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International Review on
Modelling and Simulations
(IREMOS)
April 2013
(Vol. 6 N. 2)








     Part A - Part B
 

    Analysis of Soft Switching Interleaved Boost Converters for Photovoltaic (PV) Systems Using MATLAB Simulation

    by P. Manimekalai, R. Harikumar

    Vol. 6. n. 2, pp. 311-316

     

    Abstract - In this paper the performance analysis of Zero Voltage Switching (ZVS) interleaved converter, Zero Current Switching (ZCS) interleaved converter and soft switching (resonance) interleaved converters for PV power generation system is carried out using MATLAB/SIMULINK simulation. The simulation results were compared based on efficiency, harmonic distortion and settling time. Perturb and Observe MPPT (maximum power point tracking) control is used for simulating the model.

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    Keywords: Photo-Voltaic Power Generation System, Interleaved Boost Converters, Distortion and Efficiency Analysis.

     

    Soft Switching Scheme for a Post-Regulated Current-Fed Push-Pull Converter

    by Ajith Vijayan, K. Deepa, M. Vijaya Kumar

    Vol. 6. n. 2, pp. 317-322

     

    Abstract - A high-efficiency post regulation method for a zero-voltage and zero-current switching (ZVZCS) current-fed push–pull converter is presented. An auxiliary transformer is incorporated as a post regulator. An additional voltage is either added or subtracted by the regulator to the output filter of the push-pull converter. An auxiliary regulator controls this transformer and it handles only a percentage of the total output power. Therefore, compared to a normal pre-regulator, higher efficiency is obtained. Since the converter is designed for high operational frequency the size and weight of the converter can be reduced and in order to reduce the switching losses, soft switching techniques have been employed. The remarkable feature of the paper presented is that zero voltage and zero current switching is not affected in any of the working conditions.

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    Keywords: DC-DC Isolated Converter, Post Regulator, ZVZC Switching, Push-Pull Converter.

     

    Design and Implementation of 30W DC-DC Converter for Aerospace Application

    by T. Deepti, K. Deepa, M. Vijay Kumar

    Vol. 6. n. 2, pp. 323-328

     

    Abstract - The DC-DC converter of a Spacecraft is one of the vital components of a satellite, which has a major role in ensuring the complete success of the mission. For providing a regulated voltage to various subsystems of satellites with variation in input voltage, DC-DC converter comes in picture. This paper presents the design and implementation of 30W flyback converter for providing supply for the telemetry tracking transmitter subsystem of the satellite. The input EMI filters responses and compensator for PWM UC1825 is simulated in MATLAB. The requirements for space applications are taken into consideration while designing and is successfully implemented.

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    Keywords: Pulse Width Modulation (PWM), Discontinuous mode (DCM), Continuous mode (CCM).

     

    Photovoltaic Power Generation Using Interleaved Soft Switching Boost Converter-Cascaded H-Bridge Inverter

    by V. Indragandhi, P. Veena, R. Jeyabharath

    Vol. 6. n. 2, pp. 329-335

     

    Abstract - In this paper, we deal with photovoltaic power generation using cascaded H-bridge inverter fed from interleaved soft switching boost converter. The proposed H-bridge inverter approach employs the minimum number of devices. In this approach, five-level H-bridge inverter will reduce the harmonic distortion, it improves the output voltage rating and minimize the necessity of filter. Multisampling technique is adopted for reducing the switching delay and it maximizes the performance of controller. Zero Voltage and Zero current switching methods are used to decrease the switching loss in DC/DC conversion. Interleaved operation of boost converter will reduce the switching losses. Suitable resonant components has been designed and current ripples are minimized significantly. In this paper, results of the complete power conditioning system has been analyzed, verified and presented using MATLAB/SIMULINK software tools.

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    Keywords: H-Bridge Inverter, Interleaved Boost Converter, MPPT, PV Cell, Soft Switching.

     

    Isolated High Boost DC-DC FLYBACK Converter

    by A. Gopi, N. S. Harikrishna, R. Saravanakumar

    Vol. 6. n. 2, pp. 336-341

     

    Abstract - This paper presents isolated high boost dc-dc flyback converter with high voltage gain suitable for renewable energy source. The circuit consists of active clamp circuit and boost converter with isolated transformer. The circuit employs capacitors are charged in parallel and discharged in series by isolated transformer inductors. The active clamp circuit is used during the turn off-period to reduce the voltage spike on power switch. To achieve high output voltage gain the flyback converter output terminal and boost converter output terminal are connected in serially with the isolated inductors with less voltage stress on controlled power switch and power diodes. PSIM software has been used for simulation. Hardware model implemented and tested in the laboratory.

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    Keywords: DC-DC Flyback Converter, Active Clamp Circuit, PSIM, Pulse-Width Modulation.

     

    Modeling, Simulation and Harmonic Reduction of three-phase Multilevel Cascaded Inverters with SVPWM for Photovoltaic System

    by M. Valan Rajkumar, P. S. Manoharan

    Vol. 6. n. 2, pp. 342-350

     

    Abstract - This paper presents a control for a three-phase an eleven-level cascaded H-bridge inverter for photovoltaic (PV) system. The maximum power point tracking (MPPT) is capable of extracting maximum power from the PV array connected to each DC link voltage level. The MPPT algorithm is solved by fuzzy logic controller. Space vector pulse width modulation (SVPWM) algorithm uses a simple mapping to generate gate signals for the inverter. This is done to achieve high dynamic performance with low total harmonic distortion (THD). The validity of the system is verified through MATLAB/Simulink and results are compared with three-phase three-level, five-level, seven-level and nine-level cascaded H-bridge inverter for PV system in terms of THD. Finally, simulation results are presented to verify the effectiveness and accuracy of the proposed system.

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    Keywords: Photovoltaic (PV) System, Cascaded H-Bridge Multilevel Inverter, Space Vector Pulse Width Modulation (SVPWM), Fuzzy MPPT, Total Harmonic Distortion (THD).

     

    Active Clamp Zero Voltage Switching Multiple Output Flyback Converter with Voltage Doubler

    by K. Deepa, Sanitha Mary Kurian, Vijaya Kumar M.

