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International Review on Modelling and Simulations  Vol. 5 N. 3---- Part A

International Review on Modelling and Simulations  Vol. 5 N. 3---- Part B

 

 

go to top    International Review on Modelling and Simulations (Vol. 5 N. 3)  - June 2012 - Papers (Part A)

 

 

 

go to top    International Review on Modelling and Simulations (Vol. 5 N. 3)  - June 2012 - Papers (Part B)

 

 

 

 

 

 

 

 

International Review on Modelling and Simulations - Papers (Part A)

 

 

go to top   Application of Feedback Linearization to the Virtual Flux Direct Power Control of Three-Level Three-Phase Shunt Active Power Filter
         by Benaissa A., Bouzidi M., Barkat S.

          Vol. 5. n. 3, pp. 1128-1140

        

Abstract - This paper proposes a virtual flux direct power control-space vector modulation combined with feedback linearization control for three-phase three-level neutral point clamped shunt active filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of two split dc capacitors of the three-level active filter is achieved using three-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with nonlinear control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Three-Level Shunt Active Filter, Direct Power Control, Virtual Flux Concept, Feedback Linearization, Multilevel Space Vector Modulation.

 

 

go to top   A Novel Combination of Direct and Indirect (CoDId) Method of MPPT for Power Losses Reduction
         by Mohd Najib Mohd Hussain, Ahmad Maliki Omar

         Vol. 5. n. 3, pp. 1141-1150

        

Abstract - This paper proposes a novel of maximum power point tracking (MPPT) algorithm to provide high reliability and efficiency on photovoltaic (PV) system by reducing the system power losses. The proposed algorithm is mixed reciprocity of direct methods (“true seeking”) and indirect methods (“quasi seeks methods”). The combination of direct and indirect known as (CoDId) methods resolved the limitation of traditional systems i.e. system which produce the output energy from 5% to 25% less than optimal power. These problems apparently arise from module mismatch, partial shading, MPPT inefficiencies or caused by differences of power tolerance of the modules. The MPPT algorithm modelled in MATLAB environment using System Identification toolbox which incorporates with Stateflow chart to track maximum power point (MPP) of the module. An empirical data of Building Integrated Photovoltaic (BIPV) is used for indirect approach which channeled to simple iteration of direct approach to represent the proposed algorithm. Hence, a single and string connection of PV module have been modelled to proves the validity of proposed technique to harvest maximum power of the system. The actual specifications of Kyocera (KC200GT) and Mitsubishi (MF120EC3) are selected as a model for the PV module that were incorporated with Positive Output Buck-Boost Converter for the simulation purposed. A high power efficiency of the system shows the capability of CoDId method to harvest the maximum energy.
 Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Combination of Direct and Indirect (CoDId) Method, Photovoltaic (PV) System, Maximum Power Point Tracking (MPPT), Mismatch Module, Partial Shading, Module Efficiency, PO Buck-Boost Converter.

 

 

go to top   Design and Implementation of High Frequency Driver for Pulsed Laser Diode and Optimization of Efficiency and ProtectionCircuits
         by M. H. Sarshogh, Mehrdad Jafarboland

        Vol. 5. n. 3, pp. 1151-1158

 

Abstract - In this paper a linear driver with high frequency, efficiency and power is designed and implemented to drive an array of pulsed power laser diodes. The driver’s linear regulator includes a pulsed current source and a proper controller in control loop. This driver generates an optimum rise time, overshoot and ripple current pulsed for laser diode array. Besides the protecting circuits which are required for high power applications are optimized to protect the system against load disconnection and inadmissible increase in pulse width, frequency, duty cycle and current. The resulting current pulse shape and laser diode power output, for a laser diode array that is used in an oscillator amplifier head with 27 laser diodes of 100w power and 20 mj energy are demonstrated.
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Keywords:  Pulsed Power Laser Diode Array, Linear Driver, Regulator, Current Pulse.

 

 

go to top   A Novel Approach for PID Designing for Load Frequency Control System
         by S. Jalilzadeh, M. Azari

         Vol. 5. n. 3, pp. 1159-1164

        

Abstract - The conventional techniques used in distance relay operation are not fast enough in distinguishing between a three phase fault and voltage collapse and this may lead to unintended tripping of protection devices. Therefore, there is a need for fast detection of voltage collapse so as to improve the reliability of distance relay operation. This paper presents an intelligent approach to classify a voltage collapse and a three phase fault for distance relay operation by using the under impedance fault detector and support vector machine (SVM). To illustrate the proposed approach, simulations were carried out on the IEEE 39 bus test system using the PSS/E software. Test results shows that the proposed approach can accurately detect and classify fault and voltage collapse events for correct distance relay operation. To demonstrate the effectiveness of the SVM, a comparison is made with the results obtained from the application of the probabilistic neural network.
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Keywords:  Distance Relay, Under Impedance Fault Detector, Support Vector Machine (SVM), Fault and Voltage Collapse.

