Publications

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2002
Gilany, M. I., M. M. Abdel Aziz, and D. K. Ibrahim, "High Impedance Fault Detection Using a Communication based Element", 2nd IASTED International Conference Power and Energy Systems EuroPES ,Crete, Greece , 25-28 June, 2002, Creete, Greece, pp. 661-664, 2002. Abstract

Faults on distribution circuits are normally detected by simple overcurrent relays. Faults through high impedance (HIF) such as dry earth don’t have sufficient current to operate overcurrent relays. In some cases, fault current is less than the normal current. The broken cables laid on the soil, can be left energized for long periods of time. This presents a serious hazard to the general public with risks of electric shock, fire, etc. This paper describes a new scheme for high impedance fault detection using the concept of digital communications. The proposed model posses a high capability of distinguishing the HIF from normal switching conditions.

2005
Gilany, M. I., E. M. T. Eldin, M. M. Abdel Aziz, and D. K. Ibrahim, "A pmu-based fault location scheme for combined overhead line with underground power cable", 3rd IEE International Conference on Reliability of Transmission and Distribution Networks (RTDN 2005): IET Digital Library, pp. 255-260, 2005. Abstract
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Eldin, E. M. T., M. I. Gilany, M. M. A. Aziz, and D. K. Ibrahim, "A travelling wave based fault location scheme for aged power cables", 3rd IEE International Conference on Reliability of Transmission and Distribution Networks (RTDN 2005): IET Digital Library, pp. 93-98, 2005. Abstract
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Gilany, M., E. S. T. El Din, M. M. Abdel Aziz, and D. K. Ibrahim, "An accurate scheme for fault location in combined overhead line with underground power cable", Power Engineering Society General Meeting, 2005. IEEE: IEEE, pp. 2521-2527, 2005. Abstract

This paper presents an accurate fault location scheme for transmission systems consisting of an overhead line in combination with an underground power cable. The algorithm requires phasor measurements data from one end of the transmission line and the synchronized measurements at the most far end of the power cable. Fault location is derived using distributed line model, modal transformation theory and Discrete
Fourier Transform. The technique can be used on-line or off-line using the data stored in the digital transient recording apparatus. The proposed scheme has the ability to locate the fault whether it is in the overhead line or in the underground power cable. Extensive simulation studies carried out using MATLAB show that the proposed scheme provides a high accuracy in fault location under various system and fault conditions.

Din, E. S. T. E., M. Gilany, M. M. Abdel Aziz, and D. K. Ibrahim, "An PMU double ended fault location scheme for aged power cables", Power Engineering Society General Meeting, 2005. IEEE: IEEE, pp. 80-86, 2005. Abstract

This paper presents an adaptive fault location scheme for aged power cable using synchronized phasor
measurements from both end of the cable line. The proposed fault location scheme is derived using the two-terminal synchronized measurements incorporated with distributed line model, modal transformation theory and Discrete Fourier Transform. The proposed scheme has the ability to solve the problem of cable changing parameters especially the change of the relative permittivity over its age and thus for the operating positive, negative, and zero-sequence capacitance changes. Extensive simulation studies are carried out using Alternative Transients Program ATP/EMTP. The simulation studies show that the proposed scheme provides a high accuracy in fault location calculations under various system and fault conditions. The results show that the proposed method responds very well insensitive to fault type, fault resistance, fault inception angle and system configuration. The proposed scheme solves the problem of aged cables with change of its electric parameters. In addition to, it gives an accurate estimation of the fault resistance.

Gilany, M. I., E. M. T. Eldin, M. M. Abdel Aziz, and D. K. Ibrahim, "Traveling wave-based fault location scheme for aged underground cable combined with overhead line", International Journal of Emerging Electric Power Systems, vol. 2, pp. 1032, 2005. AbstractWebsite

This paper presents a novel wavelet-based travelling wave fault location algorithm for aged underground cables in transmission systems. Such transmission systems consist of overhead lines combined with underground power cables. Applying the singularity detection feature of wavelets as a powerful signal processing tool, the first and second initial arrival of the voltage travelling waves at the first end of the overhead as well as at the terminal end of the aged cable line can be identified reliably without the need for detection the sign of these waves. In this paper modal signals, rather than the phase signals, are
the inputs to the relay. The proposed algorithm is capable of eliminating the effect of the change in the propagation velocity of the travelling waves over the age of the cable. It can be used on-line
following the operation of digital relays or off-line using the data stored in the digital transient recording apparatus. Extensive simulation studies carried out using ATP/EMTP show that the proposed algorithm provides an accepted degree of accuracy in fault location under different fault conditions.

