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Showing records 133 to 157 of 303. [First] Page: 1 3 4 5 6 7 8 9 10 11 Last
A Comparison of Impedance-Based Fault Location Methods for Power Underground Distribution Systems
Enrique Personal, Antonio García, Antonio Parejo, Diego Francisco Larios, Félix Biscarri, Carlos León
July 29, 2019 (v1)
Keywords: fault location, power delivery, power distribution network, underground distribution system
In the last few decades, the Smart Grid paradigm presence has increased within power systems. These new kinds of networks demand new Operations and Planning approaches, following improvements in the quality of service. In this sense, the role of the Distribution Management System, through its Outage Management System, is essential to guarantee the network reliability. This system is responsible for minimizing the consequences arising from a fault event (or network failure). Obviously, knowing where the fault appears is critical for a good reaction of this system. Therefore, several fault location techniques have been proposed. However, most of them provide individual results, associated with specific testbeds, which make the comparison between them difficult. Due to this, a review of fault location methods has been done in this paper, analyzing them for their use on underground distribution lines. Specifically, this study is focused on an impedance-based method because their requiremen... [more]
Nitroxide-Mediated Copolymerization of Itaconate Esters with Styrene
Sepehr Kardan, Omar Garcia Valdez, Adrien Métafiot, Milan Maric
July 29, 2019 (v1)
Keywords: copolymerization, itaconate esters, nitroxide mediated polymerization
Replacing petro-based materials with renewably sourced ones has clearly been applied to polymers, such as those derived from itaconic acid (IA) and its derivatives. Di-n-butyl itaconate (DBI) was (co)polymerized via nitroxide mediated polymerization (NMP) to impart elastomeric (rubber) properties. Homopolymerization of DBI by NMP was not possible, due to a stable adduct being formed. However, DBI/styrene (S) copolymerization by NMP at various initial molar feed compositions fDBI,0 was polymerizable at different reaction temperatures (70−110 °C) in 1,4 dioxane solution. DBI/S copolymerizations largely obeyed first order kinetics for initial DBI compositions of 10% to 80%. Number-average molecular weight (Mn) versus conversion for various DBI/S copolymerizations however showed significant deviations from the theoretical Mn as a result of chain transfer reactions (that are more likely to occur at high temperatures) and/or the poor reactivity of DBI via an NMP mechanism. In order to suppre... [more]
Internal Model Control for Rank-Deficient System with Time Delays Based on Damped Pseudo-Inverse
Meiying Jiang, Beiyan Jiang, Qi Wang
July 29, 2019 (v1)
Keywords: damped pseudo-inverse, internal model control, rank-deficient system, time delay
It is a challenge to design a satisfactory controller for a complex multivariable industrial system with minimal offsetting and a slow response. An internal model control method is proposed for rank-deficient systems with a time delay based on a damped pseudo-inverse. An internal model control was designed to obtain the desired dynamic characteristics of the system by transforming the time-delay system into a system without a time delay, following the Pade approximation approach. By introducing a damping factor, the internal model controller was designed based on a damped pseudo-inverse, since the inverse matrix of the rank-deficient system does not exist. Furthermore, a singular value decomposition was used to analyze the steady-state performance of the system. The selection of the damping factor was also presented, and a μ analysis was made to evaluate the stability of the system. To demonstrate the effectiveness of the proposed method, a crude distillation process with five inputs a... [more]
DA-Based Parameter Optimization of Combined Kernel Support Vector Machine for Cancer Diagnosis
Tao Xie, Jun Yao, Zhiwei Zhou
July 29, 2019 (v1)
Keywords: cancer, classification, combined kernel function, dragonfly algorithm, parameter optimization, support vector machine (SVM)
