Căutare după Data publicării

Afișează articolele 81-100 of 5652

    • On the Snubber Influence to the Switching and Conduction Losses in a Converter Using Switched Capacitor 

      Judele, Stelian; Solea, Răzvan; Dugan, Viorel ("Dunarea de Jos" University of Galati, 2002)
      The paper deals to design and to compute the snubber parameters influence on the switching and conduction losses of the transistors (IGBT) used as bidirectional switches in a converter with switched capacitor. The converter ...

    • Speed and Rotor Flux Estimation in Speed Sensorless Control of Induction Motor 

      Pană, Teodor; Rusu, Călin ("Dunarea de Jos" University of Galati, 2002)
      The paper compares the performances of several adaptive rotor flux and speed estimation methods used in speed sensorless vector control of induction motor. First, a short review of Luenberger, Gopinath, MRAS, Torque Error ...

    • New Power Optimization Posssibilities 

      Bitoleanu, Alexandru; Popescu, Mihaela ("Dunarea de Jos" University of Galati, 2002)
      In this paper there are given a few mathematical relations for the power analysis in un-sinusoidal regime. If the voltage is sinusoidal and the current is unsinusoidal, the apparent power will be ascertained by the active ...

    • Energetic Macroscopic Representation Applied to an Electrical Urban Transport System 

      Popa, Ioan Şerban; Popescu, Mihai Octavian; Popescu, Claudia ("Dunarea de Jos" University of Galati, 2002)
      An energetic description of the electric transport urban system ASTRAIK 415T is proposed according to a specific formalism. This is used to simulate the trolleybus system, equipped with a chopper and a direct current ...

    • Some Considerations Regarding the Efficiency of the Electromechanical Motion 

      Bivol, Ion; Munteanu, Traian; Lupea, Ionel; Destobbeleer, Eric ("Dunarea de Jos" University of Galati, 2002)
      Control techniques for servo drive which run at variable speed for prolonged time is developed on the base of minimum energy dissipation in a feed-forward structure. The optimal control laws are determinate using the ...

    • Comparison on Sensorless Control of Synchronous Motors 

      Giuclea, Radu; Bogus, Cristian; Kreindler, Liviu (Dunareade Jos University of Galati, 2002)
      The paper compares two different methods for speed and position estimation in AC permanent magnet synchronous motors vector control applications. The first method implies two observer blocks — one for the speed, and the ...

    • Optimal Control Structure for Variable Speed wind Power System 

      Cutululis, Nicolaos Antonio; Munteanu, Iulian; Ceangă, Emil; Culea, Mihai ("Dunarea de Jos" University of Galati, 2002)
      This paper presents an optimal control structure for variable speed, fixed pitch wind turbine. The control objective results from the optimization criterion that includes two contradictory demands: maximization of the ...

    • A Simulation Platform to Model, Optimize and Design Wind Turbines, the Matlab / Simulink Toolbox 

      Iov, Florin; Blaabjerg, Frede; Hansen, Anca Daniela ("Dunarea de Jos" University of Galati, 2002)
      In the last years Matlab / Simulink® has become the most used software for modeling and simulation of dynamic systems. Wind energy conversion systems are for example such systems, containing subsystems with different ...

    • A Diferent Approach in the Parameters' Identification of a Jfet Using Genetic Algorithms 

      Belea, Radu; Beldiman, Liviu ("Dunarea de Jos" University of Galati, 2002)
      The genetic algorithms are developing in three directions: the genetic algorithms theory, the genetic algorithms programming and the study of the problems that can be solved with genetic algorithms. In this paper it is ...

    • Imperfect Data in Database Context. How are they Stored in Extended Relational Databases? 

      Tudorie, Cornelia ("Dunarea de Jos" University of Galati, 2002)
      Building a more accurate reality model requires taking into account imperfect information present in our knowledge and language. This paper presents several aspects of data imperfection in the database context and the ...

    • Activitatea bibliotecilor în 2001-2010 

      Universitatea "Dunărea de Jos" din Galați (2002-2011)

    • A Study Upon Traction Systems for Technological Machines with Auto Propulsion 

      Axinti, Adrian-Sorin (Universitatea "Dunărea de Jos" din Galați, 2003)
      This paperwork presents a comparison of traction systems used for heavy machines that needs to move on public roads. (construction devices, agriculture machines, etc.). Here are presented traction charts implemented on ...

    • About Dynamic Stability Analysis of the Power Regulators With Exactly Hyperbolic Characteristic 

      Gavril, Axinti; Năstac, Silviu; Debeleac, Carmen; Axinti, Adrian-Sorin (Universitatea "Dunărea de Jos" din Galați, 2003)
      Power regulators are attached devices of hydraulic pumps with variable capacity. Theses have the means to modify the pump capacity depending of the pressure from the circuit served by the pump. In this way, it result ...

    • The Character of the Dynamic Processes in the Proportional Servodriving Systems of the Hydraulic Pumps Capacity 

      Gavril, Axinti; Năstac, Silviu; Axinti, Adrian-Sorin; Debeleac, Carmen (Universitatea "Dunărea de Jos" din Galați, 2003)
      The proportional servodriving systems of hydraulics pump capacity are used in many more applications in tehnological equipments driving. Thus, the construction of specialized pumping hydraulics units, like the A10VG and ...

    • Using Dorrenberg Steel in Mchine Industry 

      Ciurea, Aurel (Universitatea "Dunareas de Jos" din Galați, 2003)
      The steels were, are and will be o long period of time the raw material in machine industry. Using of this materials implicate a very good technical performance for each type and theirs compatibility with the working ...

    • Treating Propriety Through Cutting of Metals and Alloys in Cryogenic Condition 

      Ciurea, Aurel (Universitatea "Dunărea de Jos" din Galați, 2003)
      It is known that a base function of cutting environments is to cool the cutting tools, the tooled area and the material that is removed under the shape of chip. But it is also known that beginning with the increase of ...

    • Quality Concrete - Performing Concrete Plants 

      Ionescu, Ștefania; Poiovici, Roza; Tont, Valentin (Universitatea "Dunărea de Jos' din Galați, 2003)
      The buildings compositions quality, as well as resistance, stability and durability imposed by the law 10/1995 depends by the quality of concrete who should fulfil the conditions imposed by the Practical Code NE 012/99. The ...

    • The Dynamics Analysis of the Forced Steady-State for the Vertical Towers Chillers with Internal Axial Flow Fan 

      Drăgan, Nicușor; Debeleac, Carmen (Universitatea "dunărea de Jos" din Galați, 2003)
      This study presents some of the phases of the physical and mathematical models' elaboration of the vertical tower chillers with a single axial flow fan, which are used in social and civil buildings to prepare conditioning air ...

    • The Wear Influence on the Working Condition 

      Simionescu, Cristian-Silviu (Universitatea "Dunarea de jos' din Galaţi, 2003)
      During the operation, any machine, equipment, machine parts, or piece, is submitted to a wear. The evolution in time of the wear size, or, in other words, a real form for the characteristic of the wear depends on ...

    • Dynamic of Industrial Tractors with THM for Construction 

      Sârbu, Laurenţiu (Universitatea "Dunărea de Jos" din Galaţi, 2003)
      Traction calculus is done to determine the main parameters of the equipment’ s engine and transmission designed to achieve the performances imposed in exploitation [1, 2, 3]. One of the base problem of the traction ...