Showing papers in "Universal Journal of Electrical and Electronic Engineering in 2014"
TL;DR: In this article, the authors present the modeling and performance analysis of a standalone wind system in MATLAB/SIMULINK environment, which is useful to model, simulate and study the effect of change in wind speed of a wind system.
Abstract: The paper presents the modeling and performance analysis of a standalone wind system in MATLAB/SIMULINK environment. Stand-alone systems using renewable energy sources, such as wind energy with storage battery banks are commonly used to supply remote houses. The model of wind turbine is developed using basic circuit equations governing the operation of the wind turbine. Permanent Magnet Synchronous Generator (PMSG), which is based on variable-speed operation, has been used in this paper. Since the speed of wind turbine is variable, the generator is controlled by power electronic devices. A rectifier is used to rectify the output voltage of PMSG and DC/DC buck converter is used to decrease this rectified voltage to that of battery and connected DC load. The buck converter is controlled to extract the maximum power output of wind system. Firstly the mathematical modeling of a wind turbine is done and its different characteristics have been obtained for different parameters. Secondly a standalone model of wind system is modeled and analyzed. This paper is useful to model, simulate and study the effect of change in wind speed of a standalone wind system.
18 citations
TL;DR: In this paper, the authors presented a basic concept of nodal price modeling in a competitive electricity market and some special considerations on its formulation Nodal prices represented by locational marginal prices (LMP) based settlement strategy is carried out in a deregulated market environment to establish the amount of money received by generation companies from system operator and paid to system operator from customers.
Abstract: This manuscript presents a basic concept of nodal price modeling in a competitive electricity market and some special considerations on its formulation Nodal prices represented by locational marginal prices (LMP) based settlement strategy is carried out in a deregulated market environment to establish the amount of money received by generation companies from system operator and paid to system operator from customers In this approach, cost of transmission services is implemented together with LMP which represents energy price, network losses cost, and transmission congestion cost The results show that the proposed method has a better performance than the use of conventional approach
10 citations
TL;DR: In this paper, the authors defined the following types of relations: + ∆ ǫ ∆ ∆ ( ∆ ) ∆≅ ���� ����(∆ )
Abstract: ���� ���� �������� ���� �������� + ���� ������������ ���� = ���� ������������ ���� (���� ) + ������������ ���� ���� ���� ���� �������� ���� ���� �������� ���� �������� + ���� ���������������� = ���� ���������������� (���� ) + ���� �������� ���� �������� ���� �������� �������� ∆���� = �������� (���� ) �������� ∆����≅ ���� ����(���� )∆���� �������� ∆���� = �������� (���� ) �������� ∆����≅ ���� ���� (���� )∆����
8 citations
TL;DR: Investigations and results prove that FFANN AVR controllers are very simple and accurate than conventional AVR and also enhance the stability performance of synchronous machine in an efficient manner.
Abstract: The feedforward artificial neural network (FFANN) based automatic voltage regulator (AVR) controller for excitation system using Matlab/Simulink approach is proposed in this paper.The proposed AVR controller investigates and demonstrates the application of radial basis function (RBF) and multiplayer perceptron (MLP) architectures of FFANNs and compares the suitability of both architectures. The simulation results of suggested AVR controller not only show the encouraging responses for the application but also show the improvement in the transient responses of synchronous machine. The responses of developed RBF and MLP networks have also been compared with conventional proportional integral and derivative (PID) excitation controller of synchronous machine. Investigations and results prove that FFANN AVR controllers are very simple and accurate than conventional AVR and also enhance the stability performance of synchronous machine in an efficient manner. This research also suggests that RBF network is more simple, accurate, fast and robust controller than MLP architecture. Huge numbers of research papers have been written and published on the different types of excitation controller, but the proposed controller for excitation control system is relatively most simple and suitable for software demonstration and practical implementation.
7 citations
TL;DR: In this article, the approach and results of power quality measurement at the outputs of DC/AC inverter COTEK S1500-124 supplying a linear load were described and verified.
Abstract: This paper describes the approach and results of power quality measurement at the outputs of DC/AC inverter COTEK S1500-124 supplying a linear load. There were used load examples as a classic light bulb of 150 W nominal power and an air heater with adjustable power chosen as linear load. The measurement was realized for purposes of verification of power quality indexes at the outputs of DC/AC inverter COTEK S1500-124 declared by its manufacturer.
