Hydro-thermal power flow scheduling accounting for head variations

Variable head hydro-thermal optimal power flow in an electric power system is considered. As the hydro generation is energy limited, a dynamic optimization problem involving the daily scheduling of the system is encountered. This dynamic optimal power flow problem requires solving a large-scale set of nonlinear simultaneous equations. The computational implementation was based on a Newton-Raphson´s iterative procedure, with a special initial guess, and sparsity-based matrix manipulations to obtain improved convergence properties. The algorithm was tested with test systems that are smaller than those encountered in practice. Computational results and CPU times required are given to illustrate the impact of including head variations in the model. The effects of head variation, volume of water, and power demand are listed