 

 

go to top   Tuning of Controllers in Grid-Connected Multilevel Converters
         by E. Robles, S. Ceballos, J. Pou, F. Salcedo, M. Santos

         Vol. 5. n. 3, pp. 1165-1174

        

Abstract - This paper analyzes and compares different control tuning strategies for a grid connected converter in a Back-To-Back (BTB) topology, based on Neutral Point Clamped (NPC) converters. The NPC is modeled and linearized around an operation point characterized by the DC-link voltage and the quadrature current component. In this research, a Voltage Oriented Control (VOC) strategy is used with Proportional-Integral (PI) controllers. Current and voltage control loops are tuned designing fast and simple controllers. It is evidenced that the best tuning method depends on the features of the control loop, therefore, each PI has its own tuning method. Furthermore, the nonlinearity of the DC-link voltage performance shows some particularities in the tuning of the voltage PI that make the method less direct. Finally, the results are verified through simulation models.
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Keywords:  Grid Connected Converters, Multilevel Converter, PI Controller, Tuning Strategies.

 

 

go to top   Generalized Scalar Pulsewidth Modulation Algorithm for N-Level Multilevel Inverter Fed Direct Torque Controlled Induction Motor Drive with Reduced Complexity
         by Chalasani Hari Krishna, T. Bramhananda Reddy, J. Amarnath, S Kamakshiah

         Vol. 5. n. 3, pp. 1175-1183

        

Abstract - In this paper a generalized carrier based pulsewidth modulation (PWM) algorithm is proposed for n-level multilevel inverter fed direct torque controlled induction motor drive. The proposed PWM algorithm does not require angle and sector calculations and hence reduces the complexity involved in the classical SVPWM algorithm. The proposed algorithm uses the concept of imaginary switching times, which are proportional to the instantaneous sampled reference phase voltages. By adding the suitable offset time the modulating waveforms for a n-level inverter are generated. To validate the proposed PWM algorithm, several simulation studies have been carried out on direct torque controlled induction motor drive and results are presented. From the results, it can be observed that the proposed algorithm gives good performance and also it can be observed that as the number of level increases the harmonic distortion in line voltages and currents decreases.
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Keywords: DTC, Generalized PWM, Multilevel Inverter, SVPWM.

 


go to top   A ZCS-ZVS PWM SEPIC for High Step-Up Applications
         by A. Lotfi, M. Niroomand

         Vol. 5. n. 3, pp. 1184-1188

        

Abstract - A ZVS-ZCS PWM SEPIC for high step-Up applications is proposed in this paper. A couple of auxiliary switches work under soft switching conditions. By using this ZVS-ZCS converter topology, zero current turn-on and zero voltage turn-off of the main switch can be achieved. In addition, the auxiliary circuit enhances the energy density of the converter because of feeding the output and it can be matched easily to other kinds of converter & snubber circuits made by capacitor. The performance of the proposed converter is verified through computer-aided simulations and experimental results.
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Keywords: ZVS, ZCS, High Step Up, High Efficiency, SEPIC.

 


go to top   Isolated ZVS High Step-up DC-DC Converter with Interleaving Operation
         by Hyun-Lark Do

         Vol. 5. n. 3, pp. 1189-1195

        

Abstract - An isolated zero-voltage-switching (ZVS) high step-up DC-DC converter with interleaving operation is proposed in this paper. The proposed converter consists of two identical DC-DC converters. Their input stages are paralleled and interleaving control scheme is adopted to reduce input current ripple. In order to raise the voltage gain, output stages are connected serially. Due to this structure, the voltage gain can be increased without large turn ratios of isolation transformers. In addition, voltage doubler structure is selected for the output stage and the voltage stresses of output diodes are confined to half of the output voltage without any snubbers. Power switches and output diodes in the proposed converter can operate with soft-switching. Therefore, the switching losses are significantly reduced and high efficiency is achieved. Steady-state analysis, simulation, and experimental results for the proposed converter are presented to validate the feasibility and the performance of the proposed converter.
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Keywords: DC-DC Converter, Interleaving Operation, Step-Up Converter, Zero-Voltage-Switching.

