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28,593 Article Results

Open-switch Fault-tolerant Control of Power Converters in a Grid-connected Photovoltaic System

10.11591/ijpeds.v7.i4.pp1294-1308
Bilal Boudjellal , Tarak Benslimane
This paper presents the study of an open switch fault tolerant control of a grid-connected photovoltaic system. The studied system is based on the classical DC–DC boost converter and a bidirectional 6-pulse DC–AC converter. The objective is to provide an open-switch fault detection method and fault-tolerant control for both of boost converter and grid-side converter (GSC) in a grid-connected photovoltaic system. A fast fault detection method and a reliable fault-tolerant topology are required to ensure continuity of service, and achieve a faster corrective maintenance. In this work, the mean value of the error voltages is used as fault indicator for the GSC, while, for the boost converter the inductor current form is used as fault indicator. The fault-tolerant topology was achieved by adding one redundant switch to the boost converter, and by adding one redundant leg to the GSC. The results of the fault tolerant control are presented and discussed to validate the proposed approach under different scenarios and different solar irradiances.
Volume: 7
Issue: 4
Page: 1294-1308
Publish at: 2016-12-01

IOT Based Oil Condition Monitoring of Wind Turbine Gearboxes with Smart Sensor Technology

10.11591/ijaas.v5.i4.pp168-175
L. Chitra , V. Ramakrishnan
The performance parameters such as viscosity, humidity and pressure of the gear box lubricating oil should be monitored and controlled to improve the efficiency of the windmill. The recent technique like IOT is used for the continuous transmission of bulk data of these parameters from one machine to other machine which is situated in remote locations .Also the development of mobile technology and web made the live monitoring easier. Thus transmission and sharing of data takes place without any time delay. The technology also helps to completely eliminate the assistance nearby the site. The large wind farms in coastal areas are easily and continuously monitored and the data are recorded from remote locations with the mobile technology having internet connections. This paper also reports the design of MEMS viscosity sensor,MEMS humidity sensor and MEMS pressure sensor for continuous monitoring of the lubricating system .The main advantage of implementing MEMS devices is to reduce the size and cost and also the sensitivity is improved. Along with IOT, smart sensor technology is also introduced in the monitoring which avoids the serious problems that occur in wind mills.The performance parameters such as viscosity, humidity and pressure of the gear box lubricating oil should be monitored and controlled to improve the efficiency of the windmill. The recent technique like IOT is used for the continuous transmission of bulk data of these parameters from one machine to other machine which is situated in remote locations .Also the development of mobile technology and web made the live monitoring easier. Thus transmission and sharing of data takes place without any time delay. The technology also helps to completely eliminate the assistance nearby the site.The large wind farms in coastal areas are easily and continuously monitored and the data are recorded from remote locations with the mobile technology having internet connections. This paper also reports the design of MEMS viscosity sensor,MEMS humidity sensor and MEMS pressure sensor for continuous monitoring of the lubricating system .The main advantage of implementing MEMS devices is to reduce the size and cost and also the sensitivity is improved. Along with IOT, smart sensor technology is also introduced in the monitoring which avoids the serious problems that occur in wind mills.
Volume: 5
Issue: 4
Page: 168-175
Publish at: 2016-12-01

Hybrid Flow Architecture for Stable and Scalable Routing in Named Data Networks

10.11591/ijaas.v5.i4.pp176-182
P. Durgaprasad , K. Kranthi Kumar
The named data network is a new technology in routing were its forwarding plane helps us to recover the data on its own when the network failures occur.in this NDN the major issue are when the data is sent from one network to the other the data flow is not stable. By major survey we came to know that routing protocols plays a major role for the stable and scalable data flow. This routing protocols and be classified by forwarding process and also network topologies were the protocols have the data that can be retrieved back whenever the network faults occur. In this paper we proposed that hybrid flow architecture, network topologies and routing protocols are improved to get the stable and scalable routing when the data flow is interrupted.
Volume: 5
Issue: 4
Page: 176-182
Publish at: 2016-12-01

