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Home>Products>Journal and Reviews>I.RE.Mo.S.>Latest issue
International Review on Modelling and Simulations - December 2009 - Papers
International Review on Modelling and Simulations - Papers
Vol. 2. n. 6, pp. 611-615
Abstract - Many
economists are convinced that real time pricing (RTP) programs are the
most direct and efficient demand response (DR) programs suitable for
competitive electricity markets and should be the focus of policy
makers. So, it is more efficient for a company to define suitable RTPs.
For this purpose, it is necessary that RTP patterns follow load profiles
of customers. In this paper, a new method for determination of optimum
real-time-price patterns is proposed. This method uses pattern-based
clustering technique to achieve the best typical load profile of
customers. Thereby, RTPs are determined using extracted typical load
profiles.
Keywords: Clustering technique, Demand response programs, Improved weighted fuzzy average K-means, Real time pricing, Typical load profile.
Vol. 2. n. 6, pp. 616-624
Abstract - This paper proposes a configuration for the Dynamic Voltage Restorer (DVR) to compensate deep and long duration voltage sags and swells. The proposed configuration is a rectifier fed inverter, through DC-to-DC boost converter. With this configuration, there is no need for energy storage elements such as batteries which normally occupied large space especially for high power rating DVR and consequently no charging strategies are required. The proposed DVR is based on hysteresis voltage control. The model of the DVR is developed using SIMULINK/MATLAB environment. Time domain simulations of voltage sag and swell have been performed to verify the proposed DVR configuration. In addition, the influence of the hysteresis band and the depth of the voltage sag and swell on the harmonic contents of the load voltage, load current and DVR voltage have been studied. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Dynamic Voltage Restorer (DVR), Hysteresis Voltage Control, DC-to-DC boost Converter, SIMULINK/MATLAB, Voltage-Sourced Converter (VSC), Voltage Sags and Swells.
Vol. 2. n. 6, pp. 625-632
Abstract - With the aim of exploring and evaluating power flow based voltage stability indexes, this study first provides the main features of the ideal index and then introduces some factors for evaluating these features. Afterward five new indexes are suggested. Finally, the suggested indexes and previously introduced indexes are evaluated by the use of the suggested factors. The results of simulations performed on 9-bus and IEEE30-bus network show outperformance of the proposed indexes in comparison to the previous indexes. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Voltage Stability Index, Jacobian Matrix, Power Flow, Singular Value Decomposition.
Vol. 2. n. 6, pp. 633-638
Abstract - Static Synchronous Series Compensator (SSSC) is one of the two converters of the Unified Power Flow Controller (UPFC). It provides the main function of UPFC in controlling the amount and direction of power flow in the transmission lines by varying the additional voltage magnitude, Δv and additional voltage phase shift, . In this work, the SSSC has been constructed using 3-level Neutral-Point-Clamped (NPC) structure in order to reduce the harmonics. The effect of the variation of additional voltage magnitude, Δv and additional voltage phase shift, to the sending end voltage, V2 has been investigated. From the results obtained from simulation and laboratory models, a small THD of less of 2% has been obtained. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Static Synchronous Series Compensator, Space Vector Modulation, Neutral-point-clamped.
Vol. 2. n. 6, pp. 639-644
Abstract - In the recent years and with the strong technological development of semi conductors, the three phase induction motor is one of the most used electric machines in variable speed system in the different field of industry. Good reability of power electronic systems is essential not only for security system and for people but also to reduce coasts of maintenance. The rapid and accurate diagnosis of any system employing electrical drive system remains one of the current problems. This paper presents three methods and fault detection and isolation of an AC drive system under open fault conditions in the inverter through modeling and simulation of the system. The proposed methods are achieved by using open circuit in the inverter. The obtained simulation results show clearly the possibility of extracting signatures to detect and isolate faults. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Diagnosis, Fault Detection, Isolation, Inverter, Induction motor, Simulation.
Vol. 2. n. 6, pp. 645-649
Abstract - This paper describes development of a single phase current- fed DC/DC converter inform unidirectional with using an active clamp. The main feature of purpose converter consists of soft switching, minimization of conduction losses; high efficiency (approximately 98%) out voltage is 350Vdc, turn ratio of transformer is reduced, input current ripple and output voltage ripple are reduced. It also improves EMI and containing less segment and simple of construction. For this converter is designed a novel PWM strategy and implements of a PI controller for voltage regulation. Fast dynamic response; enhance reliability and low Sensitivity is other feature of the proposed converter. Simulation has been done by PSCAD/EMTDC and it confirms efficiency of the proposed converter. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Active clamp, Fuel Cell, ZVZCS, Unidirectional.
Vol. 2. n. 6, pp. 650-656
Abstract - This paper describes one way of assessment of exposure level to electromagnetic fields of secondary electronic equipment or personnel in or close to high-voltage facilities. Assessment of fulfilling criteria regarding allowable values of magnetic flux, according regulations, was gained by numerical calculation and experimental measurement, considering geometrical configuration of high-voltage facility elements. Correct identification of electromagnetic disturbances of transmission lines has for a result optimal geometrical disposition of electronic equipment inside a high-voltage facility. Comparing a calculation results and results of experimental measuring on particular example of high-voltage facility, can lead to a conclusion that expensive measuring can be avoided, through standardization of a mathematical model and through numerical calculation of low-frequency magnetic field distribution even in conditions of the most complex geometry. Having in mind a number of locations where interaction between high-voltage facility and electronic equipment and personnel exists, a clear intention of authors, for reducing expenses of recording interaction level, is visible. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Low-frequency Magnetic Field, Numerical Calculation of Magnetic Field, Electronic Equipment, Line Current.
