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Power and Energy Systems
^ Optimal Power Flow Application Issues in the Pool Paradigm
E. Bompard (Politecnico of Torino), G. Gross*
The Italian Fulbright Commission; U.S. State Department; PSERC

The research focuses on the application of the Optimal Power Flow (OPF) to competitive markets. Since the OPF is a central decision-making tool, its application to the more decentralized decision making in the competitive electricity markets requires considerable care. There are some intrinsic challenges associated with the effective OPF application in the competitive environment due to inherent characteristics of the OPF formulation. Two such characteristics are the flatness of the optimum surface and the consequent continuum associated with the optimum. In addition to these OPF structural characteristics, the level of authority vested in the central decision-making entity has major ramifications. These factors have wide ranging economic impacts with implications which are pronounced due to the fact that, unlike in the old vertically integrated utility environment, various market players are affected differently. The effects include price volatility, financial health of various players, and the integrity of the market itself. Researchers apply appropriate metrics to evaluate market efficiency and how the various players fare. Researchers also study the impacts of OPF applications in the Pool paradigm, with both supply and demand sides explicitly modeled, and use extensive numerical simulations. The numerical results show the variability of nodal prices and the skew possible in different "optimal" allocations among competing suppliers. Such variability in the results may lead to serious disputes among the players and the central decision-making authority.

^ Reactive Load Modeling Impacts on Nodal Prices in Pool Model Electricity Markets
E. Bompard (Politecnico of Torino), G. Gross*
The Italian Fulbright Commission; U.S. State Department; PSERC

The project is concerned with the interpretation of nodal prices in competitive electricity markets based on the Pool paradigm. Such prices are the byproducts of the optimization performed by the independent grid operator (IGO) to determine the centralized economic dispatch taking into account all the transmission network and the physical/operational constraints. The IGO implicitly takes into account congestion considerations in determining the centralized economic dispatch. Under the Pool paradigm, a system marginal price no longer exists and each bus may have different real and reactive power nodal prices due to line losses and congestion avoidance considerations that can arise when the limit of one or more constraints is reached. The objective is to explore the economic signals provided by these prices and effectively apply them in the design of markets and the rules of the road for these markets. The main focus of the research is on the explicit evaluation of the impacts of the reactive load on the nodal real and reactive prices. Researchers adopt a rather general model for the representation of the reactive load: the reactive load at each node is represented as an affine function of the real power load at that node; that is, the reactive load is the sum of a constant and a constant power factor component. This model includes as special cases the constant reactive load and the constant power factor load including the case of purely real load corresponding to unity power factor. Researchers investigate the relationship between the real and reactive nodal prices and evaluate how they are impacted by the dual variables due to the various other physical/operational constraints in the system. Additional study focuses on the significance of the nodal price observations and the effective utilization in developing appropriate price signals in the Pool paradigm.

^ The Role of Load Demand in Elasticity in Congestion Management and Pricing
E. Bompard (Politecnico of Torino), G. Gross*
The Italian Fulbright Commission; U.S. State Department; PSERC

In the open access transmission regime, the common carrier nature of the transmission system may give rise to frequent conditions of congestion. Under such conditions, a violation of one or more physical or operational constraints in the base case or one of the contingency cases is encountered. Congestion may result in certain cases in marked price volatility and leads to price spikes. This is particularly true in competitive electricity markets that lack demand response. In this study, researchers examine the role that demand responsiveness can play in competitive electricity markets.

Typically, the task of congestion management and pricing is vested in the hands of an independent grid operator (IGO). The IGO uses an optimal power flow (OPF) based tool to determine the necessary actions to relieve the system of the congestion and to determine transmission system usage charges. The actions of price responsive loads may be represented in terms of the customers' willingness to pay. From each customer's demand curve, the elasticity of the load at different prices is known and the benefit function is derived. The load at each bus ceases to be a fixed quantity and becomes a decision variable for the optimization problem of the IGO. In this way, the IGO has additional degrees of freedom in determining the necessary actions for congestion relief. The project investigates the impacts of load elasticity in congestion management and pricing. Researchers analyze the salient characteristics of the optimum determined by the IGO with elastic load demand explicitly represented. The research team is evaluating elasticity effects on consumer, producer, merchandising, and social surplus. In addition, the demand responsiveness impacts on price volatility in terms of average price and standard deviation are determined and compared to the case without load responsiveness. The increase in market efficiency attainable in the presence of load responsiveness is assessed.

