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29,734 Article Results

Active and reactive power management of grid connected photovoltaic system

10.11591/ijeecs.v13.i3.pp1324-1331
Ameerul A. J. Jeman , Naeem M. S. Hannoon , Nabil Hidayat , Mohamed.M.H. Adam , Ismail Musirin , Vijayakumar. V
Voltage-source converter (VSC) topology is widely used for grid interfacing of distributed generation (DG) systems such as the photovoltaic system (PV). Since the operation of the VSC is essential to ensure quality of active and reactive power injected to the grid, a control approach is needed to deal with the uncertainties in the grid such as faults. This paper presents a non-linear controller design for a three-phase voltage source converter (VSC). The dynamic variables adopted for the VSC are the instantaneous real and reactive power components. The control approach that interface the VSC between the PV system and the grid are subjected to the current-voltage based. PV system injects active power to the grid and local load while utility grid monitors the power compensation of load reactive power. The proposed non-linear control strategy is implemented for the VSC to ensure fast error tracking and finite convergence time. The adaptive nature of the proposed non-linear control provides more robustness, less sluggish fault recovery compared to conventional PI control. The comprehensive numerical model is demonstrated in MATLAB script environment with power system disturbances such as faults in the grid. The simulation of proposed system is being carried out in MATLAB/SIMULINK environment to validate the control scheme. The proposed control system regulates the VSC ac side real and reactive power component and the dc side voltage.
Volume: 13
Issue: 3
Page: 1324-1331
Publish at: 2019-03-01

Vocabulary size, reading motivation, reading attitudes and reading comprehension performance among Filipino college learners of english

10.11591/ijere.v8i1.15335
Rosalyn Gunobgunob-Mirasol
Reading is an indispensable tool in the academic world. Most, if not all, activities in varied collegiate courses entail the act of reading. There are many contributing factors that affect one’s ability to read and comprehend text materials effectively. Two of the many factors are the reader’s vocabulary size and their reading motivation. This study examined the relationship of the vocabulary size, reading strategies and the reading comprehension performance of college learners in a comprehensive university in the Philippines. A correlational analysis was employed to ascertain the relationship between the scores in the reading comprehension component of the course and the vocabulary levels tests by Nation [1]. The findings of this study hope to provide useful insights into the prediction of college learners’ reading performance and the teaching of vocabulary in the ESL context as well as the integration of learners’ reading motivation in the curriculum.
Volume: 8
Issue: 1
Page: 64-70
Publish at: 2019-03-01

Performance identification of the asynchronous electric drives by the spectrum of rotor currents

10.11591/ijpeds.v10.i1.pp211-218
Vladimir L. Kodkin , Aleksandr Sergeevich Anikin , Aleksandr A. Baldenkov
The efficiency of analyzing the rotor currents of asynchronous electric drives with frequency control is substantiated in the article. To assess the quality of torque generation in the engine it is suggested to use the spectral analysis of these currents and the fundamental harmonic, as the most accurate "conformity" of slip in an asynchronous motor. The proposed method showed that "sensorless vector" control leads to the appearance of high-frequency harmonics with significant amplitude. Because of these harmonics, a non-sinusoidal electromagnetic moment is created and the performance of the drive is decreased. The most effective method of torque generation is the frequency control with positive stator current feedback. This control is dominated by pronounced harmonic components, which indicates the proximity of this structure to linear and significantly better controllability of the drives, which makes promising their use in high-tech mechanisms, in particular, in industrial robots. Simulation and experiments confirm the proposed theoretical propositions.
Volume: 10
Issue: 1
Page: 211-218
Publish at: 2019-03-01

Motion control applications: observer based DC motor parameters estimation for novices

10.11591/ijpeds.v10.i1.pp195-210
Branesh M Pillai , Jackrit Suthakorn
Estimation of motor inertia and friction components is a complex and challenging task in motion control applications where small size DC motors (<100W) are used for precise control. It is essential to estimate the accurate friction components and motor inertia, because the parameters provided by the manufacturer are not always accurate.  This research proposes a Sensorless method of determining DC motor parameters, including moment of inertia, torque coefficient and frictional components using the Disturbance Observer (DOB) as a torque sensor. The constant velocity motion test and a novel Reverse Motion Acceleration test were conducted to estimate frictional components and moment of inertia of the motor. The validity of the proposed novel method was verified by experimental results and compared with conventional acceleration and deceleration motion tests. Experiments have been carried out to show the effectiveness and viability of the estimated parameters using a Reaction Torque Observer (RTOB) based friction compensation method.
Volume: 10
Issue: 1
Page: 195-210
Publish at: 2019-03-01