    Vol. 6. n. 2, pp. 351-359

     

    Abstract - This paper proposes a multi output zero voltage switching flyback converter topology with actively clamped switch and voltage doubler circuit. Flyback is the most popular topology for isolated power supply. It can provide multiple isolated outputs with a single switch and has lesser number of component counts. But it suffers from major drawback of high switch current stress high eddy current loss in the air-gap area, a large transformer core, and potential EMI problems. Now a day the latter is overcome by soft switching commutation techniques zero voltage switching (ZVS) or zero current switching (ZCS).But the device still suffers from excessive voltage stress. To triumph over these shortcomings an active clamp flyback converter is proposed. Here the active clamped switch introduced is turned on at zero voltage, this action discharges energy from active clamp capacitor to transformer leakage inductance that is then used to discharge capacitor across the switch thus bringing down voltage across the switch to zero before turn on. The capacitor also acts as clamp that avoids excessive voltage ringing across the switches. The proposed converter has a voltage doubler rectifier in the secondary. So no dissipative RC snubber across the diode is needed and thus high efficiency, low noise output voltage can be realized. The operating principle and analysis of proposed converter are discussed in this paper in detail. The closed loop simulation with fuzzy logic controller is also presented and the analysis of the converter in terms of efficiency and regulation are analysed in detailed.

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    Keywords: Active Clamp Flyback Converter, Voltage Doubler Rectifier, Zero Voltage Switching (ZVS).

     

    A Luenberger State Observer for Stator Resistance Estimation in Sensorless Induction Motor Drives

    by DJ. Cherifi, Y. Miloud, A. Tahri

    Vol. 6. n. 2, pp. 360-369

     

    Abstract - The primary objective of this paper is to elimination of the problem of sensitivity to parameter variation of induction motor drive. The proposed sensorless strategy is based on an algorithm permitting a better simultaneous estimation of the rotor speed and the stator resistance including an adaptive mechanism based on the lyaponov theory. To study the reliability and the robustness of the sensorless technique to abnormal operations, some simulation tests have been performed under several cases. The proposed sensorless vector control scheme showed a good performance behavior in the transient and steady states, with an excellent disturbance rejection of the load torque.

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    Keywords: Induction Motor Drive, Field-Oriented Control, Adaptive Speed Observer, Stator Resistance Estimation.

     

    Neural Network Based Modeling and Predictive Position Control of Traveling Wave Ultrasonic Motor Using Chaotic Genetic Algorithm

    by Mohammad Jahani Moghaddam, Hamed Mojallali

    Vol. 6. n. 2, pp. 370-379

     

    Abstract - Traveling wave ultrasonic motors (TWUSMs) possess heavy nonlinearities and load-dependent characteristics such as dead-zone. Therefore, modeling and controlling of TWUSMs are difficult and challenging tasks. In this paper, a Hammerstein model is proposed for rotary TWUSM (RTWUSM) which is proper for control purposes. This model is constructed using the chaotic genetic algorithm (CGA) and radial basis function neural network (RBFNN). Then, Model Predictive Controller (MPC) with online CGA optimizer is applied based on the presented model. Simulation results and their validation with the data derived from experiments demonstrate the effectiveness of the proposed model and controller.

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    Keywords: Traveling Wave Ultrasonic Motor, Model Predictive Control, Chaos Theory, Genetic Algorithm, Neural Network.

     

    Position Sensorless Robust Control of PMSM Using the Extended Kalman Filter Algorithm

    by K. Dchich, A. Zaafouri, A. Chbeb, M. Jemli

    Vol. 6. n. 2, pp. 380-386

     

    Abstract - This paper deals with stabilizing feedback control design for an uncertain Permanent Magnet Synchronous Motor (PMSM). The proposed approach is based on the use of quadratic Lyapunov function for stability study and the Extented Kalman Filter (EKF) for both position and speed estimation. Then, a state feedback robust control is successfully applied and good dynamic performances are obtained.

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    Keywords: Permanent Magnets Synchronous Machine, Extended Kalman Filter, Position and Speed Estimation, State Feedback Robust Control.

     

    Sensorless Sliding Mode-Backstepping Control of the Induction Machine, using Sliding Mode-MRAS Observer

    by M. Moutchou, H. Mahmoudi, A. Abbou

    Vol. 6. n. 2, pp. 387-395

     

    Abstract - In this paper we present a robust control of rotor speed and rotor flux of induction motor. The design of control is based on Backstepping and Sliding Mode techniques, which offers better performance. In this scheme the induction machine is represented by a model described in the fixed stator frame with rotor flux, stator current and rotor speed as stat variables. The backstepping technique is appropriate for such as non linear system. The outputs control can be derived step by step, over virtual-control, through appropriate Lyapunov functions. In order to improve the robustness of this control, we estimate a rotor speed and rotor flux components using a specific MRAS (Model reference adaptive system) observer, based on sliding mode technique. Simulation results are realized and presented to validate and to prove the effectiveness and robustness of the proposed Sensorless control.

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    Keywords: Backstepping Control, Sliding Mode, Lyapunov Stability, Induction Motor Drive, MRAS Observer.

     

    Comparative Study of PI and Fuzzy DC Voltage Control for a Wind Energy Conversion System

    by M. Barara, A. Abbou, M. Akherraz, A. Bennaser, D. Taibi

    Vol. 6. n. 2, pp. 396-401

     

    Abstract - Self excited induction generator has become very popular for generating power from renewable energy sources , Their main disadvantage is poor voltage regulation under varying load and speed. This paper presents a comparison between a fuzzy logic controller and a conventional PI controller used for DC voltage control of self excited induction generator in wind energy conversion System. The robustness between these two regulators was tested and validated under simulations with the presence of variations rotor speed and DC load . The simulation results obtained showed that the fuzzy controller improves the system performances compared to the PI controller.

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    Keywords: Induction Generator, Fuzzy Controller, DC Voltage Control.

     

    Successive and Parallel Optimization of Linear Actuator Behaviors

    by I. Amdouni, L. El Amraoui

    Vol. 6. n. 2, pp. 402-411

     

    Abstract - Throughout this paper a magnetostatic and a dynamic model of an incremental linear actuator are implemented in the goal to improve the static force and the overflow of the dynamic response over two successive step displacements by optimizing its design and control parameters. First a parameterized design model is built. Second, a dynamic model is implemented. This model takes into account the thrust force computed from a Finite Element model. Third, a successive optimization of design and control parameters of the incremental actuator is applied using two hybrid monoobjective algorithms implemented under the elaborated platform. Finally, a parallel optimization of control and design parameters of the studied actuator is performed using monoobjective and multiobjective algorithm developed under the OPtimization Platform (O2P).

