Multiphysics Modeling: Electro-Vibro-Acoustics and Heat Transfer of PWM-Fed Induction Machines

The design of variable-speed electrical machines involves several fields of physics, such as electromagnetism, thermics, mechanics, and also acoustics. This paper describes the analytical multiphysics models of a computer-aided-design software which is applied to inverter-fed traction induction machines. The electromagnetic model computes rotor and stator currents, the induction-machine traction characteristics, and the radial air-gap flux density. The mechanical and acoustic models compute the motor´s audible magnetic noise level due to Maxwell forces. The thermal model based on 3-D nodal network computes the transient temperature of different parts of the motor. These fast models make it possible to couple the software with some optimization tools. Some simulation results are presented on a self-ventilated closed motor and compared to experiments.