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29,939 Article Results

Improved sliding mode power control of doubly-fed-induction generator under wind speed variation

10.11591/ijpeds.v12.i4.pp2443-2450
Bouiri Abdesselam , Benoudjafer Cherif , Boughazi Othmane , Abdallah Abden , Chojaa Hamid
Due to drawbacks of classical linear controller like proportional-integral (PI), many studies have been used non-linear controller specially when it comes to robustness, but this is less efficient in sliding mode controller (SM) due to the sign function, this function is known as a problem chattering phenomenon, this main disadvantage it can be compensated by Lyapunov backstepping condition, This paper presents nonlinear power control strategy of the doubly-fed-induction generator (DFIG) for wind application system (WAS) using sliding mode combining with backstepping controller (SM-BS) to control produced statoric powers to mitigate unnecessary chattering effects inherent in traditional SMC, to check the effectiveness of the controller, we compare performance of sliding mode controller and sliding mode controller combining with backstepping (SM-BS) in terms of required reference tracking, robustness under parametric variations of the generator, sensitivity to perturbations and reaction to speed variations under investigating further of the chattering phenomenon.
Volume: 12
Issue: 4
Page: 2443-2450
Publish at: 2021-12-01

Optimized generated power of a solar PV system using an intelligent tracking technique

10.11591/ijpeds.v12.i4.pp2580-2592
Afshin Balal , Mostafa Abedi , Farzad Shahabi
Partial shading condition (PSC) is common and complicated in all types of PV power plant. Therefore, the power production of solar system would be affected by the mismatch phenomena produced by PSC. Furthermore, when the array is partially shaded, the P–V characteristics become more complex which causes multiple peaks of the P-V curve. So, the simple maximum power point tracking (MPPT) methods such as perturb and observe (P&O) will fail. To address the above issue, this paper proposes a combination of two different approaches, implementing distributed MPPT (DMPPT) and optimized fuzzy/bee algorithm (OFBA). DMPPT can be utilized to maximize solar energy by allowing each module, or group of modules, be managed independently. Also, due to the output power oscillations around the operating point in the P&O method, an OFBA is employed which allowing for the decrease of output power oscillations without the usage of temperature and light sensors. The result shows that utilizing of DMPPT control approach in conjunction with the OFBA boosts the output generated power.
Volume: 12
Issue: 4
Page: 2580-2592
Publish at: 2021-12-01

SPDT discrete switch design using switchable SIW resonators for millimeter wave MIMO transceiver

10.11591/ijeecs.v24.i3.pp1542-1549
Amirul Aizat Zolkefli , Badrul Hisham Ahmad , Noor Azwan Shairi , Adib Othman , Zahriladha Zakaria , Imran Mohd Ibrahim , Huda A. Majid
A single pole double throw (SPDT) discrete switch design using switchable substrate integrated waveguide (SIW) resonators is proposed in this paper. It was designed for the millimeter wave multiple input multiple output (MIMO) transceiver. An example application is for 5G communication in 26 GHz band. High isolation between transmitter and receiver (in the transceiver) is needed in SPDT switch design to minimize any high radio frequency (RF) power leakage in the receiver. Therefore, the use of switchable SIW resonators can achieve higher isolation if compared to the conventional series SPDT switch, where the isolation of the proposed SPDT is depend on the bandstop response of the SIW resonators. The switchable SIW resonators can be switched between allpass and bandstop responses to allow the operation between transmit and receive modes. As a result, the simulation and measurement showed that the proposed SPDT switch produced an isolation higher than 25 dB from 24.25 to 27.5 GHz compared to the conventional design.
Volume: 24
Issue: 3
Page: 1542-1549
Publish at: 2021-12-01

Overall fuzzy logic control strategy of direct driven PMSG wind turbine connected to grid

10.11591/ijece.v11i6.pp5515-5529
Mhamed Fannakh , Mohamed Larbi Elhafyani , Smail Zouggar , Hassan Zahboune
The fuzzy logic strategies reported in the literature about the control of direct drive permanent magnet synchronous generator (PMSG) connected to grid are limited in terms of inclusiveness and efficiency. So an overall control based on fuzzy logic and anti-windup compensation is proposed in this paper. Aiming at the inadequate of hill climb search (HCS) MPPT with fixed step size, the fuzzy logic is introduced in the stage of "generating rotor speed reference" to overcome the oscillations and slowness in traditional method. PI controllers are replaced by anti-windup fuzzy logic controllers in the "machine side control" stage and in "grid side control" stage to pertinently regulate the reference parameters. Then comparison tests with classical methods are implemented under varying climatic conditions. The results obtained demonstrate that the developed control is superior to other methods in response time (less than 4.528E-04 s), precision (an overshoot about 0.41%) and quality of produced energy (efficiency is 91%). The study verifying the feasibility and effectiveness of this algorithm in PMSG wind turbine connected to grid.
Volume: 11
Issue: 6
Page: 5515-5529
Publish at: 2021-12-01

