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Records with Keyword: Optimization
Showing records 101 to 125 of 884. [First] Page: 1 2 3 4 5 6 7 8 9 Last
An Optimization-Based Model for A Hybrid Photovoltaic-Hydrogen Storage System for Agricultural Operations in Saudi Arabia
Awsan Mohammed
June 7, 2023 (v1)
Subject: Optimization
Keywords: hydrogen storage, mixed-integer linear programming, Optimization, photovoltaic system
Renewable energy technologies and resources, particularly solar photovoltaic systems, provide cost-effective and environmentally friendly solutions for meeting the demand for electricity. The design of such systems is a critical task, as it has a significant impact on the overall cost of the system. In this paper, a mixed-integer linear programming-based model is proposed for designing an integrated photovoltaic-hydrogen renewable energy system to minimize total life costs for one of Saudi Arabia’s most important fields, a greenhouse farm. The aim of the proposed system is to determine the number of photovoltaic (PV) modules, the amount of hydrogen accumulated over time, and the number of hydrogen tanks. In addition, binary decision variables are used to describe either-or decisions on hydrogen tank charging and discharging. To solve the developed model, an exact approach embedded in the general algebraic modeling System (GAMS) software was utilized. The model was validated using a far... [more]
Holistic Approach for an Energy-Flexible Operation of a Machine Tool with Cooling Supply
Martin Lindner, Benedikt Grosch, Ghada Elserafi, Bastian Dietrich, Matthias Weigold
May 24, 2023 (v1)
Subject: Optimization
Keywords: demand-side management, energy flexibility, machine tool, manufacturing, Optimization
The following paper examines the practicality of a methodical approach for energy-flexible and energy-optimal operation in the field of metal-cutting production. The analysis is based on the example of a grinding machine and its central cooling-supply system. In the first step, an energy-flexibility data model is built for each subsystem, which describes energy flexibility potentials generically. This is then extended to enable combined energy cost-optimal production planning. As a basis for the links between the data model representations, the cold flows between the subsystems are modeled using parameter-estimation methods, which have a mean absolute error of only 2.3 percent, making the subsequent installation of heat meters unnecessary. Based on the presented approach, the results successfully validate the possibility of energy-flexible cost-optimal and sensor-reduced production planning by reducing energy costs by 6.6 percent overall and 1.9 percent per workpiece produced.
Variable-Speed Propeller Turbine for Small Hydropower Applications
Eva Bílková, Jiří Souček, Martin Kantor, Roman Kubíček, Petr Nowak
May 23, 2023 (v1)
Keywords: axial propeller turbine, CAESES, Computational Fluid Dynamics, Optimization, tailor-made design, variable-speed
Standard technical solutions are not cost-effective for many small hydropower sites. This study aims to demonstrate the workflow for the tailor-made variable-speed axial propeller turbine and provide proof of this concept. The turbine is designed to meet the site’s specific space limitations and operating range needs. The runner shape is adjusted to the variable-speed operation and defined hydraulic profile using a parametric geometry model and CFD-based optimization. The variable-speed propeller turbine shows excellent flow control while keeping the mechanical design simple. The tailor-made approach minimizes construction costs using existing structures and is highly suitable for mini-hydropower applications. The prototype—an atypical turbine designed for highly restricted space and installed on-site—serves as proof of the concept. The findings on the design of axial variable-speed turbines are presented.