 

 

go to top   Fuzzy Logic Based Sliding Mode Controller for DC-DC Sepic Converter
         by Azam Salimi, Majid Delshad

         Vol. 5. n. 3, pp. 1196-1201

        

Abstract - This paper presents a modified design of a sliding mode controller based on fuzzy logic for a dc-dc sepic converter. Here a proportional - integral (PI)-type current mode control is employed and a sliding mode controller is designed utilizing fuzzy algorithm. Sliding mode controller guarantees robustness against all variations and fuzzy logic helps to reduce chattering phenomenon due to sliding controller, in that way efficiency increases and error, voltage and current ripples decreases. The proposed system is simulated by MATLAB / SIMULINK. This model is tested under variations of input and reference voltages and it was found that in comparison with conventional sliding mode controllers they perform better.
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Keywords:  Switching Mode Power Supplies, SEPIC Converter, Sliding Mode Control, Robustness, Fuzzy Control, Current Mode Control, Non-Linear Behavior.

 

 

go to top   Diagnostic-Oriented Modelling of Induction Machines with Stator Short Circuits
         by S. Meo, A. Ometto, N. Rotondale

         Vol. 5. n. 3, pp. 1202-1209

        

Abstract - The steady-state behaviour of an induction machine with a symmetric rotor cage and a faulty asymmetric stator is analysed. Three different levels of complexity of the machine model are considered. The complete model takes into account the space harmonics of the air-gap flux density and the time harmonic components, produced by the asymmetric windings, in the stator and cage currents (model A). Then a reduced model is considered (model B): it takes into account the space harmonics of the air-gap flux density, the time harmonic components of the rotor bar currents and the only fundamental component of the stator currents. Finally a reduced model, in which the spatial distribution of the air-gap flux density is assumed sinusoidal, is considered (model C). Numerical computations of the stator currents, performed with model A, B and C are compared and discussed. Some considerations concerning the suitability of such models for diagnostic purposes are developed.
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Keywords:  Asynchronous Machine Diagnostic, Short Circuit, Modelling.

 

 

go to top   Vectorial Control of Linear Induction Machines Taking into Account End-Effects
         by Santolo Meo

         Vol. 5. n. 3, pp. 1210-1215

        

Abstract - The paper proposes a particular vectorial control of linear induction drive that guarantees a de-coupled control of the thrust and of the magnetic machine conditions, taking into account end-effects. The suggested algorithm, thanks to a predictive approach, links directly the space vector of the supply voltage to the reference value of the thrust and of the magnetic machine conditions. The end effects are taken into account by means of a suitable observer proposed by the same Authors and fully depicted in the paper. The obtained analytical formulation of the control algorithm is similar to that of the well known field oriented strategy and therefore easily implemented on microcontroller board. Such formulation of the control algorithm and the goodness of the numerical results prove the feasibility of a vectorial control of LIM taking into account end-effects.
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Keywords:  Vectorial Control, Field-Oriented Control, Linear Induction Motor, End-Effects.

 

 

go to top   Mixed Eccentricity Fault Diagnosis in Saturated  Squirrel Cage Induction Motor
         by A. Chaouch, A. Bendiabdellah

         Vol. 5. n. 3, pp. 1216-1223

        

Abstract - This paper describes the influence of magnetic saturation on the diagnosis of mixed eccentricity fault in squirrel induction motors by a modeling and a simulating work. The model is based on multiple coupled circuits and the modified winding function approach (MWFA) which allows for all harmonics of the magnetomotive force (MMF) to be taken into account. The effect of eccentricity and saturation are included in the calculation of motors inductances by the variation of the air gap length. Spectral analysis of stator current allows us to study and identify the saturation harmonics for the case of a healthy motor and a motor with an eccentricity fault. Our results are then validated by comparison with those experimental results and from existing work. 
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Keywords:  Squirrel Cage Induction Motor, Saturation, Eccentricity, Fault Diagnosis.
 

 

go to top   Hardware Implementing of Hysteresis based 3-Phase Induction Motor Control on FPGA
         by Yousef S. Kavian, Farzad Nekouei

         Vol. 5. n. 3, pp. 1224-1230

 

Abstract - This paper presents designing and implementing of a hysteresis closed loop speed control on field programmable gate array (FPGA) technology for a three-phase induction motor drive system. The PWM signals are generated by a Spartan3-xc3s400 FPGA from Xilinx Inc. and FPGA compares motor speed (process variable) with desired speed (set point) continuously and tries to reduce error signals by generation controlling signals through changing modulation index using an ON/OFF SPWM control algorithm. Experimental results achieved from a typical speed control scheme and comparing them with MATLAB SIMULINK based simulation results demonstrate that FPGA based drive system provides controlling signals properly to track speed set points.
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Keywords:  Hardware Implementing, FPGA, Hysteresis Control, Induction Motor, Speed Control.