Optimal Modulation Algorithm for Hybrid Clamped Three-Level Inverter

10.12928/telkomnika.v14i4.3871
Yi; China University of Mining and Technology Liu , Guojun; China University of Mining and Technology Tan , Xiaoqun; China University of Mining and Technology He
The principle of a three phase hybrid clamped three-level inverter was presented. Taking sixty-four switch states into consideration, the operational states of hybrid clamped three-level inverter and different current circuits in different switch states were detailed derived. Optimal modulation algorithm was proposed based on the neutral small vectors by different combination, which can realize the automatic balancing of the neutral-point voltage with few switching cycles and did not need to measure the voltage of the clamped capacitors. The proposed modulation algorithm was also capable of restraining the turn-off over-voltage of the power switching devices effectively. Simulation results were given to verify the feasibility and correctness. Experimental results obtained by DSP-based implementation of the controller on 1 MW prototype show good performance in terms of DC-bus voltages regulation (small neutral point potential function and low DC ripple coefficient) and good sinusoidal current.
Volume: 14
Issue: 4
Page: 1253-1262
Publish at: 2016-12-01

Implementation of Project Based Learning in Mechatronic Lab Course at Bandung State Polytechnic

10.11591/ijere.v5i4.5955
Noor Cholis Basjaruddin , Edi Rakhman
Mechatronics is a multidisciplinary that includes a combination of mechanics, electronics, control systems, and computer science. The main objective of mechatronics learning is to establish a comprehensive mindset in the development of mechatronic systems. Project Based Learning (PBL) is an appropriate method for use in the learning process of mechatronic. The use of PBL by following the V model in  system development process is expected to encourage the achievement of the main goal of learning in mechatronics lab. Demonstration of knowledge during the practical work done by drafting product development procedures documents, presentations, and project demo. The test result of mechatronics lab course based on PBL in Electronics Engineering Bandung State Polytechnic led to the conclusion that the model is acceptable and desirable to be passed with a few improvements. In addition, learners also feel there is a new challenge in following the PBL-based practicum.
Volume: 5
Issue: 4
Page: 284~291
Publish at: 2016-12-01

Fuzzy Gain-scheduling Proportional–integral Control for Improving the Speed Behavior of a Three-phases Induction Motor

10.11591/ijpeds.v7.i4.pp1161-1171
Hichem Othmani , D. Mezghani , A. Mami
In this article, we have set up a vector control law of induction machine where we tried different type of speed controllers. Our control strategy is of type Field Orientated Control (FOC). In this structure we designed a Fuzzy Gain-Scheduling Proportional–Integral (Pi) controller to obtain best result regarding the speed of induction machine. At the beginning we designed a Pi controller with fixed parameters. We came up to these parameters by identifying the transfer function of this controller to that of Broïda (second order transfer function). Then we designed a fuzzy logic (FL) controller. Based on simulation results, we highlight the performances of each controller. To improve the speed behaviour of the induction machine, we have designend a controller called “Fuzzy Gain-Scheduling Proportional–Integral controller” (FGS-PI controller) which inherited the pros of the aforementioned controllers. The simulation result of this controller will strengthen its performances.
Volume: 7
Issue: 4
Page: 1161-1171
Publish at: 2016-12-01

Design of Personalized Blended Learning Environments Based On Web-Assisted Modelling In Science Education

10.11591/ijere.v5i4.5960
Murat Çetinkaya
Positive results of science teaching studies supported with the means provided by technology require the enrichment of the content of blended learning environments to provide more benefits. Within this context, it is thought that preparing a web-assisted model-based teaching, which is frequently used in science teaching, based on the “Matter and Heat” unit will be useful. A great number of studies on “Matter and Heat” unit have reported that many students have conceptual errors. It has been found that students have difficulties in associating concepts such as matter, heat, temperature and change of state with daily life. Studies have shown the necessity of designing and using effective teaching methods in solving such problems. It is thought that the modeling based web materials developed for the unit of matter and heat will be effective in decreasing students’ conceptual errors and their learning difficulties. ASSURE teaching design model, which aims to increase the efficiency of material choice and use with systematic prior planning of teaching, was used in creating the materials which were prepared based on web-assisted modeling. The purpose of this study is to design of personalized blended learning environments which are designed based on web-assisted modeling for “Matter and Heat” unit. 
Volume: 5
Issue: 4
Page: 323~330
Publish at: 2016-12-01

Enhanced Crowbar Protection for Fault Ride through Capability of Wind Generation Systems

