Showing papers in "Bulletin of Electrical Engineering and Informatics in 2014"

A Comparision of Three Phase 27 Level Inverter Scheme under No Load and Multiple Load Conditions

Abstract: Multilevel inverters have been used in the industrial as well as the drive applications. Here three phase system of the 27 level inverter scheme with and without loads have been presented by combining the three single phase inverters of various and asymmetrical voltage ranges. Here capacitors, batteries may be used for multiple dc sources in order to achieve high voltage output. It is shown that by implementing the single phase model in the three phase system the harmonic content is lowered even in the loaded conditions than compared to the single phase system. The proposed method can be validated and simulation is carried out with the help of MATLAB/Simulink software.

Illustrate the Butterfly Effect on the Chaos Rikitake system

Abstract: This letter presents butterfly effect on a Chaos system. In this letter we want to briefly introduce Chaos Rikitake system and monitor the butterfly effect on this system. In chaos theory, the butterfly effect is the sensitive dependency on initial conditions. For this goal at the first we suppose initiation point and plot it, for base of work, later will apply small change on one item of initiation point and monitor behavior of Rikitake system. At the end we want to reclaim the famous lecture of Edward Lorenz in 1972 “Does the flap of a butterfly’s wings in Brazil set off a tornado in Texas?”. The numerical simulations by use of MATLAB software are given to illustrate the butterfly effect on this system.

Using HBMO Algorithm to Optimal Sizing & Sitting of Distributed Generation in Power System

Abstract: This paper analyzes of HBMO placement method efficiency in comparison with PSO and GA in order to sizing and sitting of distributed generation in distribution power system. These algorithms for optimization in this paper is tested on IEEE 33 bus reconfigured test system. The proposed objective function considers active power losses and the voltage profile in nominal load of system. In order to use of optimization algorithms, at first, placement problem is written as an optimization problem which includes the objective function and constraints, and then to achieve the most desirable results, Optimization methods is applied to solve the problem. High performance of the proposed algorithm in mention system is verified by simulations in MATLAB software and in order to illustrate of feasibility of proposed method will accomplish.

Indirect Vector Control of Three Phase Induction Motor using PSIM

Abstract: This paper presents the implementation of indirect vector control of three phase Induction Motor using Hysteresis Band PWM current control and Synchronous Current Control in PSIM environment. In any machine drive system, current control directly influences both flux and torque developed directly. In Hysteresis current control method, actual current tracks the command current within a hysteresis band. There is no difficulty in current control tracking when CEMF is low, but at higher speeds, current controller gets saturated due to higher CEMF and hense becomes difficult to track due to which there will be a phase lag with respect to command current. All such problems are solved using Synchronous Current Control.

Image Super-Resolution Reconstruction Based On L1/2 Sparsity

Abstract: Based on image sparse representation in the shearlet domain, we proposed a L1/2 sparsity regularized unconvex variation model for image super-resolution The L1/2 regularizer term constrains the underlying image to have a sparse representation in shearlet domain The fidelity term restricts the consistency with the measured imaged in terms of the data degradation model Then, the variable splitting algorithm is used to break down the model into a series of constrained optimization problems which can be solved by alternating direction method of multipliers Experimental results demonstrate the effectiveness of the proposed method, both in its visual effects and in quantitative terms

Study on the Rough-set-based Clustering Algorithm for Sensor Networks

Abstract: The traditional clustering algorithm is a very typical level routing algorithm in wireless sensor networks (WSN). On the basis of the classical LEACH (Low Energy Adaptive Clustering Hierarchy) algorithm, this paper proposes an energy efficient clustering algorithm in WSN. Through the introduction of rough set, the new algorithm mainly introduces how to confirm an optimized strategy to choose the cluster head effectively by the simplified decision table. That is to say, by discrete normalized data preprocessing of attribute value, getting discretization decision table. Finally, the results from simulated experiments show that the clustering algorithm based on rough set theory can optimize the clustering algorithm in network data. That is to say, the rough-set-based clustering algorithm can effectively choose the cluster head, balance the energy of the nodes in the cluster and prolong the lifetime of sensor networks.

Sliding Mode Control of Buck Converter

Abstract: DC-DC converters are used to convert DC voltage from one level to other. These converters are drastically used in industry as well as in research. One of the main limitations of these converters is unregulated supply of voltage and current. To overcome these problems there are various control techniques. This paper presents two such methods. This paper compares dynamic performance of buck Converter using PID controller and Sliding mode controller. Simulation of PI and Sliding mode control of Buck Converter is carried out in MATLAB SIMULINK.

