scholarly journals Combinatorial Optimization Method for Operation of Pumping Station with Adjustable Blade and Variable Speed Based on Experimental Optimization of Subsystem

2014 ◽  
Vol 6 ◽  
pp. 283520 ◽  
Author(s):  
Yi Gong ◽  
Jilin Cheng
Keyword(s):  
Dynamic Programming ◽  
Optimal Operation ◽  
Constant Speed ◽  
Water Quantity ◽  
Decision Variable ◽  
Variable Speed ◽  
Pump Unit ◽  
Experimental Optimization ◽  
Pumping Station ◽  
Discrete Values

A decomposition-dynamic programming aggregation method based on experimental optimization for subsystem was proposed to solve mathematical model of optimal operation for single pumping station with adjustable blade and variable speed. Taking minimal daily electric cost as objective function and water quantity pumped by units as coordinated variable, this model was decomposed into several submodels of daily optimal operation with adjustable blade and variable speed for single pump unit which was solved by experimental optimization. The constructed aggregation model took water quantity pumped by each pump unit as decision variable and discrete values of water quantity pumped by pumping station as state variable and was solved by one-dimensional dynamic programming. Taking operation of typical pumping station as a study case, optimal operation with adjustable blade and variable speed, respectively, had an average cost saving of 4.19%, 22.15%, and 29.86% compared with operation with fixed blade angle and constant speed under 100%, 80%, and 60% load, which also had a remarkable saving amplitude of 15.85% and 24.18%, respectively, corresponding to 80% load and 60% load compared with operation with adjustable blade and constant speed. Meanwhile, the proposed method has provided a new way for solving complex nonlinear mathematical models with 3 decision variables.

Research of the Influence of the Variable Tidal of the Yangtze River on Optimal Operation of Adjustable-Blade in the Large Pumping Station

2012 ◽  
Vol 212-213 ◽  
pp. 1249-1254
Author(s):  
Li Hua Zhang ◽  
Hai Tao Qian
Keyword(s):  
Yangtze River ◽  
Optimal Operation ◽  
Tidal Range ◽  
Decision Variable ◽  
The Yangtze River ◽  
Pump Unit ◽  
Tidal Variation ◽  
Pumping Station ◽  
Pump Station ◽  
Blade Pump

In this paper, a model that optimal daily operation(without considering peak and valley price) of single adjustable-blade pump unit in the large pumping station along the Yangtze River is established. Where the minimum cost of energy consumption of single pump unit is set as the objective function, the periods are defined as stage variables, the blade angle is expressed as a decision variable and the daily quantity of delivery water is considered as constraint. The No. 4 Jiangdu Pump Station is taken as a study case. Dynamic programming is adopted to carry out the tidal large pumping station along the Yangtze River. Through this method, under the condition of different water quantity constraint, different average pumping head and different average tidal range amplitude,the influence of the tidal variation on optimal operation of single pump unit in the pumping station is determined. The application results shows that: With the decreased of average pumping head and the increased of average tidal range, the effect of optimal operation of adjustable-blade pump unit in the pumping station along the Yangtze River is getting more and more obvious.

scholarly journals Optimal Operation of a Single Unit with an Adjustable Blade in an Interbasin Water Transfer Pumping Station Based on Successive Approximation Discretization for Blade Angle

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yi Gong ◽  
Jilin Cheng ◽  
Li Che ◽  
Liang Wang ◽  
Zaiyang Chen ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic Programming ◽  
Successive Approximation ◽  
Single Unit ◽  
Optimal Operation ◽  
Feasible Region ◽  
Blade Angle ◽  
Pump Unit ◽  
Step Size ◽  
Water Pumping

In the mathematical model of the optimal operation of a single pump unit with a fully adjustable blade in the Chinese South-to-North Water Diversion Project, the decision variable, namely, blade angle, was uniformly dispersed in its feasible region in a fixed step size in consideration of the requirements of the pumping head and matching motor power. 1D dynamic programming was applied to solve the original model. When the obtained blade for each time period was set as the middle reference value and the discrete region of the blade was reduced to two times of the step size in the previous time, the blade angle was correspondingly reduced and dispersed in this new discrete region, thus eliminating unnecessary optimization space. Then, 1D dynamic programming was applied again to optimize the blade angle of the single pump unit further. After a series of successive approximation discretization of the blade angle and corresponding solutions of the obtained mathematical model, the optimization process was considered completed when the given control precision met the requirement. A case study showed that under typical operating conditions, the total cost saving percentage of water pumping quantity reached 0.048%–0.463%, with an average saving rate of 0.192%. The actual total water pumping quantity of the single unit decreased by 2153 m3 on the average. The proposed discretization method exerted a better optimization effect and needed a smaller computational amount compared with traditional one-time uniform discretization in the original feasible region of the blade angle.

