Optimal localized area for security assessment in large-scale power systems operation

This paper presents a proposed procedure for on-line active power security assessment in power. system operation. An optimal effective localized area (OELA) is introduced to obtain the optimal security constrained redispatch (OSCR) in order to remove any line overloads in large scale power systems. This area includes the affected lines due to any line outage and/or sudden increase in load demand. The size of OLEA depends on the setting value of a boundary factor λ to make the calculations on a reduced area that represent the total large system. However, this area can be increased or decreased according to the rate of the emergency conditions effectiveness and the amount of active control actions requirement. Hence, the proposed procedure focuses on an OELA that is sensitive to a certain emergency condition, far from the other weak parts of the system. The particle swarm optimization (PSO) technique is applied to find out the OSCR, to remove the violated lines during the emergency conditions, depends on the OELA. Case studies for different emergency conditions applied on the standard IEEE 118-bus system demonstrates the efficiency of the proposed procedure.