^ Transmission Congestion Management Schemes: A Comparative Analysis Under a Unified Framework
E. Bompard (Politecnico of Torino), G. Gross*
The Italian Fulbright Commission; U.S. State Department; PSERC

The restructuring of the electricity industry has spawned the introduction of new independent grid operators or IGOs, typically called transmission system operators (TSOs), independent system operator (ISOs), or regional transmission organizations (RTOs), in various parts of the world. An important task of an IGO is congestion management (CM) and pricing. This activity has significant economic implications on every market participant in an IGO region. The research considers the congestion management schemes and the associated pricing mechanism used by the IGOs in five representative systems: England and Wales, Norway, Sweden, PJM, and California. Researchers developed a unified framework for the mathematical representation of the market dispatch and redispatch problems that the IGO must solve in CM in these various jurisdictions. This unified framework is used to develop meaningful metrics to compare the various CM approaches so as to assess their efficiency and the effectiveness of the market signals provided to the market participants.

^ Active Vibration Mitigation in Electric Drives Systems
P. L. Chapman,* S. A. McElhinney
Grainger Center for Electric Machines and Electromechanics

Vibration of electric machines has many detrimental effects, including acoustic noise and mechanical wear. Since there is an increasing trend in industry to utilize power electronics for torque/speed control, it is logical to consider using the electronics for vibration mitigation as well. By detailed study of the mechanical properties of the machinery at hand and by utilization of appropriate sensors, at least some of the noise can be eliminated. The goal of the project is to create a prototype system that will be significantly less noisy than a system without the proposed control.

^ Applications of GaN Technology to Power Electronics
P. L. Chapman,* K. Kim
Grainger Center for Electric Machines and Electromechanics

Recent advances in GaN semiconductor devices will enable new developments in the power electronics area. GaN diodes and transistors can operate at higher temperature, speed, and voltage than the Si counterparts. This project will investigate the use of these devices in several typical power electronics applications, as well as at least one application not previously possible with Si technology.

^ Autonomous Optimal Control of Induction Machine Drives
P. L. Chapman,* P. T. Krein, J. R. Wells
Grainger Center for Electric Machines and Electromechanics

Direct Torque Control (DTC) of induction machine drives is a straightforward method of decoupling torque and flux that in itself provides for fast response and minimal parameter sensitivity. However, setting the flux command in DTC for optimal efficiency, like most other methods of optimal control of induction machine drives, relies heavily on parameterization or involves sacrificing response time. A parameter insensitive optimization routine, known as ripple correlation control, that interferes minimally with the dynamic response of the system has been developed. The control utilizes the perturbations inherent in power electronics driven motor drives to test for optimality of the operating point. Since the perturbations are at high frequency, the optimization has high bandwidth. The machine parameters are not critical in this robust control.

^ Extraction of Low-Order Models from Finite Element Representations of Electromechanical Devices
P. L. Chapman*
Grainger Center for Electric Machines and Electromechanics

In designing complicated electromechanical systems, it is imperative to have accurate, rapidly executing dynamic models. Traditional lumped-parameter models are not usually as accurate as desired, since they rely on many assumptions in development and parameter extraction. In many respects, the finite element method is a convenient means for eliminating some discrepancies, but the method is computationally intensive. This project seeks to develop a methodology to extract a computationally nonintensive model from an ordinary finite element representation. The resulting model will retain the salient features of the finite element model, but execute rapidly enough to enable designers to consider many designs and simulate large systems with many devices.