As is well known, the correct diagnosis for cancer is critical to save patients’ lives. Support vector machine (SVM) has already made an important contribution to the field of cancer classification. However, different kernel function configurations and their parameters will significantly affect the performance of SVM classifier. To improve the classification accuracy of SVM classifier for cancer diagnosis, this paper proposed a novel cancer classification algorithm based on the dragonfly algorithm and SVM with a combined kernel function (DA-CKSVM) which was constructed from a radial basis function (RBF) kernel and a polynomial kernel. Experiments were performed on six cancer data sets from University of California, Irvine (UCI) machine learning repository and two cancer data sets from Cancer Program Legacy Publication Resources to evaluate the validity of the proposed algorithm. Compared with four well-known algorithms: dragonfly algorithm-SVM (DA-SVM), particle swarm optimization-SVM... [more]
Viscoelastic MHD Nanofluid Thin Film Flow over an Unsteady Vertical Stretching Sheet with Entropy Generation
Asad Ullah, Zahir Shah, Poom Kumam, Muhammad Ayaz, Saeed Islam, Muhammad Jameel
July 29, 2019 (v1)
Subject: Other
Keywords: entropy generation, HAM, liquid films, magnetic field, nanofluid, second-grade fluid, thin film, time depending stretching surface
The boundary-layer equations for mass and heat energy transfer with entropy generation are analyzed for the two-dimensional viscoelastic second-grade nanofluid thin film flow in the presence of a uniform magnetic field (MHD) over a vertical stretching sheet. Different factors, such as the thermophoresis effect, Brownian motion, and concentration gradients, are considered in the nanofluid model. The basic time-dependent equations of the nanofluid flow are modeled and transformed to the ordinary differential equations system by using similarity variables. Then the reduced system of equations is treated with the Homotopy Analysis Method to achieve the desire goal. The convergence of the method is prescribed by a numerical survey. The results obtained are more efficient than the available results for the boundary-layer equations, which is the beauty of the Homotopy Analysis Method, and shows the consistency, reliability, and accuracy of our obtained results. The effects of various paramete... [more]
Special Issue on “Membrane Materials, Performance and Processes”
João C. Diniz da Costa, Julius Motuzas
July 29, 2019 (v1)
Subject: Other
This Special Issue on “Membrane Materials, Performance and Processes” of Processes provides a collection of interdisciplinary work representative of the current development in the fields ofmembrane science and technology [...]
Effect of the Heterogeneity on Sorptivity in Sandstones with High and Low Permeability in Water Imbibition Process
Yang Wu, Yixin Zhao, Peng Li
July 29, 2019 (v1)
Subject: Other
Keywords: heterogeneity, neutron radiography, sorptivity, tortuosity fractal dimension
Capillary imbibition in unsaturated rocks is important for the exploitation of tight reservoirs, such as oil and gas reservoirs. However, the physical properties of natural rocks tend to be relatively uneven, mainly in the heterogeneity of material composition and pore space. Reservoir heterogeneity is an important factor affecting the exploitation of oil fields and other reservoirs, which can be evaluated by the pore structure tortuosity fractal dimension DT of rock. The greater the value of DT, the stronger the heterogeneity of sandstone. Two types of sandstone with high and low permeability were selected to study the effect of heterogeneity on the imbibition behavior by using high-resolution X-ray imaging and neutron radiography. Quantitative results of the wetting front position for each specimen were extracted from the neutron images. The wetting front advanced linearly with the power index of time t1/(2DT). Different values of DT were selected to estimate and discuss the effect o... [more]
Extended Utilization of Constraint-Based Metabolic Model in a Long-Growing Crop
Porntip Chiewchankaset, Saowalak Kalapanulak, Treenut Saithong
July 29, 2019 (v1)
Subject: Biosystems
Keywords: biomass components, biomass function, carbon flux prediction, cassava storage root model, constraint-based modeling, long-growing crop, model sensitivity, rMeCBM model, specific storage root growth rate, specific sucrose uptake rate
The constraint-based rMeCBM-KU50 model of cassava storage root growth was analyzed to evaluate its sensitivity, with respect to reaction flux distribution and storage root growth rate, to changes in model inputted data and constraints, including sucrose uptake rate-related data—photosynthetic rate, total leaf area, total photosynthetic rate, storage root dry weight, and biomass function-related data. These mainly varied within ±90% of the model default values, although exceptions were made for the carbohydrate (−90% to 8%) and starch (−90% to 9%) contents. The results indicated that the predicted storage root growth rate was highly affected by specific sucrose uptake rates through the total photosynthetic rate and storage root dry weight variations; whereas the carbon flux distribution, direction and partitioning inclusive, was more sensitive to the variation in biomass content, particularly the carbohydrate content. This study showed that the specific sucrose uptake rate based on the... [more]
