Cascade hydropower systems optimal operation: implications for Iran’s Great Karun hydropower systems

Abstract

Water resources optimal allocation in large complex water systems such as multi-reservoir dams is a challenging task for decision makers. Wide range of decision variables as well as difficult nonlinear optimization problems (highly nonlinear problems) make it difficult to use optimization approaches. Alternatively, simulation-optimization approaches are then providing more realistic and applicable solution. This study presents a simulation-optimization framework for extracting monthly long-term operation rules. This method is applied to Karun River Basin including six multi-objective (hydropower generation, agricultural and environmental water supplement) cascade dams. In this regard, Water Evaluation and Planning System is used as the simulation model coupled with an optimization model. Decision variables include (1) monthly variation of top of buffer parameter in reservoirs where the reservoir releases water to meet the required demand and (2) monthly priority for filling of the reservoirs. Two-objective NSGA-II algorithms are used to minimize sum of squares unmet energy and agricultural water demands within two scenarios. The results show that the reliability of the generation of hydroelectricity in Karun River Basin has been increased sufficiently. Results showed that the scenario 2 (an aggregate energy demand at the system level) has better performance in terms of reliability (91.4% compared to 89.6%) and efficiency of centralized approach in which all reservoirs are operated in an integrated management scheme.

Optimizing Conduit Hydropower Potential by Determining Pareto-Optimal Trade-Off Curve

“…Further research can be conducted on applying this procedure to cascading conduit hydropower installations. Although the optimization of operating cascading water infrastructure has been researched for conventional reservoir storage or run-of-river installations [95][96][97][98], it has not been attempted for conduit hydropower installations.…”

Optimal Control of Cascade Hydro Plants as a Prosumer-Oriented Distributed Energy Depot

“…In contrast, in this work, owing to their function for prosumers, smaller installations-pico and micro-are given primary emphasis. The prospective model encompasses numerous formerly abandoned mills with small ponds (run-of-river HP) [12,13], which, when engaged, may significantly…”

“…In contrast, in this work, owing to their function for prosumers, smaller installations-pico and micro-are given primary emphasis. The prospective model encompasses numerous formerly abandoned mills with small ponds (run-of-river HP) [12,13], which, when engaged, may significantly decrease capital expenditures. For instance, in Poland, currently fewer than 5% of such installations are used for energy production [14], thus the application area of the research presented here is meaningful.…”

“…In the past, the scheduling of operation of a cascade of HPs has been investigated as a case study [16], rather than a control system, i.e., each plant is manually adjusted without enforcing a common framework. Other approaches reduce the HP cascade to a single-plant case [17], where dams are at a close distance [12,18], or located on one river but not on its tributaries [13,19]. All these models and control strategies do not fit into a prosumer system.…”

Dam System and Reservoir Operational Safety: A Meta-Research

“…However, simulation models are very time-consuming in complex operation cases with a large number of operational policies. Thus, several studies of large-scale systems use optimization models to preliminary screen such operation policies to significantly improve simulation model efficiency [96][97][98][99]. In this respect, the simulation and the optimization models are preferred to work in a loop sequentially, where the optimization models use the simulation model outputs to find the optimal solution that can then be considered a bettersimplified input to the simulation model.…”