^ Fully Integrated Switch-Mode Power Supplies
P. L. Chapman,* C. Liu
Grainger Center for Electric Machines and Electromechanics

Miniaturization is of supreme interest in all facets of electronics design, and power management is no exception. While power supply components have shrunk considerably in the last decades, the size decrease is limited by the large passive components. Recent developments in MEMS technology have enabled fabrication of microscale inductors and capacitors. Coupled with the integrated switching devices, an entire power converter can be built on a single chip. The integration, which in itself results in a small package, eliminates many of the parasitic effects and enables one to use higher switching frequency, thereby reducing the size of passive components needed. One interesting application of the technology would be for power MEMS electrostatic actuators, which typically require high voltages (up to hundreds of volts). In this application, a boost converter will be used to convert a logic level voltage to the high voltage needed. The converter and actuator will be entirely on one IC, representing a very compact system.

^ Optimized Waveshaping for PM Motor Drives with Unbalanced, Arbitrary, and Asymmetrical Back EMF
P. L. Chapman*
Grainger Center for Electric Machines and Electromechanics

By precisely shaping the current in permanent magnet motor drives, considerable improvement in performance can result in terms of efficiency and vibration. Previous work in this area has limitations in that it requires the motor emf to be balanced, symmetrical, and to otherwise be restricted in shape. By eliminating these restrictions, a more flexible control has been developed. An important consequence is that with this control, the motor can be operated with one or more phases absent with only some degradation in power output.

^ Analysis and Evaluation of VAr Support as an Ancillary Service
G. Gross,* S. Tao
Power Engineering Research Center through Cornell University

The unbundling of electricity services has brought about the need to evaluate and quantify the various services. VAr support is one such service. Researchers have analyzed the principal attributes of this service and identified the dominant cost component. The research team is developing an analytic basis for the evaluation of the VAr support needs associated with transactions. The objective is to develop an allocation mechanism for VAr support among the transactions on the system.

^ Analysis of the Bilateral Transaction Paradigm for Electricity Markets
G. Gross*
The Grainger Foundation Inc.; Power Affiliates Program

Researchers are investigating the structure and functioning of bilateral-transaction-based electricity markets such as those created by restructuring in Norway and Sweden. The objective is to analyze the salient characteristics of the Nord Pool market and to perform a side-by-side comparison with the England and Wales Electricity Pool. The focus is on the assessment of congestion management and pricing. A mathematical model representing the market structure and rules governing the operation of the Nord Pool market has been developed. The study will assess the functioning of the Independent Grid Operator and the critical role of transmission services.

^ Congestion Management Scheme for Multitransaction Systems
G. Gross,* S. Tao
EPRI/DOD

Researchers are investigating the allocation of charges for congestion management (CM) in multiple transaction networks. The problem is formulated in two stages. In the congestion allocation stage, the operator determines the congestion burden attributable to each individual transaction. In the congestion relief stage, the operator used an adjustment bidding to determine the congestion relief actions. The allocation scheme is being tested on several systems.

^ Development of an Analytical Framework for Dispersed Generation
G. Gross,* Y. Lin
The Grainger Foundation Inc.; Power Affiliates Program

Increased competition in the electricity supply industry, increasing costs of transmission and distribution upgrades, greater pressures on cleaner environment, higher energy efficiency, and decreasing marginal costs of new and smaller generation technologies are some of the factors that are going to impact alternatives for adding electricity supplies. The principal objective is to formulate a comprehensive analytical framework for dispersed generation within which the economic, technological, environmental, and reliability aspects can be studied. Simulation of systems with transmission constrained load pockets and dispersed generation expansion alternatives are being performed.

^ Development of an Analytical Framework for Strategic Bidding in Competitive Electricity Markets: Modeling and Policy Analysis
G. Gross,* G. Deltas (Econ.), M. Joung
National Science Foundation, ECS-0000577

