Optimal power flow solution using HFSS Algorithm
March 2023
The optimal power flow is a pragmatic problem in a power system with complex behavior that includes many control parameters. Many metaheuristic algorithms with different search methodologies have been proposed for solving the OPF problem. However, existing algorithm faces challenges such as stagnation, premature convergence, and local optima trapping during the optimization process, which provide low-quality and...
A novel modified hexagonal fractal antenna (HFA) with band notches for WLAN rejection
September 2021
In this paper, a hexagonal fractal antenna is proposed for wireless applications. The basic shape of the fractal antenna is a hexagon which is modified by inserting smaller hexagons along the periphery of the generator structure. The proposed antenna exhibits a bandwidth of 7.5 GHz in the frequency range of 3.3-10.8 GHz. The band notch for WLAN rejection at 5.75 GHz is obtained by etching hair-pin slot in the feed...
Wire antennas for textiles applications
March 2021
This paper investigates the use of a Genetic Algorithm to produce an optimized compact monopole antenna for textile application. The antenna characteristics are examined using the Numerical Electromagnetic code (NEC2) with genetic algorithm (GA). The design objective for the antennas considered here is to drive the S11 to be less than or at least, as close as possible to -10dB, targeting this application (850-950 MHz)...
Impact of electromagnetic interface of soft magnetic sensor on IoTs current detector: Design and development
April 2019
This paper presents the electromagnetic interface (EMI) impact on the current transformer with amorphous HB1-M core, printed circuit board (PCB) power transformer and the filter of inductor for Internet of Things (IoTs) device. According to the antenna principle, the radiation emission power responses of PCB transformer and current transformer are estimated and found to be negligible due to the EMI experimental report....
Two-way comparison between stitched transmission lines with copper wires and conductive threads, and with conductive threads only
September 2017
This paper presents a two-way comparison between a stitched transmission line constructed with a copper wire and conductive thread, and a stitched transmission line constructed with conductive threads only from Light Stitches®. The stitched transmission lines which are both 150 mm long consist of a copper inner conductor surrounded by a tubular insulating layer made up of polyethylene. For shielding purpose, the...
Using COMSOL to model high frequency surface acoustic wave (SAW) device
July 2016
Finite element method (FEM) analysis of SAW devices is recently popular to be achieved using the basic information of stress and strain equations for linear elastic piezoelectric materials. A delay line is modeled using Gallium arsenide piezoelectric substrate and is modeled and simulated with center frequency of 1.5 GHz to be used in many electronic devices like oscillators at ultrahigh frequency range (RF-MEMES). A 5...
Optimization of diode cell arrangement in solar cell array
August 2015
The arrangement of diodes in a solar cell array affects the Maximum Power Point (MPP) of the solar cell system. Thus, a pre-wiring method for determining the optimal arrangement of the diodes, which results in the highest MPP, is desirable. This paper proposes a numerical algorithm that predicts the optimal diodes arrangement. A computer program, written in 'Spice', measures the MPP of many different...
Application of new modeling and control for grid connected photovoltaic systems based on artificial intelligence
January 2015
This review-paper focuses on the development the intelligent technology for modelling (Multi-Model Approach (MMA)) and control (Artificial Neural Networks Controller) of grid connected photovoltaic energy conversion system. This approach (MMA) is based on a black box modeling. A database consists of input variables (sunshine, temperature and voltage at the terminals of photovoltaic generator (PVG) and output (PVG...
Runge kutta to precise the detection of lesion for magnetic resonance imaging (MRI) image
November 2014
In this paper, we translate non linear model to linear one and used numerical analysis: “Runge kutta4 (RK4)” is mathematical solutions to study the approximation’s solutions of ordinary differential equations, then pass to the statistical study for multiple regression to applied anova technique and with it, we extract the place of the lesion on medical image MRI by two ways: Distribution of gaussien...
Transformerless impedance matching networks for automotive power line communication
August 2014
The automotive industry is constantly looking for ways of improving vehicles fuel economy, reliability, and reducing cost of manufacturing and maintenance. As a result, vehicle manufacturers have looked into power line communication (PLC) technology as a possible solution. However the nature of a vehicles power lines such as extremely low impedances, time varying channel characteristics, and noise make it difficult for...