 

 

go to top   Stray Capacitance and Sensitivity Coefficients Ratio in Multi Turn of MFCG Coil
         by M. E. Mosleh, M. R. Besmi

         Vol. 5. n. 3, pp. 1231-1238

        

Abstract - A method for stray capacitance modeling of helix magneto flux cumulative generator (HMCG) at high frequency operation is presented. The method is based on analytical approach, which can predict stray capacitance of HMCG generators by using of turn-to-turn and turn-to-liner capacitances and using physical structure of windings. In this paper, an equivalent circuit of HMCG is presented, base on the turn-to-turn and turn-to-liner capacitances.
The overall stray capacitance can be obtained through the use of the equivalent circuits. The method was described by using numerical calculations. The derived expressions can be useful for the design of HMCG. This paper applied the vespiary regular hexagonal (VRH) model to calculate the stray capacitance between conductor wire filament (CWF) of one turn of coil (OTC) and between conductor wire filament and liner and also total capacitance of N-turn of coil (NTC) with single-layer conductor. Also, the sensitivity coefficients’ ratio of total stray capacitance to the turn-liner and turn-turn capacitances are obtained. Finally, the sensitivity coefficients’ ratios of effective parameters are discussed and analyzed. By progress of explosion and volume extension of liner and decrease of the number of turns until the second turn, total capacitance of the generator increases and when there remains only one turn in the circuit, there occurs a descending decrease in total capacitance.
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Keywords:  Multi-Filaments, Sensitivity Coefficients, Single-Layer, Stray Capacitance, Vespiary Regular Hexagonal.

 

 

go to top   Comparison of Neural Learning Algorithm Based On-Line MRAS Rotor Resistance Estimator using Rotor Flux (NLRF-MRAS) and Reactive Power (NLRP-MRAS) for Field Oriented Control of Induction Motor Drive
         by M. Nandhini Gayathri, S. Himavathi, R. Sankaran

         Vol. 5. n. 3, pp. 1239-1253

        

Abstract - The invention of field oriented control of a three phase cage induction motor has enabled its adoption in variety of high performance drive applications demanding independent dynamic control of air gap flux and torque. At the same time, this technique is computationally intensive and is highly sensitive to variations in motor parameters, especially the rotor and stator resistances. Accordingly, maintaining the field orientation in the machine in the presence of environmental changes is a challenging task, necessitating on-line estimation of Rr and Rs parameters. Among the different approaches for parameter estimation proposed during the last decade, MRAS based Rotor Resistance Estimator using Rotor Flux and Reactive Power has gained prominence. In this paper, a detailed study of Neural Learning Algorithm based MRAS Rotor Resistance Estimator using Reactive power (NLRP-MRAS) for retaining field orientation is presented and compared with MRAS Rotor Resistance Estimator using Rotor Flux (NLRF-MRAS). Choice of Reactive power as the adaptive variable makes the Rotor Resistance estimation and there by field oriented control independent of stator resistance variation which is not possible with the rotor flux as the adaptive variable. This scheme also makes the estimation of parameters at low speed quite accurate. The simulation results in MATLAB/SIMULINK platform are presented for different operating conditions to verify the effectiveness of this technique.
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Keywords:  Reactive Power, Rotor Resistance, Rotor Flux, Induction Motor, Neural Learning Algorithm, NLRF-MRAS, NLRP-MRAS.

 

 

go to top   Modeling the Dynamic Behavior of 9-Phase BLDC Motor and Examining the Effect of the Increased Number of Phases
         by Seyed Mohammad Hossein Mousavi, Mehrdad Jafarboland

         Vol. 5. n. 3, pp. 1254-1265

        

Abstract - In this paper, the effect of increased number of phases of brushless direct current motor (BLDC) has been investigated on the improvement of performance of this motor. First, a new model of 9-phase BLDC motor drive is studied and the model will be implemented using Matlab/Simulink software. The motor has been simulated through dynamic modeling and using the switching functions concept. In addition, in order to create constant torque and take advantage of the maximum torque capacity of motor, hysteresis current control method is used in the internal loop of speed and torque control system. Then, the results of simulation, including transient and steady state characteristics, will be compared with 3-phase, 5-phase and 7-phase models of this motor and the advantages and disadvantages of the increased number of phases in this motor will be reviewed. The results of comparison suggest the proposed nine-phase model of this motor to be more efficient in the applications intended in this paper, which enjoy a high performance.
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Keywords:  BLDC Motor, Multiphase, PWM Inverter, Simulation, Speed Control.