The work is focused on the design, functioning, and performance of competitive mechanisms in wholesale electricity markets taking explicit account of the specific characteristics and constraints of electrical generation and consumption. The objective is to develop a general and comprehensive analytic framework that integrates the game theoretic aspects of electricity exchanges with the unique constraints under which electric power systems operate. This framework will lay the foundation for the evaluation of various designs for electricity market structures and "rules of the road" of auction mechanisms that incorporate the constraints imposed by the physical, engineering, and operational constraints inherent in electricity systems, so as to maximize economic efficiency. The in-depth analysis of the structural characteristics of electricity markets will provide a basis for the formulation of optimal bidding and offering strategies with both supply- and demand-side bidders. Researchers aim to use the framework to address the various aspects of the implementation and performance of auctions for electricity; the explicit incorporation of uncertainty; the interrelationships between the MWh commodity markets and specific markets in ancillary services; and the impacts of longer term forward and future markets. These issues will be investigated together with topics related to the opportunities for gaming, the existence and exercise of market power, and the impacts on electricity prices. In addition, the framework will serve as an effective testbed for a wide range of policy experiments, including those focused on the nature and scope of regulation in the restructured industry. Throughout the proposed work, researchers will implement simulation tools to illustrate the performance of various market designs, rule specifications, regulatory policies, and strategic behavior of various players.

^ Effective Deployment of Financial Instruments in Competitive Electricity Markets
G. Gross,* S. Tao
The Grainger Foundation Inc.; Power Affiliates Program

With the recent emergence of the well defined electricity spot markets and the establishment of the trading of electricity futures on specific exchanges, the application of financial instruments such as options, futures, and forwards provides significant new tools to players in electricity. Such instruments can be used for risk management as well as speculation. The focus of this research is on the effective incorporation of these instruments into the operation of electricity trading. Researchers will investigate certain design and definitional issues in the deployment of financial derivative concepts to electricity markets. Of particular interest is the evaluation of the risk mitigation capabilities provided by these instruments for the trading of electricity and their impacts on the spot markets. In this project, researchers will investigate the salient uniqueness of electricity derivative contracts due to the physical power system. The research team also will investigate the possibility of developing new financial instruments and strategies to accommodate the different risk preference of various participants in the spot electricity market. Moreover, researchers will study the impact of financial derivatives on various players of the market.

^ Loss Allocation Scheme for Multitransaction Systems
G. Gross,* S. Tao
The Grainger Foundation Inc.; Power Affiliates Program

Researchers are studying the allocation of losses as a function of physical power flows in multitransaction systems. The research team has recast the power flow problem in a transaction-based network and is studying the issue of appropriately allocating losses on the basis of flows that the transactions bring about. Extensive tests of the approach are being carried out on systems of varying sizes. A mechanism for loss compensation has been developed to provide choice to transacting entities.

^ Metering Requirements and Metering Data Applications in Open Access Bulk Electricity Systems
G. Gross,* J. W. Lee
Power Engineering Research Center through Cornell University; The Grainger Foundation Inc.

The FERC Order No. 888 specified six unbundled ancillary services that may be provided to transmission customers. The NERC has developed a classification of 12 separate interconnected operations services. The unbundling of the services and the disintegration of the vertical structure of the electricity business have set up new requirements for information acquisition, metering, and communications. This project will examine the communication protocols and the data management aspects of the metering activities.

^ Power Electronic Building Blocks Interconnected Network
G. Gross,* P. Krein,* D. Logue
SRI International

Conceptually, Power Electronic Building Blocks (PEBBs) are smart power electronic modules that are superior to conventional power devices in that they have increased sensing, protection control, and interfacing capability. This research is directed toward development of a conceptual framework for an interconnected network of PEBB devices. The objective is to use the framework for addressing analysis, design, and control issues. A hybrid electric vehicle at the University of Illinois is intended to be used as a testbed for this framework and other conceptual developments.

^ Real-Time Security Monitoring and Control
G. Gross*
National Science Foundation

Researchers have prepared a White Paper that outlines the scope of issues, challenges, and opportunities in the area of real-time security monitoring and control (RTSMC) of power systems in the restructured electricity industry. The counterpart of power system reliability in real-time operations is security—the ability of the power system to withstand contingencies. This White Paper is part of a set of six papers on reliability aspects of the electric power system prepared for the U.S. Department of Energy by the Consortium of Electric Reliability Technology Solutions (CERTS).

