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A VSC-based Model for Power Flow Assessment of Multi-terminal VSC-HVDC Transmission Systems

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Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1363-1374页

作者： Ricardo Martínez-Parrales Claudio R.Fuerte-Esquivel Boris A.Alcaide-Moreno Enrique Acha Faculty of Electrical Engineering Universidad Michoacana de San Nicolás de Hidalgo(UMSNH) National Center for Energy Control Secretary of Energy Department of Electrical Engineering Tampere University(TU)

This paper puts forward a new practical voltage source converter(VSC)based AC-DC converter model suitable for conducting power flow assessment of multi-terminal VSCbased high-voltage direct current(VSC-MTDC)*** model uses an advanced method to handle the operational limits and control modes of VSCs into the power flow *** new model is incorporated into a unified framework encompassing AC and DC power grids and is solved by using the Newton-Raphson method to enable quadratically convergent iterative *** use of complementarity constraints,together with the Fischer-Burmeister function,is proposed to enable the seamless incorporation of operational control modes of VSC and automatic enforcement of any converter’s operational limits that become violated during the iterative solution ***,a dedicated process for checking limits is no longer ***,all existing relationships between the VSC control laws and their operational limits are considered directly during the solution of the power flow *** applicability of the new model is demonstrated with numerical examples using various multi-terminal AC-DC transmission networks,one of which is a utility-sized power system.

关键词： Complementarity constraint current limit high-voltage direct current(HVDC) voltage source converter(VSC) multi-terminal VSC-HVDC(VSC-MTDC)system power flow

Co-Simulation Research of the Mechanical-Hydraulic-Control Coupling System of ITER Tractor

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Plasma Science and Technology 2009年第3期11卷 334-340页

作者：杨秀清骆敏舟梅涛姚达毛 Institute of Intelligent Machines(iim) Chinese Academy of Sciences University of Science and Technology of China Institute of Plasma Physics Chinese Academy of Sciences

The virtual prototyping models of the mechanical, hydraulic and control system of the ITER tractor were built with CATIA, ADAMS and MATLAB/Simulink respectively according to its heavy load and high precision characteristics, and the data transfer between the different models was accomplished by the integration interface between different software. Consequently the virtual experimental platform for the multi-disciplinary co-simulation was established. A co-simulation study of the mechanical-hydraulic-control coupling system of the ITER tractor was carried out. The synchronization servo control of parallel hydraulic cylinders was implemented, and the tracking control of the preconcerted trajectory of the hydraulic cylinders was realized on the established experimental platform. This paper presents the optimization design and technology rebuilding for the complicated coupling system with its theoretic foundation and co-simulation virtual experimental platform.

关键词： co-simulation mechanical-hydraulic coupling PID control of integral separation hydraulic synchronization servo system

Multiphase modeling of fluid dynamic in ladle steel operations under non-isothermal conditions

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Journal of Iron and Steel Research International 2017年第9期24卷 888-900页

作者： H.Gonzalez J.A.Ramos-Banderas E.Torres-Alonso G.Solorio-Diaz C.A.Hernández-Bocanegra Graduate Program in Metallurgy Morelia Technological Institute(ITM)Morelia Michoacdn 58120Mexico Graduate Program in Engineering Mechanical UMSNHMorelia Michoacdn 58140Mexico CATEDRAS CONACyT Benito JuarezCDMX 03940Mexico

A numerical simulation was performed to study the flow pattern,mixing time and open-eye slag produced by argon gas injection in an industrial scale steel ladle under non-isothermal *** liquid steel remains 5min before the injection,and thermal stratification and convective flows were *** different sequences in stages employing various argon-gas flow rates were *** the first case,a sequence with the highest flow rates of argon was applied,while in the second and the third sequences,the intermediate and the lowest flow rates of argon gas were used,*** determining the chemistry homogenization,the mixing time was computed and analyzed in all three *** was found that the cold steel is located near the walls while the steel with a high temperature is accumulated in the center of the ladle above the argon-gas *** higher and lower flows promote a faster chemistry homogenization owing to the secondary recirculations that are developed closer to the *** results from steel temperature drop show a good concordance with plant trial measurements.