Prediction of CO2 Solubility in Ionic Liquids Based on Multi-Model Fusion Method
Luyue Xia, Jiachen Wang, Shanshan Liu, Zhuo Li, Haitian Pan
July 29, 2019 (v1)
Keywords: Carbon Dioxide, ionic liquids, multi-model fusion, prediction, solubility
Reducing the emissions of greenhouse gas is a worldwide problem that needs to be solved urgently for sustainable development in the future. The solubility of CO2 in ionic liquids is one of the important basic data for capturing CO2. Considering the disadvantages of experimental measurements, e.g., time-consuming and expensive, the complex parameters of mechanism modeling and the poor stability of single data-driven modeling, a multi-model fusion modeling method is proposed in order to predict the solubility of CO2 in ionic liquids. The multiple sub-models are built by the training set. The sub-models with better performance are selected through the validation set. Then, linear fusion models are established by minimizing the sum of squares of the error and information entropy method respectively. Finally, the performance of the fusion model is verified by the test set. The results showed that the prediction effect of the linear fusion models is better than that of the other three optima... [more]
High-Temperature Permittivity and Microwave Pretreatment Characteristics of Nickel-Containing Sludge from Battery Production
Zhanyong Guo, Ping Guo, Guang Su, Demei Zhai, Fang Cheng, Fachuang Li
July 29, 2019 (v1)
Keywords: dielectric properties, microwave, nickel-containing sludge
Permittivity is a vitally important parameter for the description of the absorption and heating characteristics of materials under microwave irradiation. In this paper, the permittivity of nickel-containing sludge (NCS), which is created during battery production as a cheap secondary resource, was measured at temperatures from 20 °C to 600 °C at 2.45 GHz using the cavity perturbation method. In addition, the loss tangent (tanδ) and penetration depth (Dp) of microwaves into the material were calculated. The results of the permittivity study show that the dielectric constant (ε′) and dielectric loss factor (ε″) of the NCS increase with increasing temperature. The variations of the loss tangent (tanδ) and penetration depth (Dp) with the temperature can be divided into two parts at 200 °C. The effect of the initial moisture content on the dielectric properties of the material is notably greater than that of the temperature, which was confirmed by the heating curve. After microwave pretreat... [more]
The Effects of Water Friction Loss Calculation on the Thermal Field of the Canned Motor
Yiping Lu, Azeem Mustafa, Mirza Abdullah Rehan, Samia Razzaq, Shoukat Ali, Mughees Shahid, Ahmad Waleed Adnan
July 28, 2019 (v1)
Subject: Other
Keywords: canned motor, computational fluid dynamics (CFD), numerical simulation, three-dimensional temperature field, water friction loss
The thermal behavior of a canned motor also depends on the losses and the cooling capability, and these losses cause an increase in the temperature of the stator winding. This paper focuses on the modeling and simulation of the thermal fields of the large canned induction motor by different calculation methods of water friction loss. The values of water friction losses are set as heat sources in the corresponding clearance of water at different positions along the duct and are calculated by the analytical method, loss separation test method, and by assuming the values that may be larger than the experimental results and at zero. Based on Finite volume method (FVM), 3D turbulent flow and heat transfer equations of the canned motor are solve numerically to obtain the temperature distributions of different parts of the motor. The analysis results of water friction loss are compared with the measurements, obtained from the total losses using the loss separation method. The results show tha... [more]
Recent Advances in Fluid Flow in Fractured Porous Media
Richeng Liu, Sha Lou, Yujing Jiang
July 28, 2019 (v1)
Subject: Other
The fluid flows through both the fractures and pores in deep-seated rock masses, which is of special importance for the performance of underground facilities such as groundwater use and nuclear waste disposal [...]