Coverage Repair Strategies for Wireless Sensor Networks using Mobile Actor Based on Evolutionary Computing

Abstract: A standard traveling salesman problem(TSP) under dual-objective strategy constrained is proposed in this paper, characterized by the fact that the demand of both as many as possible the numbers of nodes be visited in time and minimum trajectory distance. The motivation for this TSP problem under dual-objective strategy constrain stems from the coverage repair strategies for wireless sensor networks using mobile actor based on energy analysis, wherein a mobile robot replenishes sensors energy when it reaches the sensor node location. The Evolutionary Algorithm (EA) meta-heuristic elegantly solves this problem by the reasonable designed operators of crossover, mutation and local search strategy,which can accelerate convergence of the optimal solution. The global convergence of the proposed algorithm is proved, and the simulation results show the effectiveness of the proposed algorithm.

Harmonic Reduction in Variable Frequency Drives Using Active Power Filter

Abstract: In this paper Voltage Source Inverter (VSI) is used to supply a variable frequency variable voltage to a three phase induction motor drive in a variable speed application. One important complication is that, Voltage Source Inverter (VSI) used in VFD causes non-sinusoidal output voltage and current due to presence of harmonics. Shunt active filter with VSI topology is proposed for current harmonic elimination. The current control scheme proposed for SAPF is Synchronous Reference Frame theory applied to SVPWM. The reference current can be calculated by using Reference Frame Transformation, reference current are transformed from a−b−c stationary frame to d−q rotating frame. In SVPWM technique, the Active Power Filter reference voltage is generated and desired Active Power Filter output voltage is generated by SVPWM. The analysis of simulation results are carried out in MATLAB/SIMULINK model.

Sampled Reference Frame Algorithm Based on Space Vector Pulse Width Modulation for Five Level Cascaded H-Bridge Inverter

Abstract: In This paper the Sampled Reference Frame Algorithm for Five Level Cascaded H-Bridge Inverter is presented. This simple method is less computation method than Sector Identification. This SVPWM can drive any Multilevel Inverter with good DC utilization, less switching stress. This is used for high voltage and high power applications. By using Sampled Reference Frame Algorithm, there is no use of look up tables, sector selection, no need of reference voltage and angle information, 3φ to 2φ transformation. The inverter’s structure of these inverters is developed by using MATLAB SIMULINK software.

Neural Network Navigation Technique for Unmanned Vehicle

Abstract: Using a neural network (ANN) for the brain, we want a vehicle to drive by itself avoiding obstacles. We accomplish this by choosing the appropriate inputs/outputs and by carefully training the ANN. We feed the network with distances of the closest obstacles around the vehicle to imitate what a human driver would see. The output is the acceleration and steering of the vehicle. We also need to train the network with a set of strategic input-output. The result is impressive, for a couple of neurons! The unmanned vehicle (UV) drives around avoiding obstacles, but some improvement or modification can be done to make this software work for a specific purpose.

Feedback Linearization of RF Power Amplifier for TETRA Standard

Abstract: In wireless transmission systems, non-ideal response of different functional components along with power amplifier’s nonlinearity plays a major role in degrading the transmitter performance. Several parameters defines the performance of a wireless transmitter, such as adjacent channel power ratio (ACPR), error vector magnitude (EVM), spectral mask, etc., and the effect of non-ideal behaviour of the transmitter affects these parameters. For many standards these parameter specifications are defined such that the concern for transmitter linearization is very much relaxed. Standards like Terrestrial Trunked Radio (TETRA) specify strict regulation on these parameters. Therefore, the requirement of linearity is a great challenge for the design of the transmitter. Many linearization schemes is available for linearizing the nonlinear effect of a transmitter, and among those the Cartesian feedback technique is a well known concept for linearization of transmitter operating according to TETRA standard, as well as employing a narrowband operation. In our research, distortion effect of the transmitter has been analysed, and a practical demonstration of the linearization effect over distortion has been implemented using the Cartesian feedback concept.

Optimal PID Controller Designing for Voltage Control of Fuel Cell

Abstract: This paper is proposed a PID optimal controller in order to control of one of the most important types of fuel cell, namely proton exchange membrane fuel cell (PEMFC). At first, the introducing and implementation of PEMFC is present and next, during system load variations the proposed controller is designed. The controller should be designed against the load variations for keeping in a fixed value of Fuel cell output voltage. Here, the PID Controller is used which its coefficients are optimized based on Invasive Weed Optimization (IWO). In order to use this algorithm, at first, problem is written as an optimization problem which includes the objective function and constraints, and then to achieve the most desirable controller, IWO algorithm is applied to solve the problem. Simulation results are done for various loads in time domain, and the results show the efficiency of the proposed controller in contrast to the previous controllers.

