Hyperchaos from DTC Induction Motor Drive System

In the present work, a 3-phase induction machine model has been derived in a stationary reference-frame. The strategy of the direct torque control (DTC) with a constant voltage-to-frequency ratio is used to control the obtained model. The obtained driven machine system involves nine nonlinear first-order differential equalities. The nine-dimensional system performance is investigated by using the numerical analysis due to changes in the parameter of the control part. The gain of the integral in the speed part of the controller is designated to investigate the dynamics of the modeled system. The results illustrate that the system has a period-doubling (period-1, period-2, and period-4) bifurcation route to chaotic oscillation. The bifurcation diagram and Lyapunov exponent spectrum assign these situations. Period-5 is noted in a window inside the bifurcation diagram. The large positive magnitudes of two of Lyapunov exponents show that the system is hyperchaos, which denotes the system shows very strong randomness and a high degree of disturbance. The system generates different coexisting attractors (periodic and chaotic attractors) for different values of the integral gain of the speed control loop. Copyright (C) 2021 The Authors.