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Ibrahim D.K.,Cairo University | Saleh S.M.,Ministry of Electricity and Energy
Electric Power Components and Systems | Year: 2011

This article presents a central relay based on wavelet transform for high-impedance earth fault detection, zone identification, location, and classification in part of the Egyptian 500-kV transmission network. The scheme recognizes the distortion of the voltage and current waveforms caused by the arcs usually associated with high-impedance earth faults for unsymmetrical faults, whether single line to ground fault The proposed discrete wavelet transform based analysis yields three phase voltages in the high-frequency range and zero-sequence root mean square current in the low-frequency range that are fed to fault detection and location algorithms, respectively, while phase currents in the high-frequency range are fed to the classification algorithm. The fault detection algorithm is based on the recursive method to sum the absolute values of the high-frequency signal generated over one voltage cycle, while the zone identification and fault location algorithms use unsynchronized zero-sequence root mean square currents. On the other hand, the fault classification algorithm is based on the currents in the high-frequency range for one-side data of the faulted line at the local relay after the detection and location process. Characteristics of the proposed central relay are analyzed by extensive simulation studies that clearly reveal that the proposed relay can accurately determine the network faulted line and can calculate fault distance with an acceptable error that does not exceed 5%. All simulation studies are carried out using a high-impedance earth fault model of a distribution system that is modified for transmission systems. An available real high-impedance earth fault case study is used to check the performance of the fault classification algorithm to classify phase and earth faults. © 2011 Copyright Taylor and Francis Group, LLC. Source


Ibrahim D.K.,Cairo University | Eldin E.S.T.,Cairo University | El-Din Abou El-Zahab E.,Cairo University | Saleh S.M.,Ministry of Electricity and Energy
IEEE Transactions on Power Delivery | Year: 2010

The general aim of this paper is to develop an accurate fault-location scheme that can solve the problems affecting the accuracy of the existing conventional fault locators achieving easier maintenance and restoration time reduction as well as economical aims. This consequently helps to fit the new deregulation policies and competitive marketing. This investigation successfully applies zero-sequence current (3I 0) from the two terminals for earth high impedance fault (HIF) location, or negative-sequence currents from the two terminals of one faulted phase for line-to-line fault location. The HIF location is determined within only a maximum time of one cycle. The proposed scheme is insensitive to variations of different parameters, such as fault type, HIF behavior, wide-range transmission-line parameters variation, and fault inception angle. Staged fault testing results demonstrate that the proposed algorithm has feasible performance. © 2010 IEEE. Source


Ibrahim D.K.,Cairo University | Tag Eldin E.S.,Cairo University | Aboul-Zahab E.M.,Cairo University | Saleh S.M.,Ministry of Electricity and Energy
Electric Power Systems Research | Year: 2010

It is possible to capture the required travelling wave information contained in fault transients using wavelet transform. This paper presents practical real time testing for the high impedance fault (HIF) detection algorithm based on real time accidents data. The proposed scheme is implemented for HIF detection in extra high voltage transmission lines. The classifier is based on an algorithm that uses recursive method to sum the absolute values of the high frequency signal generated over one cycle and shifting one sample. Characteristics of this scheme are analyzed by extensive real time studies that clearly reveal that this technique can accurately detect HIFs in the EHV transmission lines within only half a cycle from the instant of fault occurrence. The reliability of this scheme is not affected by different fault conditions such as fault distance and fault inception angle. © 2010 Elsevier B.V. All rights reserved. Source


Aboelela M.A.S.,Cairo University | Fetoh A.M.,Ministry of Electricity and Energy | Gamal A.B.,Cairo University
International Journal of Reasoning-based Intelligent Systems | Year: 2011

This paper is focused on using the conventional Proportional, Integral and Derivative (PID) controllers optimised using Genetic Algorithm (GA) to control the speed of a Combined Cycle Power Plant (CCPP). The system is simulated using MATLAB/Simulink and the PID controller is implemented as a box in the simulation where the parameters KP, KI and KD have been determined using the GA. Different types of the PID controller have been tried in order to obtain the required speed response which achieves certain transient and steady state behaviour. Copyright © 2011 Inderscience Enterprises Ltd. Source

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