Search results for "Hybrid systems"

showing 10 items of 24 documents

MODELLING OF MEMBRANE PROCESSES: FROM CFD TO PROCESS OPTIMIZATION

2020

LCDdesalinationSettore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciMembrane proceCFDprocess modellingREDhybrid systemsoptimizationED
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A General Methodology for Short-circuit Calculations in Hybrid AC/DC Microgrids

2023

In this paper, the issues related to short-circuit calculations in hybrid AC/DC microgrids are discussed. The reference standard for short-current calculations in DC systems is the IEC 61660, which provides a mathematical formulation of the problem. The standard only includes radial DC grids and does not consider a more complex system, such as meshed DC systems or a hybrid AC/DC microgrid. This paper proposes a generalized approach that can be used independently of the characteristics of the hybrid system. The proposed approach is applied to four test microgrids with different distributed sources and number of nodes and the results are compared with those obtained simulating the same grids …

Mathematical modelsStandardsResistanceShort-circuit currentsVoltageIEC StandardsShort-circuithybrid systemsIndustrial and Manufacturing EngineeringSettore ING-IND/33 - Sistemi Elettrici Per L'EnergiaAC/DC MicrogridsControl and Systems EngineeringMicrogridsElectrical and Electronic EngineeringFault calculationIEEE Transactions on Industry Applications
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Robust control of uncertain multi-inventory systems via linear matrix inequality

2008

We consider a continuous time linear multi inventory system with unknown demands bounded within ellipsoids and controls bounded within ellipsoids or polytopes. We address the problem of "-stabilizing the inventory since this implies some reduction of the inventory costs. The main results are certain conditions under which "-stabilizability is possible through a saturated linear state feedback control. All the results are based on a Linear Matrix Inequalities (LMIs) approach and on some recent techniques for the modeling and analysis of polytopic systems with saturations.

Mathematical optimizationLinear Matrix InequalitiesPolytopeDynamical Systems (math.DS)stock control93xxcontinuous systems linear matrix inequalities linear systems manufacturing systems robust control state feedback stock control uncertain systemsimpulse control inventory control hybrid systemsSettore ING-INF/04 - AutomaticaControl theoryFOS: Mathematicsmanufacturing systemsMathematics - Dynamical Systemslinear matrix inequalitiesstate feedbackTime complexityMathematics - Optimization and ControlInventory systemsMathematicsInventory controlLinear Matrix Inequalities; Inventory systemsLinear systemlinear systemsLinear matrix inequality93Cxx;93xxLinearity93Cxxhybrid systemsEllipsoidComputer Science Applicationsimpulse control; inventory control; hybrid systemsuncertain systemsControl and Systems EngineeringOptimization and Control (math.OC)Control systemBounded functioncontinuous systemsPerpetual inventorycontinuous systems; linear matrix inequalities; linear systems; manufacturing systems; robust control; state feedback; stock control; uncertain systemsinventory controlRobust controlSettore MAT/09 - Ricerca Operativarobust controlimpulse control
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Suspended and attached biomass in an mbr system treating high strength wastewater Loads

2012

abstract

Membrane foulingHybrid systemHybrid systemsEngineering (all)WastewaterMembrane foulingEnvironmental engineeringBiomassEnvironmental scienceMBBRGeneral MedicineEngineering(all)
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Photocatalytic Membrane Reactors in the Conversion or Degradation of Organic Compounds

2009

MembraneMembrane reactorChemical engineeringChemistryPhotocatalysis Hybrid systems MembranesPhotocatalysisDegradation (geology)Photocatalytic degradation
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Matching Economical, Energetic and Environmental Benefits: An Analysis for Hybrid CHCP-Heat Pumps Systems

2006

Abstract The optimization of design and operation of combined heat, cooling and power systems usually leads to select different plant lay-outs and size of components, depending on the adopted optimization criterion (maximum profit or energy saving or minimum environmental impact). This occurs when the current energy prices and the normative provisions supporting cogeneration are not able to coincide with the specific customer’s interest and the overall “social interest” for a reduction in energy consumption and in pollutants’ emissions. At EU level, polygeneration is considered to have a large potential for residential and commercial buildings district network, for the tertiary sector and f…