Reduction of side lobe level in non-uniform circular antenna arrays using the simulated annealing algorithm
August 2014
This paper investigates the reduction of side lobe level in antenna arrays. Reduction of side lobe level in antenna arrays has some limitations including fixed width of the beam. We have modeled the side lobe level reduction as an optimization problem using simulated annealing technique for side lobe level reduction of a specific beam width. The advantage of this method compared with other methods is that it can get out...
Estimating global solar radiation on horizontal surface from sunshine hours over Port Harcourt, Nigeria
June 2014
A model for estimating sunshine hours from some meteorological parameters was developed. An eleven year (1997 to 2007) period of relative humidity, maximum and minimum temperatures, rainfall and wind speed measured at Port Harcourt, Nigeria (Latitude 4°56’26.2’’N) was analyzed. The results of the correlations show that the four variable correlations with the highest value of R gives the best result...
Joint estimation of cochannel signals and direction finding
October 2013
The need for fast adaptive algorithms for signal separation in dense environments is essential aspect in modern communications systems. For example, enhancement of mobile systems performance to allow different traffics, high quality and minimum delay is achievable in condition that the channel impairments and cohannel interference is reduced. In this paper, the performance of two types of signal separation and...
Design of a double clad optical fiber with particular consideration of leakage losses
October 2013
In this paper we present a double clad optical fiber that consists of core, inner cladding and outer cladding. The refractive index of the core and the outer cladding are the same and the value of refractive index of the core is greater than the refractive index of inner cladding. The cutoff number Vc is calculated and plotted with respect to the ratio of the radius of inner cladding and the radius of the core....
Relay selection mechanism for user cooperation networks using a game-theoretic approach
September 2013
In this paper, we propose a new mechanism for selecting the most suitable partner in a cooperative wireless communication system, using a type of game called the Bidding game. Among all the previous researches in cooperative communications employing a similar game concept, none of them considered how relays are selected, but rather how power is allocated among the relays or sources. In this game, in which the...
Effect of generation rate constraint on load frequency control of multi area interconnected thermal systems
September 2013
This paper deals with automatic generation control (AGC) of two unequal interconnected thermal areas considering the reheat turbines for thermal areas and appropriate Generation Rate Constraint (GRC). The response with GRC is compared with the analysis done without the Generation Rate Constraint. Although the frequency deviation is less with suitable controllers when the GRC is not considered, it is not the actual...
A review on energy conversion efficiency mechanisms in quantum dot intermediate band nanostructure solar cells
August 2013
Quantum Dots used in so-called third-generation Solar Cells have the potential to significantly increase the photon conversion efficiency in two ways: (1) the production of multiple excitons from a single photon of sufficient energy and (2) the formation of intermediate bands in the bandgap that enhances its photogenerated current, via the two-step absorption of sub-band gap photons. Key...
Compensating linear and non linear loads using distribution static compensator (DSTATCOM)
August 2013
Distribution static compensator (DSTATCOM) is very popular in compensating the linear, nonlinear, balanced and unbalanced loads. Any change in the load affects the DC-link voltage (DCLV) directly. The proper operation of DSTATCOM requires variation of the DCLV within the prescribed limits. This paper presents modified synchronous reference frame (SRF) method for real time generation of compensating...
Fundamentals and literature review of wavelet transform in power quality issues
May 2013
The effects of power quality (PQ) disturbances on power utilities and power customers are increasing day by day with widespread use of power electronics devices. These disturbances should be detected rapid and accurate. Wavelet transform (WT) has become a popular method to detect, classify and analyze various types of PQ disturbances in power systems. In this study, the fundamentals of WT, its distinctions from Fourier...
Fundamentals and literature review of Fourier transform in power quality issues
May 2013
Economic impact of power quality (PQ) disturbances on industry is increasing day by day with widespread use of power electronics based devices. These disturbances should be detected quickly and accurately. Fourier transform (FT) has become a powerful tool to detect, classify and analyze various types of PQ disturbances in power systems and signal processing. In this paper, the fundamentals of Fourier series and FT with...
