scholarly journals Multi-Objective Optimal Scheduling Model of Dynamic Control of Flood Limit Water Level for Cascade Reservoirs

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1836 ◽  
Author(s):  
Guanjun Liu ◽  
Hui Qin ◽  
Qin Shen ◽  
Rui Tian ◽  
Yongqi Liu
Keyword(s):  
Power Generation ◽  
Water Level ◽  
Flood Control ◽  
Dynamic Control ◽  
Optimal Scheduling ◽  
Cascade Reservoirs ◽  
Multi Objective ◽  
Scheduling Model ◽  
Extreme Risk ◽  
Risk Rate

Reservoirs play a significant role in water resources management and water resource allocation. Traditional flood limited water level (FLWL) of reservoirs is set as a fixed value which over-considers the reservoir flood control and limits the benefits of reservoirs to a certain extent. However, the dynamic control of the reservoir FLWL is an effective solution. It is a method to temporarily increase the water level of the reservoir during the flood season by using forecast information and discharge capacity, and it can both consider flood control and power generation during the flood season. Therefore, this paper focuses on multi-objective optimal scheduling of dynamic control of FLWL for cascade reservoirs based on multi-objective evolutionary algorithm to get the trade-off between flood control and power generation. A multi-objective optimal scheduling model of dynamic control of FLWL for cascade reservoirs which contains a new dynamic control method is developed, and the proposed model consists of an initialization module, a dynamic control programming module and an optimal scheduling module. In order to verify the effectiveness of the model, a cascade reservoir consisting of seven reservoirs in the Hanjiang Basin of China were selected as a case study. Twenty-four-hour runoff data series for three typical hydrological years were used in this model. At the same time, two extreme schemes were chosen for comparison from optimized scheduling schemes. The comparison result showed that the power generation can be increased by 9.17 × 108 kW·h (6.39%) at most, compared to the original design scheduling scheme, while the extreme risk rate also increased from 0.1% to 0.268%. In summary, experimental results show that the multi-objective optimal scheduling model established in this study can provide decision makers with a set of alternative feasible optimized scheduling schemes by considering the two objectives of maximizing power generation and minimizing extreme risk rate.

scholarly journals Application of Marginal Rate of Transformation in Decision Making of Multi-Objective Reservoir Optimal Operation Scheme

2021 ◽  
Vol 13 (3) ◽  
pp. 1488
Author(s):  
Yueqiu Wu ◽  
Liping Wang ◽  
Yanke Zhang ◽  
Jiajie Wu ◽  
Qiumei Ma ◽  
...  
Keyword(s):  
Power Generation ◽  
Decision Making ◽  
Water Level ◽  
Level Scheme ◽  
Flood Control ◽  
Forecast Error ◽  
Optimal Operation ◽  
Total Power ◽  
Marginal Rate ◽  
Multi Objective

For reservoirs with combined storage capacity for flood control and beneficial purposes, there tends to be potential benefit loss when the flood control limited water level is used in medium and small floods. How to find the optimal water level scheme for profit-making and pursue the optimization of comprehensive benefits has always been a difficult problem in multi-objective reservoir optimal operation. Based on the principle of the maximum benefit obtained by the product conversion curve and the isorevenue line in microeconomics, taking flood control and power generation as two products of a reservoir, a multi-objective optimal operation scheme decision-making model is established to seek the highest water level scheme that can produce the maximum comprehensive benefits of flood control and power generation. A case study of the Three Gorges reservoir in the early flood season of a dry year shows that on the one hand, under the condition of deterministic inflow, the model can work out the optimal water level and the corresponding best equilibrium point for both flood control and power generation, and it can increase the total power output by 4.48% without reducing the flood control benefits; on the other hand, it can also obtain the dynamic control area of the maximum allowable water level for power generation considering inflow forecast error, which provides a theoretical reference for determining the starting water level in medium and small floods and utilizing flood resources.

scholarly journals Optimization of Year-End Water Level of Multi-Year Regulating Reservoir in Cascade Hydropower System Considering the Inflow Frequency Difference

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5345
Author(s):  
Zhiqiang Jiang ◽  
Peibing Song ◽  
Xiang Liao
Keyword(s):  
Power Generation ◽  
Dynamic Programming ◽  
Water Level ◽  
Water Levels ◽  
Least Square ◽  
Frequency Difference ◽  
Impact Factors ◽  
Cascade System ◽  
Cascade Reservoirs ◽  
Hydropower System

In order to analyze the year-end water level of multi-year regulating reservoir of the cascade hydropower system, this paper studied the joint operation optimization model of cascade reservoirs and its solving method based on multi-dimensional dynamic programming, and analyzed the power generation impact factors of cascade system that contains multi-year regulating reservoir. In particular, taking the seven reservoirs in the middle and lower reaches of Yalong River as an example, the optimal year-end water levels of multi-year regulating reservoir under the multi-year average situation and different inflow frequencies situation were studied. Based on the optimal calculation results of multi-dimensional dynamic programming, the inflow frequency difference considered operation rule of year-end water level of Lianghekou reservoir was extracted using the least square principle. The simulation results showed that, compared with the fixed year-end water level in multi-year, the extracted rule can improve the cascade power generation by more than 400 million kWh in an average year, representing an increase of 0.4%. This result means that the extracted rule can give full play to the regulation performance of multi-year regulating reservoir and improve the conversion efficiency of hydropower resources in cascade system. This is of great significance to the practical operation of cascade reservoirs system that contains multi-year regulating reservoir.

