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25,002 Article Results

Performance Evaluation of Channel Estimation in OFDM System for Different QAM and PSK Modulations

https://ijece.iaescore.com/index.php/IJECE/article/view/32
Surinder Singh , Hari Ram , Sandeep Singh Gill
To recover accurate transmitted data at the receiver end, the information regarding channel state derived from channel estimation methods play a very important role in any communication system. In this paper the performance evaluation of different types of QAM and PSK modulations with three different channel estimation methods in OFDM system for wireless communication in frequency domain for slow fading channel is compared. The results must be useful in OFDM based applications like IEEE 802.16(d) and equivalent standards.DOI:http://dx.doi.org/10.11591/ijece.v1i2.148
Volume: 1
Issue: 2
Page: 140-150
Publish at: 2011-11-08

A Voltage Controller in Photo-Voltaic System with Battery Storage for Stand-Alone Applications

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4879
Ganesh Dharmireddy , Moorthi S , Sudheer Hanumanthakari
This paper proposes the new voltage controller in photo-voltaic system for Stand-Alone Applications with battery energy storage. The output of the PV array is unregulated DC supply due to change in weather conditions. The maximum power is tracked with respect to temperature and irradiance levels by using DC-DC converter. The perturbation and observes algorithm is applied for maximum power point tracking (MPPT) purpose. This algorithm is selected due to its ability to withstand against any parameter variation and having high efficiency. The solar cell array powers the steady state energy and the battery compensates the dynamic energy in the system. The aim of the control strategy is to control the SEPIC converter and bi-direction DC-DC converter to operate in suitable modes according to the condition of solar cell and battery, so as to coordinate the two sources of solar cell and battery supplying power and ensure the system operates with high efficiency and behaviors with good dynamic performance. The output of DC-DC converter is converted to AC voltage by using inverter.  The AC output voltage and frequency are regulated. A closed loop voltage control for inverter is done by using unipolar sine wave pulse width modulation (SPWM). The regulated AC voltage is fed to AC standalone loads or grid integration. The overall system is designed, developed and validated by using MATLAB-SIMULINK. The simulation results demonstrate the effective working of MPPT algorithm, control strategy and voltage controller with SPWM technique for inverter in AC standalone load applications.DOI: http://dx.doi.org/10.11591/ijpeds.v2i1.127
Volume: 2
Issue: 1
Page: 9-18
Publish at: 2011-11-07

A 93.36 dB, 161 MHz CMOS Operational Transconductance Amplifier (OTA) for a 16 Bit Pipeline Analog-to-Digital Converter (ADC)

https://ijece.iaescore.com/index.php/IJECE/article/view/5376
Nordiana Mukahar , Siti Hawa Ruslan
A gain modified CMOS Operational Transconductance Amplifier (OTA) for a 16 bit pipeline Analog-to-Digital Converter (ADC) is presented. The circuit is designed to be used for a high resolution and low sampling rate ADC. Gain boosting technique is implemented in the design to achieve high DC gain and settling time as required. Post layout simulations for a 5 pF load capacitance shows that OTA achieves a gain bandwidth of 161 MHz at a phase margin 93.14o with 93.27 dB DC gain. The settling time for an OTA is 163 ns for 0.1 % accuracy to achieve final value and consume power about 4.88 mW from 5 V power supply.Keywords: ADC; common mode feedback; CMOS Operational Amplifier; fully differential folded cascadeDOI:http://dx.doi.org/10.11591/ijece.v2i1.121
Volume: 2
Issue: 1
Page: 106-111
Publish at: 2011-11-07

Microcontroller Based Single Phase Digital Prepaid Energy Meter for Improved Metering and Billing System

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4872
Md. Mejbaul Haque , Md. Kamal Hossain , Md. Mortuza Ali , Md. Rafiqul Islam Sheikh
This paper presents a single phase digital prepaid energy meter based on two microcontrollers and a single phase energy meter IC. This digital prepaid energy meter does not have any rotating parts. The energy consumption is calculated using the output pulses of the energy meter chip and the internal counter of microcontroller (ATmega32). A microcontroller (ATtiny13) is used as a smart card and the numbers of units recharged by the consumers are written in it. A relay system has been used which either isolates or establishes the connection between the electrical load and energy meter through the supply mains depending upon the units present in the smart card.Energy consumption (kWh), maximum demand (kW), total unit recharged (kWh) and rest of the units (kWh) are stored in the ATmega32 to ensure the accurate measurement even in the event of an electrical power outage that can be easily read from a 20×4 LCD. As soon as the supply is restored, energy meter restarts with the stored values. A single phase prepaid energy meter prototype has been implemented to provide measurement up to 40A load current and 230V line to neutral voltage.Necessary program for microcontrollers are written in c-language and compiled by Win-AVR libc compiler.DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.138 
Volume: 1
Issue: 2
Page: 139-147
Publish at: 2011-11-07