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    Keywords: Control, Design, Dynamic simulation, Magnetostatic, Model, Monoobjective, Multiobjective, Optimization.

     

    Design and Simulation of PV Driven Three Phase Induction Motor

    by T. Muthamizhan, R. Ramesh

    Vol. 6. n. 2, pp- 412-418

     

    Abstract - This Solar pumps have proven to be a cost-effective and dependable method for providing water in situations where water resources are spread over long distances and power lines are few or non-existent. The main objective of this paper is to design and simulate the photovoltaic driven three phase induction motor with increased efficiency by maximum power point tracking and proportional integral controller method. The system consists of three phase induction motor driven pump load supplied from PV generators via a dc–dc step-up converter with MPPT control and a six-step voltage source dc–ac inverter with PI controller. This system provides us the efficient way of controlling the three phase induction motor for irrigation purpose.

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    Keywords: Maximum Power Point Tracking, PI Controller, PV, Induction Motor, Pushpull Converter.

     

    Analysis of FEA Based Simulation for Torque and Force Calculation of SEIG for Wind Power Application

    by R. Janakiraman, S. Paramasivam

    Vol. 6. n. 2, pp. 419-425

     

    Abstract - This paper presents simulation approach for the performance analysis of self-excited induction generator (SEIG) for wind power application. The analysis like flux distribution, flux density distribution, and torque and force calculations through 2D finite element analysis (FEA). An induction machine model considered as phase voltage, phase angle calculations through ANSYS simulation. At the beginning, a numerical calculation of the magnetic field distribution of self-excited induction machine, under consideration is carried out. The results of numerical calculations are to be presented through ANSYS simulation and an evaluation of the steady state behavior of the self-excited induction generator is presented for the wind power application.

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    Keywords: Wind Turbine (WT), Self-Excited Induction Generator (SEIG), Wind Power Generator, Finite Element Analysis (FEA).

     

    Successive Zooming Optimization and its Application to Voltage Stability Problem

    by Vivek Kumar, C. Subramani

    Vol. 6. n. 2, pp. 426-430

     

    Abstract - Optimization became a major concern in various fields of research. There are several soft computing techniques e.g. Particle Swarm Optimization, Ant Colony Optimization etc. They differ from each other, the way particles move in search space and few other minor differences. In most of these techniques first we create several particles and find the best among them. Then the other particles move towards the best particles and we check their status. This process continues for several iterations and we find optimal value. But this social movement process requires much programming efforts, especially when the number of control variables is large. In case it is a power system problem, where load flow is required, first we create the random values for the control variables, using these variables as input we conduct power flow and then we find the local solution for the objective. After that, all the particles which we created move toward the best particle or crazy particle and we repeat the process until it converges. For movement of all these particles we need to apply velocity and position update formula to all the particles and followed by conduct of load flow repeatedly. If case the selected system is very large and we have many control variables, the movement of particles become a lengthy process and requires great computer programming effort. Hence to avoid this programming effort we propose a novel optimization technique where the created particles are not supposed to move. In spite of dragging all the particles towards the best particle, we create new particles near the best particles. This is something like zooming the small area near the best particle and then finding new potential particles. This zooming and finding new particles step continues until convergence. Based on its zooming the small area steps this technique is named as Successive Zooming Optimization or simply Zooming Optimization (Z.O.). This technique gives approximately same result as those by existing techniques. This technique is very useful for beginners because the programming effort required is comparatively less. This technique is applied to voltage stability problem. A 26- bus system of an electric utility company [1] and IEEE standard-14 bus systems are considered for analysis. Results obtained for 14-bus test system were compared with an analytical method, ‘Davidson-Fletcher-Powel-Method’ given in [20] .

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    Keywords: Successive Zooming Optimization, Voltage Stability, Voltage Collapse, Voltage Stability Index.

     

    Contribution to the Study of Simulation of Hybrid Systems (Wind-PV) for the Pumping of Water in Arid Areas

    by M. Benabdelkader, A. Malek, B. Draoui

    Vol. 6. n. 2, pp. 431-440

     

    Abstract - In Algerian Sahara, the development of date palm cultivation and preservation of existing phoenicicultural is a major concern of farmers of the oases; The extension of this activity encouraged by the support program of the state to planting of new palm plots, has faced the constraint of lack of network electrification, essential for pumping irrigation water. To this end, this paper focuses on proposing a solution based on the use of renewable energies, available in area. A simulation study of hybrid energy system (Photovoltaic-Wind), applied to the irrigation of date palm in the region of Bechar, located in southwest of Algeria was carried out. This work has treated the modeling and the dimensioning of the hybrid system, based on the satisfaction of daily flow requested by an area of one hectare planted with palm trees irrigated by drop by drop technique. The interest of the twinning of photovoltaic-wind system to the technique of micro-irrigation, witch was introduced in the South of contry during the year 2000 was highlighted. The comparative economic analysis of capital costs of the three variants, solar, wind and hybrid showed that the photovoltaic system is the optimal solution for the area of Bechar.

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    Keywords: Photovoltaic, Wind, Hybrid, Date Palm, Micro-Irrigation.

     

    Broken Conductor Detectionon Power Distribution Feeder

    by Marizan Sulaiman, Adnan Hasan Tawafan, Zulkifilie Ibrahim

    Vol. 6. n. 2, pp. 441-449

     

    Abstract - An irregular activity on electric power distribution feeder, which does not draw adequate fault current to be detected by general protective devices, is called as High impedance fault (HIF). This paper presents the algorithm for HIF detection based on the amplitude of third and fifth harmonics of current, voltage and power. It proposes an intelligent algorithm using the Fuzzy Subtractive Clustering Model (FSCM) to detect the high impedance fault. The Fast Fourier Transformation (FFT) is used to extract the feature of the faulted signals and other power system events. The effect of capacitor bank switching, non-linear load current, no-load line switching and other normal event on distribution feeder harmonics is discussed. The HIF and other operation event data were obtained by simulation of a 13.8 kV distribution feeder using PSCAD. It is evident from the outcomes that the proposed algorithm can effectively differentiate the HIFs from other events in power distribution feeder.