关键词： Thermal stratification Mixing time Open-eye slag Ladle steelmaking Multiphase modeling

Fault activation and induced seismicity in geological carbon storage--Lessons learned from recent modeling studies

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第6期8卷 789-804页

作者： Jonny Rutqvist Antonio P. Rinaldi Frederic Cappa Pierre Jeanne Alberto Mazzoldi Luca Urpi Yves Guglielmi Victor Vilarrasa Energy Geosciences Division Lawrence Berkeley National Laboratory (LBNL) Berkeley USA Swiss Seismological Service Swiss Federal Institute of Technology (ETHZ) Zürich Switzerland GeoAzur University of Nice Sophia-Antipolis Cote Azur Observatory Nice France umsnh-iim Instituto de Investigaciones en Ciencias de la Tierra Morelia Mexico Institute of Environmental Assessment and Water Research (IDAEA) Spanish Council for Scientific Research (CSIC) Barcelona Spain

In the light of current concerns related to induced seismicity associated with geological carbon sequestration(GCS),this paper summarizes lessons learned from recent modeling studies on fault activation,induced seismicity,and potential for leakage associated with deep underground carbon dioxide(CO2) *** simulations demonstrate that seismic events large enough to be felt by humans require brittle fault properties and continuous fault permeability allowing pressure to be distributed over a large fault patch to be ruptured at *** fault properties,which are commonly encountered in faults intersecting multilayered shale/sandstone sequences,effectively reduce the likelihood of inducing felt seismicity and also effectively impede upward CO2leakage.A number of simulations show that even a sizable seismic event that could be felt may not be capable of opening a new flow path across the entire thickness of an overlying caprock and it is very unlikely to cross a system of multiple overlying caprock ***-specific model simulations of the In Salah CO2storage demonstration site showed that deep fractured zone responses and associated microseismicity occurred in the brittle fractured sandstone reservoir,but at a very substantial reservoir overpressure close to the magnitude of the least principal *** conclude by emphasizing the importance of site investigation to characterize rock properties and if at all possible to avoid brittle rock such as proximity of crystalline basement or sites in hard and brittle sedimentary sequences that are more prone to injection-induced seismicity and permanent damage.

关键词： Carbon dioxide(CO_2) injection Fault rupture Induced seismicity Ground motion Leakage Modeling

How successful have the lockdowns been in controlling the(COVID-19/SARS-CoV-2)pandemic-A simulation-based analysis

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第3期12卷 14-39页

作者： Anup Kumar Niraj KrViswakarma Amit Adlakha Kampan Mukherjee Operations and Business Analytics Institute of Management Technology NagpurIndia FMS BHU VaranasiIndia IUU Dehradun India iim Kashipur India

The total number of infections(epidemic size),and the time needed for the infection to die out(epidemic duration),represent two of the main indicators for the measuring gravity of infectious disease epidemics in humans.A few attempts have been made to address the problem of controlling both the epidemic size and duration simultaneously from a theoretical point of view,by primarily using the Optimal control *** this study,a multi-objective optimal control problem has been simulated to gauge the success of the lockdowns in *** accomplish this objective,a system dynamics modeling was used to simulate the Susceptible–Infected–Quarantined–Removed epidemic model.A set of sensitivity experiments for different scenarios allows illustrating the model’s behavior and its value for decision-makers regarding the lockdown *** simulation of the model presents various scenarios,wherein the cost–benefit analysis of lockdown was ***,the lockdown success intensity was defined,post which,the findings indicate that the states of Uttar Pradesh,Kerala,Panjab,Jammu,Kashmir,Haryana,and Bihar have achieved more than 90%lockdown success ***,it was observed that these states could effectively implement lockdowns by strictly enforcing social distancing measures during the early stages of the virus spread,which in turn resulted in the high success rate of lockdowns.

关键词： COVID-19 immunity index lockdown success intensity system dynamic SEIQHRD model

Synthesis of Cu nanoparticles by chemical reduction method

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Transactions of Nonferrous Metals Society of China 2019年第7期29卷 1510-1515页

作者： M. S. AGUILAR R. ESPARZA G. ROSAS Instituto de Investigación en Metalurgia y Materiales UMSNH Morelia Michoacán 58000 Mexico Centro de Física Aplicada y Tecnología Avanzada UNAM Santiago de Querétaro 76230 Mexico

Cu nanoparticles (CuNPs) have been synthesized through an easy route by chemical reduction at room temperature. The Cu^2+ ions were reduced and stabilized with sodium borohydride and polyvinylpyrrolidone, respectively. The effect of the variation of the reducing agent/precursor-salt (RA/PS) ratio on the size and morphology of the CuNPs was evaluated. The synthesized material was studied by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The UV-Vis spectra showed a CuNPs plasmon peak at 569 nm and another peak belonging to Cu2O at 485 nm. XRD analysis showed the fcc-Cu phase with a small amount of fcc-Cu2O compound. SEM and TEM studies displayed that small semispherical CuNPs of approximately 7 nm were obtained at the RA/PS ratio of 2.6. The excess of polyvinylpyrrolidone stabilizer played an essential role in preventing CuNPs oxidation. On the other side, Cu2O polyhedral particles with larger sizes up to 150 nm were identified in the RA/PS ratio range of 2.0-1.84. In addition, Cu2O particles having star morphologies with quantum confinement at their tips were obtained at the RA/PS ratio of 1.66.

