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Surface roughness condition of field-aged polymer insulators at different installation area
A. Din;
M.A. M. Piah;
A. R. Abdullah;
N. F. Kasri
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp600-608
This paper presents surface degradation assessment based on surface roughness condition for various field-aged high voltage polymer insulators that were installed at different locations. The measurement of arithmetical mean surface roughness is done, and statistical analysis is implemented in this study. Three groups of insulators labeled as 6 years, 12 years, 18 years, and with their respective controlled samples are tested using a surface roughness tester. Data measurements from the testing are analyzed in conjunction with visual observation to investigate an indication of surface degradation within the groups. Further statistical analysis is applied for the comparison of the surface roughness conditions. In order to observe the environmental stress factors that will affect the roughness condition, within the installation area, the virtual three-dimensional mapping program represented the Earth based on satellite imagery is utilized. The correlation analysis on all that three groups has indicated the positive outcomes with the roughness increased with respect to the age of insulator that located in quite similar environmental stress conditions. Regardless of the age of an insulator, the degradation due to surface roughness condition can be used to indicate what levels of environmental stress around the installation area have.
Design of single phase inverter for photovoltaic application controlled with sinusoidal pulse width modulation
Ibrahim Alhamrouni;
N. Zainuddin;
Mohamed Salem;
Nadia H. A. Rahman;
Lili Awalin
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp620-630
The application of fossil fuels likes coal, oil and gas gives the enormous environmental impact and hazardous effects to the earth. Hence, renewable energy has become the most tremendously friendly methods to generate the electricity without pollution and emissions. Inverter is a power electronics device which is used to convert Direct Current (DC) into Alternating Current (AC). The conventional inverter no longer fulfills the requirement of reducing harmonic distortions plus it causes global warming and greenhouse effect. For increasing the efficiency and reliability of the system, the PV inverter becomes a vital part in the conversion of DC to AC output. This research thus presents a single phase photovoltaic inverter controlled with sinusoidal pulse-width-modulation (SPWM) and low pass filter connection between the inverter and the utility grid to reduce the harmonics due to intermittent nature of the renewable energy sources. Unipolar and Bipolar switching scheme are applied to control the magnitude and frequency of output voltage and result of both unipolar and bipolar are compared. The simulation of the proposed technique is executed by using Matlab/Simulink.
Prospects of using the UFMC technology In 5g / Imt-2020 networks
Ahmed Sabri Ghazi Behadili;
Emad Jadeen Abdualsada Alshebaney;
Aqeel Lateef Khudhair attaby
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp855-860
The article considers the technology of frequency multiplexing with universal filtering UFMC, planned to be introduced in the fifth generation of mobile communication networks, which allows maximizing the rate of decay of the side lobes of the multifrequency signal spectrum that cause out-of-band emissions. As a method of investigation, a computational experiment was chosen. The parameters of the OFDM and UFMC signals were compared to determine the gain of the UFMC technology in the occupied bandwidth of the signal spectrum, as well as the number of arithmetic operations, required to generate a data symbol compared to the OFDM technology, on the basis of which, conclusions were made about the practical application of UFMC technology in networks mobile communication of the fifth generation. The conducted analysis can help to select the optimal number of sub-channels in groups in order to minimize the amount of computations during the UFMC symbol generation process.
45 degree arrangement of compact array antenna for MIMO application
M. F. Ismail;
H. A. Majid;
C. Macwright;
M. N. A. H. Shaabani;
M. S. Mohd;
M. M. Zahar;
F. Zubir;
M. A. Abdullah
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp838-844
A study on the compact array microstrip patch antenna for multiple-input multiple-output (MIMO) communication system based on the antenna arrangement is performed. The 2.45 GHz rectangular array are arranged in 45 degree slanted inward and outward for each other to reduce the mutual coupling effect between the patches. The antenna properties are analyzed and compact antenna design is determined based on the simulation results. The results show the antennas can very compact while maintaining low mutual coupling. The gain of the MIMO antenna is 11.3 dBi. The simulated and tested return losses, together with the radiation patterns, are presented and discussed.
Designs of rectangular-shaped planar Inverted-F antennas at mobile operating frequencies with different ground plane techniques
Nurul Inshirah Mohd Razali;
Norhudah Seman;
Tien Han Chua
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp927-935
This article presents the designs of planar inverted-F antennas (PIFAs) at frequencies of 0.835 GHz, 0.9 GHz, 1.8 GHz, 1.9 GHz, 2 GHz, and 2.6 GHz. Initially, the designs of rectangular-shaped PIFAs are determined through the parametric studies concerning the dimensions of the antenna’s patch length, shorting plate, ground plane, and substrate. Afterward, rectangular-shaped slots are introduced into radiating element of two antennas that operate at a lower frequency range of less than 1 GHz, to tune the resonant frequency to the respective 0.835 GHz and 0.9 GHz. Different configurations of partial or full ground plane are implemented to improve the reflection coefficient, S11 performance to be below -10 dB in both simulation and measurement. The proposed six PIFAs have gain that are greater than 2 dB with the nearly omnidirectional radiation patterns. All the designs and analyses are performed using the CST Microwave Studio utilizing Rogers 4003C substrate.
