Mohamed Rhaima

Dr. Mohamed Rhaima

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 December 2023 in Chaos, Solitons & Fractals
Verified
Journal Article
Closed access
MRMohamed Rhaima
Mohamed Rhaima
LMLassaad Mchiri
Lassaad Mchiri
AMAbdellatif Ben Makhlouf
Abdellatif Ben Makhlouf
HAHassen Ahmed
Hassen Ahmed


25 March 2024 in Fractal and Fractional
Verified
Journal Article
Open access
PDF file
AMAmina Mseddi
Amina Mseddi
AAAhmed Abid
Ahmed Abid
ONOmar Naifar
Omar Naifar
MRMohamed Rhaima
Mohamed Rhaima
AMAbdellatif Ben Makhlouf
Abdellatif Ben Makhlouf
LMLassaad Mchiri
Lassaad Mchiri
This paper investigates the development of a novel analytic approach for computing Unity Magnitude (UM) shapers that deviates from established numerical methodologies. The experimental validation on a test bench confirms the practicality and benefits of the suggested UM shaper technique. The study extends the use of UM shapers to improve the control of wind conversion systems (WCSs), particularly those including hybrid excitation synchronous generators (HESGs), demonstrating their adaptability and versatility. Experimental validation guarantees real-world application, confirming the suggested UM shapers’ trustworthiness. Strict management is still required to assure the system’s efficiency and dependability. In reality, the dynamic equations of a turbine, as well as those of an HESG, are substantially nonlinear; most system parameters are very uncertain; and, finally, a WCS is always impacted by disturbance sources such as load variations, harmonics, and mechanical vibrations. Robust control measures must be used to overcome these issues. A CRONE controller (Robust Fractional Order Control) of the second generation is created. A comparative study performed on the Simulink platform reveals substantial gains brought about by UM shapers in real-world circumstances. The study demonstrates the effectiveness of UM-shaped inputs in mechanical stabilization and Maximum Power Point Tracking (MPPT), emphasizing both theoretical soundness and practical advantages. The analytic equations for UM shapers in undamped and damped systems, offered together with a real-time algorithm, contribute to the optimization of wind conversion systems.

18 October 2024 in Fractal and Fractional
Verified
Journal Article
Open access
PDF file
AJAssaad Jmal
Assaad Jmal
ONOmar Naifar
Omar Naifar
MRMohamed Rhaima
Mohamed Rhaima
AMAbdellatif Ben Makhlouf
Abdellatif Ben Makhlouf
LMLassaad Mchiri
Lassaad Mchiri
This paper presents an extensive investigation into the state feedback stabilization, observer design, and observer-based controller design for a specific category of nonlinear Hadamard fractional-order systems. The research extends the conventional integer-order derivative to the Hadamard fractional-order derivative, offering a more universally applicable method for system analysis. Furthermore, the traditional Lipschitz condition is adapted to a one-sided Lipschitz condition, broadening the range of systems amenable to analysis using these techniques. The efficacy of the proposed theoretical findings is illustrated through several numerical examples. For instance, in Example 1, we select an order of derivative r = 0.8; in Example 2, r is set to 0.9; and in Example 3, r = 0.95. This study enhances the comprehension and regulation of nonlinear Hadamard fractional-order systems, setting the stage for future explorations in this domain.

7 July 2023 in Mathematics
Verified
Journal Article
Open access
PDF file
HGHAMDI GASSARA
HAMDI GASSARA
DKDhouha Kharrat
Dhouha Kharrat
AMAbdellatif Ben Makhlouf
Abdellatif Ben Makhlouf
LMLassaad Mchiri
Lassaad Mchiri
MRMohamed Rhaima
Mohamed Rhaima
Fractional systems have been widely utilized in various fields, such as mathematics, physics and finance, providing a versatile framework for precise measurements and calculations involving partial quantities. This paper aims to develop a novel polynomial controller for a power system (PS) with fractional-order (FO) dynamics. It begins by studying the practical stability of a general class of tempered fractional-order (TFO) nonlinear systems, with broad applicability and potential for expanding its applications. Afterward, a polynomial controller is designed to guarantee the practical stability of the PS, encompassing the standard constant controller as a specific instance. The design conditions for this controller are resolved using the sum of squares (SOS) approach, a powerful technique for guaranteeing stability and control design. To showcase the practical value of the analytical findings, simulations of the PS are conducted utilizing SOSTOOLS.

9 June 2023 in Symmetry
Verified
Journal Article
Open access
PDF file
AAAli Omar M. Alsharif
Ali Omar M. Alsharif
AJAssaad Jmal
Assaad Jmal
ONOmar Naifar
Omar Naifar
AMAbdellatif Ben Makhlouf
Abdellatif Ben Makhlouf
MRMohamed Rhaima
Mohamed Rhaima
LMLassaad Mchiri
Lassaad Mchiri
In this study, an unknown input observer is proposed for a class of nonlinear GPFOSs. For this class of systems, both full-order and reduced-order observers have been established. The investigated system satisfies the one-sided Lipschitz nonlinear condition, which is an improvement of the classic Lipschitz condition. Sufficient conditions have been proposed to ensure the error dynamics’ Mittag–Leffler stability. The value of this work lies in the fact that, to the best of the authors’ knowledge, this is the first research work that investigates the issue of Observer Design (OD) for GPFOSs. To exemplify the usefulness of the suggested observers, an illustrative numerical example is suggested.