Enhancing Situation Awareness by Determining Critical Intra-Area and Interarea Transmission Lines

Due to the increment of network loads and also incredible costs of installing new transmission lines, the loading of transmission lines has been increased considerably. Therefore, determining critical transmission lines is quite important for the secure operation of power systems and enhancing situation awareness. This article offers a novel algorithm to identify critical lines from the synchronous generator oscillations (SGOs) viewpoint. The proposed method can identify both intra- and interarea transmission lines. Using the proposed method, linearization of the system's equations is performed to estimate the behavior of SGOs after a line outage. Using the developed state-space-based technique, critical lines are determined without requiring to solve the differential equations of the system and to perform time domain simulation studies. To do this, a novel dynamic index is introduced which is strongly correlated with both generator's oscillations overshoot and settling time indices. The proposed method can determine both critical intra- and interarea lines for each generator and area, respectively. The performance of the proposed method is evaluated on different test systems including the IEEE 118-bus system and some of the obtained results are reported. The numerous simulation results thoroughly verify the effectiveness and high efficiency of the proposed method.