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25,002 Article Results

Modeling of Maximum Power Point Tracking Controller for Solar Power System

10.12928/telkomnika.v10i3.819
Aryuanto; National Institute of Technology Malang Soetedjo , Abraham; National Institute of Technology Malang Lomi , Yusuf Ismail; National Institute of Technology Malang Nakhoda , Awan Uji; National Institute of Technology Malang Krismanto
 In this paper, a Maximum Power Point Tracking (MPPT) controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter using equation model approach rather than circuit model one.  The buck converter model is developed using equation model that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. From the experiment, the developed model comforms with the circuit model provided by MATLAB Simulink Power Simulation. Furher, the simulation results show that the developed model performs well in tracking the maximum power point (MPP) of the PV module using Perturb and Observe (P&O) Algorithm. 
Volume: 10
Issue: 3
Page: 419-430
Publish at: 2012-09-01

Research on the Reciprocating Sealing of Fracturing Pump

10.12928/telkomnika.v10i3.829
Wei Bing; Xihua University Zhu , Gang; Xihua University Zhou , He Shun; Xihua University Wang
The failure reasons of reciprocating sealing in OPI-1800AWS fracturing pump are analyzed by scanning electron microscope technology (SEMT). The lubrication mechanism of plunger seal friction pair is analyzed by hydrodynamic lubrication theory. During its discharge and suction stroke, the reciprocating sealing friction pair meets the conditions of hydrodynamic lubrication, a certain thickness of oil film can be formed and maintained between the plunger and V-shaped sealing interface, which can lubricate sealing pair, reduce friction and improve lifetime. The axial pressure distribution of the V-shaped sealing is carried out by theoretical analysis and experimental testing. According to the distribution curve of axial pressure, the V-shaped sealing failure and the determination of the number of loops are discussed.
Volume: 10
Issue: 3
Page: 499-504
Publish at: 2012-09-01

Time of Arrival and Angle of Arrival Statistics for Distant Circular Scattering Model

10.12928/telkomnika.v10i3.838
Guo; Central South University Limei , Nian; Central South University Xiaohong
General scattering model is local scattering process assumed that the mobile station is located inside the scattering region, in order to study distant scattering model in suburban or hilly propagation environment, a geometrically based statistical distant circular scattering mode in macrocell environment was proposed, the closed-form expressions of the joint probability density function of the time of arrival /the angle of arrival, the marginal probability density function of the angle of arrival and the angle of departure, the marginal probability density function of the time of arrival were derived, this probability density function’s provided insight into the properties of the spatial distant scattering channel model.
Volume: 10
Issue: 3
Page: 564-571
Publish at: 2012-09-01

Economic Dispatch Thermal Generator Using Modified Improved Particle Swarm Optimization

10.12928/telkomnika.v10i3.824
Andi Muhammad; Khairun University Ternate Ilyas , M. Natsir; Khairun University Ternate Rahman
Fuel cost of a thermal generator is its own load functions. In this research, Modified Improved Particle Swarm Optimization (MIPSO) is applied to calculate economic dispatch. Constriction Factor Approach (CFA) is used to modify IPSO algorithm because of the advantage to improve the ability of global searching and to avoid local minimum, so that the time needed to converge become faster. Simulation results achieved by using  MIPSO method at the time of peak load of of 9602 MW, obtained generation cost is Rp 7,366,912,798,34 per hour, while generation cost of real system is Rp. 7,724,012,070.30 per hour. From the simulation result can be concluded that MIPSO can reduce the generation cost of  500 kV Jawa Bali transmission system of Rp 357,099,271.96 per hour or equal to 4,64%.
Volume: 10
Issue: 3
Page: 459-470
Publish at: 2012-09-01

An Improved Optimization Model of Internet Charging Scheme in Multi Service Networks