Speech signal compression and encryption based on sudoku, fuzzy C-means and threefish cipher

10.11591/ijece.v11i6.pp5049-5059
Iman Qays Abduljaleel , Amal Hameed Khaleel
Compression and encryption of speech signals are essential multimedia technologies. In the field of speech, these technologies are needed to meet the security and confidentiality of information requirements for transferring huge speech signals via a network, and for decreasing storage space for rapid retrieval. In this paper, we propose an algorithm that includes hybrid transformation in order to analyses the speech signal frequencies. The speech signal is then compressed, after removing low and less intense frequencies, to produce a well compressed speech signal and ensure the quality of the speech. The resulting compressed speech is then used as an input in a scrambling algorithm that was proposed on two levels. One of these is an external scramble that works on mixing up the segments of speech that were divided using Fuzzy C-Means and changing their locations. The internal scramble scatters the values of each block internally based on the pattern of a Sudoku puzzle and quadratic map so that the resulting speech is an input to a proposed encryption algorithm using the threefish algorithm. The proposed algorithm proved to be highly efficient in the compression and encryption of the speech signal based on approved statistical measures.
Volume: 11
Issue: 6
Page: 5049-5059
Publish at: 2021-12-01

Real time simulation of reduced switch multilevel inverter with PWM switching sequence control

10.11591/ijpeds.v12.i4.pp2305-2313
Kanike Vinod Kumar , R. Saravana Kumar
Reduction of switch count in symmetrical and asymmetrical reduced switch multilevel inverter designs has been proposed regularly with operation of conventional carrier-based pulse width modulation technique. In this study, a novel structure of symmetrical Hexa shaped model reduced switch seven level output inverter is proposed without any auxiliary switch and H-bridge. Proposed structure offers a smaller number of switch count and voltage sources which results in the cost and complexity reduction of its implementation. To operate the switching sequence of inverter from carrier based alternative phase opposition disposition (APOD), phase opposition disposition (POD), and phase disposition (PD) methods, suitable logical expression to be realize which gained more prominence. Active utilization of two voltage sources in each mode of operation results in significant reduction of voltage stress across each switch is achieved. A comparative study of proposed multilevel inverters (MLI) with various reduced switch MLIs has been presented. Initially, simulation model implementation has been carried out with MATLAB/Simulink and observed the performance parameters and total harmonic distortion (THD). Simulation results are carried for the comparison of the results obtained in the real time work performed on OPAL-RT 5700 simulator.
Volume: 12
Issue: 4
Page: 2305-2313
Publish at: 2021-12-01

A novel artificial neural network for power quality improvement in AC microgrid

10.11591/ijpeds.v12.i4.pp2151-2159
Debani Prasad Mishra , Amba Subhadarshini Nayak , Truptasha Tripathy , Surender Reddy Salkuti , Sanhita Mishra
The microgrid concept provides a flexible power supply to the utility where the conventional grid is unable to supply. The microgrid structure is based on renewable energy sources known as distributed generators (DGs) and the power network. Nevertheless, the power quality (PQ) is a great challenge in the microgrid concept. Particularly the inclusion of renewable energy sources into the conventional grids increases the problems in the quality of power, like voltage sag/swell, oscillatory transient, voltage flickering, and voltage notching which reduces the quality and reliability of the power supply. In this paper, a microgrid is considered which consists of PV cells as DG, battery energy storage system (BESS), and a novel control strategy known as the nonlinear autoregressive exogenous model (NARX). The proposed controller is an improved artificial neural network (ANN). The various case studies like sag/swell, unbalanced condition, and voltage deviation have been simulated with the model. The comprehensive simulation results are compared with the proportional-integral (PI) controller. Hence in this paper, the robustness of the proposed controller has been studied through different situations.
Volume: 12
Issue: 4
Page: 2151-2159
Publish at: 2021-12-01

Overview of microgrid systems

10.11591/ijaas.v10.i4.pp378-391
V. Saravanan , K. M. Venkatachalam , M. Arumugam , M. A. K. Borelessa , K. T. M. U. Hemapala
This research paper discusses the different types of microgrids, their structural arrangements and the technology adopted for different power management projects. It also deals with various control strategies and security plans used for optimal performance. A detailed overview of the direct current (DC) microgrid system is discussed, outlining its configurations and technical-economic aspects. Performance evaluation of microgrid carried out through various reliability codes is also provided.
Volume: 10
Issue: 4
Page: 378-391
Publish at: 2021-12-01

