Considering Water Propagation impact in Short-Term Optimal Operation of Cascade Reservoirs Using Nested Progressive Optimality Algorithm

In making short-term optimal operation schemes of cascade reservoirs, water flow hysteresis between the upper reservoir and the lower reservoir is often considered as constant, which cannot really reflect the hysteresis variation between different water flows and will lead to losses of the optimal operation scheme’s benefit. To depict the water flow hysteresis, a Dynamic Water Flow Hysteresis Method (DWFHM) is proposed, based on the space mapping principle. With the mapping operator in the DWFHM, the lower reservoir inflow can be directly obtained. Besides, the DWFHM is used to deal with the hydraulic relation constraint in the short-term optimal operation model of cascade reservoirs. Then, the improved model is applied to the Jinguan cascade reservoirs in the Yalong River basin and solved by an Improved Progressive Optimal Algorithm (IPOA). The results are as follows. (1) Compared with the traditional Fixed Water Flow Hysteresis Method (FWFHM), the inflow processes of the lower reservoir obtained by the DWFHM are more in line with the actual values, due to full consideration of the attenuation effect. (2) The optimal operation with the DWFHM can effectively increase the generated energy (2827 MW·h and 504 MW·h in the non-flood season and the flood season, respectively). Through the analysis of this case, the DWFHM developed in this study can effectively improve the practicability of the optimal operation scheme and reduce the risk in the operation of cascade reservoirs.

Download Full-text

Multi-Stage Dynamic Programming Method for Short-Term Cascade Reservoirs Optimal Operation with Flow Attenuation

Water Resources Management ◽

10.1007/s11269-017-1766-7 ◽

2017 ◽

Vol 31 (14) ◽

pp. 4571-4586 ◽

Cited By ~ 5

Author(s):

Changming Ji ◽

Chuangang Li ◽

Boquan Wang ◽

Minghao Liu ◽

Liping Wang

Keyword(s):

Dynamic Programming ◽

Optimal Operation ◽

Programming Method ◽

Dynamic Programming Method ◽

Short Term ◽

Cascade Reservoirs ◽

Multi Stage ◽

Flow Attenuation

Download Full-text

Research on Cascade Reservoirs’ Short-Term Optimal Operation under the Effect of Reverse Regulation

Water ◽

10.3390/w10060808 ◽

2018 ◽

Vol 10 (6) ◽

pp. 808 ◽

Cited By ~ 9

Author(s):

Changming Ji ◽

Hongjie Yu ◽

Jiajie Wu ◽

Xiaoran Yan ◽

Rui Li

Keyword(s):

Optimal Operation ◽

Short Term ◽

Cascade Reservoirs

Download Full-text

Three Gorges Cascade Hydropower System Joint Simulative Optimal Operation Research in Power Market

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.347-353.1370 ◽

2011 ◽

Vol 347-353 ◽

pp. 1370-1373

Author(s):

Jiao Zheng ◽

Kan Yang ◽

Ran Zhou ◽

Yong Huai Hao ◽

Guo Shuai Liu

Keyword(s):

Power Market ◽

Optimal Operation ◽

Adaptive Genetic Algorithm ◽

Three Gorges ◽

Short Term ◽

Roulette Wheel Selection ◽

Generation Scheduling ◽

Hydropower System ◽

Selection Operator ◽

Hydropower Stations

The short-term joint optimal operation simulation of Three Gorges cascade hydropower system aiming at maximum power generation benefit is proposed. And a new method for optimizing cascade hydropower station based on Adaptive Genetic Algorithm (AGA) with trigonometric selective operators is presented. In this paper, the practical optimal operation in power market is described. The temporal-spatial variation of flow between cascade hydropower stations is considered, and time of use (TOU) power price is also taken into account. Moreover, a contrast between Tangent-roulette selection operator and traditional one is made. To a certain degree, the results of simulative optimal operation based on several representative hydrographs show that Tangent-roulette wheel selection operator can find a more excellent solution, because the Tangent-roulette one can overcome the fitness requirements of non-negative. The research achievements also have an important reference for the compilation of daily generation scheduling of Three Gorges cascade hydropower system in the environment of power market.

Download Full-text

The Application of DDDP Method to Optimal Operation for Cascade Reservoirs Based on State Transformation Matrix

2010 International Conference on Computational and Information Sciences ◽

10.1109/iccis.2010.26 ◽

2010 ◽

Author(s):

Zhu-ge Yi-si ◽

Xie Pin-pin

Keyword(s):

Optimal Operation ◽

Transformation Matrix ◽

State Transformation ◽

Cascade Reservoirs

Download Full-text

Optimal Short-term Cascade Reservoirs Operation using Genetic Algorithm

Asian Journal of Applied Sciences ◽

10.3923/ajaps.2011.297.305 ◽

2011 ◽

Vol 4 (3) ◽

pp. 297-305 ◽

Cited By ~ 8

Author(s):

Tilahun Derib Asfaw ◽

Saied Saiedi

Keyword(s):

Genetic Algorithm ◽

Short Term ◽

Cascade Reservoirs

Download Full-text

Synergistic gains from the multi-objective optimal operation of cascade reservoirs in the Upper Yellow River basin

Journal of Hydrology ◽

10.1016/j.jhydrol.2015.02.007 ◽

2015 ◽

Vol 523 ◽

pp. 758-767 ◽

Cited By ~ 51

Author(s):

Tao Bai ◽

Jian-xia Chang ◽

Fi-John Chang ◽

Qiang Huang ◽

Yi-min Wang ◽

...

Keyword(s):

River Basin ◽

Yellow River ◽

Yellow River Basin ◽

Optimal Operation ◽

Cascade Reservoirs ◽

Multi Objective ◽

Upper Yellow River ◽

Synergistic Gains

Download Full-text

Centralization of Pancreatic Surgery Improves Results: Review

Scandinavian Journal of Surgery ◽

10.1177/1457496919900411 ◽

2020 ◽

Vol 109 (1) ◽

pp. 4-10 ◽

Cited By ~ 1

Author(s):

R. Ahola ◽

J. Sand ◽

J. Laukkarinen

Keyword(s):

Pancreatic Surgery ◽

Length Of Hospital Stay ◽

High Volume ◽

Optimal Operation ◽

Failure To Rescue ◽

Short Term ◽

Pancreatic Resections ◽

The World ◽

Low Volume ◽

Active Research

Background and Aims: The effect of operation volume on the outcomes of pancreatic surgery has been a subject of research since the 1990s. In several countries around the world, this has led to the centralization of pancreatic surgery. However, controversy persists as to the benefits of centralization and what the optimal operation volume for pancreatic surgery actually is. This review summarizes the data on the effect of centralization on mortality, complications, hospital facilities used, and costs regarding pancreatic surgery. Materials and Methods: A systematic librarian-assisted search was performed in PubMed covering the years from August 1999 to August 2019. All studies comparing results of open pancreatic resections from high- and low-volume centers were included. In total 44, published articles were analyzed. Results: Studies used a variety of different criteria for high-volume and low-volume centers, which hampers the evaluating of the effect of operation volume. However, mortality in high-volume centers is consistently reported to be lower than in low-volume centers. In addition, failure to rescue critically ill patients is more common in low-volume centers. Cost-effectiveness has also been evaluated in the literature. Length of hospital stay in particular has been reported to be shorter in high-volume centers than in low-volume centers. Conclusion: The effect of centralization on the outcomes of pancreatic surgery has been under active research and the beneficial effect of it is associated especially with better short-term prognosis after surgery.

Download Full-text