10.11591/ijpeds.v7.i4.pp1366-1376
V. Mohana Kalyani , J. Preetha Roselyn , C. Nithya , D. Devaraj
Due to increasing demand in power, the integration of renewable sources like wind generation into power system is gaining much importance nowadays. The heavy penetration of wind power into the power system leads to many integration issues mainly due to the intermittent nature of the wind and the desirability for variable speed operation of the generators. As the wind power generation depends on the wind speed, its integration into the grid has noticeable influence on the system stability and becomes an important issue especially when a fault occurs on the grid. The protective disconnection of a large amount of wind power during a fault will be an unacceptable consequence and threatens the power system stability. With the increasing use of wind turbines employing Doubly Fed Induction Generator (DFIG) technology, it becomes a necessity to investigate their behavior during grid faults and support them with fault ride through capability. This paper presents the modeling and simulation of a doubly fed induction generator according to grid code compatibility driven by a wind turbine connected to the grid. This paper analyses the voltage sag due to a three-phase fault in the wind connected grid. A control strategy including a crowbar circuit has been developed in MATLAB/SIMULINK to bypass the rotor over currents during grid fault to enhance the fault ride through capability and to maintain system stability. Simulation results show the effectiveness of the proposed control strategies in DFIG based grid connected wind turbine system.
Volume: 7
Issue: 4
Page: 1366-1376
Publish at: 2016-12-01

Comparison of Sine and Space Vector Modulated Embedded Z-source Inverter fed Three Phase Induction Motor Drive System

10.11591/ijpeds.v7.i4.pp1240-1251
R. Malathi , M. Rathinakumar
This paper deals with performance of photovoltaic powered Embedded Z-Source Inverter (EZSI) fed Induction motor drive. The DC output from the PV-Panel is boosted and converted into AC using Embedded Z-Source Inverter. EZSI system based on the concept of Z-Source Inverter (ZSI), which provides single stage power conversion. The EZSI also produce same voltage gain as that of the ZSI based system. In EZSI the DC source is embedded within the X-shaped LC impedance network, due to this EZSI has the added advantage of inherent source filtering capability , this can be achieved without any extra passive filter. EZSI can produce the AC output voltage which is greater than the DC link voltage. EZSI system also provides ride-through capability under voltage sags. In this paper the performance of space vector modulated EZSI fed Induction Motor Drive is compared with sinusoidal PWM controlled EZSI fed Drive system. The PV powered EZSI fed three phase Induction Motor System is designed, modeled and simulated using MAT LAB-SIMULINK and the corresponding results are presented. This drive system has advantages like voltage boosting ability and reduced harmonic content.
Volume: 7
Issue: 4
Page: 1240-1251
Publish at: 2016-12-01

High-Order Sliding Mode Control of Greenhouse Temperature

10.11591/ijeecs.v4.i3.pp548-554
H. Oubehar , A. Ed-Dahhak , A. Selmani , M. Outanoute , A. Lachhab , M. Guerbaoui , M.H. Archidi , B. Bouchikhi
This paper deals with the design and implementation of the high order sliding mode controller to control temperature greenhouse. The control objective aims to ensure a favorable microclimate for the culture development and to minimize the production cost. We propose performing regulation for the greenhouse internal temperature based on the second order sliding mode technique known as Super Twisting Algorithm (STA). This technique is able to ensure robustness with respect to bounded external disturbances. A successful feasibility study of the proposed controller is applied to maintien a desired temperature level under an experimental greenhouse. The obtained results show promising performances despite changes of the external meteorological conditions.
Volume: 4
Issue: 3
Page: 548-554
Publish at: 2016-12-01

A Novel Modified Turn-on Angle Control Scheme for Torque-ripple Reduction in Switched Reluctance Motor

10.11591/ijpeds.v7.i4.pp1110-1124
Milad Dowlatshahi , Mehrdad Daryanush
In recent years, Switched Reluctance Motors (SRM) have been dramatically considered with both researchers and industries. SRMs not only have a simple and reliable structure, but also have low cost production process. However, discrete torque production of SRM along with intensive magnetic saturation in stator and rotor cores are the major drawbacks of utilizing in variety of industrial applications and also causes the inappropriate torque ripples. In this paper, a modified logical-rule-based Torque Sharing Function (TSF) method is proposed considering turn-on angle control. The optimized turn-on angle for conducting each phase is achieved by estimating the inductance curve in the vicinity of unaligned position and based on an analytical solution for each phase voltage equation. Simulation results on a four-phase switched reluctance motor and comparison with the conventional methods validates the effectiveness of the proposed method.
Volume: 7
Issue: 4
Page: 1110-1124
Publish at: 2016-12-01