Optimal Dispatching of Smart Hybrid Energy Systems for Addressing a Low-Carbon Community
Wei Wu, Shih-Chieh Chou, Karthickeyan Viswanathan
May 23, 2023 (v1)
Subject: Optimization
Keywords: forecasting, operating reserve, Optimization, power dispatch, smart hybrid energy system
A smart hybrid energy system (SHES) is presented using a combination of battery, PV systems, and gas/diesel engines. The economic/environmental dispatch optimization algorithm (EEDOA) is employed to minimize the total operating cost or total CO2 emission. In the face of the uncertainty of renewable power generation, the constraints for loss-of-load probability (LOLP) and the operating reserve for the rechargeable battery are taken into account for compensating the imbalance between load demand and power supplies. The grid-connected and islanded modes of SHES are demonstrated to address a low-carbon community. For forecasting load demand, PV power, and locational-based marginal pricing (LBMP), the proper forecast model, such as long short-term memory (LSTM) or extreme gradient boosting (XGBoost), is implemented to improve the EEDOA. A few comparisons show that (i) the grid-connected mode of SHES is superior to the islanded-connected mode of SHES due to lower total operating cost and les... [more]
Optimal Configuration of a Hybrid Photovoltaic/Wind Turbine/Biomass/Hydro-Pumped Storage-Based Energy System Using a Heap-Based Optimization Algorithm
Ahmed S. Menesy, Hamdy M. Sultan, Ibrahim O. Habiballah, Hasan Masrur, Kaisar R. Khan, Muhammad Khalid
May 23, 2023 (v1)
Keywords: biomass system, cost of energy, hybrid system, Optimization, pumped storage, Renewable and Sustainable Energy
Recently, renewable energy resources (RESs) have been utilized to supply electricity to remote areas, instead of the conventional methods of electrical energy production. In this paper, the optimal design of a standalone hybrid RES comprising photovoltaic (PV), wind turbine (WT), and biomass sources as well as an energy storage system, such as a hydro-pumped storage system, is studied. The problem of the optimal sizing of the generating units in the proposed energy system is formulated as an optimization problem and the algorithms heap-based optimizer (HBO), grey wolf optimizer (GWO), and particle swarm optimization (PSO) are applied to achieve the optimal sizing of each component of the proposed grid-independent hybrid system. The optimization problem is formulated depending on the real-time meteorological data of the Ataka region on the Red Sea in Egypt. The main goal of the optimization process is to minimize the cost of energy (COE) and the loss of power supply probability (LPSP),... [more]
Revolutionizing Photovoltaic Systems: An Innovative Approach to Maximum Power Point Tracking Using Enhanced Dandelion Optimizer in Partial Shading Conditions
Elmamoune Halassa, Lakhdar Mazouz, Abdellatif Seghiour, Aissa Chouder, Santiago Silvestre
May 23, 2023 (v1)
Subject: Optimization
Keywords: dandelion optimizer, maximum power point tracker (MPPT), Optimization, partial shading conditions (PSCs), photovoltaic
Partial shading (PS) is a prevalent phenomenon that often affects photovoltaic (PV) installations, leads to the appearance of numerous peaks in the power-voltage characteristics of PV cells, caused by the uneven distribution of solar irradiance on the PV module surface, known as global and local maximum power point (GMPP and LMPP). In this paper, a new technique for achieving GMPP based on the dandelion optimizer (DO) algorithm is proposed, inspired by the movement of dandelion seeds in the wind. The proposed technique aimed to enhance the efficiency of power generation in PV systems, particularly under PS conditions. However, the DO-based MPPT is compared with other advanced maximum power point tracker (MPPT) algorithms, such as Particle Swarm Optimization (PSO), Grey Wolf Optimization (GWO), Artificial Bee Colony (ABC), Cuckoo Search Algorithm (CSA), and Bat Algorithm (BA). Simulation results establish the superiority and effectiveness of the used MPPT in terms of tracking efficiency... [more]
Optimization of Spray-Drying Conditions of Microencapsulated Habanero Pepper (Capsicum chinense Jacq.) Extracts and Physicochemical Characterization of the Microcapsules
Kevin Alejandro Avilés-Betanzos, Juan Valerio Cauich-Rodríguez, Manuel Octavio Ramírez-Sucre, Ingrid Mayanin Rodríguez-Buenfil
April 28, 2023 (v1)
Keywords: antioxidant capacity, Capsicum chinense, Optimization, polyphenols, spray drying