Management of Urban Parking Lot Energy Efficiency with the Application of Wind Turbine and LED lights

Abstract: A study of a parking lot lighting of a large manufacturing company in Iowa was implemented to evaluate monthly energy consumption. Mercury light bulbs with 227W ratings on the light poles were replaced with low power energy efficient LEDs to increase the overall efficiency. Additionally, a small scale wind turbine was installed to supply power to experimental light poles. Migration from the current gas bulbs to the LED light results yielded about 60% energy savings, while capital gains due to the generation of wind energy returned about 80% savings per month which recovered initial investments on the assets. The environmental impact of this study cannot be neglected and it also provided opportunity for STEM education in colleges and wind energy awareness in the society in Iowa by showing benefits from current experiments. Details of the methods and analyses should be particularly useful to urban planners because they show how standard references on investment in automobile parking should be modified to include efficient energy management. The authors proposed new way to limit the cost of energy consumptions and environmental pollution on wildlife and human health. Research implications are discussed in terms of the impact of natural features in urban areas for reduction of green house gas emissions and promoting alternative energy sources.

Voltage Sag Mitigation and Load Reactive Power Compensation by UPQC

Abstract: This paper presents Unified Power Quality Conditioner(UPQC) that consist of series inverter and shunt inverter in back to back configuration which simultaneously compensate the power quality(PQ) problems of both voltage sag and load reactive power compensation . In this paper ,Neural network is tool which is considered for solving power quality problems. The simulation results from MATLAB/SIMULINK are discussed to validate the proposed method.

Optimal Determination of Size and Site of DGs in Mesh System Using PSO

Abstract: Nowadays, the penetration of Distributed Generation (DG) in power networks takes special place for them worldwide and is increasing in developed countries. In order to improve of voltage profile, stability, reduction of power losses and etc, it is necessary that this increasing of installation of DGs in Distribution system should be becomes systematically. This paper introduces an optimal placement method in order to sizing and sitting of distributed generation in IEEE 30 bus mesh test system. The algorithm for optimization is Particle Swarm Optimization (PSO). Proposed objective function is Multi Objective Function that considers active power losses of the system and the voltage profile. High performance of the proposed algorithm is proved by applying algorithm in 30 bus IEEE system using MATLAB software and in order to illustrate of feasibility of proposed method this optimization will achieved with Three DG units.

Determination of Melting Layer Boundaries and Attenuation Evaluation in Equatorial Malaysia at Ku-Band

Abstract: Upsurge in bandwidth demand in recent times for real-time data transmission have put serious constraints on satellite communication channels, leading to congestion of the lower frequency bands; necessitating migration to higher bands (Ku, Ka and V) with attendant problems such as signal fading, depolarization and attenuation due to presence of hydrometeors. There is need to separately account for attenuation due to the melting layer along the earth-space microwave links. One year data from ground-based S-band meteorological radar sourced from Kluang station of the Malaysian Meteorological Department was processed to build the vertical reflectivity of rain profile for UTM, Malaysia. Results from this work suggested that the effects of the melting layer on signal attenuation at Ku-band can be quite significant in the tropical and equatorial regions. It was estimated to be 13.36 dB and 15.44 dB at 0.01% of the time exceeded using Laws-parsons and Marshall-Palmer regression coefficients, respectively. Furthermore, it was observed that ITU-R. P.618-11 model largely under-estimated the attenuation along the slant-paths because of its failure to account for attenuation due to the melting layer in its formulation by its assumption of constant rain rate; thus rendering it unsuitable for rain attenuation predictions in the tropics.

