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23,598 Article Results

Channel Measurements and Modelling for Indoor Power Line Communications

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/2176
Zhang Peiling , Zhang Hongxin
In order to obtain power line communications channel transmission characteristics, impulse responses measurements were performed on the basis of PN sequence’s excellent periodic autocorrelation properties. Meanwhile, a compensation method in frequency domain was proposed to improve the measurement precision. Then, the empirical multipath channel model of power line is presented from the measured results. The simulation and experimental measurement results not only have verified the efficiency of the proposed model, but also showed that the measurement method has fast, simple and convenient characteristic. Finally, the statistical characteristics of path amplitude and the delay spread are obtained through the analysis of measured results. DOI: http://dx.doi.org/10.11591/telkomnika.v11i4.2366
Volume: 11
Issue: 4
Page: 1940-1947
Publish at: 2012-04-01

Techno-economical Unit Commitment Using Harmony Search Optimization Approach

10.11591/ijape.v1.i1.pp21-28
Mohammad Sadegh Javadi
In this paper, Security-Constrained Unit Commitment (SCUC) model is proposed in a restructured power system. This model consists of a closed-loop modified Unit Commitment (UC) and Security-constrained Optimal Power Flow (SCOPF). The objective of this SCUC model is to obtain the maximum social welfare-based system operating cost while maintaining the system security. In conventional power systems, the demand was forecasted before market operation and determined as a fixed constant. Supplying this demand was therefore considered as a constraint. However, in restructured power system which is based on Standard Market Design (SMD), DISCOs offer the demand and their proposed prices; therefore the demand is modeled as an elastic load. Independent System Operator (ISO) is responsible for operating the power market. The ISO performed the power market using the SCUC software to obtain feasible and economical operation as much as possible. In this paper, Harmony Search Algorithm (HSA) has been implemented to solve SCUC problem. Since the SCUC problem is a non-linear, mixed integer, large scale and non-convex problem, harmony search optimization is addressed as an efficient technique to overcome the aforementioned challenges. The simulation results show that the presented method is both satisfactory and consistent with expectation.
Volume: 1
Issue: 1
Page: 21-28
Publish at: 2012-04-01

Load Frequency Control of DFIG-isolated and Grid Connected Mode

10.11591/ijape.v1.i1.pp29-36
Krishnan Manickavasagam
Wind energy is one of the extraordinary promising sources of renewable energy due to its clean character, free availability and economic viability. A Doubly Fed Induction Generator (DFIG) feeds power from both the stator and the rotor windings at speeds above synchronous speed of the machine. This paper deals the load frequency control of doubly fed induction generator in isolated mode and grid connected mode. The wind turbine model is obtained using MATLAB/ SIMULINK which consists of DFIG, rotor side rectifier, grid side inverter and grid. This model is controlled by conventional controllerand proposed Load Frequency Control (LFC) method.  The results are proven that frequency control gives better results in all the aspects
Volume: 1
Issue: 1
Page: 29-36
Publish at: 2012-04-01

Reduced Dielectric Losses for Underground Cable Distribution Systems

10.11591/ijape.v1.i1.pp37-46
Hamzah Eteruddin
This paper describes the process to reduce dielectric losses for underground cable distribution system. As already known, that system is an alternative solution to energy distribution systems in urban areas. Influence of large capacitance is a separate issue that needs to be resolved. Large capacitance effect on Express Feeder of 10 miles long has resulted in power losses more than 100 MW per month. In the no-load condition, current dispatch has recorded 10 Amperes, and has increased the voltage at receiving end by 200-500 Volts, with leading power factors. Installation of the inductor to reduce cable loss dielectrics is done by changing the power factor (pf) to 0.85 lagging. After installation of the inductor, which is 5 mH/700 kVAR, dielectric losses is reduced to 3.57%, which is from 105,983 kW to 102,195 kWh per month. The capacitive leakage current has also been reduced from 249.61 Ampere to 245.17 Ampere.
Volume: 1
Issue: 1
Page: 37-46
Publish at: 2012-04-01

