitations, and the huge capital investments with minimal rates of return associated with central station generation. Some DG technologies are critically dependent on the fuel quality and supply parameters for optimal power delivery and overall economic operation. Currently, most DG technologies are expensive to install, operate and maintain. One of the factors that will affect feasibility and economic viability of fuel cells is the supply of fuel with the characteristics appropriate to fuel cell designs [1]. This paper deals with fuel performance indices for fuel cell DG units and analyzes their dependency on fuel characteristics for economical and optimal performance.

Uploaded: March 14, 2003. 2003 IEEE PES Transmission and Distribution Conference and Exposition, vol. 1, pp. 409-412, Dallas, Texas, September 7-12, 2003.  
Phanikrishna Gomatom and Ward Jewell 03/14/03 219.34 KB PDF 03-02
Fuel Parameter and Quality Constraints for Microturbine Distributed Generators
Distributed generation (DG) technologies are currently being discussed as the new paradigm for the electricity infrastructure, owing to growth in electric loads, de-regulated markets, and reliability constraints, emission control limitations , and the huge capital investments with minimal rates of return associated with central station generation. Some DG technologies are critically dependent on the fuel quality and supply parameters for optimal power delivery and overall economic operation. Currently, most DG technologies are expensive to install, operate and maintain. One of the factors that could enable feasible and economic viability for installation of microturbines is the supply of fuel with the characteristics appropriate to DG designs [1]. This paper deals with the performance indices of Microturbine DG units and analyzes their dependency on fuel characteristics for economical and optimal performance.

Uploaded: March 14, 2003. Power Systems 2003 Conference on Distributed Generation and Advanced Metering, Clemson, South Carolina, March 2003.  
Phanikrishna Gomatom and Ward Jewell 03/14/03 204.54 KB PDF 03-03
National Energy Supergrid Workshop Report
This report summarizes the results of the University of Illinois at Urbana-Champaign (UIUC) sponsored National Energy Supergrid Workshop, which was held on November 6-8, 2002 in Palo Alto, California. The purpose of the workshop was to investigate the technical feasibility of a proposal developed by Chauncey Starr, founder and emeritus president of EPRI, for the creation of a 'Continental SuperGrid' to meet the nation's energy needs in the mid-to-later half of the 21st Century.

Uploaded: March 28, 2003. Workshop: National Energy Supergrid, Palo Alto, California, November 6-8, 2002.  
Tom Overbye, Chauncey Starr, Paul Grant, Tom Schneider 03/28/03 213.35 KB PDF 03-04
Motion as an Effective Flow Visualization Technique for Power Systems Monitoring and Control
This report presents results of human factors studies conducted at the University of Illinois at Urbana-Champaign to assess the impact of motion for power system flow visualizations.

Uploaded: May 23, 2003. University of Illinois at Urbana-Champaign, Institute of Aviation, Aviation Human Factors Division, Technical Report ARL-03-10/PSERC-03-1, May 2003.  
Gavin R. Essenberg, Douglas A. Wiegmann, Thomas J. Overbye, Yan Sun 05/23/03 621.25 KB PDF 03-07
Three Dimensional Visualization for Power System Contingency Analysis Voltage Data
Contingency analysis (CA) as an inherent function of system security assessment is critical for detecting underlying problems in a power system. More frequent CA computation is required in the deregulated power markets to monitor the state of the system under 'what if?' situations in view of the fact that the power systems are now operated closer to their limits imposed by the increasing number of power transfers. The traditional EMS display of CA results is a list of violated elements for each contingency examined. Due to the tremendous amount of data computed and the traditional lack of a geographic connection between the violated elements and the contingency elements, interpretation of the contingency results is often time consuming. To aid power system operators with this interpretation, this paper explores several innovative and interactive 3D visualizations of CA voltage violation data. We visualize vulnerability levels of buses and severity information of outages separately and create a three-level visualization for each category. The overall CA results are conveyed at a glance by the top-level visualizations, while more detailed information can be displayed at the user's request.

Uploaded: May 23, 2003. 6th International Conference on Advances in Power System Control, Operation and Management (APSCOM 2003), Hong Kong, November 11-14, 2003.  
Yan Sun, Thomas J. Overbye 07/20/16 1.26 MB PDF 03-08
Cascading dynamics and mitigation assessment in power system disturbances via a hidden failure model?
A hidden failure embedded DC model of power transmission systems has been developed to study the observed power tails of North American blackout data. We investigate the impacts of several model parameters on the global dynamics and evaluate possible mitigation measures. The main parameters include system loading level, hidden failure probability, spinning reserve capacity and control strategy. The sensitivity of power-law behavior with respect to each of these parameters and the possible blackout mitigation are discussed and illustrated using simulation results from the WSCC 179-bus equivalent system and IEEE 118-bus test system. It is our intention that the study can provide guidance on when and how the suggested mitigation methods might be effective. Preprint submitted to International Journal of Electric Power and Energy Systems.