scholarly journals Multi-Objective Joint Optimal Operation of Reservoir System and Analysis of Objectives Competition Mechanism: A Case Study in the Upper Reach of the Yangtze River

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2542 ◽  
Author(s):  
Mufeng Chen ◽  
Zengchuan Dong ◽  
Wenhao Jia ◽  
Xiaokuan Ni ◽  
Hongyi Yao
Keyword(s):  
Power Generation ◽  
Water Supply ◽  
Yangtze River ◽  
Water Resource Management ◽  
Flood Control ◽  
Optimal Operation ◽  
Total Power ◽  
The Yangtze River ◽  
Multi Objective ◽  
Reservoir System

The multi-objective optimal operation and the joint scheduling of giant-scale reservoir systems are of great significance for water resource management; the interactions and mechanisms between the objectives are the key points. Taking the reservoir system composed of 30 reservoirs in the upper reaches of the Yangtze River as the research object, this paper constructs a multi-objective optimal operation model integrating four objectives of power generation, ecology, water supply, and shipping under the constraints of flood control to analyze the inside interaction mechanisms among the objectives. The results are as follows. (1) Compared with single power generation optimization, multi-objective optimization improves the benefits of the system. The total power generation is reduced by only 4.09% at most, but the water supply, ecology, and shipping targets are increased by 98.52%, 35.09%, and 100% at most under different inflow conditions, respectively. (2) The competition between power generation and the other targets is the most obvious; the relationship between water supply and ecology depends on the magnitude of flow required by the control section for both targets, and the restriction effect of the shipping target is limited. (3) Joint operation has greatly increased the overall benefits. Compared with the separate operation of each basin, the benefits of power generation, water supply, ecology, and shipping increased by 5.50%, 45.99%, 98.49%, and 100.00% respectively in the equilibrium scheme. This study provides a widely used method to analyze the multi-objective relationship mechanism, and can be used to guide the actual scheduling rules.

scholarly journals The multi-objective operation for cascade reservoirs using MMOSFLA with emphasis on power generation and ecological benefit

2019 ◽  
Vol 21 (2) ◽  
pp. 257-278 ◽  
Author(s):  
Zhe Yang ◽  
Kan Yang ◽  
Lyuwen Su ◽  
Hu Hu
Keyword(s):  
Power Generation ◽  
Cloud Model ◽  
Cascade Reservoirs ◽  
Multi Objective ◽  
Ecological Benefit ◽  
Ecological Water Requirement ◽  
Convergence Performance ◽  
Shuffled Frog Leaping ◽  
Conventional Models

Abstract To efficiently develop power generation and solve downstream ecological health protection in Qingjiang basin, multi-objective ecological operation for cascade reservoirs (MOEOCR) model is established in contrast to conventional models that set ecological water requirement as constraint. The basic, suitable and ideal ecological water requirements in Geheyan and Gaobazhou sections are calculated using a requirement level index. Instead of the traditional evolution mode based on population, we introduce a shuffled frog leaping algorithm (SFLA) which evolves independently in sub-populations. Moreover, the SFLA is converted into a modified multi-objective algorithm (MMOSFLA) with strategies including chaotic population initialization, renewed frog grouping method and local search method, and elite frog set evolution based on cloud model. The water level corridor is used to help effectively handle complex constraints. The IGD and GD indexes are used to evaluate quality of solutions acquired by each method. In terms of normal year, the mean IGD and GD of MMOSFLA are 1.2 × 10–1 and 2.75 × 10–2, respectively. The scheduling results verify efficient search ability and convergence performance in solution diversity and distribution in comparison with other methods. Therefore, MMOSFLA is verified to provide an effective way to fulfill hydropower and ecological benefits facing the MOEOCR problem.

scholarly journals Research on the Multi-Objective Cooperative Competition Mechanism of Jinsha River Downstream Cascade Reservoirs during the Flood Season Based on Optimized NSGA-III

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 849 ◽  
Author(s):  
Xiaokuan Ni ◽  
Zengchuan Dong ◽  
Wei Xie ◽  
Wenhao Jia ◽  
Changgui Duan ◽  
...  
Keyword(s):  
Power Generation ◽  
Flood Control ◽  
Reference Points ◽  
Jinsha River ◽  
Flood Prevention ◽  
Cascade Reservoirs ◽  
Control Power ◽  
Flood Season ◽  
Competitive Relationship ◽  
Cooperative Competition