scholarly journals Combined Aggregated Sampling Stochastic Dynamic Programming and Simulation-Optimization to Derive Operation Rules for Large-Scale Hydropower System

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 625
Author(s):  
Xinyu Wu ◽  
Rui Guo ◽  
Xilong Cheng ◽  
Chuntian Cheng
Keyword(s):  
Dynamic Programming ◽  
Stochastic Dynamic Programming ◽  
Large Scale ◽  
Simulation Optimization ◽  
Optimal Operation ◽  
Stochastic Dynamic ◽  
Operation Model ◽  
Two Stage ◽  
Operation Rules ◽  
Reservoir Systems

Simulation-optimization methods are often used to derive operation rules for large-scale hydropower reservoir systems. The solution of the simulation-optimization models is complex and time-consuming, for many interconnected variables need to be optimized, and the objective functions need to be computed through simulation in many periods. Since global solutions are seldom obtained, the initial solutions are important to the solution quality. In this paper, a two-stage method is proposed to derive operation rules for large-scale hydropower systems. In the first stage, the optimal operation model is simplified and solved using sampling stochastic dynamic programming (SSDP). In the second stage, the optimal operation model is solved by using a genetic algorithm, taking the SSDP solution as an individual in the initial population. The proposed method is applied to a hydropower system in Southwest China, composed of cascaded reservoir systems of Hongshui River, Lancang River, and Wu River. The numerical result shows that the two-stage method can significantly improve the solution in an acceptable solution time.

scholarly journals Dynamic Operation Management of a Renewable Microgrid including Battery Energy Storage

2018 ◽  
Vol 2018 ◽  
pp. 1-19 ◽  
Author(s):  
Shaozhen Jin ◽  
Zhizhong Mao ◽  
Hongru Li ◽  
Wenhai Qi
Keyword(s):  
Dynamic Programming ◽  
Energy Storage ◽  
Renewable Energy Sources ◽  
Main Idea ◽  
Optimal Operation ◽  
Optimal Control Strategy ◽  
Programming Technique ◽  
Battery Energy Storage ◽  
Comparison Results ◽  
Battery Energy

In this paper, a novel dynamic programming technique is presented for optimal operation of a typical renewable microgrid including battery energy storage. The main idea is to use the scenarios analysis technique to proceed the uncertainties related to the available output power of wind and photovoltaic units and dynamic programming technique to obtain the optimal control strategy for a renewable microgrid system in a finite time period. First, to properly model the system, a mathematical model including power losses of the renewable microgrid is established, where the uncertainties due to the fluctuating generation from renewable energy sources are considered. Next, considering the dynamic power constraints of the battery, a new performance index function is established, where the Lagrange multipliers and interior point method will be presented for the equality and inequality operation constraints. Then, a feedback control scheme based on the dynamic programming is proposed to solve the model and obtain the optimal solution. Finally, simulation and comparison results are given to illustrate the performance of the presented method.

scholarly journals Energy management of a dual-motor driven city bus based on reformed dynamic programming

2021 ◽  
Vol 236 ◽  
pp. 02020
Author(s):  
Wenwei Wang ◽  
Hong Pan ◽  
Lin Cheng
Keyword(s):  
Dynamic Programming ◽  
Energy Consumption ◽  
Energy Management ◽  
Original Method ◽  
Mode Switching ◽  
Svm Classifier ◽  
Decision Variable ◽  
State Variables ◽  
Energy Management Strategy ◽  
City Bus

This paper proposes a reformed dynamic programming (DP) based energy management strategy for a city bus driven by dual-motor coupling propulsion system(DMCPS). An instantaneous optimal problem of DMCPS’s total energy loss is constructed to solve the torque allocation between two motors. Taking the results as extra constraints, a reformed DP architecture aimed at optimal energy consumption is established, where the state variables are the battery’s SOC and operating modes of DMCPS, with a sole decision variable of mode switching action. The optimization results show a close performance to the original method, with the calculation efficiency greatly improved and the calculation time reduced by nearly 97%. To obtain practical rules for real-time application, the mode switching schedule is extracted based on a RBF-SVM classifier, and the torque allocation is ruled by linear function. Simulation results demonstrate that the extracted rules can be executed through an on-board processor, with energy consumption reduced by 2.19% compared to the original rule-based strategy.

