Articles
9,226 Documents
Delay-Dependent Observers for Uncertain Nonlinear Time-Delay Systems
Dongmei Yan;
Youwei Wang;
Jiuhong Wei;
Dongzhe Li;
Lei Chen
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 5: May 2013
Publisher : Institute of Advanced Engineering and Science
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This paper is concerned with the observer design problem for a class of discrete-time uncertain nonlinear systems with time-varying delay. The nonlinearities are assumed to satisfy global Lipschitz conditions which appear in both the state and measurement equations. The uncertainties are assumed to be time-varying but norm-bounded. Two Luenberger-like observers are proposed. One is delay observer and the other is delay-free observer. The delay observer which has an internal time delay is applicable when the time delay is known. The delay-free observer which does not use delayed information is especially applicable when the time delay is not known explicitly. Delay-dependent conditions for the existences of these two observers are derived based on Lyapunpv functional approach. Based on these conditions, the observer gains are obtained using the cone complementarity linearization algorithm. Finally, a numerical example is given to illustrate the effectiveness of the proposed method. DOI: http://dx.doi.org/10.11591/telkomnika.v11i5.2466
Multiwavelength Fiber Laser based on Bidirectional Lyot Filter in Conjunction with Intensity Dependent Loss Mechanism
A. H. Sulaiman;
N. Md. Yusoff;
N. A. Cholan;
M. A. Mahdi
Indonesian Journal of Electrical Engineering and Computer Science Vol 10, No 3: June 2018
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v10.i3.pp840-846
We experimentally demonstrate a multiwavelength fiber laser (MWFL) based on bidirectional Lyot filter. A semiconductor optical amplifier (SOA) is used as the gain medium, while its combination with polarization controllers (PCs) and polarization beam combiner (PBC) induces intensity dependent loss (IDL) mechanism. The IDL mechanism acts as an intensity equalizer to flatten the multiwavelength spectrum, which can be obtained at a certain polarization state. Using different ratio of optical splitter has affected to multiwavelength flatness degradation. Subsequently, when we removed a polarizer in the setup, the extinction ratio (ER) is decreased. Ultimately, with two segments of polarization maintaining fiber (PMF), two channel spacings can be achieved due to splicing shift of 0° and 90°.
Study of stabilty analysis of a grid connected Doubly fed induction generator based on wind energy Application
Ghulam sarwar Kaloi;
Jie Wang;
Mazhar H Baloch
Indonesian Journal of Electrical Engineering and Computer Science Vol 3, No 2: August 2016
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v3.i2.pp305-313
The present paper formulates the state space modeling of doubly fed induction generator (DFIG) based wind turbine system for the purpose of the stability analysis. The objective of this study is to discuss the various modes of operation of the DFIG system under different operating conditions such as voltage sags with reference to variable wind speed and grid connection. The proposed control methodology exploits the potential of the DFIG scheme to avoid that grid voltage unbalances compromise the machine operation, and to compensate voltage unbalances at the point of common coupling (PCC), preventing adverse effects on loads connected next to the PCC. This methodology uses the rotor side converter (RSC) to control the stator current injected through the machine and the GSC to control the stator voltage to minimize the electromagnetic torque oscillations. Extensive simulation results on a 2MW DFIG wind turbine system illustrate the enhanced system performance and verify the effectiveness of the controller.
Path Loss Models Optimization for Mobile Communication in Different Areas
Messaoud Gareh;
Lotfi Djouane;
Houcine Oudira;
Nazih Hamdiken
Indonesian Journal of Electrical Engineering and Computer Science Vol 3, No 1: July 2016
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v3.i1.pp126-135
In mobile radio systems, path loss models are necessary for proper planning, interference estimations, frequencies assignments and cell parameters which are basic for network planning process. Empirical models are the most adjustable models that can be suited to different types of environments. In this paper, data collected in Batna, Algeria is used to calculate the path loss for GSM (908-957 MHz). The measured path loss is compared with theoretical path loss estimated by the most widely empirical models «Cost123», «Hata», «SUI» and «Egli». The best model to estimate the measured path loss is optimized using genetic algorithm to predict path loss for suburban and rural area. The RMSE and the other test criteria between the actual and predicted data are calculated for various path loss models. It turned out that the adjusted COST 231 model outperforms the other studied models. The investigated results can help telecommunication engineers improve their planning and design of microcellular system.