10.12928/telkomnika.v10i3.842
Kamaruzzaman; Islamic Science University of Malaysia Seman , Fitri Maya; Islamic Science University of Malaysia Puspita , Bachok M.; Islamic Science University of Malaysia Taib , Zurina; Islamic Science University of Malaysia Shafii
This article will analyze new improved charging scheme with base price, quality premium and QoS networks involved. Sain and Herpers [5] already attempted to obtain revenue maximization by creating charging scheme of internet. The plan is attempted to solve multi service networks scheme as an optimization model to obtain revenue maximization using our improved model based on Byun and Chatterjee [2] and Sain and Herpers [5]. The results show that improved model can be solved optimally using optimization tool LINGO to achieve better revenue maximization. Better results are obtained in all cases rather than in [5]. The advantage of our new model is that ISP also can set up their base price and quality premium based on ISP preferences. For some cases for getting revenue maximization, we do not offer one service and just utilize some of the services.
Volume: 10
Issue: 3
Page: 592-598
Publish at: 2012-09-01

Optic Nerve Head Segmentation Using Hough Transform and Active Contours

10.12928/telkomnika.v10i3.833
Handayani; Sepuluh Nopember Institute of Technology (ITS) Tjandrasa , Ari; Sepuluh Nopember Institute of Technology (ITS) Wijayanti , Nanik; Sepuluh Nopember Institute of Technology (ITS) Suciati
Optic nerve head is part of the retina where ganglion cell axons exit the eye to form the optic nerve. Glaucomatous changes related to loss of the nerve fibers decrease the neuroretinal rim and expand the area and volume of the cup. Therefore optic nerve head evaluation is important for early diagnosis of glaucoma. This study implements the detection of the optic nerve head in retinal fundus images based on the Hough Transform and Active Contour Models. The process starts with the image enhancement using homomorphic filtering for illumination correction, then proceeds with the removal of blood vessels on the image to facilitate the subsequent segmentation process. The result of the Hough Transform fitting circle becomes the initial level set for the active contour model. The experimental results show that the implemented segmentation algorithms are capable of segmenting optic nerve head with the average accuracy of 75.56% using 30 retinal images from the DRIVE database.Optic nerve head segmentation using hough transform and active contours
Volume: 10
Issue: 3
Page: 531-536
Publish at: 2012-09-01

Optimal Power Flow with Hybrid Distributed Generators and Unified Controller

10.12928/telkomnika.v10i3.818
Lakshmi; Sri Venkateswara College of Engineering Ravi , Vaidyanathan R; Sri Venkateswara College of Engineering Vaidyanathan R , Shishir; Sri Venkateswara College of Engineering Kumar D , Prathika; Sri Venkateswara College of Engineering Appaiah , S.G. Bharathi; Sri Venkateswara College of Engineering Dasan
Optimal power flow (OPF) study is conducted on a power system to achieve one of the following objectives: cost/loss minimization or available transfer capability (ATC) calculation in a deregulated environment. Distributed generation (DG) is a small source of electric power conversion from non-conventional energy sources and Hybrid DGs which often the most cost-effective and reliable way to produce power. The optimality of control variables and minimum value of objective functions in OPF study would definitely change when DGs are interconnected to the grid. The change would be respect to the location, quantity and combination of power injection by DGs. On the other hand, FACTS controllers are effective in utilizing the existing of transmission network which is very important especially in a deregulated system. Unified power flow controller (UPFC), a second generation FACTS controller, is well known for minimizing the cost of generation/losses with a good voltage profile as well as for ATC improvement. This paper conducts a detailed OPF study on a 9 bus system for the above mentioned three objectives to analyze the effect of DGs with and without UPFC. From the results, it is found that hybrid DGs along with UPFC yields better performance in many aspects.
Volume: 10
Issue: 3
Page: 409-421
Publish at: 2012-09-01