Analysis of the Excess Hydrocarbon Gases Output from Refinery Plants
Jerzy Szpalerski, Adam Smoliński
July 28, 2019 (v1)
Keywords: industrial gas streams, petrochemical processes, refinery plants, waste gases
The article presents the ideas of maximizing recovery of flare gases in the industrial plants processing hydrocarbons. The functioning of a flare stack and depressurization systems in a typical refinery plant is described, and the architecture of the depressurization systems and construction of the flares are shown in a simplified way. The proposal to recover the flare gases together with their output outside the industrial plant, in order to minimize impact on the environment (reduction of emissions) and to limit consumption of fossil fuels is presented. Contaminants that may be found in the depressurization systems are indicated. The idea presented in the article assumes the injection of an excess stream of gases into an existing natural gas pipelines system. A method of monitoring is proposed, aiming to eliminate introduction of undesirable harmful components into the systems.
Extracting Valuable Information from Big Data for Machine Learning Control: An Application for a Gas Lift Process
Ana Carolina Spindola Rangel Dias, Felipo Rojas Soares, Johannes Jäschke, Maurício Bezerra de Souza Jr, José Carlos Pinto
July 28, 2019 (v1)
Keywords: echo state network, gas lift, Machine Learning, model predictive control (MPC)
The present work investigated the use of an echo state network for a gas lift oil well. The main contribution is the evaluation of the network performance under conditions normally faced in a real production system: noisy measurements, unmeasurable disturbances, sluggish behavior and model mismatch. The main pursued objective was to verify if this tool is suitable to compose a predictive control scheme for the analyzed operation. A simpler model was used to train the neural network and a more accurate process model was used to generate time series for validation. The system performance was investigated with distinct sample sizes for training, test and validation procedures and prediction horizons. The performance of the designed ESN was characterized in terms of slugging, setpoint changes and unmeasurable disturbances. It was observed that the size and the dynamic content of the training set tightly affected the network performance. However, for data sets with reasonable information co... [more]
Application of Electronic Nose for Evaluation of Wastewater Treatment Process Effects at Full-Scale WWTP
Grzegorz Łagód, Sylwia M. Duda, Dariusz Majerek, Adriana Szutt, Agnieszka Dołhańczuk-Śródka
July 28, 2019 (v1)
Keywords: electronic nose, gas sensor array, multidimensional data analysis, odor nuisances, wastewater quality, wastewater treatment processes
This paper presents the results of studies aiming at the assessment and classification of wastewater using an electronic nose. During the experiment, an attempt was made to classify the medium based on an analysis of signals from a gas sensor array, the intensity of which depended on the levels of volatile compounds in the headspace gas mixture above the wastewater table. The research involved samples collected from the mechanical and biological treatment devices of a full-scale wastewater treatment plant (WWTP), as well as wastewater analysis. The measurements were carried out with a metal-oxide-semiconductor (MOS) gas sensor array, when coupled with a computing unit (e.g., a computer with suitable software for the analysis of signals and their interpretation), it formed an e-nose—that is, an imitation of the mammalian olfactory sense. While conducting the research it was observed that the intensity of signals sent by sensors changed with drops in the level of wastewater pollution; th... [more]
Research on Identification of LVRT Characteristics of Photovoltaic Inverters Based on Data Testing and PSO Algorithm
Pingping Han, Guijun Fan, Weizhen Sun, Bolong Shi, Xiaoan Zhang
July 28, 2019 (v1)
Subject: Other
Keywords: LVRT, parameter identification, particle swarm optimization algorithm, PV inverter, real operation data
