Dynamic modeling of a synchronous reluctance machine for transient simulation of vibrations under variable rotor magnetization

Abstract

This work introduces a new approach for the dynamic simulation of a permanent magnet-assisted synchronous reluctance machine with the ability to consider dynamic changes in the rotor magnetization. The aim is to comprehensively analyze the dynamics of a machine through transient simulations of the occurring magnetic and mechanical forces that influence the noise and vibration characteristics. A simplified magnetic model considering the effects of magnetic reluctances, leakage flux, and magnetic saturation is utilized to efficiently calculate the dynamically changing magnetic forces in the air gap. Unlike conventional designs employing rare earth magnets in the rotor, the design at hand utilizes non-rare earth magnets that enable adjustments of the magnets’ flux output. The novelty of the presented approach lies in its ability to consider these dynamic changes when calculating the air gap flux. The magnetic forces are then applied to an elastic multibody model of the motor, which includes the rotor, stator, bearings, and the housing, for the computation of the bearing forces and housing deformations. The presented multi-physical model allows for transient simulations of the forces acting on the bearings and the housing, capturing the dynamic response of the motor under varying rotor magnetization, air gaps, and loads. With the proposed approach, this study offers predictions regarding critical vibration characteristics that occur during dynamic operation, providing valuable insights for noise reduction efforts.