Induction motors subject to regular voltage fluctuations: Stator and rotor current analysis from a heating perspective

Induction motors are widely applied in industry. Their performance strongly depends on relative power supply quality, such as voltage sags, harmonics, voltage unbalance and voltage fluctuations. This paper investigates the impact of voltage fluctuations on induction motor performance, particularly the stator and rotor current variation characteristics. An induction motor steady state analysis method is proposed when the motor is subjected to regular voltage fluctuations. The dynamic model of an induction motor is used in order to represent the induction motor instantaneous response. Furthermore, the correlative simulation and experiment work are presented in order to illustrate the impact of voltage fluctuations. The stator and rotor RMS current magnitudes of the motor increase dramatically and this effect keeps deteriorating with modulation frequency and voltage change increases. The increase in RMS current will increase losses, resulting in motor winding temperature rise, subsequently accelerating the ageing process.