Fuzzy linear programming: an application to hydroelectric generation scheduling

A new approach using fuzzy linear programming is proposed for solving the hydroelectric generation scheduling problem. A characteristic feature of this approach is that the errors in the forecast hourly loads and natural inflows can be taken into account by using fuzzy set notation, making the approach superior to the conventional linear programming method in which the hourly loads and natural inflows are assumed to be exactly known and there are no errors in the forecast loads and natural inflows. To reach an optimal schedule under the uncertain environment, a fuzzy linear programming model in which the hourly loads, the hourly natural inflows and the cost are all expressed in fuzzy set notations is developed. The developed fuzzy linear programming approach is applied to schedule the generation in the Taiwan power system which contains ten hydroplants including cascaded ones. It is found that the proposed approach is very effective in obtaining proper hydrogeneration schedules in uncertain conditions.