Din, E. S. T. E., M. Gilany, M. M. Abdel Aziz, and D. K. Ibrahim, "A wavelet-based fault location technique for aged power cables", Power Engineering Society General Meeting, 2005. IEEE: IEEE, pp. 2485-2491, 2005. Abstract

A novel Wavelet-based Travelling Wave cable fault locator scheme is presented in this paper. Using the theory of wavelet singularity detection as a powerful signal processing tool, the initial arrival of the voltage travelling waves at both sides of the power cable and the second arrival of the travelling waves at the first side can be identified reliably without the need for detection the sign of these waves. The developed wavelet
processing is applied on the modal coordinated instead of the phase coordinates. The proposed scheme has the ability to eliminate the effect of the change in the propagation velocity of the travelling waves. This will help solving the problem of cable changing parameters especially the changing of the relative permittivity of the cable over its age. Cable changing parameters causes a large error in all fault location techniques, which use the value of velocity of propagation in calculations. Characteristics of the proposed protection algorithm are analyzed by extensive simulation studies using ATP/EMTP. The obtained results
indicate an accepted degree of accuracy for the suggested fault locator. In addition, the results prove that the proposed wavelet based scheme solves the problem of aging cables with changing parameters over the age of the power cable.

2006
Din, E. S. T. E., and D. K. Ibrahim, "A Fault Location Scheme for High Resistance Shunt/Series Faults in Radial Cable Systems", Scientific Bulletin of Faculty of Engineering, Ain Shams University, vol. 41, issue 2: ISSN 1110-1385, pp. 587-612, 2006. Abstract
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Eldin, E. M. T., M. I. Gilany, M. M. Abdel Aziz, and D. K. Ibrahim, "An accurate fault location scheme for connected aged cable lines in double-fed systems", Electrical Engineering, vol. 88, issue 5: Springer, pp. 431-439, 2006. AbstractWebsite

This paper presents an adaptive fault location scheme for aged power cables using synchronized phasor measurements from both ends of the cable. The proposed fault location scheme is derived using the two terminal synchronized measurements incorporated with distributed line model, modal transformation theory and Discrete Fourier Transform. The proposed scheme has the ability to solve the problem of cable changing parameters, especially the change of the relative permittivity over its age and thus for the operating positive, negative, and zero-sequence capacitance changes. Extensive simulation studies are carried out using Alternative Transients Program ATP/EMTP. The simulation studies show that the proposed scheme provides a high accuracy in fault location calculations under various system and fault conditions. The results show that the proposed scheme responds very well to any fault insensitive to fault type, fault resistance, fault inception angle and system configuration. The proposed scheme solves the problem of aged cables with the change of the electric parameters. In addition to, it gives an accurate estimation of the fault resistance.

Din, E. S. T. E., M. M. Abdel Aziz, M. Gilany, and D. K. Ibrahim, "Fault location scheme for combined overhead line with underground power cable", Electric power systems research, vol. 76, issue 11: Elsevier, pp. 928-935, 2006. AbstractWebsite

This paper presents a fault location scheme for transmission systems consisting of an overhead line combined with an underground power cable. The algorithm requires phasor measurements data from one end of the transmission line and the synchronized measurements at the most far end of the power cable. Fault location is derived using distributed line model, modal transformation theory and Discrete Fourier Transform. The technique can be used on-line or off-line using the data stored in the digital fault recording apparatuses. The proposed scheme has the ability to locate the fault whether it is in the overhead line or in the underground power cable. In addition to, the proposed scheme gives an accurate estimation of the fault resistance at fault location. Extensive simulation studies carried out using MATLAB show that the proposed scheme provides a high accuracy in fault location under various fault conditions.