7 citations
TL;DR: In this article, an end-fed dipole radiator is proposed to improve the quasi-Yagi antenna performance by using the area around the radiating arms free of any conductors, which is a good candidate to create high polarization purity of radiation.
Abstract: A novel approach to improve the quasi-Yagi antenna performances by using the so-called ends-fed dipole radiator is presented. To illustrate this idea a cylindrical prototype operating at 790 MHz is developed and tested. Since the area around the radiating arms is free of any conductors, the proposed radiator is a good candidate to create high polarization purity of radiation. The measured results have revealed that such a driver is able to achieve an effective area reduction to 20% with enhanced up to 17 dB front-to-back ratio without decreasing the bandwidth.
6 citations
TL;DR: In this article, a model on alpha-power law MOSFETs based source-coupled differential pair (SCDP) is discussed and a simple design procedure for realizing a linear CMOS SCDP transconductance element is proposed.
Abstract: A model on alpha-power law MOSFETs based source-coupled differential pair (SCDP) is discussed and a simple design procedure for realizing a linear CMOS SCDP transconductance element is proposed. The proposed or modified SCDP circuit using this procedure is an alternative to that of conventional SCDP and the circuit discussed has superior linearity for a wide range ±(0-300mv) of input differential voltage at a supply voltage of 1.2v. The modified SCDP also includes the circuitry needed to suppress the variation in the quiescent current with respect to input common-mode voltage noise. The SPICE results are used to verify theoretical predictions. The results show close agreement between the predicted model behavior and the simulated performance. The simulated result on Total Harmonic Distortion (THD) shows that the modified SCDP circuit is better than the conventional SCDP by about four times at input differential voltage amplitude of ±100mv. An example circuit, a second order continuous time gm-C band-pass filter is constructed using the fully differential modified SCDP and the fully differential conventional SCDP circuit and the result shows that the modified transconductor circuit is better in linearity (THD) than the conventional SCDP by about two times at the input differential voltage amplitude of ±100mv. An automatic digital compensation scheme for temperature is also presented and the temperature coefficient of output current is reduced by about eight times to 250ppm/deg.C after compensation for the maximum change in temperature of 150deg.C and at the input differential voltage of 100mv.
5 citations
TL;DR: In this article, a new criteria has been developed to help developers and planners of local residential communities to understand the cost of intervention, in order to evaluate where the load is when the prices are high.
Abstract: In the UK there is no real time retail market, and hence no real time retail electricity pricing. Therefore domestic electricity consumers in the UK pay electricity prices that do not vary from hour to hour, but are rather some kind of average price. Real time pricing information was identified as a barrier to understanding the effectiveness of various incentives and interventions. The key question is whether we can evaluate energy management and renewable energy intervention in the behaviour of customers in real market terms. Currently only behaviour changes with respect to total consumption can be evaluated. Interventions cannot be defined for peak load behaviour. The effectiveness of the introduction of renewable energy is also hard to assess. Therefore, it is hard to justify introducing of renewable and demand side management at local community level, apart from when following government approved schemes, subsidies, and other initiatives. In this paper, a new criteria has been developed to help developers and planners of local residential communities to understand the cost of intervention, in order to evaluate where the load is when the prices are high.
4 citations
TL;DR: In this paper, the physical parameters of the special engine electronic thottle has been estimated and a controller has been designed and constructed, and the simulation results show that the controller works correctly.
Abstract: In the new Automotives Engines Electronic Throttle has been used to reduce fuel consumption and increase the torque. The throttle's butterfly valve angle is changed by Engine Control Unit (ECU) Signals. In some cases physical model of Electronic Throttle is needed for engine optimization in automotive industrial. In this paper physical parameters of the special engine electronic thottle has been gotten and estimated. After this research, a controller has been designed and constructed. Software simulation results show the controller works correctly.
4 citations
TL;DR: In this article, the authors analyzed the emitted infrared radiation from a silicon solar cell under the forward bias by polarization spectroscopy and found that the spectral response of using CCD camera with those methods is in band gap infrared wave length area.
