Optimization of multi-reservoir management

The potential of Harmony Search Algorithm (HSA) which is an optimization technique presented a few years ago, has encouraged scientists from various fields to solve complex, large scale problems. Because of its successful implementations, it is considered as a robust optimization tool and publications regarding its applications show a remarkable increase. In the present paper, along with a brief presentation of HSA, an application on the optimal management of a multi-reservoir system is presented. This particular application concerns the optimal operation of a four-reservoir system on a yearly basis. The objective is to maximize the annual benefits gained from the four reservoirs (hydropower generation and irrigation) through the optimal management of the system. The main difference between the problem we deal with and typical Dam-Scheduling problems, is that decision variables can take continuous values. This minor difference causes a huge impact and leads to a significant expansion of the search-space. As a result, convergence to the optimum solution with the use of stochastic methods becomes a challenging target. This problem was first introduced by V.T. Chow and G. Cortes-Rivera who proposed a solution using Dynamic Programming. In this paper, for the first time, a solution is derived with the application of a stochastic Algorithm. A program was created in order to optimize this particular problem using MATLAB. The successful convergence to optimum management is presented along with the main characteristics and results. The comparison between the proposed solution and the one achieved with Dynamic Programming reveals some interesting information regarding the efficiency of HSA.