scholarly journals Joint optimization of cascades in Yalong River and the middle and downstream of Jinsha River

2018 ◽  
Vol 246 ◽  
pp. 01104 ◽  
Author(s):  
Hairong Zhang ◽  
Peng Li ◽  
Yufeng Ren ◽  
Zhiming Liang ◽  
Yufan Chen ◽  
...  
Keyword(s):  
Power Generation ◽  
Large Scale ◽  
Optimization Method ◽  
Research Area ◽  
Optimal Scheduling ◽  
Joint Optimization ◽  
Total Power ◽  
Jinsha River ◽  
Hydropower System ◽  
Yalong River

The main tributaries of the upper reaches of the Yangtze River are not only the strategic base for China’s water resources, but also an important hydropower base for the “West-East Power Transmission Strategy”. With the completion of these reservoir groups, a large-scale mixed reservoir system across the different basins has been formed, which makes the requirements for joint optimization and scheduling of large-scale hydropower system getting higher and higher. This paper focuses on the key problems faced by the joint optimization of large-scale hydropower system in the basin. Taking the Yalong River and the middle and downstream of the Jinsha River as the research area, the hybrid optimization method is introduced herein to solve the joint optimal scheduling model. The results reveal that the power generation by joint optimal scheduling is much more than separately scheduling, and the total power generation increased by 2.84% on average. As Mid-Jinsha cascade and Yalong River cascade has a 690 million kW·h and 190 million kW·h decrease in power generation respectively, the downstream Jinsha River cascade has a power generation increase of 4.31 billion kW·h.

scholarly journals Research on joint generation scheduling of cascade hydro plants in the dry season

2017 ◽  
Vol 18 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Mengfei Xie ◽  
Jianzhong Zhou ◽  
Wenyu Ouyang ◽  
Liu Yuan ◽  
Hairong Zhang
Keyword(s):  
Power Generation ◽  
Average Power ◽  
Differential Evolution Algorithm ◽  
Optimization Method ◽  
Dry Season ◽  
Dispatching Rules ◽  
Total Power ◽  
Jinsha River ◽  
Generation Scheduling ◽  
Flow Compensation

Abstract As more and more reservoirs are built, concentrated water releasing in the dry season will bring about additional flow compensation and the joint operation of cascade hydro plants is quite important. This paper discusses the water level decline strategy of four cascade hydro plants in the Jinsha River and analyses the relationship between guaranteed output and total power generation. Considering stochastic inflows, an implicit stochastic optimization method is employed and a multi-objective parallel differential evolution algorithm is proposed to extract dispatching rules. Finally, a method which combines discriminant method and dispatching rules is proposed for practical operations and achieves good performance. Compared with routine scheduling, the power generations of the proposed method are improved observably in different typical years. The average power generation increases about 3% with the same cascade minimum output.

scholarly journals Joint Optimization of Pico-Base-Station Density and Transmit Power for an Energy-Efficient Heterogeneous Cellular Network

2019 ◽  
Vol 11 (10) ◽  
pp. 208
Author(s):  
Jie Yang ◽  
Ziyu Pan ◽  
Hengfei Xu ◽  
Han Hu
Keyword(s):  
Energy Efficiency ◽  
Focal Point ◽  
Transmission Rate ◽  
Optimization Method ◽  
Base Station ◽  
Base Stations ◽  
Joint Optimization ◽  
Total Power ◽  
Transmit Power ◽  
Total Power Consumption

Heterogeneous cellular networks (HCNs) have emerged as the primary solution for explosive data traffic. However, an increase in the number of base stations (BSs) inevitably leads to an increase in energy consumption. Energy efficiency (EE) has become a focal point in HCNs. In this paper, we apply tools from stochastic geometry to investigate and optimize the energy efficiency (EE) for a two-tier HCN. The average achievable transmission rate and the total power consumption of all the BSs in a two-tier HCN is derived, and then the EE is formulated. In order to maximize EE, a one-dimensional optimization algorithm is used to optimize picocell BS density and transmit power. Based on this, an alternating optimization method aimed at maximizing EE is proposed to jointly optimize transmit power and density of picocell BSs. Simulation results validate the accuracy of the theoretical analysis and demonstrate that the proposed joint optimization method can obviously improve EE.

scholarly journals Evaluation of Metaheuristic-Based Methods for Optimization of Truss Structures via Various Algorithms and Lèvy Flight Modification

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 49
Author(s):  
Gebrail Bekdaş ◽  
Melda Yucel ◽  
Sinan Melih Nigdeli
Keyword(s):  
Large Scale ◽  
Optimization Method ◽  
Scale Space ◽  
Research Area ◽  
Truss Structures ◽  
Gray Wolf ◽  
Lévy Flight ◽  
Method Performance ◽  
Levy Flight ◽  
Material Usage

Truss structures are one of the major civil engineering members studied in the optimization research area. In this area, various optimization applications such as topology, size, cost, weight, material usage, etc., can be conducted for different truss structure types. In this scope with the present study, various optimization processes were carried out concerning two different large-scale space trusses to minimize the structural weight. According to this state, three structural models provided via two different truss structures, including 25 bar and 72 bar truss models, were handled for evaluation of six different metaheuristics together with the modification of Lèvy flight for three of the algorithms using swarm intelligence by considering both constant and variable populations, and different ranges for iterations, too. Additionally, the effects of the Lèvy flight function and whether it is successful or not in terms of the target of optimization were also investigated by comparing with some documented studies. In this regard, some statistical calculations were also realized to evaluate the optimization method performance and detection of optimum values for any data stably and successfully. According to the results, the Jaya algorithm can handle the optimization process successfully, including the case, without grouping truss members. The positive effect of Lèvy flight on swarm-based algorithms can be seen especially for the gray wolf algorithm.