A Novel Direct Torque Control Permanent Magnet Synchronous Motor Drive used in Electrical Vehicle

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4871
Yaohua Li , Ma Jian , Yu Qiang , Liu Jiangyu
In this paper, a modified direct torque control (DTC) scheme for permanent magnet synchronous motor (PMSM) is investigated, which enables low torque ripple by using an improved voltage vector selection strategy instead of switching table used in conventional DTC. Based on the control of stator flux, torque angle and torque, voltage vector selection strategy of PMSM DTC drive is proposed. In the proposed voltage vector selection strategy, the applied voltage vector is determined according to outputs of hysteresis comparators for stator flux and torque, angular position of stator flux and torque angle, which is finally synthesized by space vector modulation (SVM). Modeling and experimental results for an interior PMSM used in Honda Civic 06My Hybrid electrical vehicle are given. Simulation and experimental results show torque ripple is reduced and the total harmonics of stator current is decreased when compared those of conventional DTC. And a fixed switching frequency is obtained with the help of SVM. In addition, the proposed DTC doesn’t need any additional PI controller, which maintains the simplicity in conventional DTC.DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.141Keywords: direct torque control, permanent magnet synchronous motor, electrical vehicle, torque ripple, switching frequency
Volume: 1
Issue: 2
Page: 129-138
Publish at: 2011-11-07

AVR Microcontroller Implementation for Customized Sound Generation

https://ijece.iaescore.com/index.php/IJECE/article/view/5377
Tanvir Hussain , Md Mejbaul Haque
In this paper, we have proposed a technique by which customized sound can be generated using 8 bit AVR microcontroller. Any sound file chosen from computer can be integrated in microcontroller programming which is written in C and compiled by AVR libc compiler. An 8 bit DAC connected to PORT A of AVR microcontroller takes data of  sound file as input and gives converted analog sound signal as output. An audio amplifier based on LM386 Op-Amp circuit amplifies the sound signal which is finally connected to 8Ω speaker for audible sound output. This circuit has been simulated using Proteus ISIS 7 Virtual System Modeling (VSM).DOI:http://dx.doi.org/10.11591/ijece.v2i1.139
Volume: 2
Issue: 1
Page: 112-119
Publish at: 2011-11-07

Improving Bad Data Detection in State Estimation of Power Systems

https://ijece.iaescore.com/index.php/IJECE/article/view/26
Mehrdad Tarafdar Hagh , Seyyed Mehdi Mahaei , Kazem Zare
In state estimation of power systems, it is possible that measurements include bad data, influencing on state estimations of power system. Several intelligent methods have been proposed to detect bad data which should be trained in various network situations but they are almost impractical because of abound situations of actual network. Some mathematical methods such as Chi-Square Distribution Test, Largest Normalized Residual Test and Hypotheses Testing Identification as the detectors of bad data have been presented, too. Sometimes these mathematical methods are not able to detect bad data. This paper proposes a method which can improve the detection of bad data in mentioned mathematical methods. Case studies have been done with different given errors on measurements of IEEE 14-bus system, and it was shown that this method is effective to improve the bad data detection.DOI:http://dx.doi.org/10.11591/ijece.v1i2.133 Keywords: Bad Data; Chi-Square Distribution; Largest Normalized Residual; Hypotheses Testing Identification
Volume: 1
Issue: 2
Page: 85-92
Publish at: 2011-11-05