An efficient coverage and maximization of network lifetime in wireless sensor networks through metaheuristics

10.11591/ijict.v10i3.pp159-170
A. Nageswar Rao , B. Rajendra Naik , L. Nirmala Devi
In wireless sensor networks (WSNs), energy, connectivity, and coverage are the three most important constraints for guaranteed data forwarding from every sensor node to the base station. Due to continuous sensing and transmission tasks, the sensor nodes deplete more quickly and hence they seek the help of data forwarding nodes, called relay nodes. However, for a given set of sensor nodes, finding optimal locations to place relay nodes is a very challenging problem. Moreover, from the earlier studies, the relay node placement is defined as a non-deterministic polynomial tree hard (NP-Hard) problem. To solve this problem, we propose a multi-objective firefly algorithm-based relay node placement (MOFF-RNP) to deploy an optimal number of relay nodes while considering connectivity, coverage, and energy constraints. To achieve network lifetime, this work adopted energy harvesting capabilities to the sensor nodes and backup relay strategy such that every sensor node is always connected to at least one relay to forward the data. The optimal relay placement is formulated as an objective function and MOFF is applied to achieve a better solution. Extensive Simulations are carried out over the proposed model to validate the performance and the obtained results are compared with state-of-art methods)
Volume: 10
Issue: 3
Page: 159-170
Publish at: 2021-12-01

Transfer deep learning approach for detecting coronavirus disease in X-ray images

10.11591/ijece.v11i6.pp4999-5008
Mohammed Al-Smadi , Mahmoud Hammad , Qanita Bani Baker , Saja Khaled Tawalbeh , Sa’ad A. Al-Zboon
Currently, the whole world is fighting a very dangerous and infectious disease caused by the novel coronavirus, called COVID-19. The COVID-19 is rapidly spreading around the world due to its high infection rate. Therefore, early discovery of COVID-19 is crucial to better treat the infected person as well as to slow down the spread of this virus. However, the current solution for detecting COVID-19 cases including the PCR test, CT images, epidemiologically history, and clinical symptoms suffer from high false positive. To overcome this problem, we have developed a novel transfer deep learning approach for detecting COVID-19 based on x-ray images. Our approach helps medical staff in determining if a patient is normal, has COVID-19, or other pneumonia. Our approach relies on pre-trained models including Inception-V3, Xception, and MobileNet to perform two tasks: i) binary classification to determine if a person infected with COVID-19 or not and ii) a multi-task classification problem to distinguish normal, COVID-19, and pneumonia cases. Our experimental results on a large dataset show that the F1-score is 100% in the first task and 97.66 in the second task.
Volume: 11
Issue: 6
Page: 4999-5008
Publish at: 2021-12-01

Low switching frequency modulation for generalized three-phase multilevel inverters geared toward Grid Codes compliance

10.11591/ijpeds.v12.i4.pp2349-2357
Mohammed Setti , Mohamed Cherkaoui
In this paper, a generalized three-phase multilevel power inverter (MLI) structure is proposed under asymmetric configurations. The operating mode and the switching combinations are briefly exposed according to the parity of the number of direct current (DC) voltage sources in use. Subsequently, the proposed topology is evaluated in terms of commonly used factors and then benchmarked against some of the state-of the-art cascaded MLIs featuring multiple DC voltage sources (MDCS-CMLIs) while putting emphasis on the reduction of power switching devices. Moreover, a new nearest level control (NLC)-based modulation technique is designed for the purpose of better comply with some quality grid codes, namely the European EN 50160 and the International IEC 61000-2-12. The identification of the optimal control thresholds is realized by a constrained optimization algorithm (e.g., particle swarm optimization (PSO)) which is implemented in python script and validated through SIMULINK fast fourier transform (FFT) analysis tool. Lastly, the harmonic performance of the proposed technique is compared side-by-side with that of the conventional NLC scheme and exhibits significant reduction in harmonic distortion.
Volume: 12
Issue: 4
Page: 2349-2357
Publish at: 2021-12-01