High voltage direct current (HVDC) systems controlled by genetic algorithms based fuzzy logic control
November 2012
The design methods of fuzzy logic controls (FLC's) based genetic algorithms (GA's) are used to get an optimized and additional control signal to the high voltage direct current (HVDC) systems, through genetic algorithms. The optimal values for the gain factors associated with each of the two fuzzy logic controller inputs and its output is achieved without changing the membership functions or the rule base of the...
Design of particle swarm optimization (PSO) based automatic generation control (AGC) regulator with different cost functions
November 2012
The design methods of fuzzy logic controls (FLC's) based genetic algorithms (GA's) are used to get an optimized and additional control signal to the high voltage direct current (HVDC) systems, through genetic algorithms. The optimal values for the gain factors associated with each of the two fuzzy logic controller inputs and its output is achieved without changing the membership functions or the rule base of the...
Effect of work related variables on human errors in measurement
August 2012
What one cannot measure one cannot control. Measurement plays a key role in science, technology and industry. Where there are measurements there is associated errors. Study of measurement errors has a long history. Attempts have been made to classify and understand the factors that contribute to errors in measurement. The understanding of this is useful for error reduction and also providing the margin for errors and...
Congestion management in deregulated power sector using fuzzy based optimal location technique for series flexible alternative current transmission system (FACTS) device
August 2012
The deregulated power sectors suffer from congestion management problems. The congestion occurs when the generation and consumption of electric power causes the transmission system to operate beyond transfer limits. Flexible alternative current transmission system (FACTS) devices can be used to reduce the flows in heavily loaded lines, resulting in low power loss and improved stability of the system. In this paper, a...
Multiple-input single-output current-mode universal filter using translinear current conveyors
November 2011
This paper presents a new current-controlled current-mode universal filter with multiple inputs and single output employing one translinear current conveyor (CCCII), one CCCII with controlled current gain and two grounded capacitors. The employment of grounded capacitors makes the circuit ideal for integration. The proposed circuit can provide low-pass, band-pass, high-pass, band-stop and all-pass current...
Designing the intelligent controller for photovoltaic system in islanding mode operation
November 2011
In this paper, an optimal controller is proposed to control the voltage of photovoltaic system as distributed generation (DG) using intelligent algorithm in islanding mode operation. The control algorithm used in the studied control plant during load variations is based on the reinforcement learning (RL) algorithm. To control the examined plant, this algorithm has tried to prevent controller output...
Congestion management in high voltage transmission line using thyrister controlled series capacitors (TCSC)
October 2011
Congestion management is one of the technical challenges in power system deregulation. In deregulated electricity market transmission congestion occurs when there is insufficient transmission capacity to simultaneously accommodate all constraints for transmission of a line. Flexible alternative current transmission system (FACTS) devices can be an alternative to reduce the flows in heavily loaded lines,...
Efficacious approach for satellite image classification
October 2011
The main idea behind any image classification process is to obtain highest accuracy possible. Minimum distance and parallelepiped method yielded acceptable results for image classification but they are bounded by their inherent limitations. On the other hand, fuzzy based systems are fast and provide good accuracy. In fuzzy, accuracy depends upon the type of membership function used, and how the membership...
Dependence of second order nonlinear susceptibility and efficiency on shape of CdS quantum dot
September 2011
This paper deals with the dependence of second order nonlinear susceptibility and second harmonic generation (SHG) efficiency on the shape of CdS quantum dot. A relation has been found between the electronic structure and second order nonlinear susceptibility. The effective mass approximation has been used to find the energy levels. We have considered both intra band and inter band near resonant transitions...
Transient behavior and transmission bit rates analysis of optoelectronic integrated devices laser diode (LD) and light emitting diode (LED) under amplification and ionizing irradiation environments
September 2011
This paper has proposed the device that is composed of a hetrojunction phototransistor (HPT) and a laser diode (LD). The expressions describing the transient response of the output. The rise time, and the output derivative are derived. The effect of the various device parameters on the transient response is outlined. The results show that the transient response of these types of devices is strongly dependent...
