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28,910 Article Results

Phase Sequence Online Correction Based on PIC Technique

10.11591/ijaas.v6.i1.pp49-54
Bilal A. Mubdir , Dara H. Amin
Monitoring the delivered power quality (PQ) to a critical load, is a worry issue since it is matter as much as critical or quality sensitive equipment connected to the electrical network. Various PQ problems such as noise, voltage imbalance, waveform distortion, phase imbalance, phase sequence, over voltage or sag are the most popular quality problems that could be detected and fixed if needed. The present work presents a design and practical implementation of electronic embedded system to monitoring the sequence of a three phase electrical system and detects the occurrence of any change in the sequence and fixes it online, correct the phase sequence immediately during less than 70 milli-seconds. PIC Microchip microcontroller has been used as the core of the present system, where the correction of the phases has been achieved by using traditional electromechanical relays. The system has been tested successfully and it functions properly even with multiple sequence changes.
Volume: 6
Issue: 1
Page: 49-54
Publish at: 2017-03-01

Design of Full-bridge DC-DC Converter 311/100 V 1kW with PSPWM Method to Get ZVS Condition

10.11591/ijpeds.v8.i1.pp59-68
Toni Prasetya , F. Danang Wijaya , Eka Firmansyah
Enhancing the switching frequency can increase the power density of a fullbridge dc-dc converter. However, power loss in switches will increase due to the intersection of voltage and current during turn-on and turn-off transition process. The switching power loss can be reduced by making the condition of zero voltage switching (ZVS) which in this study is obtained by using the phase-shifted PWM method. Achieving this condition requires appropriate parameters such as deadtime, leakage inductance, and the primary current of transformer in sufficient value. In this study, ZVS is achieved when the transformer leakage inductance of 14.12 μH is added with external inductance of 24.29 μH which is installed in series with transformer and when the primary current of transformer is more than 1.289 A.
Volume: 8
Issue: 1
Page: 59-68
Publish at: 2017-03-01

An Intelligent Power Management Investigation for Stand-alone Hybrid System Using Short-time Energy Storage

10.11591/ijpeds.v8.i1.pp367-375
Ben Slama Sami
Stand-alone Hybrid systems become appreciating issues that ensure the required electricity to consumers. The development of a stand-alone Hybrid system becomes a necessity for multiple applications The enhance energy security. To achieve this objective, we have proposed an accurate dynamic model using Multi-Agent System (MAS) in which a solar energy System (SES) serves as the main load supply, an energy Backup System (ERS) is based on a fuel cell and Electrolyzer for long-term energy storage and an Ultra Capacitor (UCap) storage system deployed as a short-time storage. To cooperate with all systems, an Intelligent Power Management (IPM) based on a specific MAS is included. Thus, to prove the performance of the system, we tested and simulated it using the Matlab/Simulink environment.
Volume: 8
Issue: 1
Page: 367-375
Publish at: 2017-03-01

Enhancing Students’ Communication Skills through Problem Posing and Presentation

10.11591/ijere.v6i1.6342
Sugito Sugito , Sri Mulyani Endang Susilowati , Hartono Hartono , Supartono Supartono
This study was to explore how enhance communication skill through problem posing and presentation method.  The subjects of this research were the seven grade students Junior High School, including 20 male and 14 female. This research was conducted in two cycles and each cycle consisted of four steps, they were: planning, action, observation, and reflection. This study use interview, observation, and questionnaire to measure most widely used data gathering in communication skill students, and daily test (pre-test and post-test) to measure enhance achievement the students’. The data was analyzed comparing initial and final score. If the final score is better than initial score had been enhanced. Results of this study indicated that teaching and learning science used problem posing and presentation method can enhance ability communication skill, confidence, courage and responsibility on themselves disciples. Researcher is suggestion to use another method to enhance communication skill.
Volume: 6
Issue: 1
Page: 17-22
Publish at: 2017-03-01

An Efficient Control Implementation for Inverter Based Harmony Search Algorithm

10.11591/ijpeds.v8.i1.pp279-289
Mushtaq Najeeb , Hamdan Daniyal , Ramdan Razali , Muhamad Mansor
This research implements a PI controller based on harmony search (HS) optimization algorithm for voltage source inverter to improve the output performance under step load change conditions. The HS algorithm aims to handle the trial and error procedure used in finding the PI parameters and then apply the proposed control algorithm via the eZdsp TMS320F28355 board to link the inverter prototype with the Matlab Simulink. The mean absolute error (MAE) is used as an optimization problem to minimize the output voltage error for the developed controller (PI-HS) as compared to the PI controller based particale swarm optimization algorithm (PI-PSO). Based on the experimental results obtained, it is noted that the proposed controller (PI-HS) provides a good dynamic performance, robustness, constant voltage amplitude, and fast response in terms of overshoot, transient, and steady-state.
Volume: 8
Issue: 1
Page: 279-289
Publish at: 2017-03-01

Active Node Detection in A Reconfigurable Microgrid using Minimum Spanning Tree Algorithms