Evaluation of Northwest University, Kano Post-UTME Test Items Using Item Response Theory

10.11591/ijere.v5i4.5953
Ado Abdu Bichi , Hadiza Hafiz , Samira Abdullahi Bello
High-stakes testing is used for the purposes of providing results that have important consequences. Validity is the cornerstone upon which all measurement systems are built. This study applied the Item Response Theory principles to analyse Northwest University Kano Post-UTME Economics test items. The developed fifty (50) economics test items was administered to a sample of 600 students. The data obtained was analysed using XCALIBRE 4 and SPSS 20v softwares to determine items parameters base on IRT models. Indicate that, the test measure single trait by satisfying the condition of unidimensionality. Similarly, the goodness of fit test revealed that, the two parameter IRT model was more suitable since no misfit item was observed and the test reliability was 0.86. The mean examinee ability was 0.07 (SD=0.94). The mean item difficulty was -0.63(SD=2.54) and mean item discrimination was 0.28 (SD=0.04). 16 (33%) items were identified as “problematic” based on difficulty indices, 35(71%) also failed to meet the set standards on the basis of discrimination parameters. it can be concluded that, using the IRT approach, the NWU Post-UTME items are not stable as far as item difficulty and discrimination indices are concerned. It is recommended that, the Post-UTME items should be made to pass through all process of standardisation and validation; test development and content experts should be involve in developing and validating the test items in order to obtain valid and reliable results which will lead to valid inferences
Volume: 5
Issue: 4
Page: 261~270
Publish at: 2016-12-01

Vector Control Realization of DFIG Under Grid Abnormalities using Real Time Digital Simulator

10.11591/ijpeds.v7.i4.pp1337-1347
Kanungo Barada Mohanty , Satish Choudhury , Madhu Singh
A grid connected doubly-fed induction generator (DFIG) system, driven by variable speed wind turbine is considered in this research to satisfy grid code requirements. Remaining grid synchronized and stable under voltage sag and voltage swell, obtaining power control through dc link voltage control, and providing unity power factor at grid terminals are the achievements. The DFIG system uses two back-to-back converters. Vector control strategy is used with the grid side and rotor side converters, and taken up for research for further improvement. The grid side converter controls dc-link voltage and maintains unity power factor at the grid connection point. The rotor side converter supplies the reactive power of the machine and maintains the speed constant irrespective of the transient behavior of the grid. In this paper the behavior of the DFIG system is analyzed under grid voltage fluctuation and the experimental results are obtained using RT-LAB. Main contribution of this work is in improving the DFIG system performance with grid low voltage and over voltage ride through capability through simulation, and its real time experimental verification.
Volume: 7
Issue: 4
Page: 1337-1347
Publish at: 2016-12-01

Urban Traffic Simulators

10.11591/ijict.v5i3.pp124-128
Harshita Chitla H
Computer traffic simulation is a widely used technique in modeling, coming up with and development of traffic networks and systems. It contains a various applications, like traffic forecasting, vehicle navigation devices and so on. This paper discusses about the various types of traffic simulators. Another drawback is that the factors like accidents, public events, and road closures. In addition, we are introducing algorithmic concepts, quantifiable metrics and data structural approaches that might be applied to the simulation systems.
Volume: 5
Issue: 3
Page: 124-128
Publish at: 2016-12-01

Validity and Realibility of Chemistry Systemic Multiple Choices Questions (CSMCQs)

10.11591/ijere.v5i4.5958
Erfan Priyambodo , Marfuatun Marfuatun
Nowdays, Rasch model analysis is used widely in social research, moreover in educational research. In this research, Rasch model is used to determine the validation and the reliability of systemic multiple choices question in chemistry teaching and learning. There were 30 multiple choices question with systemic approach for high school student class XI. In this research, a 164 student as the subject of the research. The data was collecting during March – April 2015. The data was analysis using Winsteps application with Rasch model. The reseach shows that 29 question of 30 questions was valid through Rasch model analysis. The reliability of systemic multiple choices question was 0.93, which is very good chategory.
Volume: 5
Issue: 4
Page: 306~309
Publish at: 2016-12-01
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