Consequence and impact of electric utility industry restructuring on transient stability and small-signal stability analysis

The electric utility industry is undergoing unprecedented changes in its structure worldwide. With the advent of an open market environment and competition in the industry, and restructuring of the industry into separate generation, transmission, and distribution entities, new issues in power system operation and planning are inevitable. One of the major consequences of this new electric utility environment is the greater emphasis on reliability and secure operation of the power system. This paper examines the impact of restructuring on power system dynamic analysis. It specifically addresses issues related to transient stability analysis and small-signal stability analysis. Four major topics to examine the effect on the nature of studies conducted are considered. These topics are 1) system adequacy and security 2) system modeling data requirements, 3) system protection and control, and 4) system restoration. The consequences and impact of each of these topics on the nature of the studies conducted ar-e examined and discussed. The emphasis on greater reliability has led to a clearer enunciation of standards, measurements, and guides in some countries. These requirements will result in: 1) more measurements on existing systems, 2) rigorous analysis of transient stability and small-signal stability to determine operating limits and plan systems; 3) greater emphasis on studies to verify coordination and proper performance of protection and controls, and 4) development of a detailed plan for system restoration in the case of wide-spread outages.