This text should be of interest to electrical engineering academics and graduate students as well as electric machine designers and engineers involved in control, mechatronics and automation. It presents the mathematical model of induction motors with two degrees of mechanical freedom (IM-2DMF), formed in the electromagnetic field as well as in circuit theory, which allows analysing the performance of these three groups of motors taking into account edge effects, winding and current asymmetry. The model derived is based on the concept of magnetic field waves moving in the air-gap with a helical motion. In general, the rotor moves helically too with the rotary-linear slip. The electromagnetic field as well as motor performance of the particular motors is analysed. The mathematical model of IM-2DMF is more general to the model of induction motors with one degree of mechanical freedom, that is, rotary and linear motors. Examples of modelling two types of rotary disc motors and flat linear motor with twisted primary part are presented with inclusion of finite stator and rotor length and width effects.
The simulation results are backed by the measurements carried out on the laboratory models, which were tested on the measurement stand.