Abstract: Diagnostic of silicon solar cells defects is permanently one of most important steps in production of solar cells. Specify of diagnostic methods leads to a better understanding and more detailed analysis of manufactured cells. Luminescence methods of solar cells are fast and some of the most common methods today. According to the excitation method of luminescence radiation from silicon solar cells we talk about electroluminescence or photoluminescence methods. Spectral response of using CCD camera with those methods is in band-gap infrared wave length area. The main idea of this paper is to analyze emitted infrared radiation silicon solar cell under the forward bias by polarization spectroscopy. This analysis opens up for potential next new questions in diagnostics defects silicon solar cells by luminescence methods.
3 citations
TL;DR: This article deals with verification of radar sensors, which are very accurate devices, but vulnerable to distortion of the measured value due to false reflections.
Abstract: This article deals with verification of radar sensors. Although these are very accurate devices, they are vulnerable to distortion of the measured value due to false reflections. Since this is an assigned measure, it must be ensured that results are fixed and reproducible. This places the onus on geometric and environmental optimalization to minimize false reflections and deliver accurate measurements.
TL;DR: In this paper, a delay-dependent criterion for determining the stabilization of a bilinear system is obtained in terms of linear matrix inequalities (LMIs) and used to express the relationships between the terms in the Leibniz-Newton formula.
Abstract: In this paper we consider the problem of stabilizing a bilinear system with time- varying delay via linear state feedback control. Based on the Lyapunov method, a delay-dependent criterion for determining the stabilization of system is obtained in terms of linear matrix inequalities (LMIs) and used to express the relationships between the terms in the Leibniz-Newton formula, which can be easily solved by efficient convex optimization algorithms. From the numerical examples, the obtained results have some significant improvements over the recent literatures.
TL;DR: In this paper, the coordination of overcurrent relays in wind power plants was demonstrated to maintain the power generation during a fault and protect the power components in case of a fault.
Abstract: Wind power plants are one of the most crucial types of renewable energies which are increasingly employed in smart grids with purpose of power generation especially as a distribution generation system. Hence, the proper protection of wind plants is an enormously significant aspect which must be taken into consideration when designing the wind plants to not only provide a suitable protection for the power components but also maintain the power generation perpetually in case of fault. The most important and common protection systems are overcurrent relays which can protect the power systems from impending faults. In order to implement a successful and proper protection for wind power plants, these relays must be set accurately and well coordinated with each other to clear the fault at the system in the shortest possible time. This paper demonstrates how the coordination of overcurrent relays can be successfully achieved in wind power plants in order to maintain the power generation during fault and protect the power components.
TL;DR: In this article, the performance of a Cuk converter DC converters MATLAB/Simulink model was compared with a DC Motor Dynamic Model (DMDM), Proportional Integral Controller (PCC) and Fuzzy Logic Controller (FLC).
Abstract: DC-DC converters are widely used in electrical machinery driver circuits. Classic controllers and fuzzy logic controllers, DC converters operating range setting switches provide control of electrical machines drives. In this study, which is one of the Cuk converter DC converters MATLAB / Simulink model was prepared, at the output of a DC Motor Dynamic Model, Proportional Integral, Proportional Integral Derivative and Fuzzy Logic Controllers to be controlled by a speed and a reference was provided and compared with the performances of these controllers.
TL;DR: The proposed technique implements the micro-controller and programmable logic controller based system in combination with capacitor bank for the power factor correction and can efficiently control the power factors.
Abstract: Low power factor is usually not a big problem in residential homes. It does, however, become a problem in industries where multiple motors are operational. Therefore, there is a dire requirement to correct the power factor in industries. To rectify the issue and providing a fruitful solution is the major task of our research work. Although there are different methods of power corrections are available with certain pros and cons. Occasionally, the power factor correction capacitors are implemented to correct the problems using pacific techniques and somehow active techniques as well. Each technique has its own limitations in terms of computational complexity and implementation cost. In the proposed technique, we implement the micro-controller and programmable logic controller based system in combination with capacitor bank for the power factor correction. This way, we can efficiently control the power factor.
TL;DR: In this article, a two area power system consisting of power generation from hydro, thermal and gas sources in area-1 and power generators from hydro and thermal sources in region-2 is studied.