The Habanero pepper (Capsicum chinense Jacq.) is recognized worldwide for its unique organoleptic characteristics, as well as for its capsaicin content; however, other bioactive compounds, such as phenolic compounds with bioactive properties (mainly antioxidant capacity), have been extracted (ultrasound) and identified in this fruit. Moreover, the extracts obtained by ultrasound present a high sensitivity to environmental conditions, making spray drying a viable option to avoid the degradation of bioactive compounds while maintaining their properties after microencapsulation. Response surface methodology (RSM) has been used to optimize spray-drying conditions such as the inlet temperature (IT) and maltodextrin:extract (M:E) ratio. Thus, the objective of this work was to establish the optimal spray-drying conditions (IT and M:E) of a Habanero pepper extract with a final characterization of the spray-dried product. Results showed that the optimal spray-drying conditions included an IT =... [more]
An Innovative Sensor-Based Approach for Evaluating Performance of Flotation Circuit at the Expansion of Toromocho Copper Mine
Wei Zhang, Zhiyong Tan, Tengfei Li, Xiaoqiang Guan, Shiqing Zhou, Haibin Li, Chao Wang
April 28, 2023 (v1)
Subject: Materials
Keywords: bubble size, cell characterization, hydrodynamics, Optimization
Chinalco’s Toromocho mine, located in the Morococha district of Peru, treated 117,200 mtpd ores during last 10 years. It is currently undergoing expansion, treating approximately 52,740 mtpd of chalcopyrite ore since 2021. As with the commissioning of most large plants, the metallurgical performance levels produced after stability was achieved were below the design criteria; more specifically, the Cu overall recoveries were 80−82% compared with the design value of 85%, and the final concentrate Cu grades were 20−23% compared with the design value of 24% over the past 2 years. It is clear that the copper losses in the fine size fraction (<10 µm) were due to unoptimized hydrodynamics. To overcome this obstacle and improve overall performance, an innovative approach for flotation circuit evaluation was designed and set up, to improve understanding of the nature of the mineral losses, benchmark the cell hydrodynamics as a platform to improve flotation cell operation, and link the circui... [more]
Wind Turbine Blade-Tip Optimization: A Systemic Computational Approach
Panagiotis Zouboulis, Elias P. Koumoulos, Anna Karatza
April 28, 2023 (v1)
Keywords: 3D printing, additive manufacturing, blade tip, bladelet, Computational Fluid Dynamics, Optimization, topology, wind energy
Curved bladelets on wind turbine blades play an important role in improving the performance and efficiency of wind turbines. Implementing such features on the tip of wind turbine blades can improve their overall aerodynamic characteristics by reducing turbulence and loading without hindering lift generation and overall efficiency, thus leading to increased energy capture and reduced costs over the life of the turbine. Subjecting the integrated blade tip to optimization procedures can maximize its beneficial contribution to the assembly in general. Within this context, a systemic workflow is proposed for the optimization of a curved bladelet implemented on a wind turbine blade. The approach receives input in the form of an initial tip geometry and performs improvements in two distinct stages. Firstly, shape optimization is performed directly on the outer shape to enhance its aerodynamic properties. Subsequently, the topology of its interior structure is refined to decrease its mass whil... [more]
Optimization of Partially Hydrolyzed Polyacrylamide (HPAM) Utilized in Water-Based Mud While Drilling
Asma Nour El Houda Sid, Benalia Kouini, Mohammed Amin Bezzekhami, Selma Toumi, Khadidja Ouchak, Sara Benfarhat, Hichem Tahraoui, Mohammed Kebir, Abdeltif Amrane, Aymen Amine Assadi, Jie Zhang, Lotfi Mouni
April 28, 2023 (v1)
Subject: Materials
Keywords: aging, drilling mud, HPAM, Optimization, rheology, thermal aging
Water-soluble polymers are becoming increasingly important in various applications, such as stabilizer fluids and drilling muds. These materials are used as viscosifiers and filtration control agents, flocculants, and deflocculants due to their superior properties in increasing viscosity and gelling ability in the presence of crosslinkers. In general, studying the rheological behavior of drilling fluids is of paramount importance to ensure successful well drilling operations. Partially hydrolyzed polyacrylamide is one of the polymers widely used in water-based muds. The main objective of this study is to optimize the rheological properties of drilling muds through a characterization study of various parameters, including rheological behavior, viscosity, temperature (23 °C, 40 °C, and 60 °C), salinity using KCl and NaCl contents, aging, pH, solubility, and structural analysis using infrared of partially hydrolyzed polyacrylamide. The study aims to demonstrate the importance of using pol... [more]
Design and Optimization of the Training Device for the Employment of Hydraulic Rescue Tools in Traffic Accidents
Michal Ballay, Bohuš Leitner, Lenka Jakubovičová
April 28, 2023 (v1)