Vol. 2. n. 6, pp. 657-660
Abstract - This paper presents a study about the influence of both temperature and barrier injecting energy on current voltage characteristics I (V) of a MOS capacity with a nanometric oxide. These characteristics are obtained by a self-consistent resolution of “Poisson” and “Schrödinger” equations. This last one permits to take into account the quantum effects which appear under the thin oxide. The obtained results shows that the Fowler-Nordheim current is inversely proportional to both temperature and barrier injecting energy, whereas, it is so indifferent to the substrate’s type. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Quantum effects, I (V) characteristics, Injecting barrier, Temperature.
Vol. 2. n. 6, pp. 661-666
Abstract - This paper presents the study of impact of sliding mode control speed on the diagnosis process in a short circuit stator. The sliding mode controller is model based approach used to improve the robustness of the control low despite the high influence of the motor parameters and to illustrate the good performance of this technique. These modes of regulators are insensitive with the parametric variation. However, we present a methodology of monitoring of defaults of short-circuits to the stator of a synchronous motor permanent magnet. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Diagnosis, Synchronous Motor, Sliding Mode, Short-Circuits.
Abstract - Accurate and efficient computation of electromagnetic parameters for different conducting bodies represents an essential part of spacecraft modern integrated circuits. In this paper, we will illustrate modeling of inhomogeneous shielded rectangular, circular, triangular, and cylindrical transmission lines using the finite element method (FEM). We specifically determine the capacitance per unit length, inductance per unit length, and characteristic impedance of shielded transmission lines. Also, excellent agreement with some results obtained previously using the analytical formulas and methods, the approximate method, and numerical method is demonstrated. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Capacitance per Unit Length, Characteristic Impedance, Inductance per unit length, Finite Element Method, Shielded Transmission Lines.
Abstract - The phenomenon of soil structure interaction influences the behavior of pile groups loaded vetiquely. This article concerns the determination of the bearing capacity for group of pile by concediring the effect of enclosing the soil between piles entangle. The theoretical tool used is the theorem cinematic theory analysis limit, in the case of a material Coulomb, developing a model in two dimensions and determinedthe limit load for the groupe of pile using the computer code mathcad. The results obtained by this method approached the results obtained by DTU.13-2 that we can conclude that this theory can be applied to calculations of the the limit load for a groupe of pile. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Soil-structure interaction, Vertical loading, Limit load, Kinematics approach, Group of piles.
Abstract - This paper presents procedure of geometrical optimization 110 kV SF6 gas insulated bushing with regards to dielectric toils. Iterative Dirichlet–Neumann sequential procedure was applied in frame of modern hybrid BEM/FEM method. The calculation of gas insulated bushing with BEM/FEM method applying improved sequential Dirichlet-Neumann’s successive underrelaxation method. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Method of successive underrelaxation, Galerkins Weighted Residuals Method procedure, gas insulated bushing, coupled BEM/FEM method.
Vol. 2. n. 6, pp. 683-686
Abstract - Voltage stability is concerned with the ability of a power system to maintain acceptable bus voltages under normal conditions and after being subjected to a disturbance, Using Fuel cells (FCs) have several benefits and in this paper we study the effects of FCs on power systems via simulation a single machine (DG as small gas turbine coupled with a FC) in the DigSilent area for different PF of FC. Different PF for FC obtained with control the DC to AC inverter. We found that by control the PF of FCs, we can increase the limitation of reactive generation of overall system and improve the V-P and V-Q characteristics of overall system. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fuel cell, Distributed generation, Voltage stability, DigSilent.
Vol. 2. n. 6, pp. 687-693
Abstract - In this paper, Lorentz force in Electromagnetic Acoustic Transducers is modeled. Using Finite Element numerical simulation, effect of various parameters on Lorentz force is studied. Genetic Programming is then utilized to convert acquired data to a symbolical model. Model is tested against numerical simulation and a less than ±%5 error is found. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: EMAT, Lorentz Force, Finite Element, Numerical Simulation, Genetic Programming.
Vol. 2. n. 6, pp. 694-699
Abstract - Nowadays by developing technology and invention of various electrical devices, voltage flicker and how to compensate it become more important for the power energy providers. One of the best ways to overcome the flicker problem is to decrease production of it by electrical devices. In this paper the effect of power line conductor and cable’ size on producing voltage flicker in distribution systems is studied. For this purpose, the electric arc furnace (EAF), as one of the biggest flicker producers, is assumed as load and simulated with chaos theory in MATLAB, then by using various kinds of power line conductors and cables and calculating produced power, the effect of power line conductor’s and cable’s size on producing voltage flicker is studied. Simulation results show the importance of cable’s size on production of flicker. In the past, the voltage and short circuit current limitations were merely parameters that effect on choosing cable’s size in distribution system planning. In this paper the effect of voltage flicker on choosing cable’s size and power grid planning will be shown and then the advantage of using cables or conductors with bigger surfaces on decreasing flicker will be proved. Copyright © 2009 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Flicker, Distribution System, Electric Arc Furnace, Cable, Line Conductor.
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