Uploaded: August 20, 2003. International Journal of Electrical Power & Energy Systems, vol. 27, issue 4, pp. 318-326, May 2005.  
Jie Chen, James Thorp, Ian Dobson 07/21/16 150.01 KB PDF 03-09
Critical points and transitions in an electric power transmission model for cascading failure blackouts
Cascading failures in large-scale electric power transmission systems are an important cause of blackouts. Analysis of North American blackout data have revealed power law (algebraic) tails in the blackout size probability distribution which suggests a dynamical origin. With this observation as motivation, we examine cascading failure in a simplified transmission system model as load power demand is increased. The model represents generators, loads, the transmission line network, and the operating limits on these components. Two types of critical points are identified and are characterized by transmission line flow limits and generator capability limits respectively. Results are obtained for tree networks of a regular form and a more realistic 118-node network. It is found that operation near critical points can produce power law tails in the blackout size probability distribution similar to those observed. The complex nature of the solution space due to the interaction of the two critical points is examined.

Uploaded: August 20, 2003. Journal: CHAOS - An Interdisciplinary Journal of Nonlinear Science, vol. 12, no. 4, pp. 985-994, December 2002.  
Ben Carreras, Vicki Lynch, Ian Dobson, David Newman 07/21/16 725.76 KB PDF 03-10
The Reliability Analysis of High Power Switches Composed of Series and Parallel Branches
This paper contains an analytical method for the failure analysis of a matrix configuration of switches in series and parallel. The concept is to use lower voltage and current rating switches in series and parallel to attain the higher ratings needed in power engineering applications. The analysis is based on probability state transition. A discussion of voltage and current snubbing is given. Representative results are illustrated and applications are suggested.

Uploaded: August 24, 2003. IEEE Power Engineering Society General Meeting, vol. 1, Toronto, Ontario, Canada, July 13-17, 2003.  
Gerald T. Heydt, Daniel S. James, Esma S. Gel, Mihaela M. Albu, Norma F. Hubele 08/24/03 129.73 KB PDF 03-11
Quantum Computing in Power System Simulation
The concept of quantum computing has been conjectured as the next major breakthrough in computing. The basis of quantum computing, its strengths, weaknesses, and challenges are outlined. The specific application to electric power engineering is discussed.

Uploaded: August 24, 2003. IEEE Power Engineering Society General Meeting, vol. 2, Toronto, Ontario, Canada, July 13-17, 2003.  
Daniel J. Tylavsky and Gerald T. Heydt 08/24/03 41.99 KB PDF 03-12
The Propagation of Disturbances in Power Distribution Systems
The propagation of power quality disturbances in distribution systems is investigated in this paper. Simulations of disturbances are accomplished using mathematical and PSpice modeling. Disturbances instrumented in the field are compared with PSpice calculations. Each component in the distribution system is modeled in detail using all available information. Measurements are used to refine the simulations, and having obtained a validated simula-tion, studies are made as to the effects of system components on the severity of power quality distur-bances. The effects of disturbances on the system components, such as transformers, distribution lines and load models, are analyzed. It is shown that when disturbances propagate through a delta / wye trans-former, many indices, such as unbalance factor, volt-age regulation, and zero sequence levels, decrease.

Uploaded: August 24, 2003. IEEE Power Engineering Society Transmission and Distribution Conference & Exposition, vol. 1, pp. 6-12, Dallas, Texas, September 7-12, 2003.  
Natthaphob Nimpitiwan, Gerald T. Heydt, Raja Ayyanar, John Belvins, Kristian Koelner, Kevin Kittridge, Michael Chandler 08/24/03 241.56 KB PDF 03-13
Design Of Delayed-Input Wide Area Power System Stabilizer Using Gain Scheduling Method
Centralized wide area control design using system-wide data has been suggested to enhance large interconnected power systems dynamic performance. Because of the nature of wide area interconnections, communication delay cannot be ignored in the wide area control. A long time delay may cause a detrimental effect to system stability and degrade system robustness. The general Linear Fractional Transformation (LFT) method to describe the time delay uncertainty can lead to a conservative design. In this paper, a Gain Scheduling (GS) method based on Linear Matrix Inequality (LMI) is proposed to design a dynamic controller to accommodate time delays in supervisory Power System Stabilizer (PSS) design. The new approach achieves better performance than the general LFT method, and the order of the controller remains the same with that of the system plant.

