Performance of the Equivalent Reservoir Modelling Technique for Multi-Reservoir Hydropower Systems

Abstract

This paper investigates the validity of a simplified equivalent reservoir representation of a multi-reservoir hydroelectric system for modelling its optimal operation for power maximization. This simplification, proposed by Arvanitidis and Rosing (IEEE Trans Power Appar Syst 89(2): [319][320][321][322][323][324][325] 1970), imputes a potential energy equivalent reservoir with energy inflows and outflows. The hydroelectric system is also modelled for power maximization considering individual reservoir characteristics without simplifications. Both optimization models employed MINOS package for solution of the non-linear programming problems. A comparison between total optimized power generation over the planning horizon by the two methods shows that the equivalent reservoir is capable of producing satisfactory power estimates with less than 6% underestimation. The generation and total reservoir storage trajectories along the planning horizon obtained by equivalent reservoir method, however, presented significant discrepancies as compared to those found in the detailed modelling. This study is motivated by the fact that Brazilian generation system operations are based on the equivalent reservoir method as part of the power dispatch procedures. The potential energy equivalent reservoir is an alternative which eliminates problems with the dimensionality of state variables in a dynamic programming model.

Long-Term Scheduling of Large-Scale Cascade Hydropower Stations Using Improved Differential Evolution Algorithm

“…In generation G, the k-th element in the memory is updated. In the update formula (21) and (22), when all individuals in generation G fail to generate an individual better than the parent, i.e., S CR = S F = ∅, the memory is not updated. Also, the weighted mean mean WA (S CR ) is computed according to formula (23) by Peng et al [44].…”

Aggregation Methods for Modelling Hydropower and Its Implications for a Highly Decarbonised Energy System in Europe

“…Of particular interest is the previous work that has been carried out to identify seasonal operation strategies for multireservoir systems by using state aggregation approaches [9]. More specifically, the concept of a composite or equivalent reservoir model for the hydro system becomes necessary because a complexity reduction of the model is inevitable.…”

“…As a notable exception, [9] examines the influence of the involved simplification procedures on the results obtained from equivalent reservoir models of the São Francisco River Hydroelectric System in Brazil by comparing them to those obtained from an operational optimisation model considering the individual reservoir characteristics. In [27], two power market models, one simplified and one detailed, are used to model possible balancing responses of Norwegian hydropower to a wind-driven exchange pattern for various amounts of exchange capacity.…”

Reservoirs Effects on the Interannual Variability of Winter and Spring Streamflow in the St-Maurice River Watershed (Quebec, Canada)

“…Numerous studies have mostly looked at the reservoir management issue (e.g. Afshar et al 2011;Ahmadi et al 2010;Brandão 2010;Celeste and Billib 2010;Choudhari and Raj 2010;Eum and Simonovic 2010;Göncü and Albek 2010;Hobson et al 2010;Hunçal et al 2011;Kumar et al 2010;Li et al 2010;Olsson et al 2010;Pradhan et al 2011;Rani and Moreira 2010;Ticlavilca and McKee 2011;Wang et al 2010;Yun et al 2010).…”