Subject: Optimization
Keywords: beam element, design, experiment, FEM analysis, firefighters’ units, hydraulic rescue tools, Optimization, training device prototype
This paper is concerned with the design and structural optimization of a training device for operators of a hydraulic rescue tool employed during traffic accidents, in conjunction with the improvement of the technical procedures used in such situations. Changes in the design process and subsequent production in the motor industry frequently result in an increased impact resistance of the used structural components. This applies, also, to extrication works and frequently used technical equipment. This paper presents its findings on the design process for the prototype of a training device designed for the extrication cutting drill with the assistance of a hydraulic rescue tool. The primary part of the research was dedicated to structural optimization; therefore, parameter dimensioning of the training device’s prototype was implemented. The device’s mechanical resistance, sturdiness, and stability during the implementation of hydraulic tools were also taken into account. A secondary part... [more]
Study on Estimation Method of Enthalpy of Evaporation Based on Elements and Chemical Bonds
Yule Pan, Wenjiao Ma, Baowei Niu, Xinyu Li, Shuguang Xiang, Li Xia
April 28, 2023 (v1)
Subject: Optimization
Keywords: chemical bonds, elements, evaporation enthalpy, group contribution method, Optimization
A new Group Contribution Method based on elements and chemical bonds was proposed to predict the enthalpy of evaporation of organic compounds at their normal boiling points. A prediction model was built using 1266 experimental data points, and the accuracy of the model estimations was evaluated using 16 experimental data points. The new method has only 42 groups, a simple way of group splitting, and a wide range of predictions with an average relative error of 5.84%. Furthermore, the inclusion of silicon elements and their chemical bonds in the group library enables the effective prediction of silicon-containing compounds with an average relative error of 2.71%. By analyzing and comparing the other three commonly used methods, it can be concluded that the new method provides accurate and reliable estimation results and has a more comprehensive application range.
Modeling and Operating Time Optimization of Layer Melt Crystallization and Sweating Processes
Yunhe Bai, Luguang Qi, Ying Sun, Zhenxing Zhu, Chuang Xie
April 28, 2023 (v1)
Keywords: layer growth rate, layer melt crystallization, Modelling, Optimization, sweating
Improving the separation efficiency of the layer melt crystallization process is a key but difficult task. Herein, a comprehensive model involving both crystallization and sweating was proposed and used to optimize the operating time of crystallization and sweating processes. The crystallization process was modeled based on the relationship between differential and integral distribution coefficients under a constant layer growth rate. For the sweating process, an empirical sweating equation was employed to govern the sweating model, the parameters of which were determined experimentally using P-xylene as the model substance. The separation efficiency was then optimized by minimizing the operating time at a given product purity and yield. A sensitivity analysis showed that the crystallization and sweating times nonlinearly increase with increasing yield. After the yield exceeds 0.65, an increasing crystallization time is the dominant factor in improving the separation efficiency, while... [more]
Methods and Tools for PV and EV Hosting Capacity Determination in Low Voltage Distribution Networks—A Review
Vincent Umoh, Innocent Davidson, Abayomi Adebiyi, Unwana Ekpe
April 28, 2023 (v1)
Keywords: deterministic, distribution network, electric vehicle, hosting capacity, Optimization, solar PV, stochastic, streamlined, time series
The increasing demand for electricity and the need for environmentally friendly transportation systems has resulted in the proliferation of solar photovoltaic (PV) generators and electric vehicle (EV) charging within the low voltage (LV) distribution network. This high penetration of PV and EV charging can cause power quality challenges, hence the need for hosting capacity (HC) studies to estimate the maximum allowable connections. Although studies and reviews are abundant on the HC of PV and EV charging available in the literature, there is a lack of reviews on HC studies that cover both PV and EVs together. This paper fills this research gap by providing a detailed review of five commonly used methods for quantifying HC including deterministic, time series, stochastic, optimization, and streamlined methods. This paper comprehensively reviews the HC concept, methods, and tools, covering both PV and EV charging based on a survey of state-of-the-art literature published within the last... [more]
