Transaction impact analysis and its application in electricity markets

System security considerations are becoming more critical for healthy and efficient electricity market operation. This paper defines and quantitatively analyzes transaction impact based on a System Security Index (SSI), which is defined to properly represent system security, and thus detect transmission congestion, taking into account thermal, voltage and voltage stability constraints. A simple and efficient method to determine the most effective market rescheduling strategy for transmission congestion relief is also presented based on a transaction impact analysis. The proposed technique is tested in a 3-area test system and a 129-bus model of a realistic system.