This paper analyzes the complex relationship among flood control, power generation and ecological maintenance for the four cascade reservoirs located on the lower reaches of the Jinsha River, China. A weighted flood control index is incorporated and a constraining method consisting of the combination of a constrained corridor and a penalty function is proposed. A comprehensive utilization model is established in this paper based on the objectives of flood prevention, power generation, and ecological maintenance of the downstream cascade reservoir group of the Jinsha River during flood season. In addition, based on the coalescent selection of reference points and vector angles, an optimized non-dominated sorting genetic algorithm (VA-NSGA-III) is proposed. The algorithm is applied to the constructed model to define the cooperative competition mechanisms among these three targets, resulting in a set of non-inferior scheduling schemes with more uniformity and better convergence acquired with VA-NSGA-III. The scheduling program shows that there is a non-linear competitive relationship between the power generation and ecological effects of the cascade reservoirs during flood season, and the competitiveness weakens as the power generation increases. Furthermore, when the flood control is at low risk, there exists a complex coupling relationship between competition and coordination of the flood control, power generation, and ecological maintenance. While the risk appears high, there is a competitive relationship between flood control and power generation, with flood control being in synergy with ecological maintenance.

scholarly journals Research and Application of Key Technologies for Dynamic Control of Reservoir Water Level in Flood Season

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3576
Author(s):  
Jun Zhang ◽  
Yaowu Min ◽  
Baofei Feng ◽  
Weixin Duan
Keyword(s):  
Water Supply ◽  
Water Level ◽  
Real Time ◽  
Flood Control ◽  
Dynamic Control ◽  
Water Levels ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Danjiangkou Reservoir ◽  
Flood Season

In today’s reservoir operation study, it is urgent to solve the issues on improving flood resource utilization, maximizing reservoir impoundment, and guaranteeing water supply through real-time regulation optimization under the premise of ensuring flood control safety and taking risks properly. Based on previous studies, the key real-time operation technologies for dynamic control of reservoir water levels in flood season are summarized. The Danjiangkou Reservoir was taken as an example, the division of flood stages, reservoir water level requirements for improving water supply guarantee, dynamic control indexes of reservoir water level for beneficial use in stages during the flood season, and flood control dispatching indexes are proposed. Moreover, a practicable real-time flood forecast operation scheme for Danjiangkou Reservoir was compiled. Its application in 2017 indicated that the established scheme can provide strong technical support to ensure the overall benefits of Danjiangkou Reservoir, including flood control, water supply, and power generation.

scholarly journals Competitive Relationship Between Flood Control and Power Generation with Flood Season Division: A Case Study in Downstream Jinsha River Cascade Reservoirs

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2401 ◽  
Author(s):  
Hongyi ◽  
Zengchuan ◽  
Wenhao ◽  
Xiaokuan ◽  
Mufeng ◽  
...  
Keyword(s):  
Power Generation ◽  
Flood Control ◽  
Nsga Ii ◽  
Jinsha River ◽  
Cascade Reservoirs ◽  
Flood Season ◽  
Competitive Relationship ◽  
Full Capacity ◽  
Strong Competition ◽  
3D Volume

The lower reaches of Jinsha River host the richest hydropower energy sources in China. With the construction of Wudongde and Baihetan, the multi-objective optimization for cascade reservoirs (along with Xiluodu and Xiangjia Dam) in the lower reaches of Jinsha River will create significant benefits. This paper focuses on the competitive relationship between flood control and power generation, and attaches attention to the measurement of different objective functions and their competitive relationship. With observations of the flood in 1974, 1981, and 1985, a 100-year return period flood with peak-3d volume pair as different inputs for the optimal model is approached by NSGA-II. Different flood seasons divided by flood feature is applied to figure out specific competitive relationship. The results can be concluded as the following: (1) Strong competitive relationship mainly occurs in pre-flood season. (2) Whether it shows a strong competitive relationship depends on the amount of discharge. If the turbine is set to full capacity, power generation is fulfilled certainly, which means that there exists a weak competitive relationship between multi-objectives. (3) The different processes of floods have an effect on the duration of a competitive relationship. A flood with a late peak causes the extension of strong competition in the pre-flood season, which lends itself to a strong competition relationship in the post-flood season. (4) The intensity of competition in the pre-flood season is higher than that in the post-flood season because it has a larger range.

scholarly journals Inflow Flood Simulation and Risk Analysis of Cascade Reservoirs

2018 ◽  
Vol 246 ◽  
pp. 01106
Author(s):  
Jing Huang ◽  
Jiqing Li ◽  
Pengteng Liang
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Flood Routing ◽  
Three Gorges ◽  
Design Flood ◽  
Flood Simulation ◽  
Cascade Reservoirs ◽  
The Three Gorges ◽  
Flood Regulation ◽  
Risk Rate

The risk of flood control in cascade reservoirs reflects the possibility of unforeseen events in upstream reservoirs under certain space-time conditions during the operation of flood control. Using @RISK software and a stochastic simulation model to simulate the inflow flood of cascade reservoirs, the flood routing of cascade reservoirs and the risk analysis of the highest water level were carried out based on the flood regulation rules of Three Gorges-Gezhouba cascade reservoirs. The results of simulation calculations show that the risk rate of the Three Gorges-Gezhouba cascade reservoir is lower than its design flood standard, which can ensure the safety of flood control.

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