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23,598 Article Results

State Space Modeling and Small Signal Stability Analysis of Synchronous Generator with Fuzzy based AVR

https://ijece.iaescore.com/index.php/IJECE/article/view/5306
Ramya R , Selvi K
This paper presents a linear mathematical model of a Synchronous Generator with excitation system for small signal stability analysis. This work aims to develop a controller based on fuzzy logic to simulate an Automatic Voltage Regulator (AVR) for a synchronous generator. The performance of fuzzy based AVR is tested on Single Machine connected to an Infinite Bus bar system (SMIB) in the MATLAB/SIMULINK platform and the results are compared with the IEEE Exciter model.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1524
Volume: 2
Issue: 6
Page: 798-805
Publish at: 2012-12-01

Quality Assessment of a Single-phase resonant inverter

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4915
Z.A. Jaffery , Sunil Kumar Chaudhary
The authors present the design, simulation and analysis of a single phase voltage source inverter using soft switching techniques. The performance of the inverter has been compared in terms of harmonic contents present in output voltage and current. The research works for a PWM inverter along with a LLCC filter has been investigated. This paper also investigated the performance of the same inverter with a feedback controller with a closed loop feedback path to maintain rated output voltage. This work is helpful for the inverter used in application where high quality ac wave is prime requirementDOI: http://dx.doi.org/10.11591/ijpeds.v2i4.277
Volume: 2
Issue: 4
Page: 364-370
Publish at: 2012-12-01

High Efficient Module of Boost Converter in PV Module

https://ijece.iaescore.com/index.php/IJECE/article/view/5300
S.Daison KumarStallon , K.Vinoth Kumar , S.Suresh Kumar
Within the photovoltaic (PV) power-generation market, the  PV module has shown obvious growth. However, a high voltage gain converter is essential for the module’s grid connection through a dc–ac inverter. This paper proposes a converter that employs a floating active switch to isolate energy from the PV panel when the ac module is OFF; this particular design protects installers and users from electrical hazards. Without extreme duty ratios and the numerous turns-ratios of a coupled inductor, this converter achieves a high step-up voltage-conversion ratio; the leakage inductor energy of the coupled inductor is efficiently recycled to the load. These features explain the module’s high-efficiency performance. The detailed operating principles and steady-state analyses of continuous, discontinuous, and boundary conduction modes are described. A 15V input voltage, 200V output voltage, and 100W output power prototype circuit of the proposed converter has been implemented; its maximum efficiency is up to 95.3% and full-load efficiency is 92.3%.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1586
Volume: 2
Issue: 6
Page: 758-765
Publish at: 2012-12-01

Jamming Effect Analysis of Two Chinese GNSS BeiDou-II Civil Signals

https://ijece.iaescore.com/index.php/IJECE/article/view/5311
Jeehyeon Baek , Seungsoo Yoo , Sun Yong Kim
Threats of electronic warfare, especially to global positioning systems (GPSs), have been rapidly increasing. The development of the Chinese navigation satellite system BeiDou has been extended to a global navigation satellite system (GNSS). In December 2011, the Chinese government released a specification document—a test version of a civil BeiDou-II signal called B1(I). A strong possibility exists that BeiDou-II (Chinese GNSS) will be adopted by North Korea in the near future. Therefore, research on BeiDou-II is essential. Since BeiDou-II is a newly-built system, few jamming effect analyses of its positioning signals have been performed. Thus, in this study, we analyze quality factors (Q) and the tolerable jamming signal power among two BeiDou-II civil signals, and two GPS civil signals, in three jamming conditions: band-limited white noise (BLWN), matched spectrum (MS), and continuous wave (CW). In addition, we present each jamming propagation range.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1815
Volume: 2
Issue: 6
Page: 840-845
Publish at: 2012-12-01