Design Optimization of High-Frequency Power Transformer by Genetic Algorithm and Simulated Annealing

https://ijece.iaescore.com/index.php/IJECE/article/view/28
Amit Kumar Yadav , O. P. Rahi , Hasmat Malik , Abdul Azeem
This paper highlights the transformer design optimization problem. The objective of transformer design optimization problem requires minimizing the total mass (or cost) of the core and wire material by satisfying constraints imposed by international standards and transformer user specification. The constraints include appropriate limits on efficiency, voltage regulation, temperature rise, no-load current and winding fill factor. The design optimizations seek a constrained minimum mass (or cost) solution by optimally setting the transformer geometry parameters and require magnetic properties. This paper shows the above design problems can be formulated in genetic algorithm(GA) and simulated annealing (SA) format. The importance of the GA and SA format stems for two main features. First it provides efficient and reliable solution for the design optimization problem with several variables. Second, it guaranteed that the obtained solution is global optimum. This paper includes a demonstration of the application of the GP technique to transformer design.Key word—Optimization, Power Transformer, Genetic Algorithm (GA), Simulated Annealing Technique (SA)DOI:http://dx.doi.org/10.11591/ijece.v1i2.88
Volume: 1
Issue: 2
Page: 102-109
Publish at: 2011-10-29

Direct Instantaneous Torque Control of 4 Phase 8/6 Switched Reluctance Motor

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4870
Srinivas Pratapgiri , P.V.N. Prasad
The applications of Switched Reluctance Motor Drives has increased  in the recent past because of advantages like simple structure, no rotor winding, high torque to weight ratio, adaptability to harsh environments like coal mining etc. But the main disadvantage is that torque ripple is high because of the double saliency. This paper presents a high dynamic control technique called Direct Instantaneous Torque Control (DITC) where in the torque is maintained within a hysteresis band by changing the switching states of the phases between 1, 0 or -1.Thus torque ripple minimization is an inherent property of DITC. DITC based SRM drive is simulated in MATLAB/SIMULINK environment and results are discussed elaboratelyDOI: http://dx.doi.org/10.11591/ijpeds.v1i2.102
Volume: 1
Issue: 2
Page: 121-128
Publish at: 2011-10-29

Thermographic evaluation of electro-mechanical relays’ quality in railway automation

https://ijece.iaescore.com/index.php/IJECE/article/view/5365
Anna Vladova Andonova
By using thermal photography the quality of an electro-mechanical relay can be examined during production and the reliability of the series can be guaranteed at higher electric current values during commutation process. During exploitation thermal photography is provided information about the degree of wearing out of contacts and to help determine which contacts need to be replaced. By means of thermal photography the duration of gas discharge is determined and this duration is an indicator about the speed of wearing out of the contacts. The article offers a method to determine the quality of electro-mechanical relays especially developed for switching of powerful electrical circuits used in railway automation.Keywords: NDE, thermography, electromechanical relaysDOI:http://dx.doi.org/10.11591/ijece.v2i1.33
Volume: 2
Issue: 1
Page: 1-6
Publish at: 2011-10-29

Harmonics Mitigation of Industrial Motor Drives with Active Power Filters in Cement Plant-A Case Study

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4878
Y Kusumalatha , Y P Obulesh , Ch Saibabu
With the increasing of use of power electronic controlled variable speed drives in industries, power quality distortion in electric power system has become a serious issue in recent years. In cement plants, because of presence of more number of adjustable speed electric drives, this problem is a greater concern. In this paper, the impacts of harmonic distortions due to Adjustable speed electric drives in Anjani Portland cement Ltd, Jaggayapet, Nolgonda (Dist), A.P, India is investigated.  Harmonic measurements at various motor drives with the help of Fluke 434 power quality analyzer have been done to determine where a significant amount of harmonic currents or voltages are presented. From these measurements and subsequent calculations, the impact of harmonics is analyzed and found that the harmonic content of the motor drives to be minimized within the limits of international harmonic standards. In recently, active power filters gained an increased attention due to their effective harmonic reduction. In this paper an active power filter has been developed for minimization of the harmonics, which is implemented in Matlab/simulink based on real time measurement of harmonic data.DOI: http://dx.doi.org/10.11591/ijpeds.v2i1.120
Volume: 2
Issue: 1
Page: 1-8
Publish at: 2011-10-29

