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Mohamed, M. S., M. A. R. Shafei, A. A. Mansour, and D. K. Ibrahim, "Coils design and parallel resonant H-bridge inverter for inductive power transfer to recharge low-power portable devices", 21st International Middle East Power Systems Conference, MEPCON , Tanta University, Egypt, December 17-19, 2019. Abstract

The capability of the inductive power transfer (IPT) for wireless charging mainly depends on both coil structure and inverter topology. The paper presents the resonant inverter based on the concept of energy injection and free oscillation which are applied to increase the resonant frequency without raising the switching frequency. The implemented inverter utilizes the variable frequency zero current switching (ZCS) control strategy for parallel configuration that ensure the high operating frequency at multiplies of the inverter switching frequency. Consequently, it will result in decreasing the inverter switching loss and also reducing the coil size that operates at resonant frequency. The coil design methodology is introduced in details while studying the different factors affecting the coil behavior. The performance of the overall designed system is evaluated via simulation tests carried out using ANSYS Maxwell and MATLAB SIMULINK.

Afifi, M. K., H. M. Sharaf, M. M. Sayed, and D. K. Ibrahim, "Comparative Study between Single-Objective and Multi-Objective Optimization Approaches for Directional Overcurrent Relays Coordination Considering Different Fault Locations", 13th IEEE PES PowerTech Conference, Milano, Italy, 23-27 June 2019. Abstract

In this paper, a comparative study of single-objective and multi-objective optimization approaches for directional overcurrent relays (DOCRs) coordination is presented. Singleobjective optimization approach is investigated using two methods; the fmincon function which is the gradient-based method, while the second method is the Genetic Algorithm which is a meta-heuristic technique. Multi-objective optimization approach is investigated using fmincon function and Goal Attainment method. All the methods are available in the MATLAB Optimization Toolbox. Different fault locations on the meshed power distribution network of the IEEE 14 bus system are considered for the investigated methods. The results of singleobjective and multi-objective approaches are compared regarding total relays operating times, mean fault clearing time, maximum primary and backup relays operating time and maximum coordination time interval. The results show that using the multi-objective optimization approach in solving the DOCRs coordination problem achieved less total relays operating time and coordination time intervals which ensure faster fault clearing.

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
Ibrahim, D. K., G. M. Abo-Hamad, A. E. E. M. Zahab, and A. F. Zobaa, "Comprehensive Analysis of the Impact of the TCSC on Distance Relays in Interconnected Transmission Networks", IEEE Access, vol. 8, pp. 228315 – 228325, 2020. Abstract

This article extensively investigates the calculations of the compensation factor of the thyristor-controlled series compensator (TCSC), which are used to accurately evaluate the negative impacts of the TCSC on the performance of conventional distance relays. To broadly evaluate the distance protection performance, the TCSC was adapted to the IEEE 9-bus system as one of the interconnected transmission networks that are increasingly spreading to improve service reliability, reduce reserve capacity, and enhance system efciency. In addition, IEEE 39-bus system, as a large interconnected system, is also examined to generalize the TCSC impact on different interconnected systems. To determine the precise impact, the impedance of the TCSC was calculated based on its practical design parameters. The impedance of the TCSC was examined as a function of transmission line impedance and ring angle. Both Mho and Quadrilateral distance relays were tested using the MATLAB/Simulink environment for different types of faults, fault locations, fault resistances, and ring angles for capacitive, inductive, and blocking modes of TCSC operation. In addition, distance relay performance was evaluated during power swing phenomenon in the presence of the TCSC. Simulation tests indicated the negative impacts of the TCSC on distance relay operation, which are not limited to over-reach and under-reach in faulty conditions but also to maloperation in dynamic disturbances that cause power swing phenomena on the protected line.

Ibrahim, D. K., E. E. - D. A. El-Zahab, and A. Galal Ahmed, "Comprehensive Fault Location Scheme for Power Transmission lines", 16th International Middle East Power Systems Conference, MEPCON 2014, 2014. Abstract

A comprehensive two-terminal impedance based fault location scheme is presented in this paper which takes into account the distributed parameter line model. The scheme utilizes unsynchronized measurements of voltages and currents from the two ends of a line. The synchronization angle is calculated using symmetrical components transformation theory. The proposed scheme integrates several fault location algorithms. In one of them, Takagi method is used taking into account the effect of distributed capacitance when the communication link between sending end and receiving end fails.
Another algorithm is embedded in the proposed scheme to accurately locate ground and phase nonlinear high impedance faults using zero and negative sequence currents gathered from the two terminals within a maximum time of 2 cycles. The proposed fault-location scheme has been thoroughly tested using ATP versatile simulations of faults on transmission lines. The presented evaluation shows the validity of the developed fault-location scheme and its accepted accuracy.