Enhancement of stability margin based on dynamic brake strategy
Majli Nema Hawas
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp571-580
The Rate of Change Kinetic Energy (RACKE) method achieves considerable reduction in computing time by virtue of the way that it does not need the solution of system equation beyond fault clearing time. In RACKE method the machine which tends to lose synchronism can be defined as that which has the largest negation RACKE value. The injection of the brake ought to be achieved when RACKE of the machine liable to be unstable reaches its maximum negative value. Elimination happens when RACKE of the machine is zero and disturbance angular velocity passes through zero changing sign from positive to negative. To defining the instant of injection and elimination of brake, RACKE method can be used to investigate the transient stability margin of a power system through evaluation of RACKE value at the instant of fault clearance. The simulation demonstrates that the applying of a braking resistor at the terminal of each of the machines, pulling of synchronism, simultaneously brings the system into stable trajectory. It is clear from the results obtained that dynamic braking depending on the RACKE criterion for insertion and removal of the brake gives excellent results in an enhancement of transient stability margin.
A weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment
Terence Jerome Daim;
Razak Mohd Ali Lee
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp894-901
Impulse Radio Ultra-Wideband (IR-UWB) radar is a type of radar functioning based on UWB transmission technology that uses an exceedingly wide bandwidth low power impulse signal to continuously transmitting and receiving the impulse signal for object detection within a range. To date, most of the proposed Ultra-Wideband (UWB) transmission technology based object positioning estimation systems for indoor environment depends on objects to be attached with an active UWB devices. In certain circumstances, it is ideal to track objects in passive manner without the requirement of any attached tracking devices or device-free object positioning estimation. IR-UWB radar has shown promising utilization in realizing device-free object positioning estimation for indoor environment. With this motivation, in this paper a work on weighted least squares consideration for IR-UWB radar based device-free object positioning estimation for indoor environment is presented.
Design and simulate a doherty power amplifier using GaAs technology for telecommunication applications
Ehsan Barmala
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp845-854
In this paper, a Doherty power amplifier was designed and simulated at 2.4 GHz central frequency which has high efficiency. A Doherty power amplifier is a way to increase the efficiency in the power amplifiers. OMMIC ED02AH technology and PHEMT transistors, which is made of gallium arsenide, have been used in this simulation. The Doherty power amplifier unique feature is its simple structure which is consisting of two parallel power amplifiers and transmission lines. In order to integrate the circuit, the Doherty power transmission amplifier lines were implemented using an inductor and capacitive components. Also, the Wilkinson power divider is used on the chip input. To improve the efficiency, the auxiliary amplifier dimensions is selected enlarge and the further input power is allocated it by the power divider. A parallel R-C circuit has been used at the input of transistors to improve their stability. Simulation results show that the Doherty power amplifier has 17.2 dB output power gain, 23 dBm maximum output power, and its output power P1dB =22.6dBm at compression point -1 dB, also, its maximum efficiency is 55.5%.
Real time object customization in CAD system
Z. F. Z. Abidin;
M. N. Osman Zahid
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp1066-1075
Object customization in Computer Aided Design (CAD) is a method used to modify the sketch parameters and change the model geometries. This method is one of important features in part modelling which empowered CAD user to simply modify their product. The conventional method of modifying CAD model is usually relied on the manual editing. This paper outlines a development of program than can be integrated in CAD/CAM system for real time object customization. It uses Visual Basic (VB) programming with custom Graphical User Interface (GUI) generated in NX10 (CAD/CAM software) interface. The main contribution of this research is a tool for real time object customization that capable to assist the modification of 3D model. In order to develop the tool, 3D model modification instructions are translated into programming codes by using Journaling tools in NX interface. Editable parameters are identified based on the model shapes. The related codes are reconstructed, modified and linked to the functional GUI. This allows user to simply modify the model shapes in real time with minimum process steps. The performance of the method is evaluated in terms of the reduction of process steps and time in modifying the 3D model in CAD system. All the findings and details of approach are presented.
A study of distilled water and zamzam water as dielecric dense patch antenna at 5 GHz
N. H. Moktar;
W. I. Roseli;
M. T. Ali;
R. A. Awang
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 2: August 2019
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v15.i2.pp942-949
This paper was performed in order to study about distilled water and zamzam water which act as dielectric dense (DD) patch antenna at 5 Ghz applications. This antenna is proposed and designed using FR-4 substrate that sandwiched together to perform DD structure. The proposed antennas employ simple rectangular structure that fed with inset feeder surround by electromagnetic bandgap (EBG) structure.In order too enhance the gain, superstrate is applied on top of the antenna. This antenna offers a wideband return loss of more than -10dB between 4.41-5.52Ghz (around 22.2%) which can be applied in 5 Ghz applications. Details of DD water antenna of center frequency for 5 Ghz is presented and discussed.