Electromagnetic, Electromechanical and Thermal Transient Characteristics of an Asynchronous Motor with Variable Parameters

摘要

Asynchronous motors with variable parameters are motors whose rotor parameters change when changing the operating mode, regardless of the motor design. Compared to conventional asynchronous motors of the same power, such motors are able to longer stay in the state matching the electromagnetic and especially the thermal transients. In such modes, some elements of an electric machine might overheat, which causes multiple electrical, magnetic, and thermal parameters thereof to alter, lowering the motor moment. In turn, an alteration of parameters affects the intensity of the running currents of the machine, thus changing the motor losses. The paper presents a mathematical model and an algorithm for computing the electromagnetic and thermal transients in an asynchronous motor with variable parameters, which takes into account the eddy currents in the state and is based on the generalized electromechanical energy converter; the model and algorithm are intended for analyzing the dynamic and energy characteristics of the machine as a function of its parameters, which depend on the saturation of the rotor and stator magnetic cores.