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24,092 Article Results

Experimental Verification of Circulating Current Mitigation Scheme in MMC by Using ISE Technique

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3399
Sreedhar Madichetty , Abhijit Dasgupta
The circulating currents of a modular multilevel converter (MMC) is ideally assumed to be the sum of an ac component and dc ac component operating with fundamental frequency. However, as ac current flows through the submodule (SM) capacitors, the capacitor voltages fluctuate with time. Consequently, the circulating current is usually distorted and allows multiple frequency components with the peak value of it is increased compared with the theoretical value. The circulating currents will increase power losses and may threaten the safe operation of the switching devices and module capacitors. This article proposes a MMC with a new controller design to mitigate circulating currents for various modulation indexes for wide ranges in load. This new controller is optimized with upper and lower module voltages as an objective function. The optimum values for controller are obtained by using conventional integral square error technique (ISE). The proposed scheme shows its effectiveness by controlling the circulating currents for various loads. It made strategic conclusions on MMC to make the system more robust in operation and less complexity in design and control. The proposed system is verified by 10 KVA prototypes MMC and results are explored. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.5364
Volume: 12
Issue: 5
Page: 3431-3443
Publish at: 2014-05-01

A Coarse-to-Fine Human Body Segmentation Method in Video

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3409
Yingna Deng , Wenqing Wang
Human body precise segmentation is difficult because of inter-occlusion when there are multiple human bodies in video. A coarse-to-fine segmentation method is proposed. In coarse segmentation, human shape models are used to get human’s position and coarse region. The human models with variant scale and posture are constructed with head, torso, and legs. For each human body, its corresponding human shape model is obtained by model matching, and by which human position is obtained roughly. Human precise contour is obtained in fine segmentation by curve evolution with initial contour obtained from coarse segmentation. Experiment results show that the proposed method could segment human object precisely. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.3539
Volume: 12
Issue: 5
Page: 3521-3528
Publish at: 2014-05-01

Fault Diagnosis Based on Wavelet Genetic Neural Network for Motor

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3415
Keyong Shao , Lijuan Han , Yang Liu , Xinmin Wang , Fengwu Zhang
In the motor fault diagnosis technology, vibration signals can fully reflect the motor operation conditions. In this paper, a linear motor fault diagnosis method based on wavelet packet and neural network was presented. The improved neural network system was designed with variable hidden layer neurons. The network chose different numerical values depending on different situations to reach the requirements that improving diagnostic accuracy and shortening the diagnosis time. The linear motor’s normal and two common faults vibration signals were analyzed and the vibration signals energy characteristics were extracted through wavelet packet, then identified fault through neural network. The experimental results show that this method can effectively improve the motor fault diagnosis accuracy. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4915
Volume: 12
Issue: 5
Page: 3570-3577
Publish at: 2014-05-01

Economic Evaluation for Peak Shaving of Wind Power Integrated System

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3422
Tingting Hou , Suhua Lou , Yaowu Wu , Zhilei Wang , Lin Yi
The variable and non-dispatchable output of wind farms brings great difficulty to the quantitative analysis of the economic operation for peak shaving of power system integrated with high penetration of wind power. For the random nature of wind power, the paper establishes a peak shaving capacity requirement model for wind power. Based on the peak shaving capacity requirement model for wind power, a model for economy evaluation of peak shaving of power system with a high penetration of wind power is proposed. The model makes it possible to quantitatively analyze the influences of wind power integration on the peak shaving capacity requirement and operation economy. The case studies were carried out for a system, and the results verified the effectiveness and accuracy of the presented model. Some conclusions are summarized about the economy evaluation method of peak shaving of systems integrated with significant wind. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.5096 
Volume: 12
Issue: 5
Page: 3625-3633
Publish at: 2014-05-01

Voltage Deviation in Breaker-testing Station Study Using ADPSS

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3438
Zhenan Zhang , Hua Wang , Qionglin Li , Xiaomeng Li
With the fast development of China power grid, more and more power system devices such as breakers are applied. Breaker testing also becomes very important. At the same time the testing procedure will cause voltage deviation around the breaker-testing station. Big voltage deviation can make severe damage for the power customers. Based on the power system simulation software ADPSS developed by China Electric Power Research Institute (CEPRI), this paper built up the simulation model using the electromechanical-electromagnetic transient hybrid method, and simulated the voltage deviation in a Henan breaker-testing station. The simulation results showed that with the higher testing breaker current level, bigger voltage deviation is caused. Finally this paper suggested a testing breaker current level for the breaker-testing station with Power Quality Criteria. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.5101 
Volume: 12
Issue: 5
Page: 3754-3760
Publish at: 2014-05-01