Automatic meter reading (AMR) based distribution security monitoring and distribution-supervisory control and data acquisition (D-SCADA) control
August 2011
Application of automatic meter reading (AMR) system is presently used for e-billing and e-monitoring. The power system of the future will incorporate advanced monitoring and control system that improve operations and system reliability. The concept presented in this paper includes installation of automatic meters in intermediate points of distribution system to monitor the load of the system and to control...
Ultra-wide microstrip band pass filter using short circuited stubs
August 2011
A novel ultra-wideband microstrip filter is proposed and physically implemented. The band pass filter is designed for short-circuited stubs with etched rectangular lattice. The etching provides better return loss. The quarter-wavelength short-circuited stubs are used to realize the lower stop-band characteristics. Simulated and measured result shows that the defected microstrip filter has a good performance, including...
High transmission bit rate of multi giga bit per second for short range optical wireless access communication networks
July 2011
In the present paper, the backbone and the broadband wireless access communication network technologies can increasingly provide unprecedented bandwidth capacities, the focus being gradually shifted toward broadband access technologies capable of connecting the customer premises to the local exchange. Optical wireless is increasingly becoming an attractive option for multi giga bit per second within short range (up...
Low-frequency power oscillation damping enhancement and voltage improvement using unified power flow controller (UPFC) in multi-machine power system
July 2011
The problem of low-frequency power swings is a matter of concern for power systems engineers in the operation and planning of power systems. Therefore, this paper is an investigation of the use of unified power flow controller (UPFC) that is suitably tuned to improve the damping of low frequency power oscillations present in Nigerian grid system. A large disturbance is initiated, during simulation in PSAT, in...
A neuro fuzzy model of an induction motor for voltage stability analysis using continuation load flow
June 2011
This paper uses the concept of the continuation power flow analysis used in voltage stability analysis. It uses the continuation load flow to plot the PV (pressure-volume)curves of an induction motor load. A neuro-fuzzy model of an induction motor load is used to represent an industrial load. In the subsequent predictor-corrector stages, the induction motors are increased to depict increment in loading....
A Tabu search algorithm for multi-objective purpose of feeder reconfiguration
June 2011
This paper presents a new method which applies the application of Tabu Search (TS) as a meta-heuristic method for network reconfiguration problems in radial distribution system. The objective of the paper presented in this work is to make a Tabu Search based algorithm for multi-objective programming to solve the network reconfiguration problem in a radial distribution system. With the appearance of the tabu...
Design and development of fuzzy logic controller to control the speed of permanent magnet synchronous motor
March 2011
The paper presents a fuzzy logic controller (FLC) for permanent magnet synchronous motor (PMSM). The fuzzy logic controller is used for speed control of this type of motor. The dynamic response of (PMSM) with the proposed controller is studied under different load disturbances. The effectiveness of the proposed fuzzy logic controller is compared with that of the conventional PI and PID controllers. The proposed...
System reconfiguration and service restoration of primary distribution systems augmented by capacitors using a new level-wise approach
March 2011
Ensuring continuous, economical and quality power supply to customers is the primary objective of suppliers. This implies quick restoration of supply in case of faults, to maximum possible load in minimum time with minimum loss. Power quality and network loss can be improved by providing reactive power compensation using capacitors. This paper proposes a new method for system reconfiguration and fault restoration of a...
High reliability single-phase uninterruptible power supply
February 2011
Generally, the largest cost reduction is achieved by reducing the number of switches employed in a converter power circuit. Diodes are less expensive than active switches and apart from this there is also a cost reduction from eliminating all the circuitry for driving active switches. Reducing the number of switches and passive elements in uninterruptible power supply topologies not only reduces the cost of the...
Torque control in magnet flux estimation method of vector control with armature resistance estimation function of SPMSM using adaptive identification
February 2011
In the conventional torque control (TC) of surface permanent magnet synchronous motor, the estimation of magnet flux becomes a big issue because the variation of permanent magnet flux that deteriorates the performance of torque controlled system. The injection molding machine contains a pressure control which is scarcely used on machine tools. The control of this pressure is very important for the operation of injection...
