In this paper, a new chaotic system is introduced. The proposed system is a conventional power network that demonstrates a chaotic behavior under special operating conditions. Some features such as Lyapunov exponents and a strange attractor show the chaotic behavior of the system, which decreases the system performance. Two different controllers are proposed to control the chaotic system. The first one is a nonlinear conventional controller that is simple and easy to construct, but the second one is developed based on the finite time control theory and optimized for faster control. A MATLAB-based simulation verifies the results.

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Using a dual air-gap structure in a disc-type motor is an effective solution to eliminate undesirable axial force between stator and rotor, by which higher power density can be achieved, too. Furthermore, some of the performance characteristics such as pulsating torque may be improved greatly by adjusting the existing extra selective design parameters in a dual air-gap motor. Accordingly, in this study, a widespread design consideration is carried out on rotor skewing arrangements of a dual rotor (DR) axial flux induction motor with the aim of pulsating torque reduction. The studied scenarios include when the slots of both rotors are skewed exactly similar with different skew angles, the slots of both rotors are skewed similarly but in the opposite directions and the slots of both rotors are not skewed but one rotor is mounted on the shaft by some shift angle relative to the other. The last one is introduced as an alternative to skewed rotors, which is easily executable in small and large size motors with DR topology. Moreover, an algorithm is proposed to determine the appropriate shift angle. Three-dimensional time stepping finite element analysis is employed in all cases for verification. Fig. 12 Torque waveforms at 20% slip for the initial design, skewed rotors and non-skewed shifted rotors

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