Abstract: In this paper, automatic generation control (AGC) of two area interconnected power system having diverse sources of power generation is studied. A two area power system comprises power generations from hydro, thermal and gas sources in area-1 and power generations from hydro and thermal sources in area-2. All the power generation units from different sources are equipped with speed governors. A continuous time transfer function model of the system for studying dynamic response for small load disturbances is presented. A proportional-integral-derivative (PID) automatic generation control scheme is applied only to power generations from thermal and gas sources and power generation from hydro source is allowed to operate at its scheduled level with only speed governor control. The two area power system is simulated for different nominal loading conditions. Particle Swarm Optimization (PSO) is used to obtain the optimal PID gains for various cases using integral squared error plus integral time absolute error (ISE+ITAE) performance index for fitness evaluation. Some of the transient responses are shown for different nominal loading conditions due to step load disturbances in the system.
TL;DR: In this paper, the difference between the mean of the Rayleigh Probability Density Function and the mean obtained from the graph of Rayleigh probability density function is minimized by changing the coefficient in the equation yielding the mean.
Abstract: In this study, the difference between the mean of the Rayleigh Probability Density Function and the mean obtained from the graph of Rayleigh Probability Density Function is minimized by changing the coefficient in the equation yielding the mean. By using various numbers of data and K values, Rayleigh Probability Density Function is plotted with the means mentioned above.
TL;DR: In this paper, a DC/DC boost converter with semiconductor switches is proposed to increase the operating range of ultrasonic range finders for both pulse-echo and pitch-catch modes of operation.
Abstract: Ultrasonic range finding instruments are utilized, e.g., for measuring liquid levels and distance to parking obstacles. However, instruments designed using the conventional electronic architectures to drive the ultrasonic transmitters cannot provide an operating range beyond a few meters for a flat solid wall with normal incidence when powered by a low voltage battery. This both limits the applicability of the existing instruments and makes it difficult to demonstrate their feasibility for new applications. The architecture described here combines a DC/DC boost converter with semiconductor switches, enabling a scalable increase in the operating range for both pulse-echo and pitch-catch modes of operation. It was fully prototyped and successfully tested for novel applications involving ultrasonic range finders, specifically intrusion detection and surface profile imaging. The limitations of the profile sensing device are rather restrictive as it only operates at the incidence angles below 18°, but this device can be developed further. The developed security system was found to be quite practical in its present state.
TL;DR: A novel current-mode analog multiplier circuit based on a pair of voltage-translinear Loop that can find application in the implementation of wide range of analog systems, Fuzzy and Neural Network circuits.
Abstract: In this paper, novel current-mode analog multiplier circuit based on a pair of voltage-translinear Loop is presented. The proposed circuit is designed in 0.18 µm standard CMOS technology. Simulation result using HSPICE that verify the functionality of circuit with 1 V supply is presented. The circuit can find application in the implementation of wide range of analog systems, Fuzzy and Neural Network circuits.
TL;DR: A comparative study of 1-dimensional and 2-dimensional bypassing multipliers using different adders on basis of delay, area and power and for 4x4, 8x8 and 16x16 bits in FPGA Spartan – 3E using Xilinx 12.4 ISE and Synopsys respectively is presented.
Abstract: Multiplication is one of the essential operations in Digital Signal Processing (DSP) applications like Fast Fourier Transform (FFT), Digital filters etc. Multiplier is designed, considering the tradeoffs between low power and high speed. The bypassing multiplier is an improvement, over Braun multiplier which is one of the parallel array multiplier. The tradeoffs i.e. dynamic power and delay of the Bypassing multipliers can be reduced by using different adders. This paper presents a comparative study of 1-dimensional and 2-dimensional bypassing multipliers using different adders on basis of delay, area and power and for 4x4, 8x8 and 16x16 bits in FPGA Spartan – 3E using Xilinx 12.4 ISE and Synopsys respectively.
TL;DR: A microprocessor controlled system that can be used in counting the number of biological species in a given environment is presented herein.
Abstract: In this technological era, there exists a growing need for pre-programmed interactive systems that ease day to day activities. Systems that utilise microprocessor-based operations to control other systems are based on coded instructions depicting their actual operation, and can be interfaced to actual systems using both software and hardware techniques. A microprocessor controlled system that can be used in counting the number of biological species in a given environment is presented herein. It uses an 8-bit microprocessor 6502 unit, a pair of infra-red emitters and detectors that can be placed at the entrance, a decade up or down counter as well as a shift register. The optical sensing mechanism detects the entry or exit of the biological species with its output signal amplified and used as an input to an asynchronous sequential combinational digital logic that generates control signals for the up and down counter. The parallel shift register then buffers the maximum count into the microprocessor via the input ports, and with the help of an assembly language code the count is stored into memory and onto the display.
