Power system security assessment

Security refers to the degree of risk in a power system´s ability to survive imminent disturbances (contingencies) without interruption to customer service. It relates to robustness of the system to imminent disturbances and, hence, depends on the system operating condition as well as the contingent probability of disturbances. DSA refers to the analysis required to determine whether or not a power system can meet specified reliability and security criteria in both transient and steady-state time frames for all credible contingencies. Ensuring security in the new environment requires the use of advanced power system analysis tools capable of comprehensive security assessment with due consideration to practical operating criteria. These tools must be able to model the system appropriately, compute security limits in a fast and accurate manner, and provide meaningful displays to system operators. Online dynamics security assessment can provide the first line of defense against widespread system disturbances by quickly scanning the system for potential problems and providing operators with actionable results. With the development of emerging technologies, such as wide-area PMs and ISs, online DSA is expected to become a dominant weapon against system blackouts.