A Study of Applying Design Patterns to A Role Playing Game

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3470
Jung-Hua Lo , Chi-Shain Yeh
With the rapid of the deployment of computer systems, people in the modern society are increasingly dependent on the hardware and software systems.  When the demand for computer systems increases, the possibility of crises from computer failure will also increase.  Therefore,, in order to achieve a desired level of quality, the experienced software team must have a better design method to establish the system.  That is, it is very important to choose a better approach that can be applicable to develop the complex software system. The experienced designers will record the design problems which they felt hard to solve or they took much time to solve. When they meet the similar problems later, they would refer to the record. Design patterns are produced from the record. This Paper aims at explaining how to apply the design patterns in the game framework through a simple example by taking the Role Playing Game as example and adding design patterns; it also tries to make a judgment whether the software quality has been improved by using the object-oriented software quality model to test the software quality of the Role Playing Game without the design patterns and that with the deign patterns. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4664
Volume: 12
Issue: 5
Page: 4018-4023
Publish at: 2014-05-01

The Contourlet Transform with Multiple Cycles Spinning for Catenary Image Denoising

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3454
Changdong Wu , Zhigang Liu , Hua Jiang
In the catenary images, noise and artifacts are introduced due to the acquisition techniques and systems, which may influence the judgement of catenary quailty and working states. In this paper, the contourlet transform (CT) with performances of multi-scale, multi-resolution and anisotropy is proposed, which can be effectively applied to image denoising. However, the CT hasn’t the spinning invariance, which will lead to the Gibbs-like phenomena. In this paper, the CT with multiple cycle spinning is introduced for image denoising, which can effectively eliminate the visual artifacts due to the lack of translational invariance. Meanwhile, the different Laplacian pyramid (LP) filters and directional filter banks (DFB) are proposed to test noisy images. Finally, test the influence of cycle spinning numbers for denoising effects by using different cycle spinning times. The experiment results show that the proposed method has excellent denoising performance in terms of the signal-to-noise ratio (SNR) and the visual effects, which is also superior to some other existing methods in overcoming the Gibbs-like phenomena, background smoothing and preservation of edge sharpness and texture. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4446  
Volume: 12
Issue: 5
Page: 3887-3893
Publish at: 2014-05-01

A Three-phase AC-Voltage Regulator System

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3406
Guoshun Zhou , Tu Ya , Shukun Zhao
Three-phase AC-voltage regulatior systems using silicon controlled rectifier (SCR) have been broadly applied in industrial field.This paper introduces a novel design of three-phase AC-voltage regulation trigger circuitry with SCR and STM32 microcontroller, and presents its application in an energy-saving design of oil extractor control system. This design employs photoelectric isolation technique and the inter-phase of three-phase power supply itself, only three groups of triggering signals are required to control the six thyristors’ conducting angles. The generation of high-precision triggering signals and PID control regulator functions are realized by programming the multiple high-performance timers and the AD interface of a STM32 microprocessor. Experiments and in-field tests have shown the feasibility of the proposed scheme. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.3503
Volume: 12
Issue: 5
Page: 3501-3508
Publish at: 2014-05-01

A Low-Voltage High PSRR and High Precision CMOS Bandgap Reference

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3449
Zhou Qianneng , Xue Rong , Li Hongjuan , Lin Jinzhao , Li Qi , Pang Yu , Li Guoquan
By adopting the technique of pre-regulator, a high PSRR and low temperature coefficient piecewise-linear bandgap reference (BGR) is designed for analog and mixed-signal application in this paper. The piecewise-linear BGR with pre-regulator, which is analyzed and simulated in SMIC 0.18μm CMOS process, has simple circuit architecture. Simulation results show that piecewise-linear BGR with pre-regulator achieves power supply rejection ratio (PSRR) of -102.488dB and -99.73dB, -82.983dB at 10Hz, 100Hz and 1kHz respectively. Piecewise-linear BGR with pre-regulator achieves the temperature coefficient of 2.235 ppm/°C when temperature is in the range from -50°C to 115°C. When power supply voltage VDD changing from 1.2V to 10V, output voltage deviation of piecewise-linear BGR with pre-regulator is only 0.2765mV, but output voltage of piecewise-linear BGR without pre-regulator has a deviation of 38.08mV. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4056
Volume: 12
Issue: 5
Page: 3832-3840
Publish at: 2014-05-01

Urban Planning Support System Based on Three Dimensional GIS

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3459
Yu Kanhua
In this study, the theory of technology analysis and decomposition of the 3-D (three dimensional) visualization of GIS (Geographic Information System) are analyzed, it divides the 3-D visualization of GIS into virtual reality technology, and it presents situation and development trend of 3-D visualization of GIS. It studies the urban model of 3-D data acquisition and processing, the classification of urban 3-D space information data and summarization of the characteristics of urban 3-D spatial data are made, and the three dimensional terrain data, building plane and building elevation data access, building surface texture are also analyzed. The high resolution satellite remote sensing data processing technology and aviation remote sensing data processing technology is studied, and the data acquisition and processing technology of airborne 3-D imager also are introduced This paper has solved the visualization of 3-D GIS data model and visual problem in the construction of the 3-D terrain and expression of choice of buildings, and it is to find suitable modeling route, and in order to provides a reference basis in realization of 3-D visualization of GIS. Visualization of 3-D model of the theory and method are studied in the urban construction, according to the 3D visualization in GIS and it proposed the two kinds of 3-D visualization model of GIS technology. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4110
Volume: 12
Issue: 5
Page: 3928-3935
Publish at: 2014-05-01