Control of grid side converter in wind power based PMSG with PLL method

10.11591/ijpeds.v12.i4.pp2191-2200
Rania Moutchou , Ahmed Abbou
Wind power is one of the most promising renewable energy sources. Due to a constantly increasing penetration rate in power grids in order to comply with interconnection requirements. This article targets the impact of a permanent magnet synchronous generator (PMSG) which is the subject of most attention due to low cost and maintenance requirements, driven by a wind turbine with the necessary power electronic converters that allow wind turbines to operate at variable speed, and connected to the grid for power generation more efficiently by the phase-locked loop (PLL) method in order to synchronize it. Thus, the proposed control technicals are based on vector control (VC) to achieve maximum power point tracking (MPPT), keep the DC link voltage constant, and control the speed and current at the generator side and grid side in PMSG which provides controllability of the reactive power supplied to the network. Therefore, the response of the PLL is analyzed and the simulation results of the dynamic model of the system is developed in Matlab / Simulink. The study results exhibit the excellent performance with high robustness, by improving the system efficiency to 98.72%.
Volume: 12
Issue: 4
Page: 2191-2200
Publish at: 2021-12-01

Four propellers submarine drone modelling in a real environment

10.11591/ijpeds.v12.i4.pp1966-1977
Mohamed Moustanir , Karim Benkirane , Adil Sayouti , Hicham Medromi
In order to reduce the hydrodynamic dampers and mechanical elements as rudders, we have in our previous publications proposed our architectural solution of an ROV with only four thrusters without rudders or diving bars. In the results we have justified the choice of the arrangement of the thrusters. Also, we have started the kinematic and dynamic studies of the marine robot and we have especially demonstrated by using the mathematical model under MATLAB in the last publication, that this ROV can move in a perfect environment without gravity or hydrodynamic dampers. In this article, we will study the behavior of this marine vehicle in a real environment with gravity and hydrodynamic dampers and we will view if this architectural solution can really allow the ROV to move and execute the given directional instructions.
Volume: 12
Issue: 4
Page: 1966-1977
Publish at: 2021-12-01

Research trend on TPACK through bibliometric analysis (2015-2019)

10.11591/ijere.v10i4.22062
Nadi Suprapto , Sukarmin Sukarmin , Rinie Pratiwi Puspitawati , Erman Erman , Dian Savitri , Chih-Hsiung Ku , Husni Mubarok
This paper aims to analyze the scientific trend of research on Technological Pedagogical Content Knowledge (TPACK) through bibliometric study and explore how the contribution of Indonesian researchers in the Scopus database from 2015 to 2019. The sample was composed of 2075 documents in total. The results revealed that scientific publication on TPACK has been increasing. United States contributed the most documents on TPACK as well as Singapore’s institutions dominated in this area. Meanwhile, Indonesia put its two representative’s institutions: Universitas Sebelas Maret and Universitas Pendidikan Indonesia, among the big ten institutions in the world. All Indonesian documents produced by teacher-producing universities and public universities. United States and Taiwan have also contributed to the most productive authors of TPACK. Then, the visualization of research trend on TPACK resulted in four major clusters: i) TPACK as a system; ii) TPACK in relating to its scale; iii) TPACK in connecting with quantitative parameters; and iv) TPACK under beliefs, intention, and technology acceptance. The research findings could aid related researchers to recognize the trend of TPACK research and recommend directions for further research.
Volume: 10
Issue: 4
Page: 1375-1385
Publish at: 2021-12-01

Managing educational institutions: School heads’ leadership practices and teachers’ performance

10.11591/ijere.v10i4.21518
Cherry Joy C. Aquino , Bonimar T. Afalla , Fitzgerald L. Fabelico
School heads are agents of change who contribute a major impression on the educational milieu through their information-sharing methods, creating supportive social connections, participating in mentoring programs, and fostering progress. Hence, this study ascertained the interrelation between the public school head’s leadership practices and teachers’ performance. As correlation research, simple random sampling was used to calculate the sample size for teachers, while total enumeration was used for school heads. A structured questionnaire was developed to gather the necessary information that reinforced the theme of this analysis. Weighted mean was used to ascertain the level of leadership practices of school heads and the level of teacher performance. T-test, F-test, post-hoc test, and Pearson r were employed to establish the degree of association between and among variables. This study concluded that the variation in leadership practices experienced by school heads and teachers is absolutely vital, confirming that their reactions are fundamentally better. Teachers' performance is consistent irrespective of age, educational achievement, or significant contributions. In terms of teaching status and number of years of experience, head teachers have improved teaching efficiency than teachers and master teachers. Teachers with shorter relevant experience showed poorer educational quality relative to those who spent more time in the school system. School heads who have obtained their doctorate degrees get a greater level of leadership practices than the holders of master's degrees. The very productive performance of teachers stays the same, regardless of whether the school heads exhibit a very high degree of authentic leadership.
Volume: 10
Issue: 4
Page: 1325-1333
Publish at: 2021-12-01
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