Enhancement of Power System Stability Using Fuzzy Logic Controller

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4918
Tejaswita Khobaragade , Amol Barve
This Dissertation includes work on the development of a fuzzy logic power system stabilizer to enhance the damping of generator oscillations In order to accomplish a stability enhancement. Speed deviation (Am) and acceleration (Aw) of the rotor synchronous generator were taken as the input to the fuzzy logic controller. These variables take significant effects on damping the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership function depending on these variables. The performance of the fuzzy logic power system stabilizer was compared with the conventional power system stabilizer and without power system stabilizer. To achieve good damping characteristics over a wide range of operating conditions, speed deviation and acceleration of a synchronous machine are chosen as the input. Signal to the stabilizers. The stabilizing signal is determined from certain rules for rule-based power system stabilizer. For fuzzy logic based power system stabilizer, the supplementary stabilizing signal is determined according to the fuzzy membership function depending on the speed and acceleration states of the generator. The simulation result shows that the proposed fuzzy logic based power system stabilizer is superior to rule-based stabilizer due to its lower computation burden and robust performance.DOI: http://dx.doi.org/10.11591/ijpeds.v2i4.2127
Volume: 2
Issue: 4
Page: 389-401
Publish at: 2012-12-01

Comparative Analysis of Image Enhancement Techniques for Ultrasound Liver Image

https://ijece.iaescore.com/index.php/IJECE/article/view/5305
Smriti Sahu , Maheedhar Dubey , Mohammad Imroze Khan
Liver cancer is the sixth most common malignant tumour in the world and the third most common cause of cancer-related deaths worldwide. To diagnose such liver diseases, In this paper comparison has been made for various image enhancement techniques that are applied to liver ultrasound image. Three types of liver ultrasound images used are normal, benign and malignant liver images. The techniques, which are compared on the basis of two evaluation parameters Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE) including, Contrast Stretching, Shock Filter, Histogram Equalization, Contrast Limited Adaptive Histogram Equalization (CLAHE).Such a comparison would be helpful in determining the best suited method for clinical diagnosis. It also has been observed that the Shock filter gives the better performance than others for liver ultrasonic image analysis.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1513
Volume: 2
Issue: 6
Page: 792-797
Publish at: 2012-12-01

Optimal Design of DC to DC Boost Converter with Closed Loop Control PID Mechanism for High Voltage Photovoltaic Application

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4923
R. Arulmurugan , N. Suthanthira Vanitha
This paper proposes a new dc to dc boost converter using closed loop control proportional Integral and Derivative mechanism for photovoltaic (PV) standalone high voltage applications. The boost converter is composed of MOSFETs which are driven by closed loop PWM control. Many advantages including high efficiency, minimum number of switch, high voltage and power, low cost. This converter is attractive for high voltage and high power applications. The analysis and design considerations of the converter are presented. A prototype was implemented for an application requiring a 410W output power, input voltage range from 17.1-V, and a 317-V output voltage. The proposed system efficiency is about 90%.DOI: http://dx.doi.org/10.11591/ijpeds.v2i4.2126
Volume: 2
Issue: 4
Page: 434-444
Publish at: 2012-12-01

Self-Tuning Fuzzy PI-Type Controller in Z-Source Inverter for Hybrid Electric Vehicles

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4914
Pham Cong Thanh , AnWen Shen , Phan Quoc Dzung , Nguyen Bao Anh , Le Hoang Viet
This paper presents new algorithms to control speed induction motor (SIM) and the peak dc-link voltage (PDV) across the inverter bridge in z-source inverters (ZSI) by applying self-tuning fuzzy PI controller (SFP) with robust structure and non-linear characteristic. In particular, this so-called SFP based control algorithm (SFPA) is applied to a closed loop speed controlsystem of induction motor, which relies on direct torque controlscheme combined with modified space vector modulation (DTCMSVM) control strategy with so many exceptional features (e.g. fast torque response, low steady state torque ripple, and high accurate). Additionally, SFPA is used to control SIM and PDV are more adaptive to the sudden change of parameters such as load torque, stator resistance and dc input voltage (DIV), respectively. The transient response of SIM and PDV are thus improved with less over shoot, short rise time, small steady-state error and fast settling time, with low disturbance for output voltage stabilization in the inverter bridge. As a result, we achieve higher accuracy and robustness of SIM control system. Our new SFPA is verified in both simulation and experimental implementation using MATLAB and dSPACE DS1103, respectively.DOI: http://dx.doi.org/10.11591/ijpeds.v2i4.571
Volume: 2
Issue: 4
Page: 353-363
Publish at: 2012-12-01