关键词： Cu nanoparticles NaBH4 chemical reduction polyvinylpyrrolidone stabilization Cu2O

Limited proteomic response in the marine snail Melarhaphe neritoides after long-term emersion

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Current Zoology 2017年第5期63卷 487-493页

作者： Angel R DIZ Margarita ALVAREZ-RODRiGUEZ Monica R. ROMERO Emilio FOLAN-ALVAREZ Juan GALINDO Department of Biochemistry Genetics and Immunology Faculty of Biology University of Vigo Vigo 36310 Spain Toralla Marine Science Station (ECIMAT) Universidad de Vigo Vigo 36331 Spain Institute of Marine Research (iim) CSIC Vigo 36208 Spain

Rocky intertidal organisms are commonly exposed to environmental gradients, promoting adapta-tions to these conditions. Emersion time varies along the intertidal range and in the supralittoralzone is frequently larger than a single tidal cycle, even lasting for weeks. The planktonic-dispersinggastropod Melarhaphe neritoides is a common species of the high shore, adapted to reduce waterloss in order to survive during long-term emersion. In this study, we investigated the molecular re-sponse, at the proteome level, of M. neritoides collected in high-shore tide pools to a series ofemersion periods, from 8 to 24 days, in laboratory conditions. We compared this response to indi-viduals maintained submerged during this period, because this was their original habitat. We alsoincluded a reversion treatment in the study, in which emersed individuals were returned to the sub-merged conditions. Although we detected an increase in overall protein concentration with longeremersion periods, contrary to general expectation, the two dimensional electrophoresis （2DE）-based proteomic analysis did not show significant differences between the treatments at the levelof individual protein spots, even after an emersion period of 24 days. Our results suggest that themetabolism remains unaltered independent of the treatment carried out or the changes are verysubtle and therefore difficult to detect with our experimental design. We conclude that M. neri-toides could be equally adapted to emersion and submersion without drastic physiologicalchanges.

关键词： daptation, 2DE proteomics, environmental gradient, intertidal zone, metabolic rate depression.

A System Identification-based Modeling Framework of Bidirectional DC-DC Converters for Power Grids

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Journal of Modern Power Systems and Clean Energy 2022年第3期10卷 788-799页

作者： Gabriel E.Mejia-Ruiz Mario R.A.Paternina Juan R.Rodriguez R. Juan M.Ramirez Alejandro Zamora-Mendez Guillermo Bolivar-O. Department of Electrical Engineering National Autonomous University of Mexico(UNAM)Mexico CityMexico Department of Electrical Engineering Center for Research and Advanced Studies(CINVESTAV)GuadalajaraMexico Electrical Engineering Faculty Michoacan University of Saint Nicholas of Hidalgo(UMSNH)MoreliaMexico Engineering Faculty Corporacion Universitaria Minuto de Dios-UNIMINUTOBelloColombia

This paper proposes a system identification framework based on eigensystem realization to accurately model power electronic *** proposed framework affords an energy-based optimal reduction method to precisely identify the dynamics of power electronic converters from simulated or actual raw data measured at the converter’s *** method does not require any prior knowledge of the topology or internal parameters of the converter to derive the system modal *** accuracy and feasibility of the proposed method are exhaustively evaluated via simulations and practical tests on a software-simulated and hardware-implemented dual active bridge(DAB)converter under steady-state and transient *** various comparisons with the Fourier series-based generalized average model,switching model,and experimental measurements,the proposed method attains a root mean square error(RMSE)of less than 1%with respect to the actual raw ***,the computational effort is reduced to 1/8.6 of the Fourier series-based model.

关键词： Dual active bridge eigensystem realization algorithm generalized average model power electronic converter identification

Data mining-based algorithm for assortment planning

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Journal of Management Analytics 2020年第3期7卷 443-457页

作者： Praveen Ranjan Srivastava Satyendra Sharma Simran Kaur Information Technology Indian Institute of Management(IIM)RohatakRohtakIndia Operation and Supply Chain Birla Institute of Technology and Science(BITS)PilaniPilaniRajasthanIndia Computer Science Birla Institute of Technology and Science(BITS)PilaniPilaniRajasthanIndia

With increasing varieties and products,management of limited shelf space becomes quite difficult for ***,an efficient product assortment,which in turn helps to plan the organization of various products across limited shelf space,is extremely important for *** can be distinguished based on quality,price,brand,and other attributes,and decision needs to be made about an assortment of the products based on these *** efficient assortment planning improves the financial performance of the retailer by increasing profits and reducing operational *** techniques can be very effective in grouping products,stores,*** help managers solve the problem of assortment *** paper proposes data mining approaches for assortment planning for profit maximization with space,and cost constraints by mapping it into well-known knapsack problem.

关键词： Retail assortment SKU rationalization data mining