Speaker: Xian Guo, ECpE student
Advisor: James McCalley, Harpole Professor of Electrical & Computer Engineering
Title: Constraint relaxation and cascading contingency monitoring: a risk-based approach
Abstract: Risk analysis has been widely used in multiple area. This presentation focuses on two related decision-problems in power system–constraint relaxation for security constrained economy dispatch (SCED) and defending against cascading contingencies.
- Risk-based constraint relaxation for SCED In the electricity markets of North America, SCED is widely implemented to make dispatch decision for day-ahead and real-time markets. To deal with infeasibility of SCED model, we propose risk-based constraint relaxation (RBCR) method, relaxing the thermal limit of individual circuits while simultaneously resisting risk increase; this approach avoids selection of penalty prices and thus reduces the tendency for LMPs to spike in certain regions of the network. However, this method only focuses on a single time interval and does not address the fact that actual limitation for line flow is conductor temperature. Based on the above analysis, we are working on a new RBCR method, which models conductor temperature with look-ahead dispatch. This method can take advantage of inter-temporal effects and handle both pre-contingency and post-contingency overflows.
- Risk-based stress indicator for cascading contingencies
In order to assess power systems for exposure to successive “cascading” contingencies, and give early warning for system operators to take action, we propose risk-based stress indicator to evaluate the stress of current power system. The Kth-order risk indicator provides the ability to continuously monitor the power system for cascading exposure. According to the value of risk index, it can identify the propagation of possible successive “cascading” contingencies and weak area in power system, thus system operators can take immediate action in risk mitigation for such areas.