^ Simulation of the Multinode Open Access Same-Time Information System
G. Gross,* Y. Tian
The Grainger Foundation Inc.; Power Affiliates Programs

A Web-based simulator of the Federal Energy Regulatory Commission (FERC) mandated Open Access Same-Time Information System (OASIS) network was implemented. The purpose of the simulator is to provide a tool to study the various aspects of an OASIS network, to gain a strong intuitive feel for its operations, and to train users. For a specified time period, the OASISNET simulator reproduces an OASIS network of multiple nodes using the same communications medium as the actual system, the Internet, and with multiple players using the simulator simultaneously. Salient features of the simulator are its modular architecture, the ability to simulate multinode OASIS network operations and to accept simultaneous access from remote users through use of client/server technology. The simulation focuses on the dissemination and use of the available transmission capability information. Applications of the new simulator for training and analysis are under study.

^ The Load Frequency Control (LFC) Performance Assessment
G. Gross,* J. W. Lee
The Grainger Foundation Inc.; Power Affiliates Programs

Load frequency control is used to regulate the frequency of the power system to be within acceptable bounds around the synchronous value. Researchers are constructing a framework for the evaluation of LFC performance assessment taking into account the random variations of the actual load over time. Appropriate metrics for the LFC performance assessment are constructed in the random process based framework. These metrics are used to formulate the criteria for LFC performance assessment. The effectiveness of industry criteria is assessed.

^ A Hybrid Systems View of Inverse Problems in Power System Dynamics
I. A. Hiskens,* D. Liberzon,* M. A. Pai*
The Grainger Foundation Inc.

Analysis of power system dynamic behavior frequently takes the form of inverse problems, where the aim is to find parameter values that achieve (as closely as possible) a desired response. Examples include parameter estimation, quantifying parameter uncertainty, boundary value problems, and optimal control. The project is developing algorithms for solving such inverse problems. Power system behavior inherently involves interactions between continuous dynamics and discrete events. A systematic hybrid systems framework for modeling, analysis, and algorithms is being pursued.

^ Battery Equalization in Series Strings
P. T. Krein,* S. West
S & C Electric Co.; The Grainger Endowments

Batteries are usually used in series strings. When a string is charged, the individual cells can become mismatched. Over time, this mismatch can grow, particularly if extreme temperature conditions occur. Mismatch is corrected by equalization, in which the battery voltages are forced to match. This is usually accomplished with a forced-overcharge process, with elevated voltage applied after the end of a charge cycle. This project studies an elegant equalization method invented at the University of Illinois. In this method, a capacitor string is switched between adjacent batteries, forcing them to reach a matching condition whether or not they are charging.

^ Coupled Filter Applications to DC Power Converters
P. T. Krein,* D. C. Hamill (Surrey), R. Balog
The Grainger Endowments, in collaboration with the University of Surrey, England

Coupled magnetic filters offer performance improvements in dc switching power circuits, but are not well understood in the field. In fact, one key coupled filter building block has been reinvented several times over an interval of 60 years or more. This work seeks a fundamental understanding of coupled filter design, performance, and applications. Coupled filters are compared with more conventional approaches for design sensitivity and utility.

^ Direct Digital Class-D Audio Amplifier
P. T. Krein,* D. Sarwate,* Z. Song, C. Pascual, X. Geng
Motorola, Inc.; University of Illinois

Conventional "linear" audio amplifiers have low power efficiency. In modern digital audio systems, amplifiers require digital-to-analog conversion, with the associated noise sensitivities and signal problems. Class-D amplifiers operate by direct pulse-width modulated (PWM) switching and in principle, can be free of power loss. Because class-D circuits operate by switching, it is feasible to maintain the audio information in digital form right through to the amplifier output. Researchers explore audio processing to convert from conventional digital formats to PWM. Class-D circuit design methods are being developed to support audiophile performance with very low power loss.

^ Hybrid Electric Vehicle Systems
P. T. Krein,* R. A. White* (Mech. & Indus. Engr.), D. Logue
University of Illinois; Grainger Center for Electric Machinery and Electromechanics; Ford Motor Co.; Deere & Co.

(In conjunction with the Department of Mechanical and Industrial Engineering)

A complete hybrid electric car, combining an electric traction system with an engine-generator set, has been built and is now under study in the laboratory and on the highway. The car is designed to meet all performance, safety, and convenience characteristics of standard automobiles, while reducing exhaust emissions by as much as 90% and tripling gas mileage. Objectives are to characterize major subsystems of a practical hybrid car in depth. Tests of efficiency and fuel economy, as well as parametric studies of subsystems, have been conducted. A complete system simulation has been prepared. Strategies for system operation and control are being tested through simulation and experiments.