Improving Control Performance in DC Micro-Grids with Distributed Generations

10.11591/ijape.v1.i1.pp1-12
Weilin Li , Huimin Li , Min Luo , Yunfei Zhang
DC micro-grids are attracting more and more attention due to their capability to lead to more efficient integration of distributed generation compared with traditional AC micro-grids. In this paper, a hierarchical control architecture is proposed to improve the control performance of DC micro-grid with distributed generations (DGs), which utilize a global controller (GC) to optimize the overall process and a number of distributed local controllers (LCs) associated with each subsystem. The measurement reliability of each LC is guaranteed by an associated measurement validation module which is developed based on Polynomial Chaos Theory (PCT). The system efficiency and robust is counted in the design of GC, where synergetic control theory is adopted. Numerical simulations have been done to verify the proposed method, and the simulation results show good consistency with theoretical analysis.
Volume: 1
Issue: 1
Page: 1-12
Publish at: 2012-04-01

Security Constraint Unit Commitment Considering Line and Unit Contingencies-particle Swarm Optimization

10.11591/ijape.v1.i1.pp13-20
Mohammad Sadegh Javadi
This paper presents a new approach for considering all possible contingencies in short-term power system operation. Based on this new approach, both generator and transmission line outages would be modeled in network-based power system analysis. Multi generator and also parallel transmission lines is modeled in this methodology. We also investigate this claim that feasibility and applicability of this approach is much more than the previous analytical methodologies. Security Constrained Unit commitment (SCUC) program which is carried out by Independent System Operator (ISO), is one of the complex problems which would be handled by this approach. In this paper, a DC-Optimal Power Flow (DCOPF) methodology has been implemented by particle swarm optimization technique. The Lagrangian Relaxation technique is based on the derivatives and the PSO is a non- derivative technique. These approaches are effective tools which can be implemented for short-term and long-term power system analysis, especially for economic analysis of restructured power systems. The DCOPF methodology has been considered for LMP calculation in LR, which is not available in PSO techniques. In the other hand, PSO technique may be able to provide the optimal solution, where LR usually getting stuck at a local optimum in a large scale power system. The simulation results show that the presented methods are both satisfactory and consistent with expectation. 
Volume: 1
Issue: 1
Page: 13-20
Publish at: 2012-04-01

Influence of Fuel Injection on Gasoline Engine Performance

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/2207
Zong-zheng Ma , Xin-li Wang
Because of the most common method of preparing the fuel-air mixture for gasoline-fueled engines is port fuel injection (PFI). For reducing the wall-film entering the cylinder in liquid phase, the phenomena of wall-film entering the cylinder in liquid phase should be at minimum lever or be avoided. So the first thing for learning the wall-film is to detect the way of the wall-film entering the cylinder. Therefore, the way of the wall-film enter the cylinder in liquid phase is detected by changing the temperature of the wall-film location and time for wall-film evaporated. Then the way is validated by experiment test bed and it is improved that the way is feasible. At the end the influence of injection timing and fuel ratio on engine performance is studied based on the test bed.The results show that regardless of the expansion stroke or the intake stroke fuel injection the injection timing delay will decrese the engine power and  make emission deterioration meanwhile the twice fuel injection can improve the fuel film evaporation resulting of high-speed airflow of intake charge. DOI: http://dx.doi.org/10.11591/telkomnika.v11i4.2398
Volume: 11
Issue: 4
Page: 2141-2147
Publish at: 2012-04-01

Transient Stability Enhancement of Power System Using TCSC

https://ijece.iaescore.com/index.php/IJECE/article/view/5323
Pasuparti Sunil Kumar
This project presents the variable effective fundamental equivalent reactance capability of TCSC for enhancing the transient stability of power systems. For obtaining the varying effective fundamental equivalent reactance, two different controllers namely a speed deviation based Self-tuning Fuzzy PID Controller and a nonlinear controller are used. To validate the performance of the control schemes, the simulation studies are carried out on a single machine infinite bus system using MATLAB/ SIMULINK software package. The results of computer simulation indicate that Self-tuning Fuzzy PID controlled TCSC can not only improve the static stability of system, but also effectively damp power oscillation and enhance the transient stability of system when the power system suffers small disturbance and short circuit. In addition, it also illuminates that Self-tuning Fuzzy PID Controlled TCSC is more effective than nonlinear control, traditional PID control and fixed series compensation.DOI:http://dx.doi.org/10.11591/ijece.v2i3.245
Volume: 2
Issue: 3
Page: 317-324
Publish at: 2012-03-15