Rain Attenuation Modelling and Mitigation in The Tropics: Brief Review

https://ijece.iaescore.com/index.php/IJECE/article/view/5299
Abayomi Isiaka Yussuff , Nor Hisham Khamis
This paper is a brief review of Rain AttenuationModelling and Mitigation in the Tropics. The fast depleting availability of the lower frequency bands like the Ku-band as a result of congestion by commercial satellite operations coupled with severe rain attenuations experienced at higher frequency bands (Ka and Q/V), particularly in the tropical regions which was caused by higher rainfall rates and bigger raindrop size, amongst others; it was pertinent that deliberate effforts be geared towards research along this direction. This became even more critical owing to a dearth database along the slant path in the tropical regions for use in rain propagation studies at microwave frequencies, especially at millimeter wave bands (where most signal depolarization and fading takes place). The results presented in this work are valuable for design and planning of the satellite link, particularly in the tropical regions.DAH, ITU-R and SAM model simulations along the slant-path were investigated using local rainfall data at 0.01% of the time, while making use of TRMM data from NigComSat-1 satellite to obtain the measured data for Lagos. Terrestrial attenuation data for 0.01% of the time for UTM were obtained from the UTM wireless communication center (WCC). The attenuation data were thereafter transformed to slant path using transformation technique proposed for Ku band byA. Y. Abdulrahman. Theattenuation exceeded for other percentages of the average year was obtained using statistical interpolation extrapolation method.It was observed that the proposed model predicts creditably well for the ka down link frequency band, by producing the best performance when compared with SAM, DAH and ITU-R models.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1222
Volume: 2
Issue: 6
Page: 748-757
Publish at: 2012-12-01

A Daily-level Purchasing Model at an E-commerce Site

https://ijece.iaescore.com/index.php/IJECE/article/view/5310
Shota Sato , Yumi Asahi
Recently, the e-commerce sites market in Japan is growing. Many companies in e-commerce sites compete for customers each other. Therefore, e-commerce managers need to find good customers who may benefit before these customers purchase at rivals. Some preceding studies discuss which visits lead to purchase. However, it is unclear when a customer visits. In our approach, we predict the day a customer will purchase. As a result, we found some customers who tend to purchase on the day after they viewed many product pages. We also found that product page viewing before purchasing may be one of good predictors.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1816
Volume: 2
Issue: 6
Page: 831-839
Publish at: 2012-12-01

Performance of Light Emitting Diode on Surface Machined Heat Sink

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4917
S. Shanmugan , D. Mutharasu , O. Zeng Yin
In the point of efficient heat removal from light emitting diode (LED) package to ambient, the surface of the heat sinks must be finished based on required condition. The surface finishing plays an important role in efficient heat dissipation. In our work, the top surface of heat sink was machined like two different shapes (slotted and ‘W’ shaped) and tested the thermal performance for 3W green LED. The total thermal resistance was high for ‘W’ shaped surface at 100 mA. Surface modification was not influenced much on the thermal resistance (Rth) value at higher operating current. Noticeable increase on junction temperature was observed for ‘W’ shaped surface at 100 mA than slotted surface. In optical properties, low lux values were recorded for ‘W’ shaped surface at all operating current. In addition, ‘W’ shaped surface showed low value in CRI than other two surfaces (plain and slotted). The observed CCT value was decreased as the measuring time increased. High value in CCT was observed for ‘W’ shaped surface at higher operating current (> 350mA). Slotted surface showed good performance on both thermal and optical properties of the given 3W green LED.DOI: http://dx.doi.org/10.11591/ijpeds.v2i4.2125
Volume: 2
Issue: 4
Page: 380-388
Publish at: 2012-12-01