^ Modeling and Simulation of Distributed Energy Systems
P. T. Krein,* D. Logue
Power Engineering Research Center

The electric power grid of the future is likely to include "distributed" generation, or small units dispersed throughout the system. This work considers a wide range of possible power sources, including engine-generator combinations, batteries, fuel cells, and solar cells. Fast models suitable for system simulation are to be developed. Buffering methods that decouple the dynamics of the power system and the small energy source are being developed. The buffering concept allows the device to act like a resistor over short time intervals.

^ Motor System Simulation for Dynamic Loads
P. T. Krein,* D. Logue
Grainger Center for Electric Machinery and Electromechanics

This project seeks to develop a general simulation tool for an ac motor in a complex system. The simulation includes electronic motor controls, load dynamics, and interactions between the motor, the load, and the controls. Time-scale models are used to capture both electrical and mechanical behavior. Losses generated by high-frequency switching are included based on behavioral models. The Simulink environment is being used. Sample applications include a complete hybrid automobile system, a dc pump motor operated with a nonlinear controller, and several induction motor applications.

^ Ripple Correlation Control for Power Converters and Motor Drives
P. T. Krein,* P. Chapman, D. Logue, R. Balog, J. Wells
Grainger Center for Electric Machines and Electromechanics

Ripple correlation control is a new technique that might be unique to power electronic systems. According to this control approach, internal ripple signals in a power converter are correlated with gate drive signals or other internal converter signals. The results provide information about state variables and converter operating points. It is known, for example, that certain correlations can be used to drive a solar power processing converter to its maximum power point. Researchers will explore a wide range of applications and related techniques.

^ Interactive Visualization of Electrical Power System Transmission System Capacity
T. J. Overbye,* D. Wiegmann, Y. Sun
Power Systems Engineering Research Center (PSERC)

One of the major goals associated with restructuring in the electrical power industry is to allow nondiscriminatory access to the high-voltage transmission grid. However, a key difficulty in achieving this goal has been the fact that the capacity of the transmission grid has a finite but not easily determined value. That is to say, the ability of the transmission system to support additional power transactions is limited by the need to maintain system security. The goal of this project is to develop and apply innovative visualization methods to aid market participants in determining this availability.

^ Optimal Bidding Strategies in Transmission Limited Electric Power Markets
T. J. Overbye,* I. Hiskens, P. Correia
National Science Foundation, ECS 00-80279

The electricity industry in the United States and throughout the world is undergoing radical restructuring, with many markets moving from a cost-based paradigm for generation dispatch to a price-based paradigm. These changes require new analysis techniques, both for market participants and for regulators. The goal of this project is the development of a market solution algorithm that allows market participants to determine optimal generation bidding strategies taking into account the constraints imposed by the electric power transmission grid.

^ A Hybrid Approach to Transport Industry Modeling: A Power System Viewpoint
M. A. Pai,* I. A. Hiskens,* V. Donde, W. Tangmunarunkit
National Science Foundation, ECS 0085755

With the emerging restructured nature of the power industry, there is a need to look at new approaches to modeling as well as tools of analysis. Among the transport industries, the power industry can both profit from the experience of other deregulated industries, as well as offer new ideas in terms of modeling and analysis. Increasingly, discrete events affect the performance of systems in real time. Such events are common in the physical system, for example relays, tap-changing transformers, and FACTS devices. However the rules underlying the market layer also introduce discrete events. System performance under these conditions, where continuous dynamics and discrete events interact, is the principal focus of the proposal. A major theme is to map formal languages that describe hybrid systems, such as Petri nets and finite state automata, into a differential-algebraic model structure. A linking strategy will be exploited to maximize model flexibility. Researchers will also focus on trajectory sensitivity analysis of hybrid systems. The results of research will be in the form of formulating new areas of research for the restructured power industry.

^ High Speed Dynamic Simulation Using the Krylov Subspace Method
M. A. Pai,* D. Chaniotis
National Science Foundation, ECS 98-03055; The Grainger Foundation Inc.