With the continuous increment of photovoltaic (PV) energy connection into a power grid, the accuracy of control parameters of PV power generation systems becomes the key to the stable operation of the power grid. At present, parameter identification based on an intelligent algorithm is a common means to obtain control parameters. However, most of the data used for identification are simulation data and the identified parameters are difficult to use in practical engineering. Therefore, aiming at the acquisition of low voltage ride through (LVRT) control parameters of PV unit, a method of identification of LVRT parameters of the PV unit is proposed, which combines sensitivity analysis with field measurement. In this paper, the test scheme of the required data is put forward through sensitivity analysis of the identified parameters, and the intelligent algorithm is used to identify the low voltage traverse parameters of the data. Finally, the optimal value is extracted from the identifica... [more]
Synthesis and Characterization of Natural Extracted Precursor Date Palm Fibre-Based Activated Carbon for Aluminum Removal by RSM Optimization
Alfarooq O. Basheer, Marlia M. Hanafiah, Mohammed Abdulhakim Alsaadi, Y. Al-Douri, M.A. Malek, Mustafa Mohammed Aljumaily, Seef Saadi Fiyadh
July 28, 2019 (v1)
Subject: Biosystems
Keywords: aluminum removal, Biomass, date palm fibre, Optimization, powder-activated carbon, wastewater treatment
The Powder-Activated Carbon (PAC) under optimum conditions from a new low-cost precursor Date Palm Fibre (DPF) biomass through a carbonization followed by KOH activation has been synthesized by response surface methodology (RSM) combined with central composite design (CCD). The special effects of activation temperature, time, and impregnation ratio on bio-PAC Aluminum (Al3+) removal and uptake capacity were examined. The optimum conditions for synthesized bio-PAC were found to be 99.4% and 9.94 mg·g−1 for Al3+ removal and uptake capacity, respectively at activation temperature 650 °C, activation time 1h and impregnation ratio 1. The optimum bio-PAC was characterized and analyzed using FESEM, FTIR, XRD, TGA, BET, and Zeta potential. RSM-CCD experimental design was used to optimize removal and uptake capacity of Al3+ on bio-PAC. Optimum conditions were found to be at bio-PAC dose of 5 mg with pH 9.48 and contact time of 117 min. Furthermore, at optimized conditions of Al3+ removal, kinet... [more]
Mechanism and Modelling of Reactive Crystallization Process of Lithium Carbonate
Shaolei Zhao, Jie Gao, Siyang Ma, Chao Li, Yiming Ma, Yang He, Junbo Gong, Fu Zhou, Bingyuan Zhang, Weiwei Tang
July 28, 2019 (v1)
Keywords: crystallization mechanisms, lithium carbonate, multi-response optimization, reactive crystallization, response surface methodology
The reactive crystallization of lithium carbonate (Li2CO3) from lithium sulfate (Li2SO4) and sodium carbonate (Na2CO3) solutions is a key process in harvesting solid lithium, whether from ores, brines, or clays. However, the process kinetics and mechanism remain poorly understood and the modelling of the reactive crystallization of Li2CO3 is not available. Hence, this work aims to determine the kinetics and mechanisms of the nucleation and growth of Li2CO3 reactive crystallization by induction time measurements and to model and optimize the crystallization process using response surface methodology. Induction time measurements were carried out as functions of initial supersaturation and temperature using a laser method. It was found that the primary nucleation mechanism of Li2CO3 varies with solution supersaturations, in which, expectedly, the heterogenous nucleation mechanism dominates at low supersaturations while the homogeneous nucleation mode governs at high supersaturations. The... [more]
Daytime/Nighttime Event-Based PI Control for the pH of a Microalgae Raceway Reactor
Enrique Rodríguez-Miranda, Manuel Beschi, José Luis Guzmán, Manuel Berenguel, Antonio Visioli
July 28, 2019 (v1)
Keywords: control problem, event-based, microalgae, PID, raceway
In this paper, a new solution to improve the traditional control operation of raceway microalgae reactors is presented. The control strategy is based on an event-based method that can be easily coupled to a classical time-driven proportional-integral controller, simplifying the design process approach. The results of a standard Proportional-Integral (PI) controller, as well as of two event-based architectures, are presented in simulation and compared with each other and with traditional On/Off control. It is demonstrated that the event-based PI controller—operating during the whole day instead of only during daytime—achieves a better performance by reducing the actuator effort and saving costs related to gas consumption.