TL;DR: A low-voltage CMOS current-mode Winner take all and looser take all circuits are designed in 0.35 µm standard CMOS technology that can find application in the implementation of Fuzzy and Neural Network circuits.
Abstract: A low-voltage CMOS current-mode Winner take all and looser take all circuits are designed in 0.35 µm standard CMOS technology.Simulation results using HSPICE that verify the functionality of circuit with 1.5 V supply are presented. The circuit can find application in the implementation of Fuzzy and Neural Network circuits.
TL;DR: In this article, the susceptibility of a microstrip transmission line (MTL) near an interfering antenna is studied using the finite integral technique, where the magnitude of transmission coefficient of a two-port network model of the system is chosen as the susceptibility criterion of the PCB.
Abstract: In this paper, the susceptibility of a microstrip transmission line (MTL) as a simple printed circuit board (PCB) near an interfering antenna is studied using the finite integral technique. Here, the magnitude of transmission coefficient of a two-port network model of the system (|���� 21|) is chosen as the susceptibility criterion of the PCB. The susceptibility is studied for the unshielded and shielded MTL. The effect of different perforation size on the susceptibility of the shielded MTL is examined and it is shown that large apertures can even increase the disagreeable effects of the interfering wave on the MTL at resonance bandwidth of the perforated enclosure. As an important result, it is shown that shielding effectiveness (SE) of an enclosure -which is defined based on plane wave incidence - can be used to predict the susceptibility behavior of the shielded MTL in the vicinity of interference. Simulation results are in good agreement with the measurements performed inside a semi-anechoic chamber.
TL;DR: In this paper, the authors presented a new method that detects the islanding condition before main circuit breaker opening, which is based on the zero sequence angle of the current measured at the utility side of the utility circuit breaker.
Abstract: The new method for islanding detection in distribution network is presented in this paper. The islanding conditions should be detected as soon as possible. Therefore, this paper presents a new method that detects the islanding condition before main circuit breaker opening. The proposed method is based on the zero sequence angle of the current measured at the utility side of the utility circuit breaker. The measured parameter has a unique characteristic in the islanding conditions. The discrete wavelet transform is applied to extract the feature from the measured angle. This feature determines the islanding condition from non-islanding ones. The accuracy and efficiency of the proposed method for islanding detection is confirmed by simulation results. This method is effective for islanding detection in distribution network with high penetration of distributed generations. The proposed method causes no power quality problems for distribution network and can be developed in smart grids.
TL;DR: In this paper, an analysis of the structure and functioning in the Pspice simulation and experiment of a discretized photovoltaic (PV) system is presented.
Abstract: In this paper, we propose an analysis of the structure and functioning in the Pspice simulation and experiment of a discretized photovoltaic (PV) system. This system is formed by two DC/DC Boost converter connected in series. Its role is to transfer electrical energy from two PV generators through two adaptation stages (upper and lower stages). We proposed a circuit control of the power switch of the DC/DC converter, specifically, the upper stage. The results show a good agreement between simulation and experience of electrical values (voltage, current, power) of each block of the PV system. The good performance of each stage (> 90%) and the complete PV system show that this architecture can provide an innovative solution in terms of reliability and performance improvement chain PV conversion.
TL;DR: In this article, a lowvoltage, low power, high gain and low noise operational transconductance amplifier (OTA) by modifying conventional one is presented and analyzed and design strategies are discussed for minimizing noise and increasing gain.
Abstract: A low-voltage, low-power, high-gain and low-noise operational transconductance amplifier (OTA) by modifying conventional one is presented and analyzed. Design strategies are discussed for minimizing noise and increasing gain. The simulation results show that the open loop gain is improved from 68 dB to 74 dB and the input referred noise is also reduced from 926 / nV Hz to 475 / nV Hz . This amplifier operates at 0.8 V power supply voltage with a power consumption of 0.9 µW. All the simulations are obtained by using Hspice tool with 0.18 µm CMOS TSMC parameters.