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    Keywords: FFT, High Impedance Faults, Subtractive Clustering, TSK Fuzzy Modeling.

     

    Short Term Load Forecasting Using BP Neural Network Optimized by Particle Swarm Optimization

    by M. A. Farahat, A. F. Abd Elgawed, H. M. M. Mustafa, A. Ibrahim

    Vol. 6. n. 2, pp. 450-454

     

    Abstract - Electric power system load forecasting plays an important role in the Energy Management System (EMS), which has great effect on the operation, controlling and planning of electric power system. A precise electric power system short term load forecasting will lead to economic cost saving and right decisions on generating electric power. A short-term load forecasting (STLF) method based on back propagation (BP) neural network which is optimized by particle swarm optimization (PSO) algorithm is presented in this paper. The PSO is used to optimize the initial parameters of the BP neural network, then based on the optimized result, the BP neural network is used for short-term load forecasting. The experiment results show the method in the paper has greater improvement in both accuracy and velocity of convergence for BP neural network. Consequently, the model is practical and effective and provides alternative for forecasting electricity load.

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    Keywords: Short Term Load Forecasting; BP Neural Network; Particle Swarm Optimization.

     

    Transient Stability Analysis in Wind Diesel Hybrid System with Fuzzy-PI based FACTS Controllers

    by Asit Mohanty, Pragyan P. Mohanty, Sthitapragyan Mohanty

    Vol. 6. n. 2, pp. 455-464

     

    Abstract - The paper presents a comparison study of Transient Stability and Reactive Power Compensation Issues in a Wind Diesel Hybrid System with different FACTS Controllers .A Small signal model of the Hybrid System is taken with the use of Fuzzy Logic based PI Controller to compensate the Reactive power generated in an Isolated Wind Diesel hybrid system. Detailed analysis of the system is undertaken with varying loading conditions. Linearised small signal models of SVC, STATCOM and UPFC are taken to study the transient stability analysis of the proposed system with IEEE type 1 Excitation System. A Self tuned Fuzzy PI Controller is implemented to tune the parameters of KP and Ki of the Hybrid System which undergoes through Voltage Instability due to sudden change in load. Simulation result shows that the proposed controller attains steady state value with less time.

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    Keywords: Hybrid System, Small Signal Analysis, Fuzzy-PI Controller, SVC, STATCOM, UPFC, Reactive Power.

     

    Optimal Location of Thyristor-Controlled Series Compensator for Optimal Power Flows

    by F. Lakdja, D. Ould Abdeslam, F. Z. Gherbi

    Vol. 6. n. 2, pp. 465-472

     

    Abstract - This paper focuses on the developing and applying an optimization method to determine what would be the optimal configuration of the TCSC controller (Thyristor-Controlled Series Capacitor) into the grid for a stationary operating regime. The ultimate purpose is to evaluate and compare the cost values of the electrical power system with and without TCSC controller. Four strategies for optimal placement of the TCSC in the transmission line are presented and discussed. We use a Newton-Raphson algorithm as an optimized method. The effectiveness of the algorithms has been demonstrated by a numerical examples applied to an IEEE test grid with 26 buses.

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    Keywords: Optimal Power Flow (OPF), FACTS, TCSC, Newton-Raphson algorithm.

     

    Static Var Compensators & Power System Stabilizers with Adaptive Neuro Fuzzy Controllers in Wind Farms

    by Manju P., Subbiah V.

    Vol. 6. n. 2, pp. 473-479

     

    Abstract - In the operation of wind farms in power system network, the voltage and power flow control is of primary concern in the efficient operation of the system. Various FACTS controllers are being used nowadays, to improve the system profile during the operation of wind farms. Power system stabilizers are used to damp out the rotor oscillations in the wind farm generator, thus enhancing the stability of the system. This paper investigates initially the effect of Static Var Compensator with conventional PI controllers and conventional Power System Stabilizer on the operation of wind farms. The Static Var Compensator are modified in the proposed work to include Fuzzy based controllers and further with Adaptive Neuro Fuzzy Controllers and their performances are compared in this paper. The conventional Power System Stabilizer in the DFIG based wind farm is also replaced with Fuzzy Stabilizers and Neuro Fuzzy Stabilizers and the effects of these intelligent controllers studied in the system performance. The results confirm that a wind farm in an interconnected power system network exhibits better performance with Adaptive Neuro Fuzzy Controllers for Static Var Compensator & Power System Stabilizers. A greater improvement in voltage profile and power control is obtained using the Hybrid Control technique. MATLAB / Simulink is used to demonstrate the application of Fuzzy and Adaptive Neuro Fuzzy Controllers in Static Var Compensator and Power System Stabilizers.

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    Keywords: FACTS Controller, Static Var Compensator, Power System Stabilizers, Fuzzy Controller, Adaptive Neuro Fuzzy Controller.

     

    Stability Enhancement of a Multimachine System using STATCOM with Supplementary controller

    by Maya G., Elizabeth P. Cheriyan, Jeevamma Jacob

    Vol. 6. n. 2, pp. 480-489

     

    Abstract - This paper investigates the improvement in the stability of a multi-machine power system using Static Synchronous Compensator (STATCOM). A systematic procedure for modelling, simulation and optimal tuning of the parameters of a STATCOM controller for stability enhancement is presented. The design of the proposed supplementary controller is formulated as an optimization problem, and adopts the particle swarm optimisation (PSO) algorithm for the optimal tuning of the controller parameters. The performance of the proposed controller is tested in a multimachine power system and results are compared with and without controller. Simulation results under different operating conditions are presented to highlight the effectiveness of the proposed controller.

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    Keywords: STATCOM, Inter Area Oscillations, PSO.