OptimizationEngineeringHybrid systemsEnergy currentEnergy Engineering and Power TechnologyEconomicComputerApplications_COMPUTERSINOTHERSYSTEMSProfit (economics)law.inventionCogenerationElectric power systemlawEnergy savingSettore ING-IND/10 - Fisica Tecnica IndustrialeEnvironmental impact assessmentProcess engineeringHeat pumpWaste managementTrigenerationRenewable Energy Sustainability and the Environmentbusiness.industryEnergy consumptionFuel TechnologyNuclear Energy and EngineeringHybrid systembusinessHeat pump
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Probabilistic Fuzzy Approach to Evaluation of Logistics Service Effectiveness

2014

Received: 9 September 2014 Abstract Accepted: 11 October 2014 Logistics service providers offer a whole or partial logistics business service over a certain time period. Between such companies, the effectiveness of specific logistics services can vary. Logistics service providers seek the effective performance of logistics service. The purpose of this paper is to present a new approach for the evaluation of logistics service effectiveness, along with a specific computer system implementing the proposed approach – a sophisticated inference system, an extension of the Mamdani probabilistic fuzzy system. The paper presents specific knowledge concerning the relationships between effectiveness i…

Organizational Behavior and Human Resource ManagementOperations researchComputer scienceeffectivenessInferenceParameterized complexityManagement Science and Operations ResearchFuzzy logicIndustrial and Manufacturing EngineeringManagement of Technology and Innovationlcsh:Production management. Operations managementBusiness and International Managementprobability of fuzzy eventService (business)Probabilistic logicConditional probabilityFuzzy control systemService providerReliability engineeringlogistics service providerlogistics serviceprobabilistic fuzzy systemsfuzzy expert systemslogistics companylcsh:TS155-194fuzzy hybrid systemsManagement and Production Engineering Review
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Power Maximization of a PV-Wind HRES via DC-link Voltage Boosting

2009

This paper describes a method for the optimization of a Hybrid Renewable Energy System applied to a low power Photovoltaic-Wind plant. This approach exploits the DC link with a voltage higher than the correspondent value of the batteries, thanks to a suitable DC/DC converter. The goodness of the methodology is firstly proved by means of a novel graphical technique and then verified through numerical simulations. The results are discussed and show that, adopting the proposed technique, a significant increase of the generated power and of the annual energy produced can be achieved.

PV-windHRESSettore ING-IND/11 - Fisica Tecnica AmbientaleDC/DC convertervoltage boostpv-wind hybrid systemsoptimization
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Optimal Impulse Control Problems and Linear Programming

2009

Optimal impulse control problems are, in general, difficult to solve. A current research goal is to isolate those problems that lead to tractable solutions. In this paper, we identify a special class of optimal impulse control problems which are easy to solve. Easy to solve means that solution algorithms are polynomial in time and therefore suitable to the on-line implementation in real-time problems. We do this by using a paradigm borrowed from the Operations Research field. As main result, we present a solution algorithm that converges to the exact solution in polynomial time. Our approach consists in approximating the optimal impulse control problem via a binary linear programming proble…

PolynomialMathematical optimizationUnimodular matrixComputational complexity theoryLinear programmingbusiness.industryImpulse control hybrid systems optimal controlLocal search (optimization)Relaxation (approximation)Optimal controlbusinessTime complexityMathematics
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Modelling hybrid systems for seawater desalination: electromembrane processes (RED, ARED and ED) coupled with RO

2018

The need to reduce energy consumption in seawater reverse osmosis processes has pushed research towards the development of new hybrid systems in which, for example, other membrane processes can be used to pre-treat seawater. Electrodialysis and reverse electrodialysis can act as a dilution step before seawater enters the RO unit, thus leading to an important energy saving in RO. In this work, two coupled models are proposed for the RED-RO and ED-RO system. Each process model was validated before being used for a sensitivity analysis in which the effect of the integration on the cost saving in the overall process was assessed. The analysis was performed by changing (R)ED voltage and RO press…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciSettore ING-IND/19 - Impianti NucleariReverse osmosis Hybrid systems Electromembrane processes Coupled model Cost saving
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