Contingency Analysis in Power System Studies: A Critical Review

The most essential and desired feature in operation and planning of the power system is the need to ensure the security and reliability under regular and emergency situations. Contingency is a problem caused by the component failure in a power system. This perturbation is a result of abrupt changes in the system configuration which leads to the violation of the operating constraints and hence leading to partial or complete blackout. Branch overloads and deficient voltage levels are most famous violations caused by the contingency problem. Thus to ensure the safe and secure operation of the system, we undergo contingency analysis (CA). It helps in finding the possible vulnerabilities present in the system, and then in order to remove the detrimental effects of these contingencies, it provides a suitable remedial action. Contingency analysis investigates potential transmission line or generation failures that could lead to breaches in line flows or bus voltages. By analyzing both the single and multiple outages, contingency analysis aims to determine the system states. This process of contingency analysis involves comparing the line flows and bus voltages against their predefined limits.