Uploaded: August 24, 2003. IEEE Power Engineering Society General Meeting, vol. 3, Toronto, Ontario, Canada, July 13-17, 2003.  
Hongxia Wu, and Gerald T. Heydt 08/24/03 78.33 KB PDF 03-14
Embedding Remote Experimentation In Power Engineering Education
Engineering education by its nature is a costly program in university environments. Perhaps the most costly component is the laboratory facilities, usually consisting of specialized equipment. Effective instruction of some topics in power engineering education requires experience with actual equipment, rather than small-scale replicas or simulation. In this paper a new laboratory approach is described, as implemented in a virtual, Internet-based, experimentation platform. This virtual laboratory (VLab) utilizes real equipment distributed among multiple universities from which remotely located students can perform experiments. The software solution is a multi-user, client-server architecture developed in the LabVIEW® environment. Implementation details including video, chat, archiving, and the hardware and software platforms are presented in the paper. An example presented herein is the study of current and voltage waveforms while controlling relays and low voltage contactors. The applications have been tested with student teams enrolled in the electrical engineering department of Politehnica University of Bucharest and the power engineering program at Arizona State University.

Uploaded: August 24, 2003. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 1, PP. 139-143, FEBRUARY 2004.  
Mihaela M. Albu, Keith E. Holbert, Gerald T. Heydt, Sorin Dan Grigorescu, Vasile Trusca 07/21/16 526.43 KB PDF 03-15
An Interactive-Dynamic Mechanism Conceptualizing the Cost and Benefit of Electric Power Quality
With the deregulation of the electric power energy market, providing power quality has become a more important concern of both power suppliers and customers. Customers require better quality with the development of digitally controlled facilities. However, there is not a specific infrastructure to motivate the design of the power system to achieve a specified level of electric power quality. This paper discusses a power quality interactive - dynamic control mechanism to conceptualize the cost and benefit of power quality. The basic objective is to provide an engineering infrastructure and procedure that 'gives the right signals' to the power supplier and the customer to balance power quality and cost. A power quality level index vector is utilized in the proposed infrastructure.

Uploaded: August 24, 2003. Journal: Electric Power Systems Research, vol. 69, issue 1, pp. 69-75, April 2004.  
Geun-Joon Lee and Gerald T. Heydt 07/21/16 181.78 KB PDF 03-16
Complex Dynamics of Blackouts in Power Transmission Systems
A model has been developed to study the global complex dynamics of a series of blackouts in power transmission systems. This model includes a simple level of self-organization by incorporating the growth of power demand, the engineering response to system failures, and the upgrade of the generator capacity. Two types of blackouts have been identified with different dynamical properties. One type of blackout involves loss of load due to transmission lines reaching their load limits but no line outages. The second type of blackout is associated with multiple line outages. The dominance of one type of blackouts versus the other depends on operational conditions and the proximity of the system to one of its two critical points. The model shows a probability distribution of blackout sizes with power tails similar to that observed in real blackout data from North America. This paper is a preprint submitted to a journal.

Uploaded: August 28, 2003. Journal: CHAOS - An Interdisciplinary Journal of Nonlinear Science, vol. 14, no. 3, pp. 643-652, September 2004.  
Ben Carreras, Vicki Lynch, Ian Dobson, David Newman 07/21/16 640.45 KB PDF 03-17
A Comparison of the AC and DC Power Flow Models for LMP Calculations
The paper examines the tradeoffs between using a full ac model versus the less exact, but much faster, dc power flow model for LMP-based market calculations. The paper first provides a general discussion of the approximations associated with using a dc model, with an emphasis on the impact these approximations will have on security constrained OPF (SCOPF) results and LMP values. Then, since the impact of the approximations can be quite system specific, the paper provides case studies using both a small 37 bus system and a somewhat larger 12,965 bus model of the Midwest U.S. transmission grid. Results are provided comparing both the accuracy and the computational requirements of the two models. The general conclusion is that while there is some loss of accuracy using the dc approximation, the results actually match fairly closely with the full ac solution.

Uploaded: September 30, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), track 2, vol. 2, Big Island, Hawaii, January 5-8, 2004.  
Thomas J. Overbye, Xu Cheng and Yan Sun 07/21/16 331.41 KB PDF 03-18
Cascading Failures: Survival vs. Prevention
Measures can be taken to reduce the number of large-scale power losses due to failures of the generation and high voltage transmission grid such as the August 14, 2003 blackout. However, such failures cannot be eliminated. The survival of essential missions is a more tractable problem than the prevention of all large cascading failures, and its solutions are verifiable. We propose that serious attention be directed towards assuring the continuation of essential missions even after the grid has failed. We outline a program to lower the social costs of power failures through successful preservation of those essential missions.