     

    A Goal Programming Approach for Optimal PMU Placement

    by V. Khiabani, M. Hamidi, K. Farahmand, R. Aghatehrani

    Vol. 6. n. 2, pp. 490-497

     

    Abstract - This article proposes a multi-objective goal programming based approach with two objectives of maximizing the reliability and minimizing the placement cost of Phasor Measurement Units (PMUs) for full observability in power systems. The weighted sum goal programming formulation incorporates the reliability of individual PMUs and finds a placement to resolve the conflicting objectives of minimum number of PMUs cost-wise and maximum level of system-wide reliability. This multi-objective problem is formulated as a nonlinear goal programming model in which weights are associated with the objectives. The model is solved for several weight scenarios for the IEEE 14, 30, 57 and 118 bus test systems. The benefit of the proposed model has been demonstrated by comparing the results with the traditional optimal cost-wise only PMU placement and existing reliability based placement models. The system reliability is improved by ~45% compared to optimal PMU placement models. Also, the number of PMUs is reduced by ~40% compared to reliability based placement models with the proposed goal programming approach.

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    Keywords: Phasor Measurement Units, Power System Observability, Goal Programming, Multi-Objective Optimization, Nonlinear Programming, Reliability Modeling.

     

    Design of D-STATCOM for Power Factor Correction in a Medium Transmission Line using Vector Based Hysteresis Current Controller

    by S. Vishnuvardhan , S. S. Sudharshan, K. Murugesan, Ranganath Muthu

    Vol. 6. n. 2, pp. 498-503

     

    Abstract - The prime focus of this paper is on power factor improvement in a medium transmission line through reactive power compensation using the distribution side – Static Synchronous Compensator (D-STATCOM). A 100 kVA, 11 kV, 80 Km transmission line is taken into consideration and shunt compensation is established through the Vector based Hysteresis Current Control (HCC) technique. The purpose of implementing the vector-based HCC is to reduce the losses associated with a high switching frequency in the conventional HCC. The simulation results are presented to show the performance of the system and are found to be satisfactory.

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    Keywords: Power Factor Correction, Reactive Power Compensation, Vector-Based Hysteresis Current Control.

     

    Active and Reactive Power Flow Control in a Grid Connected and Autonomous Microgrid

    by Guguloth Ramesh, T. K. Sunil Kumar

    Vol. 6. n. 2, pp. 504-514

     

    Abstract - These paper proposes real and reactive power management strategies of electronically interfaced distributed generation (DG) units in the context of multiple-DG of microgrid systems. In autonomous mode of microgrid, the power demand in the microgrid is supplied by the distributed generators (DGs) and controlled with the help of voltage source converters (VSCs), which control the desired real and reactive power flow between DGs to reach different load conditions. An arrangement of DGs in the microgrid is proposed to achieve load sharing in both grid connected and autonomous modes. This system can work as grid connected and autonomous mode depends on power requirement of microgrid, where power flow form grid to microgrid and vice-versa. The back-to-back converters also provide total frequency isolation between the grid and the microgrid. It is shown that the voltage or frequency fluctuation on the grid side has no impact on voltage or power on microgrid side. Different loads are considered to verify the system stability. All system model and daily load demand of microgrid has been simulated in PSCAD.

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    Keywords: Distributed Generation (DG), Grid, Microgrid, Voltage Source Converters (VSCs).

     

    Modeling of PV Standalone Microgrid Based on IEEE Standards, 1562-2007, 1361-2003 and 1013-2007

    by M. Seifi, A. Che Soh, N. I. Abd. Wahab, M. K. Hassan

    Vol. 6. n. 2, pp. 515-525

     

    Abstract - Rooftop solar panels and solar farms has become popular as a means of generating green and emission free electric energy. A standalone Microgrid is fully controlled by sophisticated controlling scheme and ready to contribute to utility grid. A standalone solar Microgrid is an economic solution in residential area as well in far off location. It consists of PV panels, DC/DC converters, storage blocks, MPPT controller, Inverter, main controller and loads. A standalone PV system has two stages design. In power stage, all components will properly be sized to supply demand loads. Control stage contains all controllers to meet the predefined requirements. There is plenty of research on each individual element; however, for system integrator there are only a few studies which have considered the whole system. This study tries to show a systematic step design for Photovoltaic-based (PV) Microgrid. All power and control design stages will be discussed. IEEE standards and recommendation for standalone PV grid and storage banks (batteries) are used as guideline.

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    Keywords: MPPT, PV, Solar cell, DC/DC converter, Inverter, filter, FLC, PI, Matlab/Simulink.

     

    A Hybrid State Estimator with Pseudo-Flows and Pseudo-Injections

    by V. Kirincic, S. Skok, V. Terzija

    Vol. 6. n. 2, pp. 526-534

     

    Abstract - The paper presents the hybrid state estimator that incorporates the conventional measurements from the Supervisory Control And Data Acquisition (SCADA) system and the synchronized phasor measurements available from Phasor Measurement Units (PMUs). The voltage and current phasors are utilized to obtain pseudo-measurements of power flows and injections. The derived pseudo-measurements are combined together with the voltage phasors and the conventional measurements as inputs for the iterative state estimator based on the Weighted Least Squares method with the addition of equality constraints for zero-injections. The proposed formulation was tested on the IEEE test systems with 14, 30, 57 and 118 buses. The Croatian transmission power system model with the deployed PMUs was used as an example of the real power system. The simulation results were compared with another hybrid state estimator and with the classical solution that does not take advantage of the synchronized phasor measurements. The developed hybrid state estimator provides higher accuracy of the estimated system state along with improved filtering of measurement errors.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Hybrid State Estimator, Power System State Estimation, Phasor Measurement Unit (PMU), Synchronized Measurement Technology, Wide Area Monitoring, Protection And Control (WAMPAC).

     

    Improving Super Grid Performances Using Multifunctional FACTS Controller

    by D. Menniti, A. Pinnarelli, N. Sorrentino, G. Brusco, A. Burgio

    Vol. 6. n. 2, pp. 535-542

     

    Abstract - Super Grid is a grid that enables to transfer huge quantity of electricity produced by renewable sources from the production places, located in remote regions, like ocean coasts and Sahara desert, to the consumptions centers. Innovative solutions with HVDC (High Voltage Direct Current) and FACTS (Flexible AC Transmission Systems) have the potential to improve static and dynamic performance of long transmission lines supporting such power flow. In this paper, the model of a switching-converter based controllers, designed in an appropriate flexible and convertible configuration, defined as Multifunctional FACTS Controller (MFC) is proposed. MFC is able to implement the control action of different FACTS devices such as SSSC, STATCOM, UPFC and IPFC. Moreover, in order to improve its performance it is equipped with Fuzzy controllers previously successfully implemented by the authors for the UPFC and IPFC. The simulation results show as the proposed MFC is able to improve the static and dynamic system performances in terms of voltage and current in long transmission lines.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Super Grid, FACTS, Power flow control, Fuzzy Logic.

