Ehab Bayoumi | British University in Egypt (BUE) (original) (raw)

Papers by Ehab Bayoumi

Journal of King Saud University: Engineering Sciences, Dec 1, 2021

The photovoltaic system is one of the sustainable renewable energy cornerstones that has piqued t... more The photovoltaic system is one of the sustainable renewable energy cornerstones that has piqued the interest of researchers in recent years. Since environmental factors such as temperature and radiation levels change over time, the system’s productive strength is impacted. Due to the system’s decreased effectiveness as a result of these changes, a technique called Maximum Power Point Tracking (MPPT) should be utilized to improve the overall system. MPPT is a programmable control innovation that is used to achieve the optimal pool of energy possible. The Maximum Power Point Tracking algorithm in a PV system under variable irradiance and temperature is presented in this paper. For MPPT, the perturb and observe (P&O) method is proposed. The proposed technique provides faster integration with the greatest strength, resulting in a more efficient overall system. The overall system is simulated using MATLAB/SIMULINK POWER LIB, and a practical prototype is implemented in the meantime. Both findings indicate that the proposed system’s anticipated outcomes are met successfully.

Balancing the capacitor voltage for the Three Level Neutral Point Clamped Converters (3L-NPC) is ... more Balancing the capacitor voltage for the Three Level Neutral Point Clamped Converters (3L-NPC) is a chronic issue especially when one capacitor is defected. This could lead to have unequal dc-link voltage distribution and the neutral point will be drifted. Several algorithms had been proposed depending on the implemented modulation method. The Space Vector Modulation (SVM) method is widely used as it offers the simplest way to balance the capacitors by intensively using the small redundant vectors which leads to having excessive switching for the semiconductors, therefore, the switching losses increase. In this paper, an effective technique to balance the voltage of the capacitor is introduced for SVM modulator. The proposed technique redistributes the SVM pattern's dwell time as a result, the switching frequency while keeping the SVM switching time intact. The proposed technique uses simple dwell time distribution factor to control the balancing regulation rate. The effectiveness of the introduced technique is verified with defected dc-link capacitors and shows a remarkable performance.

Wind Energy converter systems require a sophisticated control structure to perform accurate and e... more Wind Energy converter systems require a sophisticated control structure to perform accurate and efficient power conversion. The converter modulation is always a challenging topic. This Paper presents an efficient timing study of Space Vector Modulation (SVM) for Three Level Neutral Point Clamped Converters (3L-NPC). Various patterns have been proposed with different segments numbers and dwell time distribution. By increasing the number of segments, a fast Digital Signal Processors (DSP) is required to ensure the efficient execution of the SVM algorithm. In this paper, a systematic method to select the SVM switching time in relation to the DSP sampling time is presented. Moreover, a new technique for constructing the switching patterns is introduced. The proposed calculations are verified analytically and through simulating a detailed multilevel converter. The results demonstrate the critical relation between pattern selection, SVM switching frequency, and the DSP sampling frequency.

SAE International journal of electrified vehicles, Apr 4, 2023

In recent years we have seen a dramatic shift toward the use of lithium-ion batteries (LIB) in a ... more In recent years we have seen a dramatic shift toward the use of lithium-ion batteries (LIB) in a variety of applications, including portable electronics, electric vehicles (EVs), and grid storage. Even though more and more car companies are making electric models, people still worry about how far the batteries will go and how long it will take to charge them. It is common knowledge that the high currents that are necessary to quicken the charging process also lower the energy efficiency of the battery and cause it to lose capacity and power more quickly. We need an understanding of atoms and systems to better comprehend fast charging (FC) and enhance its effectiveness. These difficulties are discussed in detail in this work, which examines the literature on physical phenomena limiting battery charging speeds as well as the degradation mechanisms that typically occur while charging at high currents. Special consideration is given to charging at low temperatures. The consequences for safety are investigated, including the possible impact that rapid charging could have on the characteristics of thermal runaway (TR). In conclusion, knowledge gaps are analyzed, and recommendations are made as regards the path that subsequent studies should take. Furthermore, there is a need to give more attention to creating dependable onboard methods for detecting lithium plating (LP) and mechanical damage. It has been observed that robust charge optimization processes based on models are required to ensure faster charging in any environment. Thermal management strategies to both cool batteries while these are being charged and heat them up when these are cold are important, and a lot of attention is paid to methods that can do both quickly and well.

Smart Grid and Renewable Energy, 2019

Phase Locked Loop plays a crucial role in synchronizing medium voltage converters. PLL has to pre... more Phase Locked Loop plays a crucial role in synchronizing medium voltage converters. PLL has to precisely and continuously track the grid voltage vector angle and feed it to the converter control loop. Grid disturbances such as voltage dips, harmonics, DC-offset and frequency changes have undesired effects on the estimated angle and as a consequence, the rectifier behavior will be deteriorated. A robust PLL design is essential to provide high immunity to grid disturbances and enable for converter ridging-through during severe disturbances. Using pre-filters to mitigate the grid disturbances slow down the overall system dynamic performance. This paper presents a novel method to ride-through wide range of disturbances by combining an Adaptive Cascaded Delayed Signal Cancellation (CDSC) operator as a pre-filter with a Fuzzy Controller. The obtained results show that the proposed scheme has a great potential for synchronizing high power converters under highly distorted grids.