Silicon Germanium Heterojunction Bipolar Transistor for Digital Application

10.12928/telkomnika.v10i3.828
Engelin Shintadewi; Trisakti University Julian
Bipolar transistor performances can be characterized by figures of merit such as cut-off frequency, maximum frequency of oscillation and Emitter Coupled Logic gate delay. We studied the required figures of merit for digital application and the effects of lateral and vertical scaling to the figures of merit of SiGe Heterojunction Bipolar Transistor. With lateral scaling, the width of emitter finger is scaled down from 0.25 to 0.12 μm while with the vertical scaling, the base width is scaled down to reduce the base delay. We also observed the effects of Ge profile and Ge fraction to the devices performances. Bipole3 5.3.1G is used to help us in the study. We found that high frequency cut-off and maximum frequency of oscillation as well as low Emitter Coupled Logic gate delay are all important for digital applications. Scaling down the emitter finger width enhanced the maximum frequency of oscillation and reduced Emitter Coupled Logic gate delay significantly while scaling down the base width increased the cutoff frequency and current gain.
Volume: 10
Issue: 3
Page: 493-498
Publish at: 2012-09-01

A New Image Segmentation Algorithm and Its Application in Lettuce Object Segmentation

10.12928/telkomnika.v10i3.837
Jun Sun; Jiangsu University Jun Sun , Yan Wang; Jiangsu University Yan Wang , Xiaohong Wu; Jiangsu University Xiaohong Wu , Xiaodong; Jiangsu University Zhang , Hongyan; Jiangsu University Gao
Lettuce image segmentation which based on computer image processing is the premise of non-destructive testing of lettuce quality. The traditional 2-D maximum entropy algorithm has some faults, such as low accuracy of segmentation, slow speed, and poor anti-noise ability. As a result, it leads to the problems of poor image segmentation and low efficiency. An improved 2-D maximum entropy algorithm is presented in this paper. It redistricts segmented regions and furtherly classifies the segmented image pixels with the method of the minimum fuzzy entropy, and reduces the impact of noise points, as a result the image segmentation accuracy is improved. The improved algorithm is used to lettuce object segmentation, and the experimental results show that the improved segmentation algorithm has many advantages compared with the traditional 2-D maximum entropy algorithm, such as less false interference, strong anti-noise ability, good robustness and validity.
Volume: 10
Issue: 3
Page: 557-563
Publish at: 2012-09-01

A Nonlinear Directional Derivative Scheme for Edge Detection

https://ijece.iaescore.com/index.php/IJECE/article/view/5364
Muammer Catak
In this paper, a new one-stage nonlinear directional derivative scheme has been proposed for edge detection. The directional edge detection method was applied to gray and color images. The results were compared to three well-known conventional edge detectors namely Canny, Prewitt, and Sobel. The directional derivative method is an efficient edge detection tool especially in capturing details.DOI:http://dx.doi.org/10.11591/ijece.v2i4.750
Volume: 2
Issue: 4
Page: 563-570
Publish at: 2012-08-18

Multilevel Signal Analyzer Tool for Optical Communication System

https://ijece.iaescore.com/index.php/IJECE/article/view/5360
M.F.L Abdullah , Rahmat Talib
This paper presents an educational software interface tool to analyze multilevel signal at the receiver of an optical communication system. This tool provides visualization in terms of eye-diagram and bit/symbol error rate along the symbol duration using Gaussian approximation method. Besides that, maximum Q-factors, minimum BER and corresponding threshold level are also displayed. This tool is developed using Matlab as an interface programming tool. The developed analyzer has been used to analyze 2, 4 and 8-PAM signal for an optical communication system. A commercial software known as OptiSystem™ has been used to develop and simulate the multilevel optical system. The performance of the develop analyzer has been validated with the build in analyzer of OptiSystem.DOI:http://dx.doi.org/10.11591/ijece.v2i4.1464
Volume: 2
Issue: 4
Page: 529-536
Publish at: 2012-08-01