     

    Design of Sliding Mode Observer Based Optimal Controller for Load Frequency Control in Multi Area Deregulated Thermal System Connected with HVDC Link

    by T. Anil Kumar, N. Venkata Ramana

    Vol. 6. n. 2, pp. 543-553

     

    Abstract - In this paper optimal load frequency control in multi area deregulated power system using sliding mode observer based controller has been proposed when HVDC link used as an ancillary service. This proposed control strategy which is taking care of nonlinearities and uncertainties and perturbations in the measurement of certain system states of the highly non linear power system. This proposed Observer based controller tested on two areas thermal deregulated power system connected with HVDC link. The performance of proposed sliding mode observer based controller compared to Optimal sliding mode controller, Conventional PI controller.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Load Frequency Control, Deregulation, HVDC Link, Optimal Sliding Mode Controller, Sliding Mode Observer.

     



     Part A - Part B
 

    Hybrid Conversion Kit Applied to Public Transportation: a Taxi Case Solution

    by Francisco J. Pérez-Pinal, Julio C. Kota-Renteria, Jose C. Nuñez-Perez, Nafia Al-Mutawaly

    Vol. 6. n. 2, pp. 554-559

     

    Abstract - This paper reports the development procedure of an internal combustion engine vehicle to a hybrid one by using a conversion kit. It was taken as a benchmark a massive transportation vehicle used as taxi and located in Mexico City. Firstly, it is presented a brief review about hybrid vehicles architectures, after that are selected three possible configurations which are analyzed and compared between them. Finally, it is selected the most suitable configuration in terms of gasoline reduction and economic payback.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Conversion Kit, Hybrid Electric Vehicles, Parallel Configuration, Series Configuration.

     

    Modeling, Simulation and Implementation of Low Cost Calibration Method for Active Devices

    by Abdullah Eroglu

    Vol. 6. n. 2, pp. 560-566

     

    Abstract - Complete characterization of active devices has been done using accurate low cost two-port calibration method, SOLT, with vector network analyzer (VNA) using the 12-term error model. Generic SOLT test fixtures short, open, load and thru have been designed, simulated and built using grounded coplanar waveguide (GCPW) structure. The test fixtures have been first simulated for design verification and accuracy, and then built, measured and then their fixturing effects have been removed using the 12-term error model with VNA, HP8753ES. Several biasing schemes for the active devices have been simulated, implemented and measured. Results have been compared with the published manufacturer data and close agreement has been seen on all of them. It has been shown that the complete characterization of active devices using SOLT calibration method is possible when test fixtures are implemented using GCPW structure and simulated with planar electromagnetic simulators to increase the accuracy of the characterization parameters. Furthermore, this method helps identifying the best operating conditions of the device under test (DUT) for high performance.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: SOLT, 12-Term Error, Device Characterization, Coplanar Waveguides, S Parameters.

     

    A Practical Approach to the Design of Power Shunt-Reactors with Discretely Distributed Air-Gaps

    by A. Donuk, H. F. Bilgin, M. Ermis

    Vol. 6. n. 2, pp. 567-576

     

    Abstract - In this paper, a practical approach to the design of low-voltage and medium-voltage power shunt-reactors with discretely-distributed air-gaps is proposed. The reactor under design is optimized according to minimum Present Value Cost design objective. Since there is no simple and analytical calculation method for leakage inductance, percentage leakage inductances of various target reactors have been obtained by Finite Element Analysis aided design approach as a function of rated reactive power, rated operating voltage, and temperature rise above the ambient and prepared graphically in the form of nomographs. After reading the percentage leakage inductance of the target reactor on the corresponding nomograph, core and winding structures are determined entirely by analytical calculations. Practical experience has shown that the design of a power shunt-reactor can be completed nearly in one hour time by using the practical design approach presented in the paper, and therefore it is a valuable tool especially for local reactor manufacturers and researchers. The accuracy of the practical design approach has been verified by Finite Element Analysis tools for two different power shunt-reactors having 40 discretely-distributed air-gaps.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Discretely-Distributed Air- Gaps, Inductance, Power Shunt-Reactor.

     

    Degradation of Surrounding Dielectrics of a Micro-Channel Due to Partial Discharges, Part 2: Parametric Study

    by Alireza Ganjovi

    Vol. 6. n. 2, pp. 577-587

     

    Abstract - The two dimensional Particle in Cell - Monte Carlo Collision (PIC-MCC) model for simulation of partial discharges inside a narrow micro-channel presented in part 1 is used in this second part to study the effect of various parameters. The parameters studied are applied electric field, channel dimensions and gas pressure. The effect of the number of initial electrons assumed at the onset of simulation is further studied in order to validate the results. It is observed that the extent of damage caused by a PD is primarily determined by the total number of impacting electrons capable of producing bond-scission at the dielectric. Parameters that effectively cause an increase in the number of energetic electrons increases effective damage as well as surface conductivity of surrounding dielectrics.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Partial Discharges; Dielectric Degradation; PIC-MCC Simulation; Parametric Investigation.

     

    Numerical Simulation on Mixed Convection in a Square Lid-Driven Cavity Provided with a Vertical Porous layer of Finite Thickness

    by Abderrahim Bourouis, Abdeslam Omara

    Vol. 6. n. 2, pp. 588-599

     

    Abstract - The purpose of the paper is to study the steady mixed convection in a square lid-driven cavity provided with a vertical porous layer of finite thickness. The porous layer is assumed to be homogeneous, isotropic, and saturated with incompressible Newtonian fluid. The transport equations are solved using the finite volume method. The SIMPLE algorithm is used to solve the coupled system of governing equations. The power law differencing scheme is used for the formulation of the convection contribution to the coefficients in the finite-volume equations. Central differencing scheme is used to discretize the diffusion terms. The flow parameters for the problem are the permeability of the porous layer and the Grashof number. The results show that the local Nusselt number at the right hot wall (Nu Hot) increases with vertical distance (Y ) for Gr=103 whereas for Gr=104 and 105 it decreases irrespective of Da. It is also observed that for the cases with Gr=104 and 105, NuInterface displays an increases with the vertical distance (Y ) as Da number decreases, contrary to the heat transfer rate at the right hot wall, NuHot.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Mixed Convection, Porous Layer, Cavity, Numerical Simulation.

