Risk-based contingency analysis for transmission and substation planning

This paper examines the scheme of risk-based contingency analysis for transmission and substation planning. Compared to the traditional approach, in which system reliability is assessed by deterministic ‘n−1’ contingency criteria, the present method can capture the 'risk' concepts consisting of two parameters; 1) the likelihood that some events will happen and 2) the consequences if they do. The key method of this paper is to evaluate the risk considering the event probability such as two transmission lines failure and substation failure, and event consequences such as the amount of load shedding. The presented risk evaluation procedure can provide a single dimension index like 'probability−1 × consequence' representing a contingency severity level. Furthermore it can be a vehicle to perform the probabilistic contingency analysis for transmission and substation planning.