Improved Step Response of Power System Stabilizer using Fuzzy Logic Controller

Abstract: As every power system is constantly being subjected to disturbances, we should see that these disturbances do not make the system unstable. Therefor additional signals derived from speed deviation, excitation deviation and accelerating power are injected into voltage regulators. The device to provide these signals is referred as power system stabilizer. The use of power system stabilizers has become very common in operation of large electric power systems. The conventional PSS which uses lead-lag compensation, where gain settings designed for specific operating conditions, is giving poor performance under different loading conditions. Therefore, it is very difficult to design a stabilizer that could present good performance in all operating points of electric power systems. In an attempt to cover a wide range of operating conditions, Fuzzy logic control has been suggested as a possible solution to overcome this problem. In this paper, a systematic approach to fuzzy logic control design is proposed. The study of fuzzy logic power system stabilizer for stability enhancement of a single machine infinite bus system is presented. In order to accomplish the stability enhancement, speed deviation and acceleration of the rotor synchronous generator are taken as the inputs to the fuzzy logic controller. These variables take significant effects on damping the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership function depending on these variables. The performance of the system with fuzzy logic based power system stabilizer is compared with the system having conventional power system stabilizer and system without power system stabilizer

Multi Objective Optimization of Multi Component Isothermal Liquid-Phase Kinetic Sequence using Multivariable PI Control

Abstract: In this paper, an optimal tuned saturated PI type controller with anti-windup structure is used for process control. In first step, a single objective genetic algorithm is used to find the optimal values of controller parameters. To show the difference between optimal and non-optimal control, we use this controller to track the square pulse. The results show that by choosing the control parameters randomly the output cannot track the reference signal but by optimizing the control parameters, the error, and settling time decreases significantly and efficiency of control increases but it needs more control effort. To find the optimal control parameters with lower control input, a multi objective genetic algorithm is used in next step and three points in Pareto front are analysed. It is shown that this method increases the control efficiency and needs lower control input than obtained by single objective genetic algorithm.

A Similarity Detection Method Based on Distance Matrix Model with Row-Column Order penalty Factor

Abstract: Paper detection involves multiple disciplines, and making a comprehensive and correct evaluation of academic misconduct is quite a complex and sensitive issue. There are some problems in the existing main detection models, such as incomplete segmentation preprocessing specification, impact of the semantic orders on detection, near-synonym evaluation, slow paper backtrack and so on. This paper presents a sentence-level paper similarity comparison model with segmentation preprocessing based on special identifier. This model integrates the characteristics of vector detection, hamming distance and the longest common substring and carries out detection specific to near-synonyms, word deletion and changes in word order by redefining distance matrix and adding ordinal measures, making sentence similarity detection in terms of semantics and backbone word segmentation more effective. Compared with the traditional paper similarity retrieval, the present method adopts modular-2 arithmetic with low computation. Paper detection method with reliability and high efficiency is of great academic significance in word segmentation, similarity detection and document summarization.

A Power Quality Improvement for Microgrid Inverter Operated In Grid Connected and Grid Disconnected Modes

Abstract: The renewable energy based distributed generators (DGs) will plays a dominant role in electricity production. A micro grid consists of clusters of load and distributed generators that operate as a single controllable system. The interconnection of the DG to the utility/grid through power electronic converters has raised concern about safe operation and protection of the equipments. The main objective of this paper is too focused on the power quality improvement in micro grid. In the distributed power system, the increased infiltration of nonlinear loads and power electronic interfaced distribution generation systems creates power quality issues such as voltage unbalance, frequency regulation and harmonic elimination.

Health Monitoring and Control of Civil Infrastructures using Wireless Smart Sensors

Abstract: This paper investigates health monitoring and control (HMC) of civil infrastructures using wireless smart sensor networks. Two important requirements are (i) energy efficiency, and (ii) effective control to prevent damage of civil infrastructures. Fuzzy control scheme is incorporated in the system model to provide capability for addressing problems of imprecision and uncertainty that can be associated with values of dynamic response. Moreover, operation of wireless smart sensor networks is characterised as discounted semi-Markov decision process (SMDP) consisting of four states, namely: sleep, sense, store, and transmit. The objective is to choose policy that offers optimal energy-efficient transmission of vibration-based dynamic response, and subsequently activate appropriate control. Relevant mathematical representations are formulated for this model and its efficacy tested via numerical analysis,which is implemented in MATLAB software. It is shown by the results obtained that this HMC model can provide effective control and increase energy efficiency.

Leakage Analysis and Solution of the RFID Analog Front-END

Abstract: The identification and modeling of different leakage components are very important for estimation and reduction of leakage power, especially low-power applications, such as RFID chip. This paper proposes a theory about leakage mechanism of RFID chip and proves the theory. The one contribution of the paper is the proposed theory about leakage mechanism of RFID chip. The other contribution is that it proves the differences between tape-out verification results and computer simulation results and that to what degree the differences occur for different circuits. And when the source potential is much lower than the substrate potential, tape-out verification results and computer simulation results have larger differences. The test results show that the actual leakage power increases 26.3 times compares with the computer simulation results’ when the source potential is -750mV.

