Fuzzy Model for Real-Time Reservoir Operation

A fuzzy rule-based control model for multipurpose real-time reservoir operation is constructed. A new, mathematically justified methodology for fuzzy inference—total fuzzy similarity—is used and compared with the more traditional Sugeno-style method. Specifically, the seasonal variation in both hydrological variables and operational targets is examined by considering the inputs as season-dependent relative values, instead of using absolute values. The inference drawn in several stages allows a simple, accessible model structure. The control model is illustrated using Lake Päijänne, a regulated lake in Finland. The model is calibrated to simulate the actual operation, but also to better fulfill the new multipurpose operational objectives determined by experts. Relatively similar results obtained with the inference methods and the strong mathematical background of total fuzzy similarity put fuzzy reasoning on a solid foundation.