الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
Chaos is a phenomenon that exists in several practical and scientific fields especially in electrical and power engineering. As it can induce qualitative changes in the system’s steady-state trajectory, and make the system unstable. The period-1 orbit, which is the system’s nominal orbit, may lose its stability, resulting in the creation of a new orbit that is periodic, quasiperiodic, or chaotic. So, the study of periodic orbit stability has necessitated the use of specialized approaches in recent decades.
Electrical motors are essential to the development of our modern life. Therefore, it is important to design an effective controller to produce the desired response. The shaft’s speed must be regulated to guarantee optimal motor utilization. Nowadays, the most efficient way for controlling the speed is through electronic power switching, which may lead to nonlinearity in the system behavior. Moreover, complex dynamical phenomena such as bifurcations and chaos can occur in the system when changing the initial conditions.
Therefore, the purpose of this thesis is to analyze the periodic orbit of permanent magnet direct current (PMDC) motor and develop controllers that can suppress chaotic behavior resulted from initial conditions variation such as supply voltage and controller gain. Waveform, phase portrait, Filippov (Floquet), approaches are utilized for analyzing chaos in PMDC. Then by applying controller techniques such as controlling saltation matrix technique, fuzzy logic controller, and Fractional order proportional-integral derivative controller, chaotic behavior is suppressed and this leads to normal behavior for the system.
However, the applied controllers are giving a poor performance, especially when changing the load torque. So, an optimized fuzzy fractional-PID controller is proposed to control and stabilize PMDC under load variation. It eliminates the chaotic vibration in the motor’s speed and it gives better performance. The cuckoo search technique has been utilized for optimizing controller parameters by considering integral time absolute error as an objective function. The proposed controller is compared with other controllers that emphasize its superiority over all other controllers with the best time response, and least steady-state error.