N.J. Balu

CPFLOW: a practical tool for tracing power system steady-state stationary behavior due to load and generation variations

In this paper, a computer package called CPFLOW, which is a comprehensive tool for tracing power system steady-state stationary behavior due to parameter variations, is presented. The variations include general bus real and/or reactive loads, area real and/or reactive loads, or system-wide real and/or reactive loads, and real generation at P-V buses (e.g. determined by economic dispatch or participation factor). The main advantages of CPFLOW over repetitive power flow calculations are its computational speed and reliability as well as its wide applicability. A detailed description of the implementation regarding the predictor, corrector, step-size control and parameterizations employed in CPFLOW is presented. CPFLOW has comprehensive modeling capability and can handle power systems up to 12000 buses. For an illustrative purpose, CPFLOW is applied to a 3500-bus power system with a comprehensive set of operational limits and controls. >

H ∞ damping controller design in large power systems

The design of an H/sub /spl infin controller for a thyristor controlled series VAr compensator to enhance the damping of an inter-area oscillations in a large power system is presented. The paper describes a comprehensive and systematic method of applying the H/sub /spl infin control design algorithm in power systems. Two methods to obtain a satisfactory reduced order system model, which is crucial to the success of the design, are described. >

On-line power system security analysis

A broad overview of on-line power system security analysis is provided, with the intent of identifying areas needing additional research and development. Current approaches to state estimation are reviewed and areas needing improvement, such as external system modeling, are discussed. On-line contingency selection has become practical, particularly for static security. Additional work is necessary to identify better indices of power system stress to be used in on-line screening filters for both static and dynamic security analysis. Use of optimal power flow schemes to recommend optimal preventive and corrective strategies is presented on a conceptual level. Techniques must be further developed to provide more practical contingency action plans, which include real-world operating considerations and use a reasonably small number of control actions. Techniques must be developed for costing operating variables which are not easily quantified in dollars. Soft or flexible constraints and time variables must be included in the preventive and corrective strategy formulation. Finally, the area of on-line transient and dynamic security analysis is presented. >

Composite generation/transmission reliability evaluation

Surveys some of the methodologies and computational techniques used for composite generation/transmission reliability evaluation. Topics addressed include: a conceptual framework for reliability evaluation, characterization of system states, selection of a system state, assessment of the selected state, estimation of reliability indices, sensitivity analysis, and techniques for reducing computational effort. The approaches are illustrated in case studies with utility-derived systems. >

Power system reliability planning practices in North America

The authors present selected results from a recently completed research project for the Electric Power Research Institute. One component of the project was intended to develop and test methodologies for gathering data on how utility customers value service reliability, as measured by either the cost of outages or the willingness to pay for reliability. Another component of this project involved a survey of current and emerging reliability planning practices in the North American utility industry, especially regarding interest in value-based reliability planning. The results of the survey, including the survey design and methodology, are given. The authors briefly discuss potential applications of interruption costs in generation and composite system reliability planning. >

H/sub /spl infin damping controller design in large power systems

The design of an H/sub /spl infin controller for a thyristor controlled series VAr compensator to enhance the damping of an inter-area oscillations in a large power system is presented. The paper describes a comprehensive and systematic method of applying the H/sub /spl infin control design algorithm in power systems. Two methods to obtain a satisfactory reduced order system model, which is crucial to the success of the design, are described. >

Review of expert systems in bulk power system planning and operation

Advantages and disadvantages of expert systems are discussed. An overview of expert system applications being developed or considered high potential is given. >

H{sub {infinity}} damping controller design in large power systems

The design of an H/sub /spl infin controller for a thyristor controlled series VAr compensator to enhance the damping of an inter-area oscillations in a large power system is presented. The paper describes a comprehensive and systematic method of applying the H/sub /spl infin control design algorithm in power systems. Two methods to obtain a satisfactory reduced order system model, which is crucial to the success of the design, are described. >