The differential-algebraic system of equations of the power system are algebraized using the simultaneous-implicit method, and the resulting system of linear equations at each time-step is solved using the generalized minimal residual (GMRES) method. In previous research, the use of preconditioners such as the ILUs was found to speed up the convergence. Further enhancement in speed-up was obtained by using the preconditioner only when the number of iterations increased. Various schemes of using LU type preconditioners have been tried with good success for dynamic simulation and trajectory sensitivity computations.

^ New System Control Methodologies
M. A. Pai,* I. A. Hiskens,* A. Nayak, C. L. DeMarco (Univ. of Wisconsin)
PSERC Project

In this project, researchers are looking at the effect of dynamic control in the new, deregulated environment. In previous projects, researchers looked at the AGC in the new, restructured environment. Currently the research team is investigating congestion related problems and ways to alleviate congestion.

^ Trajectory Sensitivity as a Tool for Dynamic Security Assessment
M. A. Pai,* T. Nguyen
National Science Foundation, ECS 00-00474; The Grainger Foundation Inc.

In this project, researchers use trajectory sensitivity information to generate information about critical values of parameters, such as clearing time, maximum power transfer, maximum generation, and so forth, before the system becomes unstable. This is done for normal as well as contingency cases. It does not use the traditional energy function methods but rather relies on two fast simulations of the system and the sensitivity model, computing a suitable metric from the latter and extrapolating to compute the critical value of parameters. The technique has been validated on small systems and a theoretical basis is being formulated.

^ Power Industry Restructuring and Pricing in Siberia
S. Palamarchuk, G. Gross*
Bureau of Educational and Cultural Affairs; U.S. Department of State

The restructuring of the power industry in Russia is under way. The existing nationwide market is planned to be divided into three regional sectors, one of which will be set up in the Siberian region of the country. The restructuring will allow the market arrangements to take into account the regional characteristics of electricity generation, transmission, and consumption. The project aims to develop an auction mechanism for the wholesale electricity trade in Siberia. Key aspects include review of the market structures currently in operation, design of the market forward trade and the associated pricing issues, development of procedures for the evaluation of rational bidding strategies for market players, and training of the players in the new environment.

^ Available Transfer Capability of Power Systems
P. W. Sauer,* S. Grijalva
National Science Foundation, EEC 96-15792

This project examines new approaches to the rapid computation of available transfer capability in electric power systems. It focuses on efficient techniques to simultaneously include thermal, voltage, voltage collapse, and transient stability margin constraints. New approaches to quantify the transmission reliability margin and capacity benefit margin are investigated.

^ Extended Factors for Linear Contingency Analysis
P. W. Sauer,* K. Reinhard
The Grainger Foundation Inc.; Power Affiliates Program

This project is formulating new computational factors to extend linear contingency analysis to include phenomena such as angle shifts and generator torque changes in response to line outages or closings. The factors build on well-known power transfer distribution factors and line outage distribution factors.

^ Integrated Security Analysis
P. W. Sauer*
PSERC Industrial Membership through Cornell University

This project is formulating new security analysis tools for operators using existing computational software code with online data. Traditional security application programs are used to create historical security results that will be used to develop learning algorithms. These algorithms will use both new computational results and historical results. This work is being done jointly with Washington State University.

^ Minimizing Failures While Maintaining Efficiency of Complex Interactive Networked Systems
P. W. Sauer,* M. A. Pai, I. Hiskens
Electric Power Research Institute/DoD through Cornell University-PSERC

This project is task two of the overall EPRI/DoD project with this title. The task is to formulate the overall design of a link-based mathematical model that can accommodate key functional and structural attributes necessary to analyze the interaction between layered systems. It will use the four-layer power system as the testing ground for applications.

^ Reliability Tools for Power System Operators
P. W. Sauer,* T. Overbye
Department of Energy/CERTS through Cornell University-PSERC

This project is investigating advanced security analysis visualization concepts to enhance the reliability of the interconnected grid. Results from online security analysis will be presented and displayed to operators in a format suitable for rapid decision making and for assessing the acceptability of the system state.


Summary of Engineering Research