Optimal short term operation of a purely hydroelectric system

The short-term production scheduling problem for a purely hydroelectric system can be simplified so that the power production and water can be managed separately. This approximation is possible when plants have large daily reservoirs with fixed or controllable heads. The model described by the authors optimizes the hourly power production of a system of hydroplants by minimizing losses in turbines and waterways, while maintaining production to meet load. The problem is inherently of the mixed integer nonlinear type, but an algorithm has been developed to solve it in two stages by linear programming (LP). The model has been tested with data from an existing purely hydroelectric system, the Icelandic power system being the model system. Results indicate considerable savings in water usage from large seasonal reservoirs. These results also indicate the feasibility of installing the model in a control center computer when conditions are similar to the model system