Development of a generalized methodology for blackout restoration : a case study of Sri Lankan power system

Abstract

Blackouts are been reported throughout the history worldwide and nowadays, a moment without electricity causes a greater loss of lives and economy. On the other hand, restoration of a blacked-out power system requires expertise of experienced engineers which is not completely reliable under certain system complexities. Generally, it turns out to be a trial and error approach under the guidance of experts. This paper proposes a generalized aiding methodology for solving the restoration problem by assessing the next system state for a given decisions of the system operator. With adequate system information (pre-outage data, equipment availability etc.), this proposed decision support methodology could mitigate unexpected cascaded tripping events which occur owing to lack of confidence in next state during restoration. The case study considers restoring of a crucial subsystem of Sri Lankan power system, Colombo – Kelanitissa system along with Laxapana System. Successful attempts shall fulfil load flow while maintaining system parameters and stability during switching operations. The results compare and depict the success in solving the restoration problem with proposed real-time, offline methodology against trial and error approach. Further it suggests the requirement of parallel computer based simulations on restoration of other sub systems and synchronizing events during actual implementation.