The establishment of more severe hydrological environmental constraints, usually minimum flows and maximum ramping rates, on hydropower operation is a growing trend in the world. This paper presents the results of an ...
详细信息
The establishment of more severe hydrological environmental constraints, usually minimum flows and maximum ramping rates, on hydropower operation is a growing trend in the world. This paper presents the results of an attempt to assess the long-term economic impact of the above-mentioned constraints by three approximate formulae which quantify their effects, both separately and jointly, on a hydropower plant characterised by two parameters. The formulae are the result of three regression models developed from the solutions of 476 deterministic long-term hydro-scheduling problems corresponding to ten hydropower plants located in Spain. They were tested with 98 additional problems corresponding to two other Spanish hydropower plants. The formulae have a final average relative error of 8.2% and a final relative error of 19% with a confidence interval of 95%. This paper also offers some insight about the difficulties for tracking the energy prices when these constraints are present. Finally, the analysis of the hourly results indicates some additional effects of these constraints on hydropower operation related to the energy generated by the plant, the amount of water spilled from the reservoir, and the number of operating hours and of start-ups and shut-downs of the hydro units. (C) 2016 Elsevier Ltd. All rights reserved.
A new approach for optimization of long-term operation of large-scale reservoirs is presented, incorporating incremental dynamic programming (IDP) and Genetic algorithm (GA) . The immense storage capacity of the large...
详细信息
A new approach for optimization of long-term operation of large-scale reservoirs is presented, incorporating incremental dynamic programming (IDP) and Genetic algorithm (GA) . The immense storage capacity of the large scale reservoirs enlarges feasible region of the operational decision variables, which leads to invalidation of traditional random heuristic optimization algorithms. Besides, long term raised problem dimension, which has a negative impact on reservoir operational optimization because of its non-linearity and non-convexity. The hybrid IDP-GA approach proposed exploits the validity of IDP for high dimensional problem with large feasible domain by narrowing the search space with iterations, and also takes the advantage of the efficiency of GA in solving highly non-linear, non-convex problems. IDP is firstly used to narrow down the search space with discrete d variables. Within the sub search space provided by IDP, GA searches the optimal operation scheme with continuous variables to improve the optimization precision. This hybrid IDP-GA approach was applied to daily optimization of the Three Gorges Project-Gezhouba cascaded hydropower system for annual evaluation from the year of 2004 to 2008. Contrast test shows hybrid IDP-GA approach outperforms both the univocal IDP and the classical GA. Another sub search space determined by actual operational data is also compared, and the hybrid IDP-GA approach saves about 10 times of computing resources to obtain similar increments. It is shown that the hybrid IDP GA approach would be a promising approach to dealing with long-term optimization problems of large-scale reservoirs.
One of the most serious problems of water resources development planning is the lack of acceptable procedures to deal with conflicts among different purposes at the early conceptual planning stage of any water resourc...
详细信息
暂无评论