TL;DR: In this paper, a 27-level cascaded multilevel inverter (CMLI) is proposed to provide output voltage regulation against many fluctuations in these sources while keeping low value of the total harmonic distortion (THD) in its output voltage.
Abstract: This paper proposes a 27-level cascaded multilevel inverter (CMLI) as an interface between renewable energy sources and the grid, that can provide output voltage regulation against many fluctuations in these sources while keeping low value of the total harmonic distortion (THD) in its output voltage. Renewable energy sources of different types are treated as dc sources (e.g. dc voltage from PV panels, rectified ac voltage from wind turbines, etc.) that represent a part of, or all, the input dc sources of the individual H-bridges of the CMLI. The values of these sources are subject to natural fluctuations. An approach using a mixed integer linear programming (MILP) optimization model is applied to determine the switching angles of the power switches of this CMLI to minimize the values of the undesired low order harmonics equally till the 31 st harmonic. . The model is applied for the single phase and three phase cases. For each case, an output voltage amplitude is selected first for normal operation at the nominal values of the dc sources , whose harmonics absolute values agree with the IEEE standards 519-1992 for voltage distortion limits. Then some disturbances are analyzed, including fluctuations of all the dc sources within ±20% of their nominal values, dropping some dc sources to 50% of their values and dropping of some dc sources to zero values, and the model is applied under the required value of the output voltage with an allowed deviation within ±5%. Solutions are obtained that give the switching angles of the inverter at these disturbances in the dc sources while keeping low values of the output voltage THD.
TL;DR: In this paper, high-voltage transmitter to the controlled switched my order to make semiconductor power electronic switching elements connected with the resistance and capacitance cargoes including ferroresonance instantly switches opening and closing built resonance will occur in the electrical events, actual circuit conditions were investigated.
Abstract: Power transmission and distribution, system reliability, and to provide the basis for the protection of electrical equipment is important. The Transformers in the power system is one of the most widely used elements. Transformers working in the linear region with a yield of electromagnetic energy provide a high rate conversion. However, with the onset of saturation of the transformer ferromagnetic core begins to fall due to the efficiency of energy conversion losses start to increase. Any power system elements constituting a sudden ferroresonance are enough potential for the realization of the event. These elements of the transformer inductance and non-linear loads can be summarized in the resistance and capacitance. In this study, high-voltage transmitter to the controlled switched my order to make semiconductor power electronic switching elements connected with the resistance and capacitance cargoes including ferroresonance instantly switches opening and closing built resonance will occur in the electrical events, actual circuit conditions were investigated.
TL;DR: In this paper, a detailed impedance analysis of Musa acuminata colla (common name of commercially available banana) peel was made at room temperature in the frequency range of 0.001 Hz to 1 M Hz.
Abstract: Typical Electrical feature of Musa acuminata colla (common name of commercially available banana) peel was identified as inhomogeneous lossy-dielectric. Considering in this direction, detailed impedance analysis was made at room temperature in the frequency range of 0.001 Hz to 1 M Hz. Impedance relaxation was well-fitted into Gaussian curves. The complex impedance plot, associated with two depressed semicircles, indicates Warburg-diffusion phenomenon. Randles's plot and frequency vs. admittance plot confirm the same. The results were corroborated by Jonscher's Universal law for better understanding of the inhibitor (corrosion-free) nature of the banana-peel.
TL;DR: In this article, a robust backstepping control structure was designed using the two-time scale control procedure of the dynamic of a small-size autonomous helicopter in hover, taking advantage of the 'decoupling' of the translational and rotational dynamics of the rigid body, resulting in a two-level hierarchical control scheme.
Abstract: This paper presents an investigation into the design of a flight control system, using a robust backstepping control structure, designed using the two-time scale control procedure of the dynamic of a small-size autonomous helicopter in hover. The two-time scale controller takes advantage of the 'decoupling' of the translational and rotational dynamics of the rigid body, resulting in a two-level hierarchical control scheme. The inner loop controller (attitude control) tracks the attitude commands generated by the outer loop controller and sets the main rotor thrust vector, while the outer loop controller (position control) tracks the reference position. The controller is designed using the backstepping method based on Lyapunov function. Lyapunov function is used to show the robustness of the proposed control method under the consideration of wind gusts. Simulation results are finally given showing the effectiveness of the proposed control and its ability to cope with external wind gusts on the plant model.