Analysis of joint optimization scheduling rules for Jinsha River cascade and Yalong River cascade

2019 ◽  
pp. 1522-1528
Author(s):  
Zhang Hairong ◽  
Tang Zhengyang ◽  
Li Peng ◽  
Ren Yufeng ◽  
Liang Zhiming
Keyword(s):  
Joint Optimization ◽  
Jinsha River ◽  
Yalong River ◽  
Optimization Scheduling

scholarly journals Joint Optimization Strategy of Coverage Planning and Energy Scheduling for Wireless Rechargeable Sensor Networks

2020 ◽  
Author(s):  
Cheng Gong ◽  
Chao Guo ◽  
Haitao Xu ◽  
Chengcheng Zhou ◽  
Xiaotao Yuan
Keyword(s):  
Sensor Networks ◽  
Communication Networks ◽  
Energy Supply ◽  
Large Scale ◽  
Optimization Method ◽  
Joint Optimization ◽  
Second Phase ◽  
Optimization Strategy ◽  
Game Equilibrium ◽  
Wireless Rechargeable Sensor Networks

Wireless Sensor Networks (WSNs) has the characteristics of large-scale deployment, flexible networking, and wide application. It is an important part of the wireless communication networks. However, due to limited energy supply, the development of WSN is greatly restricted. Wireless Rechargeable Sensor Networks (WRSNs) transform the distributed energy around the environment into usable electricity through energy collection technology. In this work, a joint optimization strategy is proposed to improve the energy management efficiency for WRSNs. The joint optimization strategy is divided into two phases. In the first phase, we design an Annulus Virtual Force based Particle Swarm Optimization (AVFPSO) algorithm for area coverage planing. It adopts the multi-parameter joint optimization method to improve the efficiency of the algorithm. In the second phase, a Queuing Game-based Energy Supply (QGES) algorithm is designed for energy scheduling. It converts energy supply and consumption into network service. By solving the game equilibrium of the model, the optimal energy distribution strategy can be obtained. The simulation results show that our scheme improves the efficiency of coverage and energy, and extends the lifetime of WSN.

The Research of Power Generating Self-Optimization Mode Based on the Objective Function Optimization

2014 ◽  
Vol 953-954 ◽  
pp. 884-889
Author(s):  
Zhi Gang Hua ◽  
Guang Yu Hu ◽  
Zhi Gong Wu ◽  
Yong Jie Zhai
Keyword(s):  
Power Generation ◽  
Optimization Method ◽  
Function Optimization ◽  
The Self ◽  
Total Power ◽  
Initial Allocation ◽  
Generation Scheduling ◽  
Power Generation Unit ◽  
Important Means ◽  
Generation Unit

The self-optimization method for power generation proposed in this paper is an initial allocation of power energy. Every unit is according to the same principles of utilization hours in the same province. Under the premise of unchanged total power of each power generation unit and the security of the power system as well as the discharge standards, this method can achieve the minimum social resource consumption and the minimum discharge meet the demand of power energy at the same time by adjusting of autonomy optimization among internal different units. It is an important means and effective way to carry out energy generation scheduling work.

Application of Wind Energy Source to Large Scale Desalination System Prefeasibility Analysis-Investigation of Wind Power Potential in Coastal Areas of Tamilnadu

2013 ◽  
Vol 768 ◽  
pp. 57-63
Author(s):  
B. Shanthi Saravana ◽  
V. Rajini
Keyword(s):  
Power Generation ◽  
Wind Energy ◽  
Wind Power ◽  
Large Scale ◽  
Coastal Areas ◽  
Total Power ◽  
Energy Sources ◽  
Power Demand ◽  
Coastal Regions ◽  
Grid Connection

The total power demand in our country is increasing every year because of the increasing population. Conventional energy sources are limited by the constraints such as emission of CO2, increasing price of oil etc. To increase the power generation we need to go for non conventional energy sources among which wind energy is available in abundance. This paper discusses the possibility of using wind energy for the stand alone large scale applications eliminating the constraints on the grid connection. This is the pre feasibility study of wind power generation by analyzing the daily wind patterns in the coastal areas. This forms a good base for analyzing the feasibility of standalone wind system to large scale applications. HOMER software is used as an optimization tool. From the results Chennai has better energy density and Tutukurin has higher capacity factor. The study makes it feasible to next step in analyzing the feasibility of implementing a standalone desalination unit in coastal regions of Tamilnadu.