10.11591/ijeecs.v5.i3.pp502-507
Anay Majee , Souradeep Nanda , Gnana Swathika O.V
Microgrids are the solution to the growing demand for energy in the recent times. It has the potential to improve local reliability, reduce cost and increase penetration rates for distributed renewable energy generation. Inclusion of Renewable Energy Systems (RES) which have become the topic of discussion in the recent times due to acute energy crisis, causes the power flow in the microgrid to be bi-directional in nature. The presence of the RES in the microgrid system causes the grid to be reconfigurable. This reconfiguration might also occur due to load or utility grid connection and disconnection. Thus conventional protection strategies are not applicable to micro-grids and is hence challenging for engineers to protect the grid in a fault condition. In this paper various Minimum Spanning Tree (MST) algorithms are applied in microgrids to identify the active nodes of the current topology of the network in a heuristic approach and thereby generating a tree from the given network so that minimum number of nodes have to be disconnected from the network during fault clearance. In the paper we have chosen the IEEE-39 and IEEE-69 bus networks as our sample test systems.
Volume: 5
Issue: 3
Page: 502-507
Publish at: 2017-03-01

Material Development Based on Digital Storytelling Activities and Assessment of Students’ Views

10.11591/ijere.v6i1.6347
Ozlem Ayvaz Tunc
This study was designed as a case study. The study was conducted in Anatolian Fine Arts High School during the spring semester of 2014-2015 academic year. The sample of the study consisted of a total of 10 students from 9th and 10th grades who voluntarily participated in the study. Semi-structured interviews were conducted with the 10 students named at the end of every activity. Assure instructional design model was used while designing digital storytelling activities. The data obtained from the study were analyzed through thematic analysis based on qualitative research method. Reliability method suggested by Miles and Huberman was used for reliability assessment of the study. The reliability of the thematic coding of the results was found to be 0,95 as a result of assessments. Based on the findings that digital storytelling has multidisciplinary interaction competence, it is thought that it will be appropriate to conduct future studies in different schools and fields.  
Volume: 6
Issue: 1
Page: 54-63
Publish at: 2017-03-01

Variational Iteration Method for Solving Riccati Matrix Differential Equations

10.11591/ijeecs.v5.i3.pp673-683
Khalid Hammood Al-jiz , Noor Atinah Ahmad , Fadhel Subhi Fadhel
Riccati matrix differential equation has long been known to be so difficult to solve analytically and/or numerically. In this connection, most of the recent studies are concerned with the derivation of the necessary conditions that ensure the existence of the solution. Therefore, in this paper, He’s Variational iteration method is used to derive the general form of the iterative approximate sequence of solutions and then proved the convergence of the obtained sequence of approximate solutions to the exact solution. This proof is based on using the mathematical induction to derive a general formula for the upper bound proved to be converge to zero under certain conditions. 
Volume: 5
Issue: 3
Page: 673-683
Publish at: 2017-03-01

Motor Command and Supervision Using the Magnetic Components of the Insulation Fault Protection System for Power Line Communication

10.11591/ijpeds.v8.i1.pp204-212
Matias Fernando Bulacio , Hernan Emilio Tacca
This work proposes an additional function for a VSD (Variable Speed Drive) which sends and receives information over the power lines and simultaneously, implements the protection against insulation faults to earth. Using the magnetic components of the insulation fault protection system of the motor, the prototype injects and detects the communication signals over the power line. The system works on both communication schemes, with and without the PWM (Pulse Width Modulation) perturbation in the power lines, which are the two possible real applications. In order to set a proper communication between the motor and the drive, the communication channel was modeled and the noise was characterized. An FSK modulation and demodulation scheme was developed and tested. A 10 kbps communication over a 125 m length of cable and over a 1 km pi-section model of the same cable was successfully achieved with the laboratory prototype.
Volume: 8
Issue: 1
Page: 204-212
Publish at: 2017-03-01

Nurses’ Spirituality Improves Caring Behavior

10.11591/ijere.v6i1.6343
Abu Bakar , Nursalam Nursalam , Merryana Adriani , Kusnanto Kusnanto , Siti Nur Qomariah , Laily Hidayati , Ika Nur Pratiwi , Lailatun Ni'mah
Caring was the behavior provide assistance holistically to individuals. In fact, nurses Caring behaviors made only modest, yet an art in nursing care which should always be a nurse. The good personality and spiritual be one of the factors that affect the formation of nurses Caring behaviors. Spiritual was the passion or impulse that comes out from within themselves to do the noble. The research objective was explained a spiritual relationship nurses with nurses caring behaviors. The research design was used cross sectional. The population in this researchs were associate nurses in the ward. A sample were taken of 88 nurses with consecutive sampling technique. Data collection was done at the General Hospital of Haji Surabaya, Al Irsyad General Hospital Surabaya and Muhammadiyah Gresik Hospital. Data collection was used questionnaire, with multivariate data analysis Structural Equation Modeling- Partial Least Square (PLS-SEM). The results showed no significant relationship between demographic with spiritual nurses. Demographic indicators for the hypothesis test was psychological, length of work, education, and wards. Demographics nurses with nurse caring no significant relationship. Spiritual nurses significant relationship with the caring nurses at 7.061. These results indicated that modeling should be done was draw line from the spiritual to the caring nurses and the others deleted. The conclusion of the research was the spiritual nurses significant relationship with the nurses caring behaviors. Suggestions have to do is always give spiritual training to nurses as one of supporting the implementation of nursing care.
Volume: 6
Issue: 1
Page: 23-30
Publish at: 2017-03-01

