Hydro-dominated short-term hydrothermal scheduling via a hybrid simulation-optimisation approach: a case study

The paper is concerned with the problem of short-term hydrothermal scheduling for hydro-dominated power systems. The problem is to determine hydro and thermal generation scheduling for a day or a week ahead, usually on an hourly basis, simultaneously satisfying hydraulic, thermal and electrical operational constraints while optimizing a criterion of performance. Reservoir release targets suggested by mid/long-term operational planning models are also considered. The paper presents a case study based on a hybrid optimisation-simulation approach. The procedure consists of hydraulic system simulation on an hourly basis, with release decisions based on optimal DC power flow. Reservoir release targets are enforced through a dual-penalty approach which assigns shadow costs to hydro generation. The case study was conducted using part of the Brazilian interconnected power system and progressively developed through the use of various scripts. The study provides an insightful analysis of the nature of the problem and reveals a practical and efficient technique for its solution