 

 

go to top   Evaluation of In-plane Flux Distribution in 3Phase 100kVA Transformer Core
         by Dina Maizana

         Vol. 5. n. 3, pp. 1266-1273

        

Abstract - These papers describe the result of measurement and evaluate the behaviours of in-plane flux distribution on 100kVA 3phase distribution transformer assembled with the combination of 60o-45o T-joint. Methodology that is used in this investigation is measurement of flux distributions in transformer core by using no load test and arrays of search coil in Cold Roll Grain Oriented (CRGO) material of transformer core lamination. The measurement involves the fundamental and third harmonics component of the easy and hard direction of flux density at each location measurement. The instantaneous flux flow through the core within one magnetising cycle is analysed with displaced by 120o in time. The locus of the localised flux distribution throughout the magnetising cycle is illustrated the rotational flux produced in the T-joint region of the three-phase three limbs transformer core. The localized flux density at the outer of combination of 60o- 45o T-joint is 1.4T and rises to be 1.68T at the inner edges of right yoke passes over to the butt joint of middle limb when the transformer core energized at flux density 1.5 T 50Hz. At the same place the high third harmonic of peak in-plane flux is 0.23T. The transfer of flux between lamination takes place until a point is reached where the material in the region butt joint of yoke lamination, which is directly above the butt joint and the flux higher but did nott, reaches saturation.
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Keywords:  Transformer Core, In-Plane Flux, Magnetic Behavior, Locus.

 

 

go to top   Experimental Study and Simulation of the Influence of the Rotor Geometry on the Performances of Solid Rotor Induction Motor
         by Hachemi Mabrouk, Hemsas Kamel Eddine, Kadri Riad, Abdessemed Rachid

         Vol. 5. n. 3, pp. 1274-1281

        

Abstract - This paper presents an experimental investigation and simulation on the effect of the rotor geometry on the performances of a solid rotor induction motor. The practical tests and simulation have been done on five solid rotors (1 smooth and 4 grooved) by making grooves and varying: the grooves number, the grooves depth (constant grooves width), and the grooves width (constant grooves depth).The objective of this study is to examine the influence of the geometric parameter’s solid rotor on the performances of such motor. The experimental and simulation results are exposed by considering two essential parameters: the electromagnetic torque and the power factor.
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Keywords:  Induction Motor, Smooth Solid Rotor, Grooved Solid Rotor, Geometry, Experimental Study, Simulation.

 

 

go to top   Simulation and FPGA Modeling of a Virtual BLDC Motor
         by K. Giridharan, A. Chitra, J. Vanishree, W. Razia Sultana

         Vol. 5. n. 3, pp. 1282-1288

        

Abstract - The Brushless Direct Current (BLDC) motors are widely used in consumer electronics, electric vehicles and medical applications. BLDC motors have many advantages over brushed DC motors and induction motors, such as better speed versus torque characteristics, good dynamic response, higher efficiency and large speed ranges. These applications have made it important to develop BLDC motor controllers. This paper presents the development of a virtual motor, a set of programs that represent the BLDC motor, which is modeled and simulated in LabVIEW. The BLDC motor characteristics are implemented on the Field Programmable Gate Array (FPGA). This is used as a virtual motor for the testing and validation of digital controllers; in addition, this can also be used for educational purposes. Such a virtual motor will allow for realizing motors of various ratings by changing the parameters. This will allow the testing and validation of different controllers, without the risk of damage in extreme conditions of operations.
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Keywords:  BLDC simulation, LabVIEW model, virtual motor, FPGA.

 

 

 

International Review on Modelling and Simulations - Papers (Part B)

 

 

go to top   Augmentation of Electrolyzer Control by SFCL for Isolated Power System Stabilization Using Bee Colony Optimization
         by Theerawut Chaiyatham, Issarachai Ngamroo

         Vol. 5. n. 3, pp. 1289-1295

        

Abstract - Recently, the hybrid diesel generations and renewable energy sources which consist of wind turbine generators and fuel cells equipped with electrolyzers (EZ) have been proposed for isolated power systems. In this hybrid system, the EZ can be controlled to rapidly absorb the fluctuating power output from wind generators in addition to the hydrogen production for fuel cells. Nevertheless, under the occurrence of the severe faults in the system, the EZ may fail to absorb the transient power fluctuation which may result in the system instability. To enhance the control effect of EZ, this paper applies the resistive type superconducting fault current limiter (SFCL) for stabilization of an isolated power system with hybrid wind/fuel cell and EZ/diesel generations. The bee colony optimization is automatically applied to achieve the optimal resistance value of SFCL and power controller parameters of EZ based on the minimization of power fluctuation. Simulation study confirms that the SFCL not only suppresses the transient power fluctuation considerably, but also augments the EZ control performance robustly against severe faults, high load demands, and various wind power patterns.
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Keywords:  Superconducting Fault Current Limiter, Power System Stability, Fuel Cell, Electrolyzer, Bee Colony Optimization.

