On-Line Transient Stability Assessment Scoping Study

This is a project report from the Power Systems Engineering Research Center (PSERC). PSERC is a multi-university Center conducting research on challenges facing a restructuring electric power industry and educating the next generation of power engineers. More information about the center can be found at the Center's website: Notice Concerning Copyright Material PSERC members are given permission to copy without fee all or part of this publication for internal use if appropriate attribution is given to this document as the source material. This report is available for downloading from the PSERC website. We wish to thank all the vendor companies who participated in the survey of available on-line stability assessment tools and the PSERC member companies who provided invaluable support in terms of a user needs survey for on-line transient stability assessment i Executive Summary With the increase in transactions on the bulk power system, there is a critical need to determine transient security in an on-line setting, and to perform preventive or corrective control if the analysis indicates that the system is insecure. In recent years the industry has seen the development of large generation projects near locations of fuel supplies. As a result, the stability properties of the system have been altered. Unfortunately, the developers of the new " non-utility " plants are not cognizant of the impact of the plants on system stability. In this environment, new stability conditions may actually reduce available transfer capability. Stability problems may not occur frequently, but when they occur, their impact can be enormous. Most of the time, off-line studies are performed to determine conservative estimates of stability limits. In today's bulk power market, the responsibility for monitoring system stability may be vested with an independent system operator. On-line stability monitoring may be even more necessary than in the past as power system operators try to facilitate as many economic transactions as possible. This project's objectives were to review the state of art in on-line transient stability assessment; evaluate promising new technologies; and identify technical and computational requirements for calculating transient stability limits and corrective and preventive control strategies for operating situations that are transiently insecure. Six on-line transient stability package vendors were identified by conducting a literature survey. A detailed questionnaire which addressed several pertinent issues relating to on-line transient stability assessment was prepared. All six vendors responded to the questionnaire. The responses received were carefully analyzed. This analysis provided …