Uploaded: September 30, 2003. Journal: The Electricity Journal, vol. 16, issue 9, pp. 25-31, November 2003.  
Sarosh N. Talukdar, Jay Apt, Marija Ilic, Lester B. Lave, and M. Granger Morgan 07/21/16 212.71 KB PDF 03-19
A branching process approximation to cascading load-dependent system failure
Networked infrastructures operated under highly loaded conditions are vulnerable to catastrophic cascading failures. For example, electric power transmission systems must be designed and operated to reduce the risk of widespread blackouts caused by cascading failure. There is a need for analytically tractable models to understand and quantify the risks of cascading failure. We study a probabilistic model of loading dependent cascading failure by approximating the propagation of failures as a Poisson branching process. This leads to a criticality condition for the failure propagation. At criticality there are power tails in the probability distribution of cascade sizes and consequently considerable risks of widespread catastrophic failure. Avoiding criticality or supercriticality is a key approach to reduce this risk. This approach of minimizing the propagation of failure after the cascade has started is complementary to the usual approach of minimizing the risk of the first few cascading failures. The analysis introduces a saturating form of the generalized Poisson distribution so that supercritical systems with a high probability of total failure can be considered.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), Big Island, Hawaii, January 5-8, 2004.  
Ian Dobson, Ben Carreras, David Newman 10/13/03 172.54 KB PDF 03-20
The influence of futures markets on real time price stabilization in electricity markets
Markets can interact with power systems in ways that can render an otherwise stable market and an otherwise stable power system into an unstable overall system. This unstable system will be characterized not only by fluctuating prices that do not settle to constant values, but, more worrisome, it creates the possibility of inducing slow electromechanical oscillations if left unchecked. This will tend to happen as a result of 'price chasing' on the part of suppliers that can react (and over-react) to changing system prices. This paper examines the role that futures markets may have on the clearing prices and on altering the volatility and potential instability of real time prices and generator output.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), track 2, vol. 2, Big Island, Hawaii, January 5-8, 2004.  
David Watts and Fernando L. Alvarado 07/21/16 159.90 KB PDF 03-21
Coordinated Interchange Scheduling and Opportunity Cost Payment: A Market Proposal to Seams Issues
This paper presents a joint market structure for energy, spinning reserves and VAR support in a multi-area setting. It is based on a co-optimization that can simultaneously optimize all three commodities across the "seams". An auxiliary problem principle based decomposition scheme is applied to the overall optimization for coordinating interchanges of energy and ancillary services between control areas. The proposed decomposition approach preserves independent dispatching for neighboring areas while achieves overall optimum. Nodal prices for energy and opportunity cost payments to forgone energy profit due to providing reserves and VAR support are also addressed. We believe the algorithm is of particular interest in the restructuring electricity industry for resolving seams issues. An illustrative example of a modified IEEE 30-bus system is used to demonstrate the validity of the proposed algorithm.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), track 2, vol. 2, Big Island, Hawaii, January 5-8, 2004. .  
Jie Chen, James S. Thorp and Timothy D. Mount 07/21/16 146.00 KB PDF 03-22
New Solutions for Substation Sensing, Signal Processing and Decision Making
This paper describes a new solution for integrating substation sensing, signal processing and decision making for more efficient monitoring, control and protection applications. The paper points out deficiencies of the existing approach and sets the requirements for the new approach. Once an architecture of the new solution is defined, further description of each of the elements of the new solution, namely optical sensor multiplexed network, distributed signal processing, and neural network based decision making are discussed. At the end, a concept of how all the mentioned components of the solution can be integrated is given.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), track 2, vol. 2, Big Island, Hawaii, January 5-8, 2004.  
Mladen Kezunovic and Henry Taylor 07/21/16 152.14 KB PDF 03-23
Dynamical and probabilistic approaches to the study of blackout vulnerability of the power transmission grid
The CASCADE probabilistic model for cascading failures gives a simple characterization of the transition from an isolated failure to a system-wide collapse as system loading increases. Using the basic ideas of this model, the parameters that lead to a similar characterization for power transmission system blackouts are identified in the OPA dynamical model of series of blackouts. The comparison between the CASCADE and OPA models yields parameters that can be computed from the OPA model that indicate a threshold for cascading failure blackouts. This is a first step towards computing similar parameters for real power transmission systems.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), track 2, vol. 2, Big Island, Hawaii, January 5-8, 2004.  
Ben Carreras, Vicki Lynch, Ian Dobson, David Newman 10/13/03 246.65 KB PDF 03-24
The Effect of Customer Participation in Electricity Markets: An Experimental Analysis of Alternative Market Structures
An experimental structure is demonstrated that represents end-use customers in electricity markets who can substitute part of their usage between day and night. Individuals’ demand relationships are represented by a two-step value function for each period that are disaggregated from observed market demand relationships. Demand varies between day and night and during heat waves. Three alternative demand-side market structures are evaluated:
    1) customers pay the same fixed price (FP) in all periods – the base case,
    2) a demand response feature (DRP) is added in periods of supply shortages, wherein buyers receive a pre-specified credit for reduced purchases, and
    3) a real time pricing (RTP) case where prices are forecast for the upcoming day/night pair, then buyers select their quantity purchases sequentially and are charged the actual market-clearing prices.
Initial experiments were conducted with active demand-participants, but with a predetermined typical 'hockey-stick' supply structure that was varied randomly, over eleven day-night pairs that included heat wave and supply shortages. The RTP structure resulted in the greatest market efficiency, despite the more difficult cognitive problem it poses for buyers. Furthermore, a preference poll comparing DRP and RTP was conducted after each trial; and while 64% of the participants said they preferred DRP before RTP experiments, 76% selected the RTP structure afterwards, a statistically significant reversal of preferences.