 

 

go to top   Energy Control of Dynamic Voltage Restorer for Voltage Sag Mitigation
         by A. O. Al-Mathnani, M. A. Mohd Ali, A. Mohamed, H. Shareef, M. A. Hanan

         Vol. 5. n. 3, pp. 1296-1300

        

Abstract - Voltage sag is one of the very severe power quality (PQ) problems encountered by the customers and utilities. Dynamic voltage restorer (DVR) is one of the devices that compensate PQ problems of the loads against sags. The energy storage in the DVR is limited and cannot inject large amount of active power to the system during the sag. The objective of this paper is to control the exact amount of active power from the DVR and to avoid the increase in the injected voltage amplitude so that the voltage magnitude of the load is kept at 1p.u. It can be achieved by controlling the angle between the injected voltage and the load voltage. In this paper a new controller is proposed to control the energy source of the DVR. The proportional integration (PI) and phase locked loop (PLL) controller are used to track the signal and regulate the load voltage. The Photovoltaic (PV) source is also incorporated to charge the energy source and maintain dc voltage at the nominal value. The results show that the proposed controller can control the exact power injection during the sag. The dc magnitude is obtained by connecting the external source directly to the DVR with the energy source capacitor (ESC).
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Keywords:  DVR, PI, PLL and PV

 

 

go to top   V2G-Based PHEV for Load-Frequency Control and its Capacity Reduction Effect on BESS in A Smart Grid with Wind Power Penetration
         by Issarachai Ngamroo

         Vol. 5. n. 3, pp. 1301-1307

        

Abstract - The increasing penetration of wind power in the future smart grid may considerably affect the system frequency. Especially, the frequency fluctuation may be severe when the capacity of generators for load-frequency control (LFC) is insufficient in the nighttime. In general, the battery energy storage system (BESS) is used to alleviate the frequency fluctuation. Nevertheless, the installation cost of BESS with large capacity is very high. On the other hand, in the demand side, the installation of plug-in hybrid electric vehicles (PHEV) tends to increase significantly. The PHEV is normally plugged into the home outlet in the nighttime. Based on the vehicle-to-grid (V2G) control, the distributed batteries installed in PHEVs can be applied to LFC. As a result, the required capacity of BESS installed in the system can be reduced. This paper proposes the new contribution of the PHEV based on V2G control not only to alleviate frequency fluctuation in a smart grid with large wind farms, but also to reduce the BESS capacity. In the PHEV model, the charging schedule and battery state of charge are taken into account. To guarantee the well cooperative control of PHEV, BESS and conventional frequency controller, the proportional-integral parameters of BESS and frequency controller are tuned by the particle swarm optimization while the V2G control of PHEV is performed. Simulation study confirms that the PHEV can effectively cooperate with BESS and frequency controller for alleviation of frequency fluctuation. Furthermore, it significantly reduces the required capacity of BESS.
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Keywords: Load-Frequency Control, Plug-In Hybrid Electric Vehicle, Battery Energy Storage System, Vehicle-To-Grid, Smart Grid, Particle Swarm Optimization.

 

 

go to top   Assessment of Voltage Stability Margin Constrained by Electricity Market Uncertainties
         by Sara Nourollah, Abolfazl Pirayesh

         Vol. 5. n. 3, pp. 1308-1312

        

Abstract - : Because of less regulation and more uncertainties in an open access power system, voltage stability analysis has become a challenging problem for independent system operators. It is known that Loading Margin Index (LMI) is the most basic and widely accepted index of voltage collapse in security studies of power systems. In this paper an algorithm for calculating the expected value of LMI considering uncertainties of consumer's loads, offers by generation companies and the reliability of network elements is proposed. The method is based on Monte Carlo Simulation (MSC) and the results on IEEE 24-bus RTS system are included in the paper. The sensitivity of the voltage stability margin to uncertainty modeling is presented and output parameters calculated through MCS are compared with the indices assessed by deterministic i.e., the expected values of the input parameters.
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Keywords:  Electricity Market, Uncertainties, Loading Margin Index, Network Stability.

 

 

go to top   Optimal Reactive Power Dispatch Using Imperialist Competitive Algorithm (ICA)
         by V. Rashtchi, S. H. Rafiei

         Vol. 5. n. 3, pp. 1313-1321

        

Abstract - In this paper, Imperialist competitive algorithm (ICA) was employed as one of the techniques to solve optimal reactive power dispatch (ORPD) problem. Imperialist Competitive Algorithm (ICA) is one of the recent meta-heuristic algorithms proposed for solving optimization problems. It is based on a socio-politically inspired optimization strategy. The problem formulation included a continuous variable (generator voltages) and a discrete variable (transformer tap ratios and the amount of reactive compensation devices). The objective function was power transmission loss. This technique was tested on the standard IEEE 30-bus to demonstrate the applicability and efficiency of the proposed algorithm. The results were compared with those of another algorithm reported in the literature. The simulation results showed that ICA can be efficiently used for the ORPD problem.
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Keywords:  Imperialist Competitive Algorithm, Optimal Reactive Power Dispatch, Loss Minimization.