Linguistic Application Using Transitivity-Appraisal Analysis

https://ijece.iaescore.com/index.php/IJECE/article/view/35
Alexander Setiawan , Djoni Haryadi Setiabudi , Yanuar Simon
AbstractIn conducting research and linguistic analysis, researchers often find a variety of obstacles because of their limitations as human beings. A large number of articles data that must be processed and calculated increase the risk of error in the analysis, either in error in classification or error in the calculation. That’s why an application is made to assist researchers in conducting their research. This research was provided a specific framework to support the needs analysis process. This program is specifically designed to support the entire process of analysis required by using the method of analysis transivity analysis and assessment, which include searching and data processing articles, clauses classification process, and analytical assessment of this clause. The results of this study are to perform data storage process of said search results of an article, save the data analysis process from an article, the classification of phrase in the sentence in the article, and can minimize risk of calculation errors that occur in analysis. Test carried out using aplha reliability coeficient 0,75 (75%). Keywords: Analyze, Linguistic, Application.DOI:http://dx.doi.org/10.11591/ijece.v1i2.11
Volume: 1
Issue: 2
Page: 171-181
Publish at: 2011-10-29

A Cost Effective sensorless vector control of 4- Switch 3-Phase Inverter Fed IM using MRAS

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4869
Haitham Zaki Azazi , M. K. Metwally , Z. M. El-Barbary
This paper investigates performance of a Model reference adaptive system (MRAS) based cost-effective drive system of an induction motor (IM) for low-cost applications. In this paper, the MRAS is used as a speed estimator and the motor is fed from a four-switch three-phase (FSTP) inverter instead of a conventional six-switch three-phase (SSTP) inverter. This configuration reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms. The robustness of the proposed MRAS-based FSTP inverter fed IM drive is verified by Experimental results at different operating conditions. A comparison of the proposed FSTP inverter fed IM drive with a conventional SSTP inverter system is also made in terms of the performance analysis. The proposed FSTP inverter fed IM drive is found quite acceptable considering its performance, cost reduction and other advantages.DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.100
Volume: 1
Issue: 2
Page: 113-120
Publish at: 2011-10-29

Comparative Performance Investigations of Stochastic and Genetic Algorithms Under Fast Dynamically Changing Environment in Smart Antennas

https://ijece.iaescore.com/index.php/IJECE/article/view/5375
Jafar Ramadhan Mohammed
In a mobile communication systems, the number of observation data (snapshots) used for covariance matrix estimation can be insufficient, which often occurs due to fast dynamically changing environment or signal characteristics are rapidly changing. In these situations, the performance of the standard adaptive algorithms such as LMS are known to degrade substantially. In this paper, we propose the use of a Genetic Algorithm (GA) to perform the adaptation control of the system parameters under dynamically changing environments The GA-based beamformer has nearly optimal interference cancellation under dynamic conditions, and makes the output SINR consistently close to the optimal one regardless of the number of snapshot used. Other advantages of the GA is its simplicity and fast convergence provided that the parameters are appropriately chosen, which makes it a practical algorithm for beamforming in smart antenna. Simulation results validate substantial performance improvements relative to other standard adaptive algorithms. Although, the use of GA is not new in smart antenna technology, the performance evaluation of the genetic optimization under fast dynamically changing environment has not been investigated to the best of my knowledge and it is of great practical significance.DOI:http://dx.doi.org/10.11591/ijece.v2i1.119
Volume: 2
Issue: 1
Page: 98-105
Publish at: 2011-10-29

Buck-Converter Photovoltaic Simulator

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4874
Feri Yusivar , M. Y. Farabi , R. Suryadiningrat , W. W. Ananduta , Y. Syaifudin
This paper presents a Photovoltaic Simulator Simulation using Buck Converter with analysis using bode diagram. A state space simulator model is derived to provide a detail non-linear model. The PV Static Model is modified by adding a low pass filter in order to avoid an algebraic loop problem and able to analyze easier. PV simulator is realized by controlling buck converter’s current using PI Controller with reference from PV model. Then the model is linearized which is used for analysis purpose. The system is analyzed using bode diagram for its output voltage against its inputs of solar irradiance and cell’s temperature. The Load, Proportional Gain Kp, and Integral Gain Ki are varied to observe their effects into the system stability. It is noticed that the limits of gain stability system are so high at all values of load and gains so the Buck-Converter Photovoltaic Simulator, which is proposed here, can be declared as a robust system.DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.92
Volume: 1
Issue: 2
Page: 156-167
Publish at: 2011-10-29
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