Uploaded: October 13, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), Big Island, Hawaii, January 5-8, 2004.  
Richard E. Schuler, William D. Schulze, Nodir Adilov and David Toomey 07/21/16 175.18 KB PDF 03-25
An Essential Industry at the Crossroads: Deregulation, Restructuring, and a New Model for the United States? Bulk Power System
This thesis proposes a new architecture, or model, for this industry. This new architecture will ensure all consumers throughout the United States, receive reliable and cost-effective electricity. This thesis briefly reviews the history of the electric utility industry, from its competitive beginnings to its regulation as a natural monopoly and finally, to its evolution into the present day configuration of three interconnected transmission networks that cover North America. The thesis also examines the effects on the industry of several compounding factors. Finally, the problems associated with present-day restructuring efforts are summarized, and an architecture, or model, which resolves these problems and introduces benefits to industry restructuring, is proposed.

Uploaded: November 20, 2003. Master of Science student thesis, Electrical Engineering, University of Colorado at Denver, 2003.  
Jeffrey Hein 11/20/03 3.32 MB PDF 03-27
Collaboration to Facilitate Research and Education in a Transitioning Electric Power Industry
The electric supply industry is in transition from its traditional objectives, structure, ownership, operating practices, planning processes, and customer services. The transition may be characterized as 'end-less' without a well-defined end-point. From this perspective, thinking about the challenges of transition should not only focus on 'solutions', but also on means and processes for finding the solutions. Research and education can make significant contributions if they are considered as much a part of the electric supply industry infrastructure as poles and wires. By putting greater reliance on collaborative research programs involving the 'triple helix' of industry, universities and government, synergies can be captured from multi-institution, multi-discipline collaboration for clarification of research needs and developing research plans to address them. But collaboration requires attendance to interpersonal dynamics as well as other principles of effective collaboration. In this paper, we give examples of structures of collaborative research programs and offer some principles of effective collaboration. An extended case study is used to illustrate ways in which the principles of collaboration can be applied. The paper concludes with comments about possible issues facing developing countries in using collaborative research.

January 14-16, 2004: International Conference on 'Electric Supply Industry in Transition: Issues and Prospect for Asia' will be held at the Asian Institute of Technology (AIT) Conference Center. The conference are co-organized by Power Systems Engineering Research Center (PSERC), more than a dozen leading universities in the USA, including Berkeley), University of Technology, Sydney, Australia, and Asian Institute of Technology. The conference is coordinated by Professor Surapong Chirarattananon, SERD, AIT The conference focus will be on 'Electricity Supply Industry in Transition': pertinent issues and prospects for Asia. The topic is timely as most of the utilities around the world, including developing nations, are changing the way they do businesses in electricity supply. A variety of people, power utilities, private power producers and academic institution, are expected to benefit from this conference.

Uploaded: March 5, 2004. Conference Paper for Asian Institute of Technology Conference: Electricity Industry in Transition: Issues and Prospects for Asia, Bangkok, Thailand, January 14-16, 2004.  
Dennis Ray and Frank Wayno 03/05/04 189.74 KB PDF 03-28
Perturbations of Weakly Resonant Power System Electromechanical Modes
It is not uncommon for oscillatory electric power system modes to move close to a resonance in which eigenvalues coincide. In a weak resonance the modes are decoupled and the eigenvalues do not interact. We analyze general perturbations of a weak resonance and find two distinct behaviors, including interactions near strong resonances in which the eigenvalues quickly change direction. The possible perturbations are illustrated with interactions between electromechanical modes in a 4 bus power system. Some of the interactions are similar to subsynchronous resonance and can lead to oscillatory instability.