High-performance active power filter implementation based on predictive current control

10.11591/ijpeds.v10.i1.pp277-287
Bachar Rahima , Golea Amar , Benchouia Mohamed Toufik , Chebaani Mohamed
This paper presents the use of the predictive strategy concept to improve the Active Power Filter (APF) performance, by compensation of the reactive power and elimination of the harmonic currents generated by non-linear loads. Predictive control is generating considerable interest when it comes to implementing current control strategies in active power filter. The proposed strategy provides a simple controller incorporating Phase Locked Loop (PLL) independency. The prediction is evaluated using a cost function that quantifies the desired system behavior. The cost function used in this work evaluates the filtered error of the currents. This strategy minimized the number of sensors, ease of practical implementation and reduced system size and cost. The effectiveness of the proposed controller is confirmed through simulation and experimental validation using a hardware prototype based on dSPACE-1104
Volume: 10
Issue: 1
Page: 277-287
Publish at: 2019-03-01

A simple constant switching frequency of direct torque control of brushless DC motor

10.11591/ijpeds.v10.i1.pp10-18
Yusnida Ahmad Tarmizi , Auzani Jidin , Kasrul Abdul Karim , T. Sutikno
This paper discusses about direct torque control of Brushless DC motor by injecting the triangular waveform and using PI controller in order to reduce the torque and obtain constant switching frequency. Brushless DC motor are widely used in applications which require wide range of speed and torque control because of robust, longer lifespan, faster torque response and able to operate at high speed.  Unlike conventional three phase DTC of induction machine (IM),the proposed DTC approach introduces two phase conduction mode. Besides that, the magnitude flux is considered constant in which the results only gains from constant torque region. Thus, the flux control loop is eliminated while implement this scheme. Using the triangular waveform that will be compare with actual torque, the proper switching pattern can be selected to control the generated torque and reducing commutation torque ripple. The torque response depends on the speed of the stator flux linkage which is directly controlled by selecting appropriate voltage space vectors from a look-up table to make sure the torque error within the band. The validity of the proposed control scheme for constant switching frequency and reduce torque ripple are verified through simulation and experimental results.
Volume: 10
Issue: 1
Page: 10-18
Publish at: 2019-03-01

Verification and validation of IM-DeCRuD approach using DESMET for its applicability

10.11591/ijeecs.v13.i3.pp1311-1317
Jamaluddin Jasmis , Shamsul Jamel Elias , Azlan abdul Aziz , Mohd Zaki Zakaria , R Badlishah Ahmad , Roshidi Din , Rosmadi Bakar
Requirements crosscutting in software development and maintenance have gradually become an important issue in software engineering with a growing need of traceability support to better understand the requirements crosscutting processes to comply with industrial standards. However, many recent works focusing on identification, modularization, composition and conflict dissolution of requirements crosscutting are mostly saturated at requirements level. Hence, these works fail to specify crosscutting properties for functional and non-functional requirements at other phases leading to insufficient support for software engineers. Recently, a new approach called the Identification, Modularization, Design Composition Rules and Conflict Dissolutions (IM-DeCRuD) was proposed to provide a special traceability to facilitate better understanding and reasoning towards requirements crosscutting implementation, along with a tool as a proof-of-concept. In this paper, the tool was evaluated and the results were verified by some experts in the industries. The feedbacks on applicability aspect were then gathered and analyzed using DESMET qualitative method. The outcome showed that the IM-DeCRuD was applicable to cope with the tedious engineering processes in handling crosscutting properties at requirements, analysis and design phases for system development and evolution.
Volume: 13
Issue: 3
Page: 1311-1317
Publish at: 2019-03-01

Speech recognition of moroccan dialect using hidden markov models

10.11591/ijai.v8.i1.pp7-13
Bezoui Mouaz , Beni-hssane Abderrahim , Elmoutaouakkil Abdelmajid
This paper addresses the development of an Automatic Speech Recognition (ASR) system for the Moroccan Dialect. Dialectal Arabic (DA) refers to the day-to-day vernaculars spoken in the Arab world. In fact, Moroccan Dialect is very different from the Modern Standard Arabic (MSA) because it is highly influenced by the French Language. It is observed throughout all Arab countries that standard Arabic widely written and used for official speech, news papers, public administration and school but not used in everyday conversation and dialect is widely spoken in everyday life but almost never written. we propose to use the Mel Frequency Cepstral Coefficient (MFCC) features to specify the best speaker identification system. The extracted speech features are quantized to a number of centroids using vector quantization algorithm. These centroids constitute the codebook of that speaker. MFCC’s are calculated in training phase and again in testing phase. Speakers uttered same words once in a training session and once in a testing session later. The Euclidean distance between the MFCC’s of each speaker in training phase to the centroids of individual speaker in testing phase is measured and the speaker is identified according to the minimum Euclidean distance. The code is developed in the MATLAB environment and performs the identification satisfactorily.
Volume: 8
Issue: 1
Page: 7-13
Publish at: 2019-03-01