 

 

go to top   An Adaptive Filter for Noise Cancelling in Mammography Images Based on Cellular Automata
         by H. Farrokhbakht, A. Masoumzadeh Tork, E. Yazdan Talab, H. Ramezanpour, G. Darmani

         Vol. 5. n. 3, pp. 1322-1326
        

Abstract -  In recent years, several techniques based on repetition of the image are used to remove noise. In this paper a new method based on Cellular Automata for image noise removal in mammography images is recommended. We present a new formulation that makes improvements. The formulation uses a neighborhood with sizes and format adapted to the features of the image on reconstruction. We demonstrated through experiments and comparison with other common used techniques that this procedure produces excellent results for the problem of restoring true color images
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Keywords:  Cellular Automata, Mammography Images, Neighborhood, Noise Reduction, Repetition.

 

 

go to top   Study of a Pendulum in Vivo Electromechanical Generator to be Used in a Knee Prosthesis
         by Sylvie Turri, Mohamed Benbouzid, Abdeslam Mamoune, Sylvie Breton

         Vol. 5. n. 3, pp. 1327-1334
        

Abstract -  This paper presents the principle and the energy potential of an original electromechanical generator that uses human body natural motions during walking, in order to create an autonomous generator. This in vivo and noninvasive system is intended to be used in intelligent knee prosthesis. As the combined human, mechanical, and electrical phenomena are very significant, a mechanical and an electrical study are then carried to evaluate the recoverable power.
 Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Human motion, human-powered systems, direct drive generator, knee prosthesis.

 

 

go to top   Numerical Simulation of Flow over Semicircular Cavity
           by Nor Azwadi Che Sidik, Mehran Salehi

           Vol. 5. n. 3, pp. 1335-1338

        

Abstract - – A numerical technique to predict channel flow with semi-circular cavity is presented. The method is based on improved finite difference scheme to achieve higher order of accuracy in space. After a description of the simulation principle, we examine the structure of vortices inside the cavity located on the channel floor. As a test case, a horizontal pipe with semi-circular cavity was investigated at wide range of Reynolds numbers. Results concerning the flow behavior are presented. Comparisons are made in terms of streamlines plots at each Reynolds numbers, revealing that the structure of vortices significantly dependence on the dimensionless parameter of Reynolds numbers.
 Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Finite Difference, Cubic Interpolated Method, Channel Flow, Semi-Circular Cavity, Reynolds Number.

 

 

go to top   Numerical Prediction of Mixed Convection Heat Transfer in an Enclosure
         by Nor Azwadi Che Sidik, Mehran Salehi

         Vol. 5. n. 3, pp. 1339-1343

 

Abstract - In this article the transport mechanism of laminar mixed convection in a shear and buoyancy driven cavity flow with locally heated lower wall and moving cooled sidewalls is numerically studied using cubic interpolation profile method. This study focused on the interaction of forced convection with natural convection. The heat is locally introduced into the cavity with the dimensionless value of ԑ=1/5 of the non dimensional length of the bottom wall. Studies were conducted on the effect of mixed convection parameter Gr/Re2 (known as Richardson Number) in the range of 0.1-10. The results were illustrated in the form of streamline and isotherms. Three different regions can be detected as the Richardson number is increased: forced convection, mixed convection and natural convection.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Mixed Convection, Computation, Cubic Interpolation Profile.

 

 

go to top   Prediction of Particle Dynamics in Lid-Driven Cavity Flow
         by Ali Akbari Sheldareh, Arman Safdari, Mohammad Pourtousi, Nor Azwadi Che Sidik

         Vol. 5. n. 3, pp. 1344-1347

        

Abstract - The prediction of the flow of solid particle through fluid has been an important research topic in the past decades. The difficulties arise to understand the interaction between the particle and surrounding fluid. Therefore, in the present study, the Cubic Interpolated Pseudo-Particle Navier Stokes equation (CIPNSE) was applied to investigate the two-dimensional square lid driven cavity flow of water at wide range of Reynolds numbers. The CIPNSE scheme was used to solve hyperbolic term of the vorticity transport equation. In the CIPNSE scheme, the gradient and the value of the vorticity at the nodes are determined and the stream function is then determined using the vorticity equation. It is discovered that the numerical simulation of CIPNSE provided a very good agreement with the established benchmark results by previous researchers. Then, in order to predict the velocity and position of the particle in the fluid flow, we applied the 4th order Runge-Kutta method to solve the effect from the drag and gravitational forces on the particle.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Solid Particle, Navier-Stokes, Cubic Interpolated Pseudo Particle (CIP), Lid-Driven Cavity, Particle Collisions, Numerical Methods.

