New strategies to improve bulk power system security: lessons learned from large blackouts

Blackouts occur in electric power grids for a variety of reasons that include lack of investments in transmission network, control equipment failure, human errors, atmospheric phenomena, etc. Understanding these causes and implementing actions to correct them represents the basis for minimizing the load cuts resulting from major disturbances in a transmission network. Starting with an analysis of the main blackouts experienced in Brazil, this paper will compare these events by using a set of indexes. After discussing these evaluations, we will describe the measures adopted to create a general vision of the problem and consolidate the lessons learned from each disturbance.