A 5.9 GHz Low Power and Wide Tuning Range CMOS Current-controlled Ring Oscillator

https://ijece.iaescore.com/index.php/IJECE/article/view/5317
Prapto Nugroho , Ramesh K. Pokharel , Haruichi Kanaya , Keiji Yoshida
Designing low power, low noise, wide tuning range and small size circuit in one single chip is very challenging. This paper describe a low power, wide tuning range three-stage current-controlled ring oscillator (CCO) designed on 0.18um CMOS technology. The CCO circuit has tuning range from 251 MHz to 5.5 GHz or 183% wide. It consumes only 144 uA to 9.76mA by using 1.8V power supply. Phase noise is -104 dBc /Hz at 5.5 GHz and 4 Mhz offset frequency.  Calculated FoM is -154.4 dBc /Hz which is the best among published counterpart papers. The size of the core oscillator circuits without bonding pads is only 0.0003 mm2.DOI:http://dx.doi.org/10.11591/ijece.v2i3.229
Volume: 2
Issue: 3
Page: 293-300
Publish at: 2012-03-15

Modal Coupling Coefficients and Frequency/Bias Planes for Gyromagnetic Boundary Value Problems

https://ijece.iaescore.com/index.php/IJECE/article/view/5322
Junaid Zafar , Tasneem Zafar , Haroon Zafar
In this paper, electromagnetic and uniform precession magnetostatic mode interaction theory is reformulated to include comprehensive electromagnetic modal impact in the determination of modal coupling calculations. For this purpose orthogonal electromagnetic and normal magnetostatic modes character is solved with coupled field Maxwell’s equations and vectorized magnetization expression to model the interactions between electromagnetic modes and magnetostatic uniform precession mode. Calculations for modal coupling factors are presented here for the first time and frequency/ bias planes are constructed using the developed modal interaction formulation with an ameliorated accuracy. The proposed formulation is validated and tested against closed form frequency/ bias solutions concerning these gyromagnetic boundary value problems.DOI:http://dx.doi.org/10.11591/ijece.v2i5.222
Volume: 2
Issue: 5
Page: 609-614
Publish at: 2012-03-15

Study of Wind Turbine based SEIG under Balanced/Unbalanced Loads and Excitation

https://ijece.iaescore.com/index.php/IJECE/article/view/5333
Ashwani Kumar Sharma , A. Kumar , K. S. Sandhu
This paper presents the performance of a stand-alone self-excited induction generator (SEIG) driven by fixed pitch wind turbine. The main objective of the paper is: (i) dynamic study of SEIG under balanced R-L/R-C loads (ii) dynamic study of SEIG under balanced and unbalanced excitation, (iii) Fixed pitch wind turbine model has been considered for driving induction generator. An approach based on dynamic equations of an isolated SEIG under balanced/unbalanced conditions of loads is employed to study the behaviour of the system. The SEIG model with balanced/un-balanced load and excitation has been simulated using MATLAB/SIMULINK.DOI:http://dx.doi.org/10.11591/ijece.v2i3.303
Volume: 2
Issue: 3
Page: 353-370
Publish at: 2012-03-15