Abdel Aziz, M. M., E. S. T. E. Din, D. K. Ibrahim, and M. Gilany, "A phasor-based double ended fault location scheme for aged power cables", Electric Power Components and Systems, vol. 34, issue 4: Taylor & Francis, pp. 417-432, 2006. AbstractWebsite

This paper presents a fault location scheme for aged power cables using phasor measurements from both ends of the cable line. The proposed fault location scheme is derived using two-terminal measurements incorporated with a distributed line model, modal transformation theory, and discrete Fourier transforms. The proposed scheme can solve the problem of cable changing parameters, especially the change of the relative permittivity and thus for the operating positive, negative, and zero sequence capacitance changes. Extensive simulation studies are carried out using the alternative transients program ATP/EMTP. The simulation studies show that the proposed scheme provides a high accuracy in fault location calculations under various system and fault conditions. The results show that the proposed method responds very well, being insensitive to fault type, fault distance, fault resistance, and fault inception angle. The
proposed scheme solves the problem of aged cables with change of electric parameters. In addition, it gives an accurate estimation of the fault resistance in all fault types.

El-Sonbaty, A. E. - S., H. K. M. Yonssef, and D. K. Ibrahim, "A proposed particle swarm optimization technique for solving non-linear economic dispatch problem", Power Systems Conference, 2006. MEPCON 2006. Eleventh International Middle East, vol. 2, El-Minia, Egypt, IEEE, pp. 606-611, 2006. Abstract

This paper proposes a particle swarm optimization (PSO) method for solving the economic dispatch (ED) problem in power systems. Many nonlinear characteristics of the generator are considered for practical generator operation, such as ramp rates, prohibited operating zones, and non smooth cost functions. The feasibility of the proposed .method is demonstrated for two different systems, and is compared with both Genetic Algorithm (GA) method and another PSO method in terms of the cost optimization and computation time where an improvement in both terms is achieved.

2007
Eldin, E. S. T., D. K. Ibrahim, E. M. Aboul-Zahab, and S. M. Saleh, "High impedance faults detection in EHV transmission lines using the wavelet transforms", Power Engineering Society General Meeting, 2007. IEEE: IEEE, pp. 1-7, 2007. Abstract

High impedance faults (HIFs) are difficult to be detected by overcurrent protection relays. This paper presents an ATP/EMTP fault simulations studies based algorithm for high impedance fault detection in extra high voltage transmission line. The scheme recognizes the distortion of the voltage waveforms caused by the arcs usually associated with HIF. The discrete wavelet transform (DWT) based analysis, yields three phase voltage in the high frequency range which are fed to a classifier for pattern recognition. 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. A HIF model of distribution is modified for EHV transmission lines. Characteristics of the proposed fault detection scheme are analyzed by extensive simulation studies that clearly reveal that the proposed method can accurately detect HIFs in
the EHV transmission lines.

Gilany, M., D. K. Ibrahim, and E. S. T. E. Din, "Traveling-wave-based fault-location scheme for multiend-aged underground cable system", Power Delivery, IEEE Transactions on, vol. 22, issue 1, pp. 82-89, 2007. Abstract

This paper presents a novel wavelet-based fault-location scheme for aged cable systems when synchronized digital fault recorded data are available at the two terminals of each cable. The proposed scheme estimates the fault location in multiend-aged cable systems using the theory of wavelet singularity detection as a powerful signal processing tool. The arrival of the first and second voltage traveling waves at both ends of the power cables can be identified reliably. The developed wavelet processing scheme is applied on the modal coordinates instead of the phase coordinates. The proposed scheme has the ability to eliminate the impact of the change in the propagation velocity of the traveling waves on the fault-location calculations. This will help solve the problem of cable changing parameters, especially the change of the relative permittivity of the cable with age. The method is valid even with faults that are very close to busbars. Characteristics of the proposed fault-location scheme are analyzed by extensive simulation studies using Alternative Transients Program/Electromagnetic Transients Program. The results indicate an accepted degree of accuracy for the suggested fault locator.

2008
Aboul-Zahab, E. M., E. - S. T. Eldin, D. K. Ibrahim, and S. M. Saleh, "High impedance fault detection in mutually coupled double-ended transmission lines using high frequency disturbances", Power System Conference, 2008. MEPCON 2008. 12th International Middle-East: IEEE, pp. 412-419, 2008. Abstract