scholarly journals Optimal Scheduling of Power System Incorporating the Flexibility of Thermal Units

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2195 ◽  
Author(s):  
Tong Guo ◽  
Yajing Gao ◽  
Xiaojie Zhou ◽  
Yonggang Li ◽  
Jiaomin Liu
Keyword(s):  
Power Systems ◽  
Power System ◽  
Wind Power ◽  
Power Unit ◽  
Large Scale ◽  
Thermal Power ◽  
Entropy Method ◽  
Optimal Scheduling ◽  
Evaluation Index System ◽  
Total Power

Due to the randomness, volatility and intermittent nature of wind power, power systems with significant wind penetration face serious “curtailment” problems. The flexibility of a power system is an important factor that affects the large-scale consumption of wind power. Based on this fact, this paper takes into account the economics and flexibility of the system, and proposes an optimal scheduling method that takes the flexibility of each thermal power unit into account. Firstly, a comprehensive evaluation index system of thermal power unit flexibility is designed by an analytic hierarchy process and entropy method. The system covers the technical indexes and economic characteristics of thermal power units and is able to quantitatively evaluate the different types of thermal power units in the system. Secondly, a multi-objective optimization scheduling model involving the overall flexibility of the unit and the total power generation cost is established. Finally, the correctness and effectiveness of the proposed indicators and models are verified by a case study.

scholarly journals Upper Limit and Power Generation Loss of Water Supplement from Cascade Hydropower Stations to Downstream Under Lancang-Mekong Cooperation

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2826
Author(s):  
Jiahui Deng ◽  
Yu Li ◽  
Wei Ding ◽  
Bingyao Zhang ◽  
Bo Xu ◽  
...  
Keyword(s):  
Power Generation ◽  
Water Resources ◽  
Optimization Problem ◽  
Optimization Method ◽  
Joint Optimization ◽  
Cross Border ◽  
Upper Limit ◽  
Cascade Hydropower Stations ◽  
Firm Power ◽  
Hydropower Stations

In cross-border water supplement cooperation, the supplement water discharged from upstream hydropower stations is the key to improving downstream benefits, but will lead to upstream power generation loss, so the upstream hydropower stations have to be aware of how much water they can offer and how much power they will lose to make the water supplement cooperation more reasonable. Therefore, this study puts forward a model to calculate the upper limit flow of water supplement of cascade hydropower stations under firm power constraints and water level constraints and proposes a new optimization method called the “collaborative-independent” joint optimization method to calculate the power generation loss under water supplement constraints. The results show that the upper limit flow will increase with the increase of annual inflow, and the uncertainty of the distribution of inflow in the year will also affect the upper limit flow: the larger the proportion of non-flood season inflow, the higher the upper limit flow. In normal and wet years, delaying water supplement time can significantly increase the upper limit flow by about 5% per month. Additionally, the “collaborative-independent” joint optimization method newly proposed in this paper can significantly improve the local optimization problem compared to the traditional optimization method. The power generation loss increases with the increase of water supplement flow, and delaying water supplement time can significantly reduce the power generation loss. The results of this paper can provide essential data support for future water resources cooperation negotiations in the Lancang-Mekong river basin to promote efficient and orderly water resources cooperation in the basin.

scholarly journals Reservoir Scheduling Using a Multi-Objective Cuckoo Search Algorithm under Climate Change in Jinsha River, China

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1803
Author(s):  
Yu Feng ◽  
Jijun Xu ◽  
Yang Hong ◽  
Yongqiang Wang ◽  
Zhe Yuan ◽  
...  
Keyword(s):  
Climate Change ◽  
Power Generation ◽  
Search Algorithm ◽  
Cuckoo Search ◽  
Cuckoo Search Algorithm ◽  
Total Power ◽  
Jinsha River ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Hydropower Stations

Changes in rainfall and streamflow due to climate change have an adverse impact on hydropower generation reliability and scheduling of cascade hydropower stations. To estimate the impact of climate change on hydropower, a combination of climate, hydrological, and hydropower scheduling models is needed. Here, we take the Jinsha River as an example to estimate the impact of climate change on total power generation of the cascade hydropower stations and residual load variance of the power grid. These two goals are solved by applying an improved multi-objective cuckoo search algorithm, and a variety of strategies for the optimal dispatch of hydropower stations are adopted to improve the efficiency of the algorithm. Using streamflow prediction results of CMIP5 climate data, in conjunction with the Xinanjiang model, the estimated results for the next 30 years were obtained. The results indicated that the negative correlation between total power generation and residual load variance under the RCP 2.6 scenario was weaker than that under the RCP 8.5. Moreover, the average power generation and the average residual load variance in RCP 2.6 was significantly larger than that in RCP 8.5. Thus, reducing carbon emissions is not only beneficial to ecological sustainability, but also has a positive impact on hydropower generation. Our approaches are also applicable for cascade reservoirs in other river catchments worldwide to estimate impact of climate change on hydropower development.

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