A contingency analysis for managing the risk of water spillage and shortage in a mid-term hydro scheduling model

This paper proposes a methodology to determine secure operation policies of hydro systems through a contingency scenario analysis in order to prevent the risk of spillage or shortage due to inflows different to those of the nominal case. The methodology is applied within a general mid-term hydro scheduling model used to find optimal and feasible schedules of cascaded reservoirs and hydro plants. The operation criterion is to maximize the expected income of a hydro generator but minimizing the possible damaging effects of the contingency scenarios considered. In order to obtain a set of realistic scenarios which considers the seasonal and spatial correlations of inflows, the contingency scenarios are created and chosen following a pattern and clustering analysis based on the statistical analysis of historic data. An example case is presented in order to illustrate the essential features of the proposed methodology