Operating an electric motor in saturation – mechanical vibrations and other effects

Abstract

This  paper  addresses  some  of  the  effects  of running an electric motor near and in the saturation zone of the electromagnetic  hysteresis  curve,  namely  mechanical  effects such as mechanical vibrations and rotation speed apart from the classic electrical and thermal effects. Mechanical vibrations are intrinsically   characteristic   of   rotating   machines,   and   other turbomachine  characteristics,  such  as  rotor  unbalance,  non-linearity   and   shaft   variable   stiffness   can   introduce   severe disturbances in the operation of the machine. Rotation speed is also   affected   by   electric   parameters,   when   the   mechanical machine  is  connect  to  an  electric  machine,  meaning  both  the electric  machine  type  and  the  process  by  which  it  is  driven affects both the value of speed and its constancy.