Coupling Capacitor Voltage Transformer (CCVT) secondary voltages, normally applied to conventional schemes, do not comprise appropriate information for schemes that operate on high frequency fault generated transients. However it is possible to capture the required travelling wave information contained in fault transients using a high frequency tap from a CCVT. This paper presents an ATP/EMTP fault simulations studies based algorithm for half cycle high impedance fault detection. The proposed scheme implemented on two different models of HIF in extra high voltage mutually coupled double-ended transmission lines. The scheme recognizes the distortion of the voltage waveforms caused by the arcs usually associated with HIFs. The high pass filter tap yields three phase voltage in the high frequency range which are fed to Clarke’s transformation to decouple the traveling waves of the mutually coupled lines and produces ground mode and aerial modes voltage components to
the classifier for pattern recognition. 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 the proposed fault detection scheme are analyzed by extensive simulation studies that clearly reveal that the proposed method can accurately detect HIFs in the EHV transmission lines within only half a cycle from the instant of fault occurrence. The reliability of the proposed scheme does not affected by different fault conditions such as fault distance and fault inception angle.

Ibrahim, D. K., E. - S. T. Eldin, E. M. Aboul-Zahab, and S. M. Saleh, "High-impedance fault detection in EHV transmission lines", Power System Conference, 2008. MEPCON 2008. 12th International Middle-East: IEEE, pp. 192-199, 2008. Abstract

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Abdel Aziz, M. M., A. F. Zobaa, D. K. Ibrahim, and M. M. Awad, "Transmission lines differential protection based on the energy conservation law", Electric Power Systems Research, vol. 78, issue 11: Elsevier, pp. 1865-1872, 2008. AbstractWebsite

This paper proposes a differential protection scheme for transmission lines using the energy conservation law. The real power signals at both ends (sending and receiving) of the line are compared with a prespecified value, if the resultant is more than this value, an internal fault is indicated in the transmission line zone. The proposed technique is evaluated using PSCAD/EMTDC program configurated to model the effect of faults on typical 500 kV transmission line. Extensive simulation studies show that this protection scheme has the ability to discriminate internal faults fast and accurately, and is more reliable than conventional biased differential protection scheme, and suitable for all types of lines. Details of the proposed relay design are given in the paper; also results of some performance studies are given.

Gilany, M., E. S. T. El Din, and D. K. Ibrahim, "Travelling Wave-based Fault Location Scheme for Multi-End Aged Underground Cable System", International Journal of Power and Energy Systems, vol. 28, issue 2: IASTED ANAHEIM, pp. 160, 2008. AbstractWebsite

Abstract—This paper presents a novel wavelet-based fault-location scheme for aged cable systems when synchronized digital fault recorded data are available at the two terminals of each cable. The proposed scheme estimates the fault location in multiend-aged cable systems using the theory of wavelet singularity detection as a powerful signal processing tool. The arrival of the first and second voltage traveling waves at both ends of the power cables can be identified reliably. The developed wavelet processing scheme is applied on the modal coordinates instead of the phase coordinates. The proposed scheme has the ability to eliminate the impact of the change in the propagation velocity of the traveling waves on the fault-location calculations. This will help solve the problem of cable changing parameters, especially the change of the relative permittivity of the cable with age. The method is valid even with faults that are very close to busbars. Characteristics of the proposed fault-location scheme are analyzed by extensive simulation studies using Alternative Transients Program/Electromagnetic Transients Program. The results indicate an accepted degree of accuracy for the suggested fault locator.

2009
El Din, E. S. T., D. K. Ibrahim, E. M. Aboul-Zahab, and S. M. Saleh, "High impedance fault detection in EHV series compensated lines using the wavelet transform", Power Systems Conference and Exposition, 2009. PSCE'09. IEEE/PES, Washington, U.S.A., IEEE, pp. 1-10, 2009. Abstract

Coupling capacitive voltage transformers behave as low pass filters which reject the high frequencies associated with voltage signals, so the effect of HIF on voltage signals is neglected. In addition, using series capacitors (SCs) equipped with metal oxide varistors (MOVs) increases the protection relaying problems and complicates the trip decision. This paper presents a high impedance fault detection algorithm for maximum trip time required of 3/4 cycle. The proposed scheme implemented on two different models of HIF in extra high voltage double-ended transmission lines with series capacitors at the middle of the line. The scheme recognizes the distortion of the voltage waveforms caused by the arcs usually associated with HIFs. The discrete wavelet transform (DWT) based analysis, yields three phase voltages in high frequency range which are fed to Clarke’s transformation to produce ground and aerial modes
voltage components for pattern recognition. The classifier is based on an algorithm that uses recursive method to sum the absolute values of high frequency signals generated over one cycle and shifts one sample. Characteristics of the proposed scheme are fully analyzed by extensive ATP/EMTP simulation studies that clearly reveal that the proposed method can accurately detect HIFs in EHV transmission lines and does not affected by different fault conditions such as fault distance and fault inception angle.

