Speed regulation of induction motors with wound rotor

The regulation of speed is required in many applications of induction motors, including in electric locomotives and electric driving vehicles. In this paper the speed control problem for a wound rotor induction motor is considered. The speed is controlled by changing the external resistance in the rotor circuit. It is assumed that induction motors operate under constant load conditions during changes of the external resistance. A mathematical model of the induction motor with wound rotor proposed in this paper has periodical solutions. In such model the complex effects, which can‘t be found numerically, may appear such as hidden oscillations (see, e.g., [J. de Bruin et al., 2009; M.A. Kiseleva et al., 2012]). Using the non-local reduction method the system of induction motors is studied and analytical estimations of speed control range are obtained. Analytical results are compared with computer experiments.