Radio access network (RAN) architecture development for a 4G Mobile system with reduced interference
January 2011
The fourth-generation wireless network communications technology standard is called 4G. Users of 4G devices will have the ability to access applications ranging from basic voice communication to seamless real-time video streaming. This paper proposes new techniques for the 4G mobile system, which include base station and cell distribution, channel allocation, and carrier frequencies. In addition, the connection between...
Artificial neural networks applied to DGA for fault diagnosis in oil-filled power transformers
January 2011
Dissolved Gas Analysis (DGA) is a popular method to detect and diagnose different types of faults occurring in power transformers. This objective is obtained by employing different interpretations of dissolved gases in the mineral oil insulation of such transformers. This paper engages these interpretations and applies appropriate Artificial Neural Networks (ANN) to classify the different faults. Each interpretation...
Non-polarizing beam splitter and antireflection coating design
December 2010
The optical coating design of beam splitters and antireflection coatings that are non-polarizing, those that have the same reflection for both “s- and p-polarizations” at specified angles, is a challenge. This is because the effective indices of refraction for the media and coating layer materials have a different function of the angle of incidence for each polarization. This limits what can be...
Locational marginal pricing approach to minimize congestion in restructured power market
December 2010
The privatization and deregulation of electricity markets has a very large impact on almost all the power systems around the world. Competitive electricity markets are complex systems with many participants who buy and sell electricity. Much of the complexity arises from the limitations of the underlying transmission systems and the fact that supply and demand must be in balance at all times. When the producers and...
Reducing torsional oscillation and performance improvement of industrial drives using PI along with additional feedbacks
December 2010
Torsional oscillations in electrical drive systems with elastic shafts are a well known problem. In the industrial drive systems, a shaft torsional vibration or oscillation is often generated when a motor and a load are connected with a flexible shaft. Large inertias of the motor and load side and a long shaft create an elastic system. The motor speed is different from the load side and the shaft undergoes large...
Rotor angle stability analysis of a distributed generator connected to distribution network
November 2010
This paper describes the rotor angle stability analysis of a distributed generators connected to a 10 kv distribution network consisting of wind generators, microturbines, and CHP plants. The distribution network being modeled in Matlab/Simulink/Sim Power-system takes into account detailed dynamic models of the generators. Fault simulations at various locations are investigated. For the studied cases, the critical...
A new scheme of image watermarking based on fuzzy clustering theory
November 2010
Digital watermarking technology has the advantages of easy implementation and capability of providing wide security services such as copyright protection, authentication and secret communication. In this paper, a novel image watermarking approach based on embedding watermarks in different domains, without any distortion of the watermarked image is used. In the spatial domain, the processing method is based on...
A feed antenna for dielectric spheres lens in the Ka band
November 2010
In this paper, a feed antenna for dielectric spheres lens in the Ka band, which is a circularly polarized short dielectric rod antenna, is presented. The structure combines with circular polarizer and short dielectric rod antenna skilfully. The circular polarizer with dielectric septum realizes the circular polarization. The short dielectric rod antenna achieves the high gain. Compared with the long dielectric rod...
Comparison performance evolution of different transmission techniques with bi-directional distributed Raman gain amplification technique in high capacity optical networks
September 2010
In the present paper, we have modeled parametrically the comparison performance evolution of different transmission techniques such as maximum time division multiplexing (MTDM) technique, and soliton technique with bi-directional Raman amplification technique in high capacity optical communication networks over wide range of the controlling parameters. Moreover, we have analyzed and investigated the soliton and MTDM...
Permanent magnet flux estimation method of vector control SPMSM using adaptive identification
September 2010
The variation of permanent magnet flux deteriorates the performance of a torque controlled (TC) system. Without the torque sensor, the magnet flux information is indispensable for controlling the torque of the surface permanent magnet synchronous motor (SPMSM) with vector control. The magnet flux depends on variations of temperature inside of the motor. With the increase of stator winding temperature, the magnet...
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