Uploaded: December 6, 2003. 2003 IEEE Power Tech Conference, Bologna, Italy, June 23-26, 2003.  
Ian Dobson, Emilio Barocio 07/21/16 1.35 MB PDF 03-29
Scaling of normal form analysis coefficients under coordinate change
Power system normal form analysis has developed coefficients and indices in modal coordinates to quantify nonlinear modal interactions. We study the changes in the coefficients and indices when the power system equations are expressed in different coordinates or units and show that they can be normalized to be invariant to coordinate changes and thus intrinsic to the power system. The results are illustrated on a 4 generator system. An example shows that the coefficients and indices not only detect nonlinear interactions but also can become very large near a strong resonance in the system linearization.

Uploaded: December 6, 2003. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 19, NO. 3, PP. 1438-1444, AUGUST 2004.  
Ian Dobson, Emilio Barocio 07/21/16 275.94 KB PDF 03-30
Dynamic Security-Constrained Rescheduling of Power Systems Using Trajectory Sensitivities
In the deregulated environment of power systems, the transmission networks are often operated close to their maximum capacity to achieve transfer of power. Besides, the operators must operate the system to satisfy its dynamic stability constraints under credible contingencies. This paper provides a method using trajectory sensitivity to reschedule power generation to ensure system stability for a set of credible contingencies while satisfying its economic goal. System modeling issue is not a limiting concern in this method, and hence the technique can be used as a preventive control scheme for system operators in real time.

Uploaded: December 16, 2003. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 2, PP. 848-854, MAY 2003.  
Tony B. Nguyen, and Mangalore A. Pai 12/16/03 250.42 KB PDF 03-31
Trajectory Sensitivity Theory in Non Linear Dynamical Systems: Some Power System Applications
Trajectory sensitivity analysis (TSA) has been applied in control system problems for a long time in such areas as optimization, adaptive control etc. Applications in power systems in conjunction with Lyapunov/transient energy functions first appeared in the 80's. More recently, it has found applications on its own by defining a suitable metric on the trajectory sensitivities with respect to the parameters of interest. In this paper we present the theoretical as well as practical applications of TSA for dynamic security applications in power systems. We also discuss the technique to compute critical values of any parameter that induces stability in the system using trajectory sensitivities.

Uploaded: December 16, 2003. Book: Stability and Control of Dynamical Systems with Applications: A Tribute to Anthony N. Michel (Series: Control Engineering), Chapter 14, pp. 271-292, Editors: Derong Liu, Panos J. Antsaklis, Publisher: Birkhäuser, Boston, 1st Edition, 2003; Reprint: Springer Science+Business Media, LLC, New York, October 4, 2013.  
Mangalore A. Pai, and T. B. Nguyen 12/16/03 380.71 KB PDF 03-32
The Inherent Inefficiency of the Point-to-Point Congestion Revenue Right Auction
Empirical evidence shows that the clearing prices for point-to-point congestion revenue rights, also known as financial transmission rights (FTRs), resulting from centralized auctions conducted by Independent System Operators differ significantly and systematically from the realized congestion revenues that determine the accrued payoffs of these rights. The question addressed by this paper is whether such deviations are due to price discovery errors which will eventually vanish or due to inherent inefficiencies in the auction structure. We address this question by studying a hypothetical DC-flow approximation model of a six-node system with known outage probabilities of each element and known statistical demand variability.
We show that even with perfect foresight of average congestion rents the clearing prices for the FTRs depend on the bid quantity and therefore may not be priced correctly in the financial transmission right (FTR) auction. In particular, we demonstrate that if all FTR bid quantities are equal to the corresponding average transaction volumes and the bid values are set at the expected congestion rent level, then the resulting auction prices systematically deviate from the known FTR values. We conclude that price discovery alone would not remedy the discrepancy between the auction prices and the realized values of the FTRs. Secondary markets or frequent reconfiguration auctions are necessary in order to achieve such convergence.

Uploaded: December 9, 2003. 37th Annual Hawaii International Conference on System Sciences (HICSS 2004), Big Island, Hawaii, January 5-8, 2004.  
Shi-Jie Deng, Shmuel Oren, and Sakis Meliopoulos 07/21/16 103.90 KB PDF 03-33
The New York Transmission Congestion Contract Market: Is It Truly Working Efficiently?
An analysis indicates that the financial point-to-point transmission rights auction implemented by the New York Independent System Operator may not work efficiently, and that rights sold in auctions may sometimes be greatly over- or under-priced.

