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PII: S232251141300008-2

Optimum Coordination of Overcurrent Relays with Active Superconducting Current Controller In Distribution Systems

Original Research, B8
Ghafari A., Razaz M., Seifossadat S. Gh.
J. World. Elect. Eng. Tech., 2(3): 37-42, 2013.

ABSTRACT: The Active Superconducting Current Controller (ASCC) is a new type of Fault Current Limiters which can limit the fault current in different modes and also has the particular abilities of compensating active and reactive power for AC main circuit in the normal state. The use of the ASCC disturbs the operation of Over Current Relays (OCR) used in the distribution system. In this paper, an optimum method is proposed for protective coordination of OCR when the ASCC is applied in the system and operates in different modes. By adjusting the magnitude and phase angle of compensation current and also by adjusting the setting parameters of OCR such as Time Dial and Pick up Current in the optimum values, the protective coordination is obtained. By using MATLAB, the model of the distribution system with the ASCC is built and the impact of this type of FCL on the over current relays protection is studied in detail under different current-limiting modes.
Key words: Superconducting fault current limiter, Voltage compensation, Over current relay,Power   distribution system.

PII: S232251141300009-2
Primary synchronization signal in LTE/LTE-Advanced systems

Original Research, B9
Taghavifar L., Kouhi B.
J. World. Elect. Eng. Tech., 2(3): 43-46, 2013.

ABSTRACT: The study is aimed at improvement of Primary Synchronization Signal (PSS) detection in synchronization procedure. The proposed algorithm modifies PSS structure in Long Term Evolution / Long Term Evolution - Advanced (LTE/LTE-A) systems and exploits cross correlation properties of Zadoff-Chu sequences in the other way. We focused on FDD duplexing mode in downlink of LTE radio frame with normal cyclic prefixes and also we applied multipath fading channel in the estimations. Simulation results show that when channel experiences noisy environment or low SNR, the algorithm can work better.

Key words: Synchronization; LTE; Zadoff-Chu; cell search

PII: S232251141300010-2
A Hybrid Method for Gesture Recognition

Original Research, B10
Khalilpour M., Razmjooy N.
J. World. Elect. Eng. Tech., 2(3): 47-53, 2013.

ABSTRACT: In this article, we propose a new hybrid approach with Fourier technique well known as Fourier descriptor and HU moments to detect hand gesture signatures for vision-based applications. Fourier descriptors are efficient specifications of image feature extraction. They can be used for shape characterization by preventing the scale, translation, and rotation invariance, as well as their independent from small shape deviations. To obtain good results for hand images, they converted into HSV color space. HSV unlike RGB color space has some features help users understand the nuances in the images; since, if one color be similar to another color, HSV can get better results. After that, Hand image will be extracted from HSV image by implementing the threshold operation. The Fourier Descriptors of extracted hand images are hybridized with HU moments and are compared with the reference dictionary to perform gesture recognition. Experiments are performed on the Bochum Gestures database. Finally the performance of the gesture recognition using Euclidean distance investigated. Results show that proposed hybrid method gives a high performance for hand gesture applications.

Key words: Hand gesture, HSV Color space, Hybrid Fourier Descriptor, Geometric Invariant Moments.

PII: S232251141300011-2
The Effect of the Appropriate Placement of UPFC on Static Loading Limit in the Power System

Original Research, B11
Ahmadi Kamarposhti M., Nouri P.
J. World. Elect. Eng. Tech., 2(3): 54-60, 2013.

ABSTRACT: Proper placement of reactive power sources, which are parallel capacitors or flexible alternating current transmission systems controllers (FACTS), can effectively improve loading level and the system voltage stability margin. The aim of this study is to investigate the effect of UPFC (Unified Power Flow Controller) on power system static loading. To this end, continuation power flow is used to calculate the maximum loading point and its corresponding megawatts margin. Using PSAT (Power System Analysis Toolbox) software, the proper place of this controller on the IEEE 14-bus power system, is determined. The results show that UPFC effectively increases the static loading margin of power system.

Key words: loading, voltage stability margin, megawatts, UPFC.

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