Artificial Neural Networks Approach for a Multi-Objective Cavitation Optimization Design in a Double-Suction Centrifugal Pump
Wenjie Wang, Majeed Koranteng Osman, Ji Pei, Xingcheng Gan, Tingyun Yin
July 28, 2019 (v1)
Keywords: artificial neural network, cavitation optimization, Computational Fluid Dynamics, multi-objective optimization, NPSHr prediction
Double-suction centrifugal pumps are widely used in industrial and agricultural applications since their flow rate is twice that of single-suction pumps with the same impeller diameter. They usually run for longer, which makes them susceptible to cavitation, putting the downstream components at risk. A fast approach to predicting the Net Positive Suction Head required was applied to perform a multi-objective optimization on the double-suction centrifugal pump. An L32 (84) orthogonal array was designed to evaluate 8 geometrical parameters at 4 levels each. A two-layer feedforward neural network and genetic algorithm was applied to solve the multi-objective problem into pareto solutions. The results were validated by numerical simulation and compared to the original design. The suction performance was improved by 7.26%, 3.9%, 4.5% and 3.8% at flow conditions 0.6Qd, 0.8Qd, 1.0Qd and 1.2Qd respectively. The efficiency increased by 1.53% 1.0Qd and 1.1% at 0.8Qd. The streamline on the blade... [more]
Microstructure and Resistivity Analysis of Silver Nanoparticle-Based Crystalline Conductive Films Synthesized using PEG Surfactant
Faisal Mustafa, Muhammad Razwan, Saima Shabbir
July 28, 2019 (v1)
Subject: Materials
Keywords: PEG, resistivity, silver nanoparticles, surfactant
Silver nanoparticle-based crystalline conductive films were synthesized using a simple and environmentally friendly method centered on chemical reduction. A stoichiometric balance of three different molecular weights of polyethylene glycol (PEG) was used as a capping agent. Resistivity, and its correlation with temperature and the particle size of nanoparticle films, was probed. The silver nanoparticles were characterized using thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). Further silver films deposited on a glass substrate were characterized by FESEM, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and resistivity measurements. Particle size distribution and room temperature electrical conductivity were also investigated. The high conductivity of sintered films suggested applications for the ink-jet printing of electronic circuitry on thermally sensitive substrates.