Evaluation of Flashover Voltage on Hydrophobic Polymer Insulators with Artificial Neural Network

https://ijece.iaescore.com/index.php/IJECE/article/view/5355
L. S. Nasrat , Saleh Aly
This paper presents an experimental measurement of ac 50 Hz flashover voltage (kV) of hydrophobic polymer insulators. Hundred thirty five different testing conditions were used to evaluate the electrical performance of hydrophobic surfaces of composite polymer insulators. The study of flashover voltages depend on the silicone rubber (SiR) content (%) in Ethylene propylene diene monomer (EPDM) rubber, water conductivity (µS/cm), volume of water droplet (ml) and number of water droplets on the surface of polymer insulators. Artificial neural network (ANN) is used successfully to model nonlinear functions which are difficult to model using classical methods. ANN can estimate the values of flashover voltage (kV) for different polymer insulators. The proposed network is trained using different environmental wet condition such as; water conductivity, volume of water droplet and number of water droplets on the surfaces of composite different polymer. After training, the network can estimate the flashover voltage for different inputs. A comparison between the laboratory measurements of flashover voltages and computational results of ANN were convergent. The results obtained from applying ANN show that it can be used to model the data with accuracy of 96%. These results prove that ANN can be considered a successful model to evaluate the electrical performance of hydrophobic polymer insulators and predicts the best hydrophobic composite surface that withstands higher flashover voltage under wet contaminated weather condition.DOI:http://dx.doi.org/10.11591/ijece.v2i4.580
Volume: 2
Issue: 4
Page: 487-494
Publish at: 2012-08-01

Ferranti Effect in Transmission Line

https://ijece.iaescore.com/index.php/IJECE/article/view/5349
Gagari Deb
A temporary overvoltage is an oscillatory phase to ground or phase to phase over voltage that is relatively long duration and is undamped or only weakly damped.Temporary over voltages usually originate from faults, sudden charge of load, Ferranti effect, linear resonance, ferroresonance, open conductor, induced resonance from coupled circuits and so forth.The steady voltage at the open end of an uncompensated transmission line is always higher than the voltage at the sending end.This phenomenon is known as the Ferranti effect. This paper presents a study of Ferranti effect in electrical transmission line.The study is based on both software and hardware.The MATLAB program gives the locus of sending end voltage with line length which shows that receiving end voltage is greater than sending end voltage.From the experiment with transmission line simulator the values of three phase voltages at  sending end and receiving end were found which proves the Ferranti effect.These two methods were used to give the idea about the Ferranti effect.DOI:http://dx.doi.org/10.11591/ijece.v2i4.451
Volume: 2
Issue: 4
Page: 447-451
Publish at: 2012-08-01

Fingerprint Authentication by Wavelet-based Digital Watermarking

https://ijece.iaescore.com/index.php/IJECE/article/view/5359
Rajlaxmi Chouhan , Agya Mishra , Pritee Khanna
In this manuscript, a wavelet-based blind watermarking scheme has been proposed as a means to provide protection against false matching of a possibly tampered fingerprint by embedding a binary name label of the fingerprint owner in the fingerprint itself. Embedding watermarks in the detail regions allow us to increase the robustness of our watermark, at little to no additional impact on image quality. It has been experimentally shown that when a binary watermark is embedded into detail coefficients of an indexed fingerprint image in a spread spectrum fashion, the perceptual invisibility and robustness have anticlinal response to change in amplification factor “K” and smaller watermarks have better transparency than the larger ones. The DWT-based technique has been found to give better robustness against noises, geometrical distortions, filtering and JPEG compression attack than other frequency domain watermarking techniques.DOI:http://dx.doi.org/10.11591/ijece.v2i4.505
Volume: 2
Issue: 4
Page: 519-528
Publish at: 2012-08-01

Variable Sign-Sign Wilcoxon Algorithm: A Novel Approach for System Identification

https://ijece.iaescore.com/index.php/IJECE/article/view/5354
Mihir Narayan Mohanty , Sidhartha Dash
Behavioral study of a system is an important task. It is mostly used in real world environments and became an emergent research area. Various approaches have been proposed since last two decades. In this paper, we have proposed a Variable Step-Size Sign-Sign Wilcoxon Approach, that is robust against outliers in the desired data and also convergence speed is faster than Wilcoxon norm based approach. In initial stage, Sign-Sign Wilcoxon norm based approach has been verified. Next to it, the proposed approach is verified and compared for the application in Linear and Non-linear system identification problems in presence of outliers.DOI:http://dx.doi.org/10.11591/ijece.v2i4.837
Volume: 2
Issue: 4
Page: 481-486
Publish at: 2012-08-01
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