Design of a Real-Time Security Assessment Tool for Situational Awareness Enhancement in Modern Power Systems

Detailed security analysis for N - k ontingencies (k = 1, 2, 3, ...) in a real-time setting is still a great challenge due to the significant computational burden. This paper takes advantage of phasor measurement units (PMUs) and decision trees (DTs) to develop a real-time security assessment tool to assess four important post-contingency security issues, including voltage magnitude violation (VMV), thermal limit violation (TV), voltage stability (VS) and transient stability (TS). The proposed scheme is tested on the Salt River Project (SRP) power system represented by a series of operating conditions (OCs) during a representative day. The properly trained DTs demonstrate excellent prediction performance. Robustness tests for the offline trained DTs are performed on a group of changed OCs that were not included for training the DTs and the idea of tuning critical system attributes for preventive controls is also presented to improve system security.