R.D. Christie

Bio: R.D. Christie is an academic researcher. The author has contributed to research in topics: Power system simulation & Electric power system. The author has an hindex of 1, co-authored 1 publications receiving 22 citations.

Visualizing voltage profiles for large scale power systems

Abstract: To be effective for large-scale power system simulation, the bus voltage representation has several issues to be resolved. The selected method must be able to handle a large amount of information effectively. For that purpose, each element must be simple and small, easy to identify and to discern in any environment. This is the principal objective of the authors' research, and of this article. They detail how their representations use a scale of carefully chosen colors based on characteristics of human visual perception and mental models of color usage in the power industry.

Voltage contours for power system visualization

Abstract: Power system engineers are presented with vast amounts of information to analyze during daily operations. In systems containing thousands of buses, it can be very difficult to assess the state of the power system in an intuitive and rapid manner. The paper discusses the use of contours for visualizing power system voltage data. Also, because of the low computation requirements of the contouring algorithm, the algorithm is implemented into a real-time animation of the voltage profile of a power system. The contouring routines are implemented into the PowerWorld/sup TM/ Simulator software package, with results shown for systems with up to several thousand buses. Experiments and interviews with system engineers are also discussed to measure the applicability of voltage contouring as an add-on to practical EMS systems.

Visualizing Real-Time Security Threats Using Hybrid SCADA / PMU Measurement Displays

Abstract: This paper explores ways to highlight threats to power system security by displaying data from phasor measurement units (PMUs) and SCADA data sources simultaneously. SCADA measurements provide a picture of the steady-state health of the system, whereas PMUs capture the faster variations that may indicate small-signal stability problems. The software system described in this system gathers SCADA and PMU data and displays them on a geographic map of the system. The system uses contour plots to show the variation of a measurement with location, even when adjacent measurement points are widely spread. The system superimposes trend plots on this display to show the past variation of a quantity over a user-specified time window. The goal of the system is to help operators gauge the present security of the grid.

An advanced visualization platform for real-time power system operations

Abstract: The size and complexity of the intercon- nected power grid pose significant challenges to system operators. The requirement of rapid response under di- verse conditions in a highly complex environment under- scores the need for tools that can help operators detect potential problems and identify solutions quickly and accurately. This paper discusses the design, development, and deployment of a software application that attempts to address this need. The software illustrates system condi- tions on a geographic map of the interconnection using a variety of innovative visualization techniques that help the application convey the current state of the system in a clear, unambiguous, and engaging way. This paper dis- cusses the architecture of the application, the benefits, design, and implementation of each of its visualization tools, guidelines for designing displays that take maximum advantage of the platform's strengths, and planned future enhancements. It also emphasizes a key ingredient to the success of the application: seeking and responding to the ideas and needs of the operators who depend on the plat- form for the information they require to operate the power system. Several figures are included that demon- strate the types of displays currently being shown in the control room.

Human factors aspects of power system voltage contour visualizations

Abstract: This paper presents experimental results associated with human-factors aspects of utilizing color contours to visualize electric power system bus voltage magnitude information. Participants were divided into three groups: the first group saw only one-line numeric data, the second only one-line contour data, while the third saw both. The purpose of the experiment was to determine how quickly participants could both acknowledge low voltage violations and perform corrective control actions. Results indicated the contour-only visualization resulted in the quickest voltage violation acknowledgments, while the numeric-data-only visualization resulted in the quickest solution times. Testing was done using a modified version of the IEEE 118 bus system.

Individual Welfare Maximization in Electricity Markets Including Consumer and Full Transmission System Modeling

Abstract: ii RED-BORDERED FORM iii ABSTRACT This dissertation presents a new algorithm that allows a market participant to maximize its individual welfare in the electricity spot market. The use of such an algorithm in determining market equilibrium points, called Nash equilibria, is also demonstrated. The start of the algorithm is a spot market model that uses the optimal power flow (OPF), with a full representation of the transmission system. The OPF is also extended to model consumer behavior, and a thorough mathematical justification for the inclusion of the consumer model in the OPF is presented. The algorithm utilizes price and dispatch sensitivities, available from the Hessian matrix of the OPF, to help determine an optimal change in an individual's bid. The algorithm is shown to be successful in determining local welfare maxima, and the prospects for scaling the algorithm up to realistically sized systems are very good. Assuming a market in which all participants maximize their individual welfare, economic equilibrium points, called Nash equilibria, are investigated. This is done by iteratively solving the individual welfare maximization algorithm for each participant until a point is reached where all individuals stop modifying their bids. It is shown that these Nash equilibria can be located in this manner. However, it is also demonstrated that equilibria do not always exist, and are not always unique when they do exist. It is also shown that individual welfare is a highly nonconcave function resulting in many local maxima. As a result, a more global optimization technique, using a genetic algorithm (GA), is investigated. The genetic algorithm is successfully demonstrated on several systems. It is also shown that a GA can be developed using special niche methods, which allow a GA to converge to several local optima at once. iv Finally, the last chapter of this dissertation covers the development of a new computer visualization routine for power system analysis: contouring. The contouring algorithm is demonstrated to be useful in visualizing bus-based and transmission line-based quantities. v ACKNOWLEDGMENTS I would like to thank Professor Thomas J. Overbye for his knowledge, guidance, and support throughout my doctoral studies. He and his family have been a great help to me. I would also like to thank all the other professors who have helped and continue to help me in my academic career. I also say thanks the University of Illinois Power Affiliates Program and Grainger Foundation for their generous financial …