Essence of Electric Charge of elementary particles according of New axioms and Laws

2020 ◽  
Vol 3 (4) ◽  
Keyword(s):  
Electromagnetic Field ◽  
Electron Pair ◽  
Constant Speed ◽  
Longitudinal Vortex ◽  
Uniform Motion ◽  
Variable Velocity ◽  
Variable Speed ◽  
External Observer ◽  
Closed Circle ◽  
The Waves

Two new Axioms and eight new Laws have been proposed and developed in previous reports. This report uses both axioms and only four laws. According to the first axiom (Axiom1), we can replace uniform motion in a closed circle with non-uniform motion in an open vortex. According to the second axiom (Axiom2), there are pairs of vortices that are mutually orthogonal or they tend to work in a system by a special type of resonance. Of all the variants of vortex pairs, the most probable is the pair: accelerating vortex from the center outwards connected with a delayed vortex from the periphery inwards. This pair is a model of the connected proton-electron pair. The behavior of a free electron and a proton in an Electromagnetic Field is studied. Actually like a cross vortex from outside to inside the electron will be directed to the positive pole. Therefore, an external observer who does not know what the internal structure of the electron is will think and will be deceived that the electron carries a negative charge. The exact opposite is observed for the proton. The properties of a system of linked electrons and protons are also studied. It is known that the Electromagnetic Field propagates at a constant speed and when pulsating the waves are only transverse. According to the new Axioms and Laws in the electron-proton system, the internal connections are of variable speed and when pulsating, the waves are not only transverse and longitudinal. Because the Electromagnetic field is only transverse at a constant speed , it appears that the interaction between the proton and the electron is not Electromagnetic but some other interaction. The interaction between the protons includes cross vortex with variable velocity and longitudinal vortex with variable velocity

scholarly journals Blasting-Induced Permeability Enhancement of Ore Deposits Associated with Low-Permeability Weakly Weathered Granites Based on the Split Hopkinson Pressure Bar

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Lei Yan ◽  
Wenhua Yi ◽  
Liansheng Liu ◽  
Jiangchao Liu ◽  
Shenghui Zhang
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Deformation Modulus ◽  
Constant Speed ◽  
Initial Porosity ◽  
Peak Strain ◽  
Variable Speed ◽  
Hopkinson Pressure Bar ◽  
Impact Compression ◽  
Split Hopkinson ◽  
Pressure Bar

By utilizing the improved split Hopkinson pressure bar (SHPB) test device, uniaxial, constant-speed cyclic, and variable-speed cyclic impact compression tests were conducted on weakly weathered granite samples. By combining nuclear magnetic resonance (NMR) and triaxial seepage tests, this study investigated the change laws in the mechanical properties, porosity evolution, and permeability coefficients of the samples under cyclic impacts. The results showed that in constant-speed cyclic impacts with increasing impact times, deformation modulus decreased, whilst porosity firstly decreased and then increased. Furthermore, dynamic peak strength firstly increased and then decreased whereas peak strain constantly increased before failure of the samples. In the variable-speed cyclic impacts, as impact times increased, deformation modulus firstly increased and then declined with damage occurring after four impact times. The compaction process weakened and even disappeared with increasing initial porosity. Three types of pores were found in the samples that changed in multiscale under cyclic loading. In general, small pores extended to medium- and large-sized pores. After three variable-speed cyclic impacts, the porosity of the samples was larger than the initial porosity and the permeability coefficient was greater than its initial value. The results demonstrate that the purpose of enhancing permeability and keeping the ore body stable can be achieved by conducting three variable-speed cyclic impacts on the samples.

scholarly journals Improvement of Intake Structures in a Two-Way Pumping Station with Experimental Analysis

2020 ◽  
Vol 10 (19) ◽  
pp. 6842
Author(s):  
Yanjun Li ◽  
Rong Lu ◽  
Huiyan Zhang ◽  
Fanjie Deng ◽  
Jianping Yuan
Keyword(s):  
Frequency Domain ◽  
Great Influence ◽  
Operating Conditions ◽  
Stable Operation ◽  
Pressure Pulsations ◽  
Pump Unit ◽  
Measuring Point ◽  
Time Frequency ◽  
Pumping Station ◽  
Bell Mouth

Pumping stations are important regulation facilities in a water distribution system. Intake structures can generally have a great influence on the operational state of the pumping station. To analyze the effects of the bell mouth height of the two-way intake on the performance characteristics and the pressure pulsations of a two-way pumping station, the laboratory-sized model pump units with three different intakes were experimentally investigated. To facilitate parameterized control, ellipse and straight lines were used to construct the profile of the bell mouth. The frequency domain and time-frequency domain of the pressure pulsations on the wall of intakes were analyzed by the Welch’s power spectral density estimate and the continuous wavelet transform (CWT) methods, respectively. The results showed that the bell mouth height (H) has significant influences on the uniformity of the impeller inflow and the operation stability of the pump unit. When H = 204 mm, the data fluctuated greatly throughout the test process and the performance curves are slightly lower than the other two schemes. As the bell mouth height gradually decreases, the average pressure difference of each measuring point began to decrease, more homogeneous velocity distribution of impeller inflow can be ensured. The amplitude of blade passing frequency is obvious in the spectrum. While when (H) is more than 164 mm, the main frequency of pressure pulsations at three points fluctuates with the rotation of the impeller. When H decreases to 142 mm, pressure pulsations will be independent of the operating conditions and positions which contributes to the long-term stable operation of the pump unit.

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