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Atta, M. E. E. - D., D. K. Ibrahim, and M. I. gilany, "Detection and Diagnosis of Bearing Faults under Fixed and Time-Varying Speed Conditions Using Persistence Spectrum and Multi-Scale Structural Similarity Index", IEEE Sensors Journal, vol. 22, issue 3, pp. 2637 – 2646, 2022. Abstract

With the widespread use of variable speed drives, a robust scheme that can detect and diagnose bearing faults under fixed and variable speed conditions becomes essential for reliable operation. Unfortunately, most of the reported methods in the literature are dedicated to working under fixed speed and will face challenges under variable speed conditions. Besides, most of them require detailed bearing information that may be unavailable in the real world. Therefore, in this paper, a new scheme is proposed for bearing faults detection and diagnosis under fixed and time varying speed conditions. The proposed scheme is based on the analysis of vibration signals using the persistence spectrum that can provide images rich with health-related features largely independent from rotating speed. Then, the produced image is compared with priorly stored images of the persistence spectrum of a healthy case. This comparison is performed using the multi-scale structural similarity index, which is a robust basis for images comparison without the need for training or expert knowledge. The obtained index is compared against an adaptive threshold for fault detection. Upon detecting a fault, the persistence spectrum image is compared with that of stored different fault types for fault diagnosis. The proposed scheme is extensively validated using three experimental datasets under different speed conditions. The results show that it can detect bearing faults in an earlier stage without the need for bearing specifications or shaft speed. Moreover, it can successfully diagnose bearing faults severity with accuracy reaching 100% with the minimum required data.

Ibrahim, D. K., M. M. Abdel Aziz, N. M. Abdel Fattah, and A. Ramadan, "Detection and Location of Distribution Systems Faults using Wavelet Packet Transform Based Overcurrent Relay", Proceedings of the 8th International Conference on Electrical Engineering, ICEENG Conference, Military Technical College, Cairo, Egypt, 29-31 May, 2012., Egypt, 2012. Abstract

This paper presents a scheme to increase the sensitivity of overcurrent protection. The proposed scheme applies wavelet packet transform, since it can preserve both time and frequency information with high resolution. The proposed scheme demonstrates its feasible performance in detecting short circuit faults, calculating fault location with moderate accuracy and detecting nonlinear high impedance faults. In addition, the proposed scheme examines the load current continuously and has the ability of changing the relay pick up value adaptively. The examined tested cases include different internal short circuit fault conditions, different nonlinear high impedance faults, and non fault situations such as normal load changing. The obtained results indicate that the developed scheme is fast, robust, reliable and suitable for power distribution systems.

Mohamed Sharaf, H., H. H. Zeineldin, D. K. Ibrahim, and E. E. L. - D. A. EL-Zahab, "Directional Inverse Time Overcurrent Relay for Meshed Distribution Systems with Distributed Generation with Additional Continuous Relay Settings", 12th International Conference on Developments in Power System Protection, 31 March - 3 April 2014 Copenhagen., Copenhagen, IET, 2014. Abstract

Coordination between inverse time overcurrent relays within meshed systems are achieved by adjusting two relay settings; pick up current and time multiplier settings. The operating time of these relays is also a function of two additional constants; one represents the constant for relay characteristics and the other one represents the inverse time type. For typical relays, each of these two constants has four definite values and choosing between them indicates the selected relay operating curve: either standard inverse, very inverse, extremely inverse or long time standby earth fault time-current relay characteristics. In this paper, a coordination strategy, that takes advantage of the available capabilities in microprocessor based relays, is proposed by considering the two relay characteristic constants as continuous variable settings that can be adjusted in addition to the conventional pickup current and Time Dial Setting (TDS). The protection coordination problem is formulated as a nonlinear programming problem where the main objective is to minimize the overall time of operation of relays taking into account protection coordination constraints. The proposed approach is applied to the IEEE 14 bus system and is compared with the conventional two setting relay.

