Ensuring Survival of Equilibrium After Any Single Line Outage in a Power System Network

Brian Raczkowski, Electrical and Computer Engineering, UIUC,

For a given power system network, many lines contribute to the goal of delivering power from point A to point B - some more important than others. This paper deals with the challenge of identifying the lines that need to be upgraded to ensure the existence of an equilibrium condition after any single line outage. The concepts of Static Transfer Stability Limits (STSLs) and Transfer Loss Stability Limits (TLSL) and their relation in minimum cutsets of lines are discussed. The Line Outage Loss Condition (LOLC) is proposed and explored. LOLCs arise from making a discrete event of a line outage into a continuous set of events. These ideas help reveal more information about the system as it approaches static collapse. A method based on LOLC is proposed for detecting the limiting lines. This method recommends the amount of change in line impedance of the limiting lines to avoid static collapse from line outages. Multiple power system models are analyzed to experimentally support the conjecture and the method.