 


go to top   Frequency Modulation Response for Effective Dielectric Response of New Nanocomposite Liquids
         by A. Thabet, A. Z. El-Dein, N. M. Youssef

         Vol. 5. n. 3, pp. 1348-1355

        

Abstract - This paper has been investigated an equivalent circuit model for evaluating the dielectric relaxation frequency and the dielectric strengths; it has been succeeded in studyingcharacteristics of newnanocomposite liquids and enhanced their dielectric and electrical properties. Thus, this paper has been studied the effective permittivity prediction of adding various types and percentages of nano-particles (TiO2, SiO2, Al2O3, ZnO, MgO, LiTaO2, Graphite, and Clay) for formulatingnewnanocomposite liquids; these new nanocompositesliquids have been enhanced dielectric and electrical properties with varying frequencies. Finally, it has been explained that the characterization of dielectric relaxation frequency and the dielectric strengths of newnanocomposite liquids by usingnano-particles basedon advanced used recent model thatdiscussed the observed dielectric relaxation frequency or dielectric relaxation time depends on the concentration of the doped nano-particles and so their electric and dielectric properties. 
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Keywords: Dielectric constant, Nanocomposite liquids, Frequency response, Nano-fillers.

 

 

go to top   Study and Comparison of Fuzzy Logic and PI Controller Based on Pressure Control System
         by Prabhu Ramanathan, A. Arjun, Kochuthomman J. Mampilly, Marimuthu R., Sudha Ramasamy

         Vol. 5. n. 3, pp. 1356-1359

        

Abstract - This project discusses the implementation of pressure control on a real time process using fuzzy logic controller. This project aims to develop a control strategy using a fuzzy based controller as an alternative to the existing PI controller in NI LabVIEW. It consists of controlling a certain process in a much simpler and easy manner by taking the control action. This involves designing and tuning of the membership functions and input/output rules. 
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords: Fuzzy logic Control, PI controller, Membership function, Pressure Control system.

 

 

go to top   Dynamic Investigational Using the Spectral Chart Wizard and Modal Testing Data in Rotors Systems
         by H. Al-Khazali, M. Askari

         Vol. 5. n. 3, pp. 1360-1367

        

Abstract - Structural design in the mechanical engineering world involves a wide variety of applications. One aspect of mechanical structures is that they can be used in moving, dynamic situations in rotor system. This can make the design process more complicated, but modern tools in the analytical regime make the engineering process easier. Experimental results indicate invariable fault features embedded in vibration observations can be effectively captured and different fault patterns (for example imbalance, impact and loose foundation) can be correctly classified, both of which imply great potential of the proposed the Spectral chart (Map) Wizard and Modal Testing Data classifier in fault diagnosis of rotor systems that be used in this research. Getting the evolution of a phenomenon with these techniques requires long and repetitive procedures. Waterfall plug-in Spectral Map Wizard adds a new dimension to your results view point. This specific plug-in is able to collect and to synchronize all data coming from the plug-in analyzers in a stack. Results are arranged regarding the different references (RPM, Time, and levels) and represented in 3D or profiles views. The experimental technique used thus far is called Modal Testing; the technique has recently been applied to rotating structures. This paper presents a new method for updating an analytical model using experimental data, by illustrates the results of the experimental modal analysis to provide the best order signal is resample in function of the precise tachometer and then angular domain blocks are converted to the order domain, you will get the right results immediately that could help the designers to have better understanding of rotor performance at the system design stage.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Dynamic Rotor, Modal Data, Spectral Map, Tachometer, Waterfall.

 

 

go to top   Precise Non Linear Modeling of Flexible Link Flexible Joint Manipulator
         by M. Pala Prasad Reddy, Shihabudheen K. V., Jeevamma Jacob

         Vol. 5. n. 3, pp. 1368-1374

        

Abstract - This paper describes the complete dynamic model of a flexible link-flexible joint (FLFJ) manipulator clamped at its actuated base and carrying a payload at its end point. Dynamic model is derived based on combined Euler-Lagrangian and assumed modes approaches. In particular, damping and friction effects have been included in addition to rotor inertia and joint flexibility while modeling. This model is complete even if the effect of gravity and shear deformation are neglected because of the flexible nature of the link. Numerical Simulations are performed in time domain with bang-bang torque input applied at its actuator to show the free vibration behavior of the modeled system. Performance of the system is evaluated by varying payloads and the effect of joint flexibility and damping is also addressed.
Copyright © 2012 Praise Worthy Prize S.r.l. - All rights reserved

 

Keywords:  Flexible Link Flexible Joint, Assumed Mode Method, Rotor Inertia, Payload, Structural damping.

 

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