     

    Dynamic Synthesis of the Rotary Cam and Translated Tappet with Roll

    by Florian Ion T. Petrescu, Relly Victoria V. Petrescu

    Vol. 6. n. 2, pp. 600-607

     

    Abstract - This paper presents an original method to determine the dynamic parameters at the camshaft (the distribution mechanisms). The authors introduce a new pressure angle, alpha, and a new method to determine the two pressure angles, alpha and delta, at the rotary cam and tappet with translational motion with roll, with a great precision. We determine initially the mass moment of inertia (mechanical) of the mechanism, reduced to the element of rotation, ie at cam (basically using kinetic energy conservation). The rotary cam with translated follower with roll is synthesized geometric, kinematics and dynamic.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Cam Mechanisms, Distribution Mechanisms, Camshaft, Tappet With Roll.

     

    Similarity Coefficient Measures Applied to Assessment the Cell Formation Problem: a Comparative Investigation

    by Sanaa Ali Hamza, Erry Yulian T. Adesta

    Vol. 6. n. 2, pp. 608-612

     

    Abstract - Similarity coefficient (SC) measures are used to evaluate cellular manufacturing system. Those measures have variation in the accuracy. The researchers Yin and Yasuda had conducted comparative study to compare the accuracy of the measures in cell formation phase. The results showed minor differences among the majority, while few measures are less accurate. However, the researchers Basher and Karaa have tried one of the measures (Jaccard) in different phase - feasibility assessment. In this paper, Basher approach has been repeated with other nineteen General Purpose Similarity Coefficients (GPSCs) measures in order to prove that any of the measures evaluated by Yin and Yasuda in cell formation can be utilized in feasibility assessment. The results have revealed that more than 80% of the measures are capable to be used in feasibility assessment.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Cellular Manufacturing, Feasibility Assessment; Cell Formation; General Purpose Similarity Coefficient.

     

    Passive Range Estimation Using Two and Three Optical Cameras

    by M. H. Ferdowsi

    Vol. 6. n. 2, pp. 613-618

     

    Abstract - In passive tracking of a flying object with bearing only measurements, range information is needed. This is accomplished by applying more than one passive optical imager. Active sensing systems have disadvantages for low-flying targets in cluttered backgrounds meanwhile are simply detected. In the observable regions of the target range, using two cameras, target range can be calculated by triangulation. If the target locates in the vicinity of sensors baseline, low observable target range will be resulted. This problem can be solved using three cameras. In this paper novel equations to calculate the target range using 3-D triangulation by two cameras are extracted, observability condition for target range is stated, target range is estimated by extended Kalman filter, observable target range is resulted by using three bearing sensors placed at a distance not along a straight line, and finally sensor fusion for estimated target range is performed.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Passive Tracking, Sensor Fusion, Target Range Estimation, Triangulation.

     

    Thermal Simulation Approach to the Cooling of a Power IGBT by Heat Pipe Systems

    by A. Driss, S. Maalej, M. C. Zaghdoudi

    Vol. 6. n. 2, pp. 619-629

     

    Abstract - In this work, we have developed a model in order to simulate the cooling of a power IGBT by heat pipe systems. The IGBT is modeled by RC thermal circuit approach on the basis on its thermal characteristics that are delivered by the manufacturer. The heat pipe is also modeled by RC thermal circuit. The thermal resistances and capacitances of the heat pipe model are determined both by experiments and theoretical calculations. The model aims to determine the junction temperature of the IGBT as well as the heat pipe temperatures in response to a periodic heat input power as a function of different parameters such as the cyclic ratio and the witching frequency. The simulations results indicate that for, a given switching frequency, the cyclic ratio affects the junction temperature which oscillates between a minimum value and a maximum one. Indeed, the maximum as well as the minimum junction temperatures increase with increasing cyclic ratio. For a given cyclic ratio, the junction temperature is also affected by the switching frequency. The maximum junction temperature decreases as the switching frequency increases, however, the minimum junction temperature increases with increasing switching frequency. In all cases, the junction temperature values remain less than the maximum temperature allowed for the safety operation of the IGBT.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Electronics Cooling, Heat Pipe, IGBT, Thermal Analysis.

     

    An Improved Prediction Model for Drilling Characteristics of Al/SiC Metal Matrix Composites

    by S. Senthil Babu, B. K. Vinayagam

    Vol. 6. n. 2, pp. 630-638

     

    Abstract - Aluminium Silicon Metal Matrix Composites (ASMMCs) are new generation engineering materials that possess improved physical and mechanical and thermal properties. The drilling of Al/SiC metal matrix composite has received a serious attention for many years. The drilling is a process of high complexity due to its special difficulties such as cutting in a closed and limited space, high cutting temperature and the difficulty of chip formation and removal. These types of operations, known as cutting speed, cutting environment, point angle, feed rate and devices. Surface finish has been an important factor of machining in predicting performance of any machining operation. A lot of researches have focused on modelling and prediction of surface roughness of Al/Sic MMCs, however, the modelling fails when the input models and output categorization varies. In this paper, we propose an improved prediction technique, which is from the inspiration of artificial neural network, to learn the drilling performance of MMCs under various inputs and output characteristics. This paper is considers two Al/SiC and Al/SiC/B4C MMCs and their different test data on drilling performance. The experimental results prove that the error gets minimized in the improved prediction model when compared to earlier neural models.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Al/ Si, MMC, Prediction Model, Particle Swarm Optimization (PSO), Fine Tuning.