Mostafa, S. A. E. A., D. K. Ibrahim, and E. E. - D. A. El-Zahab, "Directional Overcurrent Relays Coordination Restoration By Reducing Minimum Fault Current Limiter Impedance", Proceedings of the 15th International Middle East Power Systems Conference, MEPCON 2012; Alexandria, Egypt, December, 23-25, 2012, 2012. Abstract
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Mostafa, S. A. E. A., D. K. Ibrahim, and E. E. - D. A. El-Zahab, "Directional Overcurrent Relays Coordination Restoration By Reducing Minimum Fault Current Limiter Impedance", Journal of Energy and Power Engineering, vol. 8, pp. 1132–1141, 2014. AbstractWebsite

FCL (fault current limiter) is used to solve relays miscoordination problem arises from DG (distributed generation) installation. In most published researches, different optimization methods are developed to obtain optimal relay settings to achieve coordination in case of not installing DG, then depending on the achieved optimal obtained relay settings, FCL impedance is deduced to ensure relays coordination restoration in case of installing DG. Based on original optimal relay settings, obtained FCL impedance is not the minimum one required to achieve relay coordination. The contribution of this paper is the generation of multi sets of original relay settings that increase the possibility of finding FCL impedance of minimum value which is lower than the calculated value based on original optimal relay settings. The proposed method achieves better economic target by reducing FCL impedance. The proposed approach is implemented and tested on IEEE-39 bus test system.

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.

Alham, M. H., M. Elshahed, D. K. Ibrahim, and E. E. D. A. El Zahab, "A dynamic economic emission dispatch considering wind power uncertainty incorporating energy storage system and demand side management", Renewable Energy, vol. 96: Pergamon, pp. 800-811, 2016. AbstractWebsite

Reducing carbon emissions is an important goal for the whole world; a high penetration of wind energy can help in reducing emissions. However, great increase in wind energy usage raises some issues concerning its variability and stochastic nature. These issues increase the importance of studying methods of wind energy representation, and in the same time studying the effect of using some flexible resources in decreasing those issues. This paper proposes a dynamic economic emission dispatch (DEED) model incorporating high wind penetration considering its intermittency and uncertainty. Energy storage system (ESS) and demand side management (DSM) are implemented in order to study their effect on the cost, emission, and wind energy utilization. The GAMS software has been utilized to solve this DEED problem. The achieved results show the importance of using ESS and DSM in decreasing both cost and emission, and increasing the wind energy utilization.

Abo-Hamad, G. M., D. K. Ibrahim, E. A. M. Zahab, and A. F. Zobaa, "Dynamic Quadrilateral Characteristic-Based Distance Relays for Transmission Lines Equipped with TCSC", Energies , vol. 14, issue 21, pp. Article 7074, 2021. Abstract

A two-fold adaptive dynamic quadrilateral relay is developed in this research for protecting
Thyristor-Controlled Series Compensator (TCSC)-compensated transmission lines (TLs). By
investigating a new tilt angle and modifying the Takagi method to recognize the fault zone identifier,
the proposed relay adapts its reactive reach and resistive reach separately and independently. The
investigated tilt angle and identified fault zone use the TCSC reactance to compensate its effect
on the TL parameters and system homogeneity. Excessive tests are simulated by MATLAB on the
non-homogenous network, IEEE-9 bus system and further tests are carried out on IEEE-39 bus
system in order to generalize and validate the efficiency of the proposed approach. The designed
trip boundaries are able to detect wide range of resistive faults under all TCSC modes of operations.
The proposed approach is easy to implement as there no need for data synchronization or a high
level of computation and filtration. Moreover, the proposed adaptive dynamic relay can be applied
for non-homogeneity systems and short as well as long TLs which are either TCSC-compensated or
-uncompensated TLs.

Ibrahim, D. K., A. Ibrahim, and I. Hussein Ammar, "Dynamic Voltage Restorer for Deep Voltage Sags and Harmonics Mitigation in Industrial Plant with Sensitive Loads", 16th International Middle East Power Systems Conference, MEPCON 2014, 2014. Abstract

Dynamic Voltage Restorer (DVR) is a fast, flexible and efficient solution for voltage sag problem. It is a power electronic based device that used to compensate voltage sags and harmonics. The DVR has different system topologies for compensation by using battery as an energy storage unit or by using shunt and series converters. In this paper, the DC-DC boost converter is used to connect between shunt and series converters, which allows the DVR to compensate deep sags for long durations. A real case study of Egyptian industrial plant includes a lamp factory as a sensitive load is modeled and simulated using MATLAB/SIMULINK environment to test the effectiveness of using different system topologies of DVR: a battery, shunt and series converters, and finally shunt and series converters with boost converter. Satisfactory performance is achieved using the topology of using shunt and series converters with boost converter for compensating deep voltage sags and harmonics. The financial assessment of using DVR is also investigated.

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