Analysis on Electromagnetic Interference with Different Polarization of Electric Field

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3429
Yanpeng Sun , Lele Qu , Liwei Sun
A simplified modeling of shielding cavity with a wire penetrated was established, in order to study the coupling effects of electromagnetic pulse (EMP) with different incident angles when the shielding cavity has a penetrated wire. Finite-Difference Time-Domain (FDTD) was applied to analyze the rule of variation of coupling current magnetic field on the penetrated wire, with the variation of angles of incident wave. Further study shows that the electromagnetic energy coupled by penetrated wire when incident wave radiates aslant is more than the coupling energy when incident wave radiates the target vertically in the condition of vertical polarized direction of electric field, and less in the condition of horizontally polarized direction of electric field. And compared with the situation of horizontal polarized direction of electric field, more electromagnetic energy is coupled when the direction of electric field is vertically polarized. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.5014
Volume: 12
Issue: 5
Page: 3684-3689
Publish at: 2014-05-01

An Adaptive Vertical Handoff Algorithm Based on UMTS and WLAN

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3461
Jin Ling , Zhang Hui , Yang Long-Xiang , Zhu Hong-Bo
According to the characteristics of heterogeneous networks and user demand for seamlessly connection, the necessity of handoff to WLAN was researched.  First of all, in order to reduce the influence of shadow fading on received signal strength (RSS), a smoothing algorithm based on support functions was proposed. Then, considering the context of mobile terminals and networks, and by using probabilistic knowledge, we propose an adaptive vertical handoff algorithm based on compensating time. The simulation results show that, compared with two algorithms, the proposed algorithm can make more effective and accurate handoff decisions, reduce the ping-pong effect and interruption probability, thereby greatly improving handoff performance. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4276
Volume: 12
Issue: 5
Page: 3943-3954
Publish at: 2014-05-01

Image Deformation Based on Wavelet Filter and Control Curves

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3458
Hong-an Li , Jie Zhang , Baosheng Kang
We provide an image deformation method based on wavelet filter using control curves and moving least squares. The image is preprocessed firstly instead of being directly deformed by the old ways. And the original image will be filtered into a high frequency part and a low frequency part by the wavelet, and then use the moving least squares and the control curves only to deform the low frequency part, but not the high frequency part. The key points are set to create control curves according to shape information or deformation requirement, and moved to new position to deform the image using moving least squares. The final result of image deformation is obtained by adding the deformed low frequency part to the high frequency part of the original image. Experiments show that the high frequency detail information is well preserved and the image shape and contour are also well described, and so the deformation results are satisfactory and realistic. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4390
Volume: 12
Issue: 5
Page: 3920-3927
Publish at: 2014-05-01

Forecasting Spatial Migration Tendency with FGM(1,1) and Hidden Markov Model

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3390
Chang Jiang , Jun Wang , Yunsong Shi
Population spatial migration tendency forecasting is very important for the research of spatial demography. Traditional approaches are too complex to be used for time series prediction. This paper presents a method combinating Hidden Markov Model(HMM) and Fourier Series Grey Model(FGM) based on Grey Model(GM) to predict the trend of Jiangsu Province’s migration in China. There are three parts of forecast. The first one is to build GM from a series of coordinate data, the second uses the Fourier series to refine the residuals produced by the mentioned model and the third uses HMM to refine the residuals of FGM .It is evident that the proposed approach gets the better result performance in studying the population migration. Satisfactory results have been obtained, which improve HMM-FGM reached when only GM was used for the population spatial migration tendency forecasting. DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4936
Volume: 12
Issue: 5
Page: 3348-3356
Publish at: 2014-05-01

Adaptive Two-Stage Sensing in Cognitive and Dynamic Spectrum Access Networks

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/3379
Yang Yu , Yanli Ji , Weidong Wang , Yinghai Zhang
In this paper, we first investigate and contrast the features of energy detection and cyclostationary feature detection for spectrum sensing. Combining the advantages of both, we propose an adaptive two-stage sensing scheme which first performs spectrum sensing using an energy detector in cognitive and dynamic spectrum access networks. Then this scheme decides whether or not to implement cyclostationary feature detection based on the sensing results of the first stage. On the premise of meeting a given constraint on the probability of false alarm, our proposed scheme aim to optimize the probability of detection. In order to obtain the optimal detection thresholds, the detection model is formulated as a nonlinear optimization problem. Furthermore, the performance of our scheme in sensing speed is also analyzed. The simulation results show that the proposed scheme improves the performance of spectrum sensing compared with the ones where only energy detection or cyclostationary feature detection is performed.DOI : http://dx.doi.org/10.11591/telkomnika.v12i5.4944 
Volume: 12
Issue: 5
Page: 3257-3265
Publish at: 2014-05-01
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