A battery-less power supply using supercapacitor as energy storage powered by solar

10.11591/ijpeds.v10.i1.pp568-574
Mohammad Hadin A. Malek , Farahiyah Mustafa , Anis Maisarah Mohd Asry
This paper presents a battery-less power supply using supercapacitor as energy storage powered by solar. In this study the supercapacitor as energy storage, as opposed to batteries, has widely researched in recent years. Supercapacitors act like other capacitors, but their advantage is having enormous power storage capabilities. Maximum charging voltage and capacitance are two variables of storage in the supercapacitor. The supercapacitor is used as energy storage to charge a low power device wirelessly and act as a power supply. The solar energy is used as a backup power supply if there is no electricity in the remote or isolated area to charge the supercapacitor. The time taken to charge the supercapacitor depend on the amount of current rating of the solar panel. The higher the current, the shorter the time taken to charges the supercapacitor. Power supply using supercapacitor can store up to 30 Vdc using a DC-DC boost converter.
Volume: 10
Issue: 1
Page: 568-574
Publish at: 2019-03-01

Optimization of PFC cuk converter parameters design for minimization of THD and voltage ripple

10.11591/ijpeds.v10.i1.pp514-521
M. A. Z. A. Rashid , A. Ponniran , M. K. R. Noor , J. N. Jumadril , M. H. Yatim , A.N. Kasiran
This paper presents the optimization of PFC Cuk converter parameter design for the minimization of THD and voltage ripple. In this study, the PFC Cuk converter is designed to operate in discontinuous conduction mode (DCM) in order to achieve almost unity power factor. The passive components, i.e., inductor and capacitor are designed based on switching frequency and resonant frequency. Nevertheless, the ranges of duty cycle for buck and boost operations are 0<D<0.5 and 0.5<D<1, respectively for the output voltage variation of the converter. The principle of the parameters design optimization is based on the balancing energy compensation between the input capacitor and output inductor for minimization of THD current. In addition, the selection of high output capacitance will minimize the output voltage ripple significantly. A 65 W PFC Cuk converter prototype is developed and experimentally tested to confirm the parameters design optimization principle. The experimental results show that the THD current is reduced to 4.5% from 61.3% and the output voltage ripple is reduced to 7 V from 18 V after parameters optimization are realized. Furthermore, it is confirmed that the output voltage ripple frequency is always double of the input line frequency, 50 Hz and the output voltage ripple is always lower than the maximum input voltage ripple.
Volume: 10
Issue: 1
Page: 514-521
Publish at: 2019-03-01

GA-ANFIS PID compensated model reference adaptive control for BLDC motor

10.11591/ijpeds.v10.i1.pp265-276
Murali Dasari , A Sreenivasula Reddy , M Vijaya kumar
Adaptive control is one of the widely used control strategies to design advanced control systems for better performance and accuracy. Model reference adaptive control (MRAC) is a direct adaptive strategy with some adjustable controller parameters and an adjusting mechanism to adjust them. In this work Model Reference Adaptive Control for BLDC motors has been designed with a PID controller tuned by GA-ANFIS. GA-Trained ANFIS framework for tuning the PID controller has been proposed. This is used along with the MRAC to deliver enhanced performance in the control of BLDC motor. The performance of the proposed approach is validated for motor control under conditions of change in speed, change in load, change in inertia and change in phase resistance.. The performance is validated against convention PID and self tuning PID controllers. The result demonstrates a superior performance of the proposed approach
Volume: 10
Issue: 1
Page: 265-276
Publish at: 2019-03-01