Capacitance-Voltage Characteristics of Nanowire Trigate MOSFET Considering Wave Function Penetration

https://ijece.iaescore.com/index.php/IJECE/article/view/5304
Md. Alamgir Hossain , Arif Mahmud , Mahfuzul Haque Chowdhury , Md. Mijanur Rahman
Short channel  effects on the gate capacitance of nanowire trigate MOS field-effect transistors are studied considering wave function penetration. Capacitance-Voltage (C‑V) measurements are commonly used in studying gate-oxide quality in detail.  C‑V test results offer a wealth of device and process information, including bulk and interface charges. Capacitance indicates switching speed of the MOSFET. It is our goal to minimize capacitance as possible as we can in MOSFET. Due to our necessary to compact the Integrated Circuit as possible as we can for getting small electronics devices. Capacitance determines the speed of the IC. Every engineer in this section should know capacitance of his implementing device MOSFET to get exact result from this device. Whenever we deal with 10X10 nm scale or less device of MOSFET. We must concern the effect of wave function penetration into device in this stage classical mechanics fails to describe exact result of the system because electron can move in only one direction (x), in 3 Dimension, it cannot move in other two direction (y, z). i.e. confined in two direction which is not predictable by classical mechanics here quantum mechanics (QM) gives better solution of this problem. Therefore we consider QM in our study. Here we presented how wave function play vital role considering small area of trigate MOSFET. It is the analytical approach of QM and highly recommendation to use QM rather than CM to get accuracy. This result will be helpful for determining capacitance of trigate MOSFET.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1785
Volume: 2
Issue: 6
Page: 785-791
Publish at: 2012-12-01

Real time control of an active power filter under distorted voltage condition

https://ijpeds.iaescore.com/index.php/IJPEDS/article/view/4922
Ahmed Safa , Gouichiche Madjid , Meslem Youcef , Tedjini Hamza
This paper, presents three phase shunt active filter under distorted voltage condition, the active power filter control is based on the use of self-tuning filter (STF) for reference current generation and on space vector PWM for generation of pulses. The dc capacitor voltage is controlled by a classical PI controller.  The diode rectifier feed RL load is taken as a nonlinear load. The self-tuning filter allows extracting directly the voltage and current fundamental components in the axis without phase locked loop (PLL) under distorted voltage condition. The experiment analysis is made based on working under distorted voltage condition, and the total harmonic distortion of source current after compensation .Self tuning filter based extraction technique is good under distorted voltage conditions. The total harmonic distortion (THD) of source current is fully reduced. The effectiveness of the method is theoretically studied and verified by experimentation.DOI: http://dx.doi.org/10.11591/ijpeds.v2i4.397
Volume: 2
Issue: 4
Page: 424-433
Publish at: 2012-12-01

ARIMA Model for Gold Bullion Coin Selling Prices Forecasting

10.11591/ijaas.v1.i4.pp153-158
Lazim Abdullah
Time series forecasting is an active research area that has drawn considerable attention for applications in a variety of areas. Auto-Regressive Integrated Moving Average (ARIMA) models are one of the most important time series models used in financial market forecasting over the past three decades but not very often used to forecast gold prices.  This paper attempts to address the forecasting of gold bullion coin selling prices. The forecasting models ARIMAs are applied to forecast the gold bullion coin prices. The result suggests that ARIMA (2, 1, 2) is the most suitable model to be used for forecasting gold bullion coin prices. Closer examination suggests that the gold bullion coin selling prices are in upward trends and could be considered as a worthy investment.
Volume: 1
Issue: 4
Page: 153-158
Publish at: 2012-12-01

Byssus as a Means of Metal Excretion Route and High Metal Levels in Fecal Materials as Metal Retention: An Experimental Laboratory Study Using Perna viridis

10.11591/ijaas.v1.i4.pp191-196
C. K. Yap
The present study aimed at determining the concentrations of Cd, Pb and Zn in fecal materials, byssus and different soft tissues of Perna viridis under controlled laboratory conditions during accumulation and depuration tests and to discuss the roles played by byssus and fecal materials in the coastal waters. The present findings indicated that the byssus of P. viridis acted as an excretion routes for Cd, Pb and Zn while mussels have a retention mechanism of metals as evidenced in the high metal levels found in the fecal materials during the experimental study. This implied that mussel population played an important role in expediting the metal cycling as well as supposedly nutrient cycling in the coastal ecosystem by rapidly recycling back to the coastal environment in the underlying sediments.
Volume: 1
Issue: 4
Page: 191-196
Publish at: 2012-12-01
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