Centralized coordination of emergency control and protection system using online outage sensitivity index

This paper determines the best locations for centralized load shedding considering the protection systems that can be monitored from transmission system to avoid cascading failures. The vulnerability of power system integrity is determined and ranked using online outage sensitivity index (OSI) considering ampacity of transmission lines, over excitation of generators and transformers, under frequency and under voltage protection relays and low voltage ride through capability of grid connected renewable energy sources. The power system elements are ranked based on the results of outage sensitivity index (OSI) to concentrate the load shedding as control action on areas containing most critical elements prone to outage. The efficiency of proposed multi objective approach is validated through numerical simulations of severe contingencies carried out in DigSilent Power Factory software on 39 bus IEEE standard test system.