Vulnerability assessment of power system using various vulnerability indices

Vulnerability assessment in power systems is important so as to determine how vulnerable a power system in case of any unforeseen catastrophic events. To assess the level of system strength or weakness relative to the occurrence of an undesired event, a quantitative measure based on vulnerability index is often considered. The objective of this paper is to investigate and compare the performance of various vulnerability indices used for assessing the vulnerability of power systems when subjected to various contingencies. The vulnerability indices are based on anticipated loss of load as well as vulnerability information of individual system components such as real and reactive power generation, generation loss due to outage, bus voltage, loadability, transmission line real and reactive powers and line bus voltage angle difference. The vulnerability indices are compared so as to determine the effectiveness and accuracy of the indices in assessing the system vulnerability. In this study, power flow simulations were carried out on the IEEE 24 bus test system using the Power System Analysis and Toolbox (PSAT) and the vulnerability indices were calculated using the MATLAB program.