Uploaded: September 17, 2005. Journal: The Electricity Journal, vol. 16, no. 9, pp. 14-24, November 2003.  
Emily S. Bartholomew, Afzal S. Siddiqui, Chris Marnay, and Shmuel S. Oren 09/17/05 266.75 KB PDF 03-34
The 2003 Blackout: Did the System Operator have Enough Power?
The paper provides an exposition on how a well functioning market based system could have prevented the disastrous consequences by providing early signals of impeding shortages that would have enabled timely response that could have contained the problem.

Uploaded: September 2003. Report prepared by Christensen Associates, Madison, Wisconsin, August 26, 2003.  
Fernando L. Alvarado, and Rajesh Rajaraman 09/26/05 146.54 KB PDF 03-35
Converting System Limits to Market Signals
This paper compares methods for converting system limits into market signals. One classification of methods is according to reliability driven (TLR and similar) versus market driven (LMP and similar) methods. A second classification is according to direct versus indirect methods. Direct methods deal with individual limits and constraints. Indirect methods include various ways of converting one type of limit to another, equivalent limit for purposes of making the handling of the limit more expeditious. An example of an indirect method is the conversion of a voltage limit to either a flow limit or an interface limit. Another example is the use of flow limits on interfaces as surrogates for stability limits. These transformed limits are often represented by nomograms. Conversion of one type of limit to another and the construction of nomograms has the advantage of reducing the problem of imposing system limits within a market context to a “previously solved” market problem. If a market already has learned how to cope with an import limit into a load pocket, conversion of a voltage limit into a load pocket import limit makes it easy for a market to react and respond to the condition. However, any conversion from one type of limit to another entails an approximation. This paper discusses the nature of some of these approximations.

Uploaded: September 26, 2005. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 2, PP. 422-427, MAY 2003.  
Fernado Alvarado 09/26/05 190.67 KB PDF 03-36
Transmission Congestion-Management Schemes: A Comparative Analysis Under a Unified Framework
The paper briefly reviews the congestion management schemes and the associated pricing mechanism used by the IGO’s in five representative schemes. These were selected to illustrate the various congestion management approaches in use: England and Wales, Norway, Sweden, PJM and California. We develop a unified framework for the mathematical representation of the market dispatch and redispatch problems that the IGO must solve in managing congestion in these various jurisdictions. We use this unified framework to develop meaningful metrics to compare the various approaches so as to assess their efficiency and the effectiveness of the market signals provided to the market participants. We compare, using a small test system, side by side, the performance of these schemes.

Uploaded: September 26, 2005. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 1, PP. 346-352, FEBRUARY 2003.  
Ettore Bompard, Pedro Correia, George Gross and Mikael Amelin 09/26/05 481.24 KB PDF 03-37
The Effects of the Dysfunctional Spot Market for Electricity in California on the Cost of Forward Contracts
The unexpectedly high spot prices for electricity in the summer of 2000 that occurred in California led to a number of regulatory interventions. Initially, price caps were lowered in California from $750/MWh to $250/MWh during the summer. However, Out-Of Market (OOM) purchases were still made above the price cap if capacity shortfalls occurred in the market run by the California Independent System Operator (CAISO). After evaluating the price behavior during the summer months, the Federal Energy Regulatory Commission (FERC) declared that the market in California was "seriously flawed" and proposed a number of changes to the market rules. Two important proposals made by the FERC were
    1) to require greater dependence on forward markets by entities with obligations to serve customers, and
    2) to replace the price cap of $250/MWh by a new type of "soft-cap" auction with the price cap at $150/MWh.
Unfortunately, spot prices in the winter of 2001 were persistently much higher than the soft cap. These high spot prices created uncertainty that resulted in high premiums for risk and high forward prices. Hence, forward contracts executed at this time were very expensive for buyers, and many contracts were executed due to the directive of the FERC. After the FERC imposed a system-wide price cap on the whole Western Inter-Connection in June 2001, both the spot prices and forward prices for electricity returned to normal levels.