Integration Optimization of Integrated Solar Combined Cycle (ISCC) System Based on System/Solar Photoelectric Efficiency
Zuxian Zhang, Liqiang Duan, Zhen Wang, Yujie Ren
April 28, 2023 (v1)
Subject: Optimization
Keywords: integrated solar combined cycle, Optimization, solar photoelectric efficiency, system efficiency
Integrated solar combined cycle (ISCC) systems play a pivotal role in the utilization of non-fossil energy; however, the efficient application of solar energy has emerged as a primary issue in the study of ISCC systems. Therefore, it is extremely urgent to propose the best optimization scheme for ISCC under different operating conditions. In this paper, according to the idea of temperature matching and cascade utilization, the optimization of the ISCC system is carried out with the genetic algorithm for the whole working conditions, and the optimization schemes with the highest photoelectric efficiency and system efficiency under different working conditions are derived. In comparison with two optimization schemes with different objective functions, the conclusion can be drawn that: At 100% gas turbine load—30% DNI and 100% gas turbine load—100% DNI working conditions, respectively, the maximum system efficiency of 56.32% and the maximum solar photoelectric efficiency of 35.5% are atta... [more]
P2P Electricity Trading Considering User Preferences for Renewable Energy and Demand-Side Shifts
Daishi Sagawa, Kenji Tanaka, Fumiaki Ishida, Hideya Saito, Naoya Takenaga, Kosuke Saegusa
April 28, 2023 (v1)
Keywords: electric vehicle, heat pump water heater, Optimization, P2P energy trading
In the global trend towards decarbonization, peer-to-peer (P2P) energy trading is garnering increasing attention. Furthermore, energy management on the demand side plays a crucial role in decarbonization efforts. The authors have previously developed an automated bidding agent that considers user preferences for renewable energy (RE), assuming users own electric vehicles (EVs). In this study, we expand upon this work by considering users who own not only EVs but also heat pump water heaters, and we develop an automated bidding agent that takes into account their preferences for RE. We propose a method to control the start time and presence of daytime operation shifts for heat pump water heaters, leveraging their daytime operation shift function. Demonstration experiments were conducted to effectively control devices such as EVs and heat pumps using the agent. The results of the experiments revealed that by controlling the daytime operation of heat pumps with our method, the RE utilizat... [more]
A Review of Research on Advanced Control Methods for Underground Coal Gasification Processes
Ján Kačur, Marek Laciak, Milan Durdán, Patrik Flegner, Rebecca Frančáková
April 28, 2023 (v1)
Keywords: advanced control, automation, control algorithm, control methods, Modelling, Optimization, review, UCG
Underground coal gasification (UCG) is a clean coal mining technology without significant environmental impacts. This technology can also be used in deep, hard-to-reach seams or deposits affected by tectonic disturbances, where conventional mining is impossible. Several techniques and methods have been investigated worldwide to support the process control of UCG. Global research focuses on the control of UCG operating parameters to stabilize or to optimize the performance of the underground reactor during energy conversion. This paper studies recent research in the field of UCG control and compares individual control techniques and possibilities for practical application. The paper focuses on advanced control methods that can be implemented in an in situ control system (e.g., adaptive control, extremum seeking control, and robust control). The study investigates control methods that ensure desired syngas calorific value or maximization. The review showed that robust control techniques... [more]
Energy Management in a Standalone Microgrid: A Split-Horizon Dual-Stage Dispatch Strategy
Aslam Amir, Hussain Shareef, Falah Awwad
April 28, 2023 (v1)
Keywords: economic dispatch, energy management, energy storage system, microgrids, Optimization, Renewable and Sustainable Energy
Microgrid technology has recently gained global attention over increasing demands for the inclusion of renewable energy resources in power grids, requiring constant research and development in aspects such as control, protection, reliability, and management. With an ever-increasing scope for maximizing renewable energy output, there is also a need to reduce the curtailment of power on both the generation and demand sides by increasing forecasting accuracies and using resources more effectively. This paper proposes a dual-stage dispatch employing a novel “split-horizon” strategy, in a bid to enhance energy management in a standalone microgrid. The split-horizon is essentially the considered time horizon split into equal operational periods of the dual-stage dispatch. The proposed strategy utilizes a custom-designed novel variant of the inertia-weight-based particle swarm optimization (PSO), termed customized PSO, to perform the optimal schedule and dispatch operation by benefitting from... [more]
