Optimal dispatch of generating units in hydroelectric systems by heuristic based on langrangean relaxation and dynamic programming / Despacho otimo de unidades geradoras em sistemas hidreletricos via heuristica baseada em relaxação lagrangeana e programação dinamica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The daily scheduling operation of the electrical energy system has by target to find the dispatch generation to the next day which must be compatible with the daily generation target defined by the energy planning models and to be an operational guide. Because of its proximity with the real time operation the modeling must represent the main characteristic of the generation and transmission systems, requirements market?s, security criterion and operational costs. This work is concerned with the dispatch of hydro generating units. The performance criterion adopted takes into account variations in tailrace elevation, penstock head losses, turbine-generator efficiencies and start-up and shutdown costs. In the hydro generating units dispatch problem formulation there are integer, non-linear variables, constraints concerned with the generation capacity, load attainment and daily generation target, this last defined by the energy planning models. According above mentioned the dispatch of hydro generating units is a combinatorial and mixed integer non-linear programming problem whose solution can be quite complex for large hydroelectric system such as the Brazilian?s generation system. A heuristic procedure based on Lagrangian Relaxation and Dynamic Programming is adopted as solution methodology. The approach has been tested on a hydro system composed of seventy and eight hydro plants with three hundred and ninety eight generating units of the Brazilian power generation system. The generation scheduling verified on a typical day was considered for comparison with the solution provided by the approach and the results show significant improvement in term of minimization looses and the importance of to consider the start-up and shut-down costs of hydro generating units

ASSUNTO(S)

dynamic programming usinas hidreletricas lagrangean relaxation otimização matematica dispatch startup programação dinamica heuristica hydro generating units shutdown cost

ACESSO AO ARTIGO

Documentos Relacionados