Benefits of coordination in the operation of cascaded hydroelectric power systems

This paper aims to estimate the benefits of coordination in the operation of cascaded hydroelectric power systems. A deterministic nonlinear optimization model that represents the operating characteristics of power plants in detail has been used. The benefits of coordination have been estimated through the application of the optimization model in two different approaches. The first approach corresponds to the coordinated operation (CO) where the system is optimized as a whole. The second approach corresponds to the non-coordinated (NCO) operation where each plant optimizes its own operation without caring about the others downstream plants. Based on the difference of average and standard deviation values of total hydro generation of each approach, the benefits of coordination have been estimated. In order to evaluate the benefits of reservoir operation, (CO) and (NCO) solutions have been compared with the run-off-river solution (ROR), where the plants are operated without varying their storage. Eight hydro plants from the Brazilian system have been used for numerical results. The case studies were performed in a progressive way in order to highlight the relation between the benefits and the system installed capacity.