Voltage and Reactive Power Control of Front-end Speed Controlled Wind Turbine via H∞ Strategy
Haiying Dong;
Shuaibing Li;
Lixin Cao;
Hongwei Li
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 8: August 2013
Publisher : Institute of Advanced Engineering and Science
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According to the characteristics like rapidity, time variability and the uncertainty of the input mechanical torque of the front-end speed control wind turbine (FSCWT) with directly grid-connected electrically excited synchronous generator (EESG), a double-loop H∞control approach was proposed. In which, a simpilified structure of brushless excitation system was used. For the inner loop, first H∞excitation controller was designed for realizing a fast excitation control; the second H∞power system stabilizer (PSS) was designed by solving the Riccati equation for the purpose of eliminating the oscillation and desynchronization of generator may caused by fast excitation and improving the system transient stability, which ensured the generator with stable operation in grid-connecting and effectively solved the contradiction between fast excitation and transient stability. Then the designed H∞controllers were applied to the voltage and reactive power control system (VRCS), which realized the output voltage and reactive power control requriements by tuning the weighting functions. Simulation results show that the double-loop H∞control approach was more effective than the single H∞excitation control in voltage and reactive power control of FSCWT. DOI: http://dx.doi.org/10.11591/telkomnika.v11i8.2423
Mobile Computing Clouds Interactive Model and Algorithm Based On Multi-core Grids
Liu Lizhao;
Zhu Shunzhi;
Sun Zhonghai;
Li Qi
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 9: September 2013
Publisher : Institute of Advanced Engineering and Science
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Multi-core technology is the key technology of mobile cloud computing, with the boom development of cloud technology, the authors focus on the problem of how to make the target code computed by mobile cloud terminal multi-core compiler to use cloud multi-core system construction, to ensure synchronization of data cross-validation compilation, and propose the concept of end mobile cloud entity indirect synchronization and direct synchronization; use wave ormation energy conversion, give our a method to calculate indirect synchronization value and direct synchronization value according to the cross experience and cross time of compilation entity; construct function relative level algorithm with Hellinger distance, and give an algorithm method of comprehensive synchronization value. Through experiment statistics and analysis, take threshold limit value as the average, self-synchronization value as deviation, the update function of indirect synchronization value is constructed; an inter-domain multi-core synchronization flow chart is given; then inter-domain compilation data synchronization update experiment is carried out with more than 3000 end mobile cloud multi-core compilation environment. Through the analysis of data compilation operation process and results, the synchronization algorithm is proved to be reasonable and effective. DOI: http://dx.doi.org/10.11591/telkomnika.v11i9.3279
Intelligent power monitoring and control with wireless sensor network techniques
Iman Mohammed Nayyef;
Anas Ali Hussien
Indonesian Journal of Electrical Engineering and Computer Science Vol 18, No 2: May 2020
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v18.i2.pp1112-1122
Undoubtedly, there is a necessity for establishing a more intelligent power system in the existing energy system, which is increased according to the development of wireless system network (WSN) and the Internet of Things (IoT). This study presents intelligent power monitoring and control with wireless sensor network techniques, based on WSNs and IoT technologies is designed to manage real-time power at buildings. This system includes a complete network of wireless sensing node, base station and a smart home gateway. A sensing node is utilized as wireless sensors to measure voltage and current and to calculate power consumption of connected appliances that are transmitted wirelessly to a base station via Zigbee node. A base station is designed to receive all data transmitted from the sensing node and display it through GUI available at the personal computer with the possibility of controlling ON and OFF appliances according to consumer requirements. All of these readings are stored at database for analysis. In addition, a smart home gateway is used to connect the system with internet, allowing consumers to continuous monitoring and remote control the appliances via a smartphone application. The benefit of this system is that the mechanism of appliances control can be done in different ways (manually, automatically and remotely). To ensure better accuracy of the equipment many appliances are tested and compared with practical measurement. Best results are obtained for the error, voltage, current and the power.
Study of Layers Construct for Data Mining Platform Based on Cloud Computing
Yongzheng Lin
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 3: March 2014
Publisher : Institute of Advanced Engineering and Science
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AT the present time, data separately stored in network can’t be mined efficiently, the layers construct for data mining platform based on cloud computing is put forward in this paper, and, all the function modules and the main designed methods are analyzed in details. The construct has been proved to be scientific and feasible by researches. DOI : http://dx.doi.org/10.11591/telkomnika.v12i3.3864
Component Content Soft-Sensor of SVM Based on Ions Color Characteristics
Lu Rongxiu;
Yang Hui;
Zhang Kunpeng
Indonesian Journal of Electrical Engineering and Computer Science Vol 10, No 6: October 2012
Publisher : Institute of Advanced Engineering and Science
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In consideration of different characteristic colors of Ions in the P507-HCL Pr/Nd extraction separation system, ions color image feature H, S, I that closely related to the element component contents are extracted by using image processing method. Principal Component Analysis algorithm is employed to determine statistics mean of H, S, I which has the stronger correlation with element component content and the auxiliary variables are obtained. With the algorithm of support vector machine, a component contents soft-sensor model in Pr/Nd extraction process is established. Finally, simulations and tests verify the rationality and feasibility of the proposed method. The research results provide theoretical foundation for the online measurement of the component content in Pr/Nd countercurrent extraction separation process. DOI: http://dx.doi.org/10.11591/telkomnika.v10i6.1418
Symbiotic Organisms Search Technique for SVC Installation in Voltage Control
Mohamad Khairuzzaman Mohamad Zamani;
Ismail Musirin;
Saiful Izwan Suliman
Indonesian Journal of Electrical Engineering and Computer Science Vol 6, No 2: May 2017
Publisher : Institute of Advanced Engineering and Science
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DOI: 10.11591/ijeecs.v6.i2.pp318-329
Increasing demand experienced by electric utilities in many parts of the world involving developing country is a normal phenomenon. This can be due to the urbanization process of a system network, which may lead to possible voltage decay at the receiving buses if no proper offline study is conducted. Unplanned load increment can push the system to operate closes to its instability point. Various compensation schemes have been popularly invented and proposed in power system operation and planning. This would require offline studies, prior to real system implementation. This paper presents the implementation of Symbiotic Organisms Search (SOS) algorithm for solving optimal static VAr compensator (SVC) installation problem in power transmission systems. In this study, SOS was employed to perform voltage control study in a transmission system under several scenarios via the SVC installation scheme. This realizes the feasibility of SOS applications in addressing the compensating scheme for the voltage control study. Minimum and maximum bound of the voltage at all buses have been considered as the inequality constraints as one of the aspects. A validation process conducted on IEEE 26-Bus RTS realizes the feasibility of SOS in performing compensation scheme without violating system stability. Results obtained from the optimization process demonstrated that the proposed SOS optimization algorithm has successfully reduced the total voltage deviation index and improve the voltage profile in the test system. Comparative studies have been performed with respect to the established evolutionary programming (EP) and artificial immune system (AIS) algorithms, resulting in good agreement and has demonstrated its superiority. Results from this study could be beneficial to the power system community in the planning and operation departments in terms of giving offline information prior to real system implementation of the corresponding power system utility.