AI-Based Scheduling Models, Optimization, and Prediction for Hydropower Generation: Opportunities, Issues, and Future Directions
Yoan Villeneuve, Sara Séguin, Abdellah Chehri
April 28, 2023 (v1)
Keywords: deep neural networks, hydropower, hydropower scheduling, linear regression, Machine Learning, Optimization, random forest, reinforcement learning, stochastic programming
Hydropower is the most prevalent source of renewable energy production worldwide. As the global demand for robust and ecologically sustainable energy production increases, developing and enhancing the current energy production processes is essential. In the past decade, machine learning has contributed significantly to various fields, and hydropower is no exception. All three horizons of hydropower models could benefit from machine learning: short-term, medium-term, and long-term. Currently, dynamic programming is used in the majority of hydropower scheduling models. In this paper, we review the present state of the hydropower scheduling problem as well as the development of machine learning as a type of optimization problem and prediction tool. To the best of our knowledge, this is the first survey article that provides a comprehensive overview of machine learning and artificial intelligence applications in the hydroelectric power industry for scheduling, optimization, and prediction.
Optimal Allocation of Distributed Generation Considering Protection
Hamza M. Bakr, Mostafa F. Shaaban, Ahmed H. Osman, Hatem F. Sindi
April 25, 2023 (v1)
Subject: Optimization
Keywords: distributed generation, Optimization, power system protection, renewable resources, smart grids
The integration of distributed generation (DG) into the power grid has increased in recent years due to its techno-economic benefits for utilities and consumers. However, due to the fact that distribution systems were not originally designed to accommodate such DG units, many challenges are being faced by utilities to seamlessly integrate them into their systems. One of the critical challenges is their effect on protection system settings and coordination. The DG units will affect the pickup current settings of the protection relays, coordination between the primary and secondary relays, and even the direction of the fault current. Failing to consider DG’s effect on the protection system may lead to serious equipment damage or system failure, causing huge financial setbacks for utilities. To that end, this work proposes a new dynamic approach to optimally allocate different types of DG units over the planning horizon. The objective is to minimize the overall costs of the system while t... [more]
Wave Exciting Force Maximization of Truncated Cylinders in a Linear Array
Constantine Michailides, Eva Loukogeorgaki, Ioannis K. Chatjigeorgiou
April 25, 2023 (v1)
Subject: Optimization
Keywords: hydrodynamic loads, linear array, Optimization, truncated cylinders, wave diffraction, wave-structure interaction
This study focuses on the determination of optimum layout configurations for a linear array of identical mutually interacting truncated cylinders. Optimum configurations correspond to those that maximize either the total heave exciting force acting on all cylinders of the array or the heave exciting force applied on pairs of cylinders within the array. For achieving this goal, we developed and applied an efficient optimization numerical process (ONP), where a robust hydrodynamic numerical model, capable of solving the diffraction problem of the examined multi-body arrangement in the frequency domain, was appropriately coupled with a genetic algorithm solver in an integrated computational environment. Initially, the efficiency of the ONP is demonstrated by comparing results with those of other investigations that resulted from the deployment of classical optimization methods. Then, ONP is applied for a linear array of nine cylinders for determining the optimum layout configurations unde... [more]
Reliability-Based Optimization for Energy Refurbishment of a Social Housing Building
Marco Manzan, Giorgio Lupato, Amedeo Pezzi, Paolo Rosato, Alberto Clarich
April 25, 2023 (v1)
Subject: Optimization
Keywords: building refurbishment, discounted cash flow analysis, Optimization, polynomial chaos, reliability analysis