Seven Levels Symmetric H-bridge Multilevel Inverter with Less Number of Switching Devices

10.11591/ijpeds.v8.i1.pp109-116
Megat Azahari Chulan , Mohd Junaidi Abdul Aziz , Abdul Halim Mohammed Yatim , Mohd Zaki Daud
This paper proposes a new topology of a cascaded multilevel inverter that utilises less number of switches than the conventional topology. The proposed topology maintains the performance of conventional 7-levels output multilevel inverter while reducing the loss of power, installation area, converter size as well as development cost. The circuit development consists of six switches and one diode. With less number of switching devices in the circuit, there will be a reduction in the gate driver circuits and also in effect fewer switches required for specific intervals of time. Simulation works have been conducted to validate the proposed MLI topology. It is envisaged that the proposed topology can be applied for the system that requires high efficiency and a low electromagnetic interference.
Volume: 8
Issue: 1
Page: 109-116
Publish at: 2017-03-01

Direct Power Control of Brushless Doubly-fed Induction Generator Used in Wind Energy Conversion System

10.11591/ijpeds.v8.i1.pp417-433
A. Rahab , F. Senani , H. Benalla
This article describes firstly a wind power production line, principally a wind turbine constitutes her and brushless doubly fed induction generator (BDFIG). The models of these components are developed, and control objective of BDFIG is to achieve a dynamic performance similar to the doubly fed induction generator (DFIG) using a stator flux field oriented control (FOC) and direct power control (DPC) strategy. After, the simulation program using Matlab/Simulink has been developed. The performances of this strategy are evaluated and analyzed, so the results show a good robustness great dynamic and a precision of speed.
Volume: 8
Issue: 1
Page: 417-433
Publish at: 2017-03-01

Investigating College Students’ Views on Mathematics Learning Through Reflective Journal Writing

10.11591/ijere.v6i1.6345
Ivee Kalalo Guce
The study on reflective journal writing (RJW) and its benefits as assessed by the teachers has long been an inclination in mathematics education. However, little research has been done to explore the feelings of students towards RJW and how such has an effect on their mathematics learning. This study aimed to describe the feelings of the students about RJW. Being a qualitative type of research study, data were acquired through focus group discussion and were analyzed using axial coding. Results revealed that RJW (i) provided opportunities for the students to construct meaning and express personal views and ideas; (ii) built a connection between the teacher and the students; (iii) through the use of prompts, allowed the students to relate mathematics to real-life facts improving their understanding of the subject; (iv) helped the students build association of ideas using their prior knowledge and experiences; and (v) enabled the students to develop self-awareness. The findings suggest that when students are engaged in reflective writing experiences which explicitly promote meaning-making or self-questioning, teachers create an opportunity for them to see how the process of writing can enrich their mathematical learning.
Volume: 6
Issue: 1
Page: 38-44
Publish at: 2017-03-01

Crowbar Resistance Setting and its Influence on DFIG Low Voltage Based on Characteristics

10.11591/ijra.v6i1.pp31-38
Li Shengqing , Yao Ming , Yuwen Zhang
In the case of low voltage fault cases,doubly fed induction generator (DFIG) with Crowbar protection circuit to realize low voltage ride through (LVRT),and the choice of crowbar resistance of unit LVRT effects is very large.In this paper, from the DFIG wind power system steady state and transient mathematical model of voltage drop down, using space vector analysis method and Laplace transform, deduced the time domain transient current expressions of voltage drop Put forward the method for calculating the maximum fault current and the rotor side crowbar resistance setting method, solve the crowbar protection circuit for tilting rotor current and DC bus over-voltage problems. Numerical example and simulation shows that, The proposed method, effectively suppress the transient component of fault current, significantly improved the automation level of the wind power system.
Volume: 6
Issue: 1
Page: 31-38
Publish at: 2017-03-01

Primary and Secondary Education in Morocco: From Access to School into Generalization to Dropout

10.11591/ijere.v6i1.6341
Zoulal Mansouri , Mohamed El Amine Moumine
This article provides an overview of school wastage, namely repetition and dropout in primary and secondary schools in Morocco. It describes how this phenomenon has progressed since school was implemented in the 1960s. It shows that the fundamental principles of the education system established in the aftermath of Morocco’s independence in 1956 did not succeed in providing a clear, stable education program. The article concludes that despite the tremendous efforts made in enrollment, school wastage persists, and the educational system is still trapped in the idealistic principles of the 1960s, causing education to flounder in the dramatic triangle of schooling, generalization, and dropout.
Volume: 6
Issue: 1
Page: 9-16
Publish at: 2017-03-01
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