Short-term coordination of hydro-thermal systems with cascaded reservoirs using bacterial foraging algorithm

A modified bacterial foraging algorithm (MBFA) is presented in this paper to solve the short-term generation coordination problem of hydro-thermal systems with multi-chain reservoirs. The short-term hydro-thermal coordination problem (STHTC) is a dynamic nonlinear large-scale optimization problem which requires solving unit commitment and economic power load dispatch problems. The original bacterial foraging algorithm (BFA) is a recently developed evolutionary optimization technique based on the foraging behavior of the E. coli bacteria. The BFA has been successfully employed to solve various optimization problems; however, for large-scale problems such as the STHTC problem, it shows poor convergence properties. To tackle this complex problem considering its high-dimensioned search space, critical improvements are introduced to the basic BFA. The chemotactic step is modified to decrease nonlinearly and dynamically in order to improve the convergence characteristics. A multi reservoir cascaded hydro-thermal generation system is employed to test the proposed algorithm and demonstrate its capability to tackle this complex problem.