This paper investigates the influence of a stochastic variation of both energy and economic parameters in an optimization loop applied to a refurbished social housing building. Usually, energy and economic optimization procedures rely on the results of an underlying numerical deterministic model which influences both energy gains and economic figures. However, an analyst must always face the random variation of input and parameter data. The unknown data can represent poor initial information or data that can change in a long time; this is the case of fuel cost and economic indexes in particular. This paper deals with both problems for building refurbishment optimization, the former related to the initial state of a building, and the latter to the energy cost variability. Reliability analysis considers a stochastic variation of parameters looking for solutions that incorporate a risk level; in this case, it deals with optimization objectives related to different impacts on economic, env... [more]
Optimal Parameters of Volt−Var Function in Smart Inverters for Improving System Performance
Hyeong-Jin Lee, Kwang-Hoon Yoon, Joong-Woo Shin, Jae-Chul Kim, Sung-Min Cho
April 25, 2023 (v1)
Subject: Optimization
Keywords: distribution system, Optimization, photovoltaic (PV), smart inverter, volt–var function
This paper proposes a method to improve the performance of a distribution system by optimizing volt−var function of a smart inverter to alleviate the voltage deviation problem due to distributed generation connection. In order to minimize voltage deviation and line losses which represent the performance of a distribution system, this paper proposes an algorithm that optimally sets the parameters of the volt−var function. In the process of optimizing the parameters of the volt−var function, the algorithm proposed in this paper considers minimizing the contribution of the reactive power in order not to affect the output of the distributed generation. In order to apply to the field, the distribution system in South Korea considering the configuration and operation regulation was selected as a test model for algorithm verification. As a result, the system performance was successfully improved by optimally setting the volt−var function of the smart inverter which is an effective way to solv... [more]
Optimization of a Small Wind Turbine for a Rural Area: A Case Study of Deniliquin, New South Wales, Australia
Nour Khlaifat, Ali Altaee, John Zhou, Yuhan Huang, Ali Braytee
April 25, 2023 (v1)
Keywords: aerodynamic, computational fluid dynamics (CFD), Genetic Algorithm, horizontal-axis wind turbine (HAWT), Optimization
The performance of a wind turbine is affected by wind conditions and blade shape. This study aimed to optimize the performance of a 20 kW horizontal-axis wind turbine (HAWT) under local wind conditions at Deniliquin, New South Wales, Australia. Ansys Fluent (version 18.2, Canonsburg, PA, USA) was used to investigate the aerodynamic performance of the HAWT. The effects of four Reynolds-averaged Navier−Stokes turbulence models on predicting the flows under separation condition were examined. The transition SST model had the best agreement with the NREL CER data. Then, the aerodynamic shape of the rotor was optimized to maximize the annual energy production (AEP) in the Deniliquin region. Statistical wind analysis was applied to define the Weibull function and scale parameters which were 2.096 and 5.042 m/s, respectively. The HARP_Opt (National Renewable Energy Laboratory, Golden, CO, USA) was enhanced with design variables concerning the shape of the blade, rated rotational speed, and pi... [more]
The Impact of Surrogate Models on the Multi-Objective Optimization of Pump-As-Turbine (PAT)
Stephen Ntiri Asomani, Jianping Yuan, Longyan Wang, Desmond Appiah, Kofi Asamoah Adu-Poku
April 25, 2023 (v1)
Keywords: Adaptive Neuro-Fuzzy Inference System, General Regression Neural Network, multi-objective, Optimization, pump as turbine
Pump-as-turbine (PAT) technology permits two operating states—as a pump or turbine, depending on the demand. Nevertheless, designing the geometrical components to suit these operating states has been an unending design issue, because of the multi-conditions for the PAT technology that must be attained to enhance the hydraulic performance. Also, PAT has been known to have a narrow operating range and operates poorly at off-design conditions, due to the lack of flow control device and poor geometrical designs. Therefore, for the PAT to have a wider operating range and operate effectively at off-design conditions, the geometric parameters need to be optimized. Since it is practically impossible to optimize more than one objective function at the same time, a suitable surrogate model is needed to mimic the objective functions for it to be solvable. In this study, the Latin hypercube sampling method was used to obtain the objective function values, the Adaptive Neuro-Fuzzy Inference System... [more]
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