A Time-Varying System - Missile Dynamics

Abstract: Most of the control theory is developed around time-invariant systems where the state matrix A consists of scalars which are not functions of time. However, many physical systems are naturally modeled with the elements of the state matrix A depending on time. One example is the dynamics of a missile. Time- varying systems also arise when non-linear systems are linearized about a trajectory. In this work, the state-transition matrix is studied for time-varying systems in order to reach a general solution. The computational effort is significantly more complicated that the time-invariant case. There are many different methods in the literature for finding the state-transition matrix and one of them is adopted. Finally, a case study of Missile Dynamics will be analyzed and simulated in MATLAB.

High-Conversion-Ratio Bidirectional DC–DC Converter With Dual Coupled Inductors

Abstract: In this paper, a high-conversion-ratio bidirectional DC–DC converter with dual coupled inductors is proposed. In the boost mode, two capacitors are parallel charged and series discharged by the dual coupled inductors. Thus, high step-up voltage gain can be achieved with an appropriate duty ratio. In the buck mode, two capacitors are series charged and parallel discharged by the dual coupled inductors. The bidirectional converter can have high step-down voltage gain. The stress voltage of all switches can be reduced, and the switching loss and efficiency can be improved. The operating principle and the steady-state analyses of the voltage gain are discussed. Finally, in 24V for low voltage, and 400V for high voltage, and 200W for output power, this converter simulated in MATLAB.

Improved Dynamic Response of Buck Converter using Fuzzy Controller

Abstract: This paper presents comparative performance of Buck Converter in both open as well as closed loop. With the help state equations Mathematical Model of Buck Converter is designed in MATLAB/SIMULINK. The obtained output response of open loop Buck Converter is sluggish, not optimum and consists of peak overshoots. PI Controller is used in closed loop model of Buck Converter. Output Voltage is compared with a reference signal, which then is processed through a controller (PI/Fuzzy). The obtained signal is superimposed with a carrier signal and given to switching device used. To further optimize the performance of Buck Converter and eliminate the peak overshoot present in output response, Fuzzy controller is used. Here Suguno type Fuzzy is used.

Two Parameter Controller for a Single Machine Infinite Bus System

Abstract: This paper shows the application of two parameter controller with internal-Model principle to a single machine- infinite bus system (SMIB), to achieve design specifications and disturbance rejection. In the two parameter model the feedback- compensator is used to achieve required transient response by pole placement and input compensator is used to achieve required steady state response. Finally this method concludes that the method is systematic, general and yields good results.

Inductive Generalization in Logical Inference and Techniques to Estimate It

Abstract: The paper presents a novel approach to problems of deductive reasoning in frames of n-tuple algebra (NTA) earlier developed by the authors. Investigations of such problems let us determine the minimal consequence in logical inference and develop techniques to find it. Besides, we have proved that many formally correct consequences are inductive generalizations of this minimal consequence. An NTA-based method is proposed to obtain a numerical estimation for the degree of such an inductive generalization. In particular, it becomes possible to predict the number of consequences for a given system of premises and the share of a minimal consequence in a universe.

Implementation of Buck-Boost Converter with Coupled Inductor for Photo-Voltaic System

Abstract: The solar energy is a very interesting alternative on supplement the electrical system generation. In this paper, a photovoltaic based system is obtained from a boost cascaded with a buck converter along with Coupled inductor. Due to its novel operating modes, high efficiency can be achieved because there is only one switch operating at high frequency at a time, and the converter allows the use of power MOSFET and ultra-fast reverse recovery diode. This paper begins with theoretical analysis and modeling of this boost–buck converter. The model indicates that the coupled inductance will lead to an increase in the gain and the decrease in ripples. Finally, this paper analyzes and describes step by step the process of designing, and simulation of high efficiency low ripple voltage buck boost DC-DC converter for the photovoltaic solar conversion system

A Genuine Random Sequential Multi-signature Scheme

Abstract: The usual sequential multi-signature scheme allows the multi-signers to sign the document with their own information and sequence, and the signature is not real random and secure. The paper analyzes the reasons for the insecurity of the previous multi-signature scheme, and puts forward a Genuine Random Sequential Multi-signature Scheme based on The Waters signature scheme, and the experiment proves that this scheme is a good scheme suitable for the practical application with high computing efficiency.