An Efficient Adaptive Noise Cancellation Scheme Using ALE and NLMS Filters

https://ijece.iaescore.com/index.php/IJECE/article/view/5325
Jafar Ramadhan Mohammed , Muhammad Safder Shafi , Sahar Imtiaz , Rafay Iqbal Ansari , Mansoor Khan
The basic theme of our paper is to implement a new idea of noise reduction in the real time applications using the concepts of adaptive filters.  Our model which is presented as one of the solutions is based on two stages of operation with the first stage based on the ALE (Adaptive Line Enhancer) filters and the second stage on NLMS (Normalized Least Mean Square) filter. The first stage reduces the sinusoidal noise from the input signal and the second stage reduces the wideband noise. Two input sources of voice are used; one for the normal speech and the other for the noise input, using separate microphones for both signals. The first signal is of the corrupted speech signal and the second signal is of only the noise containing both wideband and narrowband noise. In the first stage the narrowband noise is reduced by using the ALE technique. The second stage gets a signal with ideally only the wideband noise which is reduced using the NLMS technique.  In both the stages the concerned algorithms are used to update the filter coefficients in such a way that the noise is cancelled out from the signal and a clean speech signal is heard at the output.DOI:http://dx.doi.org/10.11591/ijece.v2i3.246
Volume: 2
Issue: 3
Page: 325-332
Publish at: 2012-03-15

An Intelligent Online Vehicle Tyre Pressure Monitoring System

https://ijece.iaescore.com/index.php/IJECE/article/view/5319
Santhosh krishna venkata , Pankaj Kumar Bhowmik
This paper aims at designing an intelligent online tyre pressure monitoring system (TPMS). The objective of this work is to display the tyre pressure of the tyre and also give the indication about the quality. The data corresponding to the tyre pressure is obtained with a high precision MEMS pressure sensor. The output of the MEMS pressure sensor is amplified and transmitted to the processing unit placed on the dash of the vehicle using wireless communication (RF). The processing is carried on using fuzzy logic algorithms on LabVIEW platform. The output pressure is displayed along with the indicator representing the quality. Indicator is green when the tyre pressure is in the desired range specified by the manufacturer. Yellow when the pressure has dropped and need to be inflated. Red indicates tyre pressure is below the safety driving conditions. After testing and validating the entire system using LabVIEW. The entire code is converted to verilog code and dumped on to FPGA chip (Spartan 3E) using FPGA module of LabVIEW with CompactRIO, for implementation of FPGA chip on real time system.DOI:http://dx.doi.org/10.11591/ijece.v2i3.239
Volume: 2
Issue: 3
Page: 301-308
Publish at: 2012-03-15

A Novel Approach For Face Recognition Using Fusion Of Local Gabor Patterns

https://ijece.iaescore.com/index.php/IJECE/article/view/5330
Santosh Nagnath Randive , Anil Balaji Gonde
For face recognition, Gabor features are effectively used. But, only a few approaches used Gabor phase features and they are performing worse than the Gabor magnitude features. To determine the potential of Gabor phase and its fusion with magnitude for face recognition, in this paper, we have proposed local Gabor XOR pattern (LGXP) operator, which encode Gabor phase. Then we introduce block-based Fisher’s linear discriminant (BFLD) for reduce dimensionality of proposed operator and at same time discriminative power also get enhanced. At last, by using BFLD we fuse Gabor phase and Gabor magnitude for face recognition. We evaluate our method for FERET database. Also, we perform comparative experimental studies of different local patterns.DOI:http://dx.doi.org/10.11591/ijece.v2i3.279 
Volume: 2
Issue: 3
Page: 345-352
Publish at: 2012-03-15

Simulation and Implementation of a High Performance Torque Control Scheme of IM Utilizing FPGA

https://ijece.iaescore.com/index.php/IJECE/article/view/5313
R. Rajendran , N. Devarajan
Thi paper presents a novel approach to design and implementation of a high perfromane torque control scheme i.e. direct torque control with space vector modulation(DTC-SVM) of three phase induction motor using Field Programmable gate array (FPGA). The conventional direct torque control (DTC) is one of control scheme that is used commonly in induction motor control system. This method supports a very quick and precise torque response. However, the conventional DTC is not perfect and has some disadvantages. To minimize the ripples of the electromagnetic torque and flux linkage and to fix the variable switching frequency produced in the conventional DTC, this paper proposes improved DTC-SVM concept. Both simulation and experimental results show that the proposed scheme can dramatically improve the steady state performance while preserving the dynamic performance of the conventional DTC.DOI:http://dx.doi.org/10.11591/ijece.v2i3.208
Volume: 2
Issue: 3
Page: 277-284
Publish at: 2012-03-15
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