Evaluation of Percolation Theory Insisted Resilience Index for Indian 62 Bus Utility System in Cascading Failure Situation

With the ever-increasing natural extreme events as well as the cyber-physical attacks, the vulnerability of the transmission and the distribution lines are also increasing manifold. From the system resilience point of view, continuous power supply is to be ensured to the larger portion of the consumers during the crisis and make the recovery time as less as possible. This requires less fragmentation of the system. If the fragmentation goes beyond a threshold value, the system will be divided into several nodal elements and thereby it will take much time to recover. In this paper, the fragmentation factor has been considered as an indicator of power system resilience and calculated its threshold value using percolation theory for the standard IEEE 57 bus system and Indian Utility 62 bus real system and analyzed how it changes with different distribution and edge betweenness centrality. Also, it is observed that the critical fragmentation factor is declining in different stages of cascading failure after initialization of a particular line failure.