Smart database concept for Power Management in an electrical vehicle

10.11591/ijpeds.v10.i1.pp160-169
Chokri Mahmoudi , Flah Aymen , Sbita Lassaad
As world population continues to grow and the limited amount of fossil fuels begin to diminish, it may not be possible to afford the needed amount of energy demanded by the world by only using fossil fuels. Meanwhile, the abundant nature of renewable energy sources brings new beginning for next generations. Greater penetration of electric vehicles will play an important role in building green and healthy world. The main remaining issue to make the switch from conventional to electric vehicle is performance cost; Efficient EVs that can drive for long distances, on single charge, are still expensive for ordinary consumer. To address this range problem, many attempts have been made during last decade. The goal was to conceive a power efficient electric vehicle, capable of managing its energy and reach longer distances. It depends on the electrical architectures and used algorithms.This paper adds new perspective for power Management in EVs; The proposed methodology introduces a new power management architecture based on communication and car learning. The conventional software level in EV has been replaced with self readjustable software. EVs are connected through a database, and can upload or download adjustment parameters while software is running.To take advantage of the new architecture, a new learning technique concept is introduced too, based on Cloud experience exchange between Electric Vehicles. This enhancement aims to build a better EV experience in power management through Cloud sharing and definitely cut with conventional architecture that may have reached its boundaries.
Volume: 10
Issue: 1
Page: 160-169
Publish at: 2019-03-01

NSGA-II and MOPSO based optimization for sizing of hybrid PV/wind/battery energy storage system

10.11591/ijpeds.v10.i1.pp463-478
Mohamed Izdin Hlal , Vigna K. Ramachandaramurthya , Sanjeevikumar Padmanaban , Hamid Reza Kaboli , Aref Pouryekta , Tuan Ab Rashid bin Tuan Abdullah
This paper presents a Stand-alone Hybrid Renewable Energy System (SHRES) as an alternative to fossil fuel based generators. The Photovoltaic (PV) panels and wind turbines (WT) are designed for the Malaysian low wind speed conditions with battery Energy Storage (BES) to provide electric power to the load. The appropriate sizing of each component was accomplished using Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi-Objective Particle Swarm Optimization (MOPSO) techniques. The optimized hybrid system was examined in MATLAB using two case studies to find the optimum number of PV panels, wind turbines system and BES that minimizes the Loss of Power Supply Probability (LPSP) and Cost of Energy (COE). The hybrid power system was connected to the AC bus to investigate the system performance in supplying a rural settlement. Real weather data at the location of interest was utilized in this paper. The results obtained from the two scenarios were used to compare the suitability of the NSGA-II and MOPSO methods. The NSGA-II method is shown to be more accurate whereas the MOPSO method is faster in executing the optimization. Hence, both these methods can be used for techno-economic optimization of SHRES. 
Volume: 10
Issue: 1
Page: 463-478
Publish at: 2019-03-01

Good teacher perceptions of students attending the pedagogical formation certificate program

10.11591/ijere.v8i1.17093
Zeynep Ayvaz-Tuncel , İbrahim Tuncel
A pedagogical formation certificate is required to become a teacher in secondary schools in Turkey. This certificate program, which is required to obtain in addition to a bachelor’s degree from any faculty other than the education faculties, aims at providing the knowledge, capabilities and attitudes required by the profession of teaching. This study aims at determining the perceptions of prospective teachers attending the pedagogical formation program about the properties of a good teacher. Data were collected using a survey comprising an open-ended question and content analysis was conducted to obtain the themes in this study, which adopted a descriptive method. Based on the properties of a good teacher, expressed by the prospective teachers, the themes “personal characteristics”, “enforcement of teaching process”, “establishing a democratic classroom environment” and “assessment and evaluation” are obtained.
Volume: 8
Issue: 1
Page: 165-172
Publish at: 2019-03-01

Adaptive filter-FLC integration for torque ripples minimization in PMSM using PSO

10.11591/ijpeds.v10.i1.pp48-57
Yasser Ahmed , Ayman Hoballah
The article presents torque and flux ripples minimization based on adaptive filter. The adaptive filter coefficients optimized and adapted on line by using particle swarm optimization (PSO) technique. The proposed methodology applied on closed loop speed control based on direct torque control (DTC) for surface mounted permanent magnet synchronous motor (PMSM). Fuzzy logic controller (FLC) used as speed controller while proportional-integral (PI) controller used as torque and flux controllers. Second order infinite impulse response (IIR) filter is used for ripple reduction generated due to FLC. The drive system modeled using Matlab/Simulink software in order to dynamically evaluate the performance of the proposed drive system at different operating conditions. The results provide evidence that the adaptive filter-FLC integration with optimal coefficients minimizes torque and flux ripples with reduction of total harmonic distortion generated in the three-phase currents.
Volume: 10
Issue: 1
Page: 48-57
Publish at: 2019-03-01
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