Power Transmission Congestion Management Based on Quasi-Dynamic Thermal Rating
Yanling Wang, Zidan Sun, Zhijie Yan, Likai Liang, Fan Song, Zhiqiang Niu
July 28, 2019 (v1)
Keywords: meteorological parameter, quasi-dynamic thermal rating (QDR), transmission congestion, transmission line
Transmission congestion not only increases the operation risk, but also reduces the operation efficiency of power systems. Applying a quasi-dynamic thermal rating (QDR) to the transmission congestion alarm system can effectively alleviate transmission congestion. In this paper, according to the heat balance equation under the IEEE standard, a calculation method of QDR is proposed based on the threshold of meteorological parameters under 95% confidence level, which is determined by statistical analysis of seven-year meteorological data in Weihai, China. The QDR of transmission lines is calculated at different time scales. A transmission congestion management model based on QDR is established, and the transmission congestion alarm system including conductor temperature judgment is proposed. The case shows that transmission congestion management based on QDR is feasible, which improves the service life and operation flexibility of the power grid in emergencies and avoids power supply shor... [more]
A Process for the Separation of Noble Metals from HCl Liquor Containing Gold(III), Palladium(II), Platinum(IV), Rhodium(III), and Iridium(IV) by Solvent Extraction
Wei Dong Xing, Man Seung Lee
July 28, 2019 (v1)
Keywords: gold, HCl, platinum group metals, solvent extraction
The demand for noble metals is increasing, owing to their excellent chemical and physical properties. In order to meet the demand, the recovery of noble metals with high purity from diverse secondary resources, which contain small amounts of noble metals, is of immense value. In this work, the possibility of the separation of Au(III), Pd(II), Pt(IV), Rh(III), and Ir(IV) by solvent extraction from a synthetic HCl solution is investigated. Only Au(III) was selectively extracted by Cyanex 272 in the HCl concentration range from 0.5 M to 9 M, leaving the other metal ions in the raffinate. The loaded Au(III) in Cyanex 272 was efficiently stripped by (NH2)2CS. The other four noble metals were sequentially separated on the basis of the procedures reported in the previous work. The mass balance showed that about 98% of each metal, except Pt(IV), was recovered by the proposed process. An efficient process for the recovery of the five noble metal ions from the HCl leaching solution of secondary... [more]
Treatment of Saline Water Using Electrocoagulation with Combined Electrical Connection of Electrodes
Abbas A. Al-Raad, Marlia M. Hanafiah, Ahmed Samir Naje, Mohammed A. Ajeel, Alfarooq O. Basheer, Thuraya Ali Aljayashi, Mohd Ekhwan Toriman
July 28, 2019 (v1)
Keywords: desalination, electricity, electrocoagulation, electrode consumption, static anode reactor
Saline water treatment has become increasingly important for drinking water supplies. The aim of this study was to evaluate the ability of the electrocoagulation (EC) process with combined aluminum electrodes in removing various types of salt from water samples collected at Sawa Lake, Al-Muthanna, Iraq. The targeted types of salt include total dissolved solids (TDS), chloride salt (Cl−), bromine (Br−), and sulphate (SO42−). A bench scale consisting of combined EC configurations with static electrodes was employed under combined electrical connections. The effect of the six variables factors, such as applied current density (I), reaction time (RT), pH, temperature (T), stirring speed (Mrpm) and inter electrode distance (IED) were observed to achieve a higher removal of TDS, Cl−, Br− and SO42−. Initial results showed the following optimum operating conditions: I = 2 mA/cm2, RT = 80 min, pH = 8, T = 25 °C, IED = 1 cm and Mrpm = 500. The maximum removal efficiency of TDS, Cl−, Br− and SO42... [more]
Bidding Strategy for Aggregators of Electric Vehicles in Day-Ahead Electricity Markets
Yunpeng Guo, Weijia Liu, Fushuan Wen, Abdus Salam, Jianwei Mao, Liang Li
July 26, 2019 (v1)
Keywords: bidding strategy, economic dispatch, electric vehicle (EV), electric vehicle aggregator, electricity market
To make full use of the flexible charging and discharging capabilities of the growing number of electric vehicles (EVs), a bidding strategy for EV aggregators to participate in a day-ahead electricity energy market is proposed in this work. The proposed bidding strategy is able to reduce the operating cost of the EV aggregators and to handle the uncertainties of day-ahead market prices properly at the same time. Agreements between the EV owners and the aggregators are discussed, and a hierarchical market structure is proposed. While assuming the aggregators as economic rational entities, the bidding strategy is established based on the market prices, extra battery charging/discharging costs and the expected profits. The bidding clearing system will display the current/temporal market clearance results of the day-ahead market before the final clearance, and hence the market participants can revise their bids and mitigate the risks, to some extent, of forecasted market price forecast err... [more]
Showing records 133 to 157 of 303. [First] Page: 1 3 4 5 6 7 8 9 10 11 Last