     

    Modelling and Controlling of Two Conical Tank Interacting Level System using Regime based Multi Model Adaptive Concept

    by V. R. Ravi, T. Thyagarajan, G. Uma Maheshwaran

    Vol. 6. n. 2, pp. 639-648

     

    Abstract - The implementation of modelling and control algorithms for multi-input/multi-output (MIMO) systems is often complicated due to variations in process dynamics that occur because of change in operating point and characteristics of nonlinear dynamic coupling. Such difficulties often affect performance of modelling techniques and existing industrial controllers such as decoupled based decentralized fixed gain PID and Gain scheduled PID controllers unsatisfactory. In this paper, authors have represented nonlinear dynamics of process as a family of local linear models and local Dynamic Matrix Controllers (DMC) have been designed on the basis of linear models. Using Regime based Multi Model Adaptive Control (MMAC) strategy, Adaptive Dynamic Matrix Controller (ADMC) has been designed to control the nonlinear process. The applicability of the developed ADMC scheme using Regime based Multi Model Adaptive concept has been demonstrated on Two Conical Tank Interacting Level System (TCTILS) which exhibits dynamic nonlinearity and coupling dynamics. Simulation results show that the designed ADMC scheme overcome coupling effects among each degree of freedom and meet the design specifications for each loop independently in each operating regime.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Dynamic Matrix Control, Multi Model Adaptive Control, Interacting Level System, Model Predictive Control, Real Coded GA.

     

    A Spin Ring Crossover Operator Using FPGA

    by A. Ruhan Bevi, S. Malarvizhi

    Vol. 6. n. 2, pp. 649-653

     

    Abstract - The genetic algorithms are adaptive search algorithms based on natural evolution and selection. The concept in genetics is based on simulating a population in a natural process that is considered to be fittest. Every individual from a population is said to undergo a specific selection rules to maximize the fitness function. To overcome the fitness function, the genetic algorithm should have an efficient crossover operator. The cross over is one of the major operation as it aims to produce an offspring with the best properties of the parents. The resultant fittest offspring termed as a new population, replaces the parent set in generational genetics. In this paper, a new crossover operator called as spin ring crossover operator (SRC) has been proposed and implemented in hardware. The SRC is designed, simulated and implemented in vertex 2 FPGA. The comparisons with other conventional crossover operators are carried out in terms of resource and delay parameters.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Population, Crossover, Offspring, Recombination, Fitness.

     

    Improved Takagi Sugeno Fuzzy Modeling with FLEXFIS-Overlapping Clustering Approach for Efficient Classification Under Conflicts of Interest

    by S. Anandhavalli, S. K. Srivatsa

    Vol. 6. n. 2, pp. 654-662

     

    Abstract - Takagi Sugeno Fuzzy models have been successfully applied to a number of scientific and engineering problems during recent years. A lot of investigations have been done to modify systematic design of Takagi Sugeno fuzzy model. Besides the other, FLEXFIS algorithm is widely used to improve the learning process of Takagi Sugeno model. However, the performance of FLEXFIS algorithm lacks when using the microarray gene expression data i.e. there may be a chance of identifying same data item in two clusters. This will produce the conflict while taking decision about the availability of the data set present in the particular cluster (rule). So to avoid such drawbacks in the existing FLEXFIS algorithm a new technique is proposed in this paper. The proposed method comprises of two stages viz., FLEXFIS with overlapping clustering approach and conflict analysis. The Takagi Sugeno Fuzzy model uses the improved version of FLEXFIS with overlapping clustering approach to cluster the incoming data into the respective clusters. The conflict analysis is performed on the resulting clustered data from the previous stage. The identification and analysis of the data which are present in more than one cluster based on similarities in the behavior is considered. The partitioning of the data into a particular cluster or rule base in a defined manner is carried out in the conflict analysis phase. The implementation result shows the effectiveness of proposed conflict analysis technique in clustering the data in a defined cluster. The performance of the proposed conflict analysis technique is evaluated by conducting different experiments on different microarray gene expression datasets. Moreover, the performance of the proposed technique is compared with the existing FLEXFIS algorithm. The comparison result shows that the proposed technique more accurately clusters the gene data into their corresponding cluster or rule than the existing approach.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Clustering, Fuzzy Rules, Takagi Sugeno Fuzzy Model, Conflict Analysis.

     

    Analysis of Reduced Complexity Nonbinary LDPC Coding Based on Matrix Structure Modifications

    by M. Anbuselvi, S. Salivahanan

    Vol. 6. n. 2, pp. 663-667

     

    Abstract - Nonbinary LDPC coding is a class of excellent error correcting codes in wireless communication systems. The hardware realization of this decoder architecture put forth a challenge at making a better tradeoff between the computation complexities and decoding performance. This letter proposes modifications in the structure of H-matrix which characterizes the Low Density Parity Check (LDPC) codes. The modification is aimed towards the reduction of computation complexity by retaining the properties of H-matrix. Two masking matrices are proposed with reduced number of non- zero elements, forming the diagonals of the parity check matrix. Simulation results indicate improved decoding performance and reduced computational complexity with the proposed H-matrix structures.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Channel Coding, Nonbinary LDPC, Min-Max Algorithm, H-Matrix, Array Dispersion.

     

    A New Dual Tree Wavelet Based Image Denoising Using Fuzzy Shrink and Lifting Scheme

    by Rajathi G. M., R. Rangarajan

    Vol. 6. n. 2, pp. 668-675

     

    Abstract - Images are often corrupted by noise owing to channel communication errors, defective image acquisition plans or devices, engine sparks, power interference and atmospheric electrical emissions. In proposed method a new wavelet shrinkage algorithm based on fuzzy logic and the lifting scheme is used. In particular, intra-scale dependency within wavelet coefficients is modeled using a fuzzy feature. This fuzzy feature differentiates between important coefficients, namely, image discontinuity coefficients and noisy coefficients. The same is used for enhancing wavelet coefficients' information in the shrinkage step, which results in the fuzzy membership function shrinking the wavelet coefficients based on the fuzzy feature. Examine that the proposed image denoising algorithm in the new shiftable and modified version of discrete wavelet transform, is the dual-tree discrete wavelet transform. Also that the lifting scheme is there it allows a faster implementation of the WT and a fully in-place calculation of the WT. In addition, no extra memory is needed and the original signal can be replaced with its WT. The method transforms an image into the wavelet domain using lifting based wavelet filters in the wavelet domain and finally transforms the result into the spatial domain and the fuzzy threshold is used to extract out the Speckle in highest subbands. Experimental Result shows that the resultant enhanced image obtained has a better performance in noise suppression and edge preservation.

    Copyright © 2013 Praise Worthy Prize S.r.l. - All rights reserved

     

    Keywords: Image Denoising, Fuzzy Shrink, Wavelet Domain Denoising, Lifting Scheme, Fuzzy Thresholding.

     







 
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