Saleh, S. M., E. M. Aboul-Zahab, E. Tag Eldin, D. K. Ibrahim, and M. I. Gilany, "Neural network-based technique used for recovery the CCVT primary signal", Power & Energy Society General Meeting, 2009. PES'09. IEEE: IEEE, pp. 1-7, 2009. Abstract

The coupling capacitor voltage transformers transient response during faults can cause protective relay mal-operation or even prevent tripping. This paper presents the CCVT transient response errors and the use of artificial neural network (ANN) to correct the CCVT secondary waveform distortion. In this paper, an ANN program is developed to recover the primary voltage from the distorted secondary voltage. The ANN is trained to achieve the inverse transfer function of the coupling capacitor voltage transformer (CCVT), which provides a good estimate of the true primary voltage from the distorted secondary voltage. The neural network is developed and trained using MATLAB simulations. The accuracy of the simulation program is
confirmed by comparison of its response with that of the target value from the simulation data.

2010
Ibrahim, D. K., M. M. Abd-elaziz, and M. B. Youwakim, "Comparison of Maximum Power Point Tracking Techniques for Different Types of Photovoltaic Models", Proceedings of the 7th International Conference on Electrical Engineering, (ICEENG) Conference, 25-27 May, Cairo, Egypt, 2010, 2010. Abstract
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Ibrahim, D. K., A. F. Zobaa, E. Abo El-Zahab, and G. M. Abo-Hamad, "A Hybird Algorithm for Blocking Power Swings", Proceedings of the 7th International Conference on Electrical Engineering, (ICEENG) Conference, 25-27 May, Cairo, Egypt, 2010., 2010. Abstract
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Nasr, A. M., D. K. Ibrahim, S. Fakhry, and M. M. Abdel Aziz, "A Study of Single Phase Static Energy Meter Behavior during Voltage Dips", 14th International Middle East Power Systems Conference (MEPCON’10), Cairo University, Egypt, 2010. Abstract
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Metwally, M. A., A. Aboshosha, D. K. Ibrahim, and E. E. L. - D. A. EL-Zahab, "Applying Neurofuzzy Computing for Safety Improvement of Nuclear Power Reactor", 14th International Middle East Power Systems Conference (MEPCON’10), Cairo University, Egypt, 2010. Abstract

Nuclear Power Reactors (NPRs) are large in scale and complex, so the information from local fields is excessive, and therefore plant operators cannot properly process it. When a plant malfunction occurs, a great data influx is occurred, so the cause of the malfunction cannot be easily or promptly identified.
A typical NPR may have around 2,000 alarms in the Main Control Room (MCR) in addition to the display of analog data. During plant transients, hundreds of alarms may be activated in a short time. Hence, to increase the plant safety, this paper proposes a support system based on neurofuzzy that assists alarming and diagnosis systems. Throughout this framework the neurofuzzy fault diagnosis system is employed to fault diagnosis of nuclear reactors. To overcome weak points of both linguistic and neuro learning based approaches, integration between the neural networks and fuzzy logic has been applied by which the
integrated system will inherit the strengths of both approaches.

Yousef, W. H., D. K. Ibrahim, and E. Abo El-Zahab, "Discrimination of Internal Faults and Inrush Currents For Large Modern Power Transformer", 14th International Middle East Power Systems Conference (MEPCON’10), Cairo University, Egypt, 2010. Abstract

This paper presents a differential protection approach for large high quality power transformers that have
low inrush currents of about 3.14 times rated currents. Such transformers have low second harmonic level, which results in conventional differential protection malfunction. A scheme for internal faults and inrush currents discrimination based on both discrete Fourier transform DFT and discrete Wavelet Transform
DWT is proposed. The proposed method has been designed based on the percentage of the sum of wavelet transform coefficients D1 and fundamental differential current (based on a 1 kHz sampling
rate). It has been tested by extensive EMTP/ ATP simulations for different faults and switching conditions on El Tebbin Power Plant 220/21 kV generator/power transformer. It is proved that it has a high capability for discrimination even in the case of inrush with low second harmonic content and internal fault currents with high second harmonic component. All tests proved that the proposed scheme is reliable, accurate, and fast.

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