Power System Congestion - In Search of an Index from LP Basis Matrices

This paper analyzes the high nodal prices that occur typically during network congestions in electricity markets based on decomposition of the basis matrix obtained from LP solution. More specifically we examine the singular value and condition number of basis matrix with and without congestion and discuss its applicability as a congestion indicator. A procedure to rank the severity of the constraints during congestion is discussed. We also present three types of price based indices that can indicate the degree of congestion in electricity markets. These metrics could potentially be used to alert the system operator of the existence of dispatches that will tend to trigger the extreme price conditions in a scheduling horizon.