Uploaded: June 27, 2006. Presented at the 16th Annual Western Conference, Advanced Workshop in Regulation and Competition, Center for Research in Regulated Industries, The State University of New Jersey, Rutgers Business School, held at San Diego, California, June 25-27, 2003.  
Timothy Mount, Yoo-Soo Lee 06/27/06 546.97 KB PDF 03-38a
The Effects of the Dysfunctional Spot Market for Electricity in California on the Cost of Forward Contracts
Program Agenda: 16th Annual Western Conference, Advanced Workshop in Regulation and Competition, Center for Research in Regulated Industries, The State University of New Jersey, Rutgers Business School, held at San Diego, California, June 25-27, 2003.  
07/21/16 174.00 KB PDF 03-38b
A Revenue Sensitivity Approach for the Identification and Quantification of Market Power in Electric Energy Markets
In this paper we present a practical approach in identifying and measuring market power in an electric energy market. To do so we determine which participants or groups of participants have the ability to increase their own revenues without affecting the rest of the market and then apply a relative measure to quantify the extent of market power exploitation. We present a 30-bus, 6-generator example in which two generators in a load pocket are found to have and use market power. Using price and revenue signals from a repeated auction, we explain how these generators learn to exploit their power over time. Experimental results are also presented and analyzed.

Uploaded: June 27, 2006. IEEE Power Engineering Society General Meeting, vol. 2, Toronto, Ontario, Canada, July 13-17, 2003.  
Bernard C. Lesieutre, Robert J. Thomas, Timothy D. Mount 06/27/06 385.28 KB PDF 03-39
Comparing the Behavior of Agents to Human Subjects in a Uniform Price Auction
The idea that large-scale generating units will operate at marginal cost when given the ability to offer their power for sale in a uniform price auction is at best wishful thinking. In fact, both real and experimental data show that the more uncertainty a supplier faces (e.g., load uncertainty, uncertainty of other suppliers, etc.) the more they will try to increase their profits by submitting offers to sell higher than marginal cost and by withholding units if permitted. This makes predicting unit commitment and dispatch ahead of time difficult. This paper explores characteristics of software agents that were designed based on the outcome of tests with human subjects using a uniform price auction with stochastic load. The agent behavior is compared to the behavior of the subjects. Both subject and agent behavior is classified based on the data. Differences and similarities are noted and explained.

Uploaded: June 27, 2006. 36th Hawaii International Conference on System Sciences (HICSS 2003), pp. 54-60, Big Island, Hawaii, January 6-9, 2003.  
HyungSeon Oh, Robert J. Thomas, Bernie Leiseutre, Timothy D. Mount 06/27/06 383.89 KB PDF 03-40
User Friendly, Open System Software for Teaching Protective Relaying Application and Design Concepts
This paper describes modeling and simulation software developed specifically for teaching protective relaying application and design concepts. The emphasis was on implementing user-friendly and open-system solution that will allow an easy use and straight-forward future expansion. This is achieved by introducing new libraries of signal sources and relay elements developed for the SIMULINK environment of MATLAB. Combined with the Power Block Set (PBS) toolbox of MATLAB, the mentioned libraries allow for a variety of studies aimed at better understanding protective relay design approaches and related applications.

Uploaded: June 30, 2006. IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 18, NO. 3, PP. 986-992, AUGUST 2003.  
Mladen Kezunovic 07/21/16 1.12 MB PDF 03-41
Transient Testing of Protection Relays: Results, Methodology, and Tools
The paper presents a new approach to application testing of protective relays. The approach utilizes a test methodology based on the use of transients. The paper outlines examples of test results that can be obtained using the new test methodology for assessing important application features of protective relays such as the response time and trip selectivity. Assessing these features may be extremely important for troubleshooting relay misoperations, adjusting relay settings, or when purchasing new relays. The paper also discusses the requirements for the testing tools to be used. For this particular methodology, a new testing tool called Batch Generator has been developed for the purpose of automating not only the process of testing, but the process of creating test cases as well. The need for selecting suitable commercial testing tools and using the newly developed tool - batch generator are given at the end.

Uploaded: June 30, 2006. International Conference on Power Systems Transients (IPST 2003), New Orleans, Louisiana, September 28 - October 2, 2003.  
Mladen Kezunovic, Tomo Popovic, Donald Sevcik, Hyder DoCarmo 06/30/06 187.94 KB PDF 03-42a
International Conference on Power Systems Transients (IPST 2003) Technical Program Agenda
International Conference on Power Systems Transients (IPST 2003), New Orleans, Louisiana, September 28 - October 2, 2003.  
07/25/16 98.62 KB PDF 03-42b
International Conference on Power Systems Transients (IPST 2003) Keynote Speech
International Conference on Power Systems Transients (IPST 2003), New Orleans, Louisiana, September 28 - October 2, 2003.  
07/25/16 250.59 KB PDF 03-42c
International Conference on Power Systems Transients (IPST 2003) Closing Address
International Conference on Power Systems Transients (IPST 2003), New Orleans, Louisiana, September 28 - October 2, 2003.  
07/25/16 164.12 KB PDF 03-42d