Journal européen des systèmes automatisés, Dec 29, 2021

Energies

A photovoltaic generator connected to a large network and supplying a nonlinear load (source of h... more A photovoltaic generator connected to a large network and supplying a nonlinear load (source of harmonics) injects distorted current into the grid. This manuscript presents an invariant-ellipsoid set design of a robust controlled active power filter to inject current into the large grid with minimum total harmonic distortion (THD). The nonlinear load current is considered an external disturbance to minimize its effect on the injected grid current. Moreover, the large grid is modeled as a fixed voltage source in a series with a Thevenin impedance whose value changes within an interval. Using the invariant-ellipsoid technique, the problem is cast as a robust disturbance-rejection tracking control. The volume of the ellipsoid is minimized, which results in minimizing the effect of disturbance on system performance and keeping the trajectories as close as possible to the origin. The design is cast into a set of nonlinear matrix inequalities that are linearized by fixing a scalar. The re...

Advances in Environmental Engineering and Green Technologies, 2022

This chapter develops a robust decentralized voltage tracker for islanded MGs. The proposed contr... more This chapter develops a robust decentralized voltage tracker for islanded MGs. The proposed controller is robust against the plug and play operation of the MG, loads, and line parameter uncertainties. The problem is solved in the framework of linear matrix inequality (LMI). The proposed robust control represents the load changes and the parameter variations of lines connecting the DGs as a norm-bounded uncertainty. The proposed controller utilizes local measurements from DGs (i.e., it is totally decentralized). Control decentralization is accomplished by decomposing the global system into subsystems. The effect of the rest of the system on a specific subsystem is considered as a disturbance to minimize (disturbance rejection control). The controller is designed by the invariant-sets (approximated by the invariant ellipsoids). Different time-domain simulations are carried out as connecting and disconnected one or more DGs, connecting and disconnecting local loads DGs and transmission...

International Journal of Modelling, Identification and Control, 2009

ABSTRACT The paper presents a design technique for proportional integral (PI) robust current and ... more ABSTRACT The paper presents a design technique for proportional integral (PI) robust current and speed controllers of switched reluctance motor (SRM) drives. The variations of stator inductance, equivalent resistance, moment of inertia and coefficient of friction are considered leading to uncertain plant representation of the drive. Robustness of the controllers is achieved through Kharitonov theorem considering parameter uncertainties over wide ranges of operation. To attain best performance, the design is cast as an optimisation problem solved by particle swarm optimisation (PSO) to ensure maximum possible degree of stability. Extensive comparisons with the classical methods are carried out showing noteworthy advantages of the proposed routine.

International Journal of Modelling, Identification and Control, 2011

ABSTRACT In this paper, a new control law is designed for flexible manipulator systems. Kharitono... more ABSTRACT In this paper, a new control law is designed for flexible manipulator systems. Kharitonov theorem is used as a design tool to derive the robust control in robotic systems. Stability is guaranteed not only at one operating condition but also for a wide range of system uncertainty. Both the non-linear behaviour of the gearbox stiffness and the end load variations are tackled as interval uncertainties in the model. Particle swarm optimisation (PSO) is used to tune controller parameters, such that, the greatest real parts of closed loop eigenvalues among Kharitonov-extreme polynomials is minimised to assure the highest possible relative stability. The flexible manipulator is a realistic industrial benchmark robot manipulator. The proposed controller is tested as well for rejecting disturbances injected at the motor and the tool. The robustness performance of the controller is evaluated in terms of reference tool position tracking in the presence of the mentioned disturbances and uncertainties. The results of the simulation are presented and compared to the results of traditional controllers and very promising outcomes are obtained.

International Journal of Industrial Electronics and Drives, 2014

Electric Power Components and Systems, 2008

Power systems are subjected to severe repetitive oscillations that might cause generator shaft fa... more Power systems are subjected to severe repetitive oscillations that might cause generator shaft fatigue and, consequently, breakdown. In this article, we consider the problem of designing a power system stabilizer that alleviates generator shaft fatigue through the minimization of the maximum overshoot. Moreover, through our design, the levels of control signal, as well as controller parameters, have to be maintained

Electric Power Components and Systems, 2010

This article presents a design technique for reconfigurable fault-tolerant controllers acting on ... more This article presents a design technique for reconfigurable fault-tolerant controllers acting on a flexible AC transmission system power system. A classical power system stabilizer of the generator excitation system and a controller of the thyristor-controlled series capacitor are considered. Sound operation of both controllers yields the required dynamic performance of the system. However, a faulty condition signifies a degraded control signal of one controller at a time. The proposed scheme suggests that the parameters of one controller switch to some predetermined values if the other controller is faulty with any degradation percentage. Maintaining a specific settling time of the dynamic response is assured against continual degradation of either controller as the design is carried out through the Kharitonov theorem and particle swarm optimization. The proposed design represents an indirect adaptive power system stabilizer. Simulation results denote distinct effectiveness of the proposed design in maintaining the desired system performance under sound and different faulty conditions.Mohamed A. Awadallah is currently on leave at Yanbu Industrial College, Saudi Arabia.