Effects of voltage unbalance on IM power, torque and vibrations

Effects of voltage unbalance on the induction motors power, torque and vibrations are analyzed in this paper. Voltage unbalance produces power oscillations at twice the supply frequency, which introduces, in turn, torque oscillations and vibrations at this frequency. The dependence of these power oscillations on the unbalance level and motor load is analyzed by simulation. The effects of voltage unbalance on the oscillation of motor power, torque and vibrations are extensively analyzed through experimental results. These experiments are performed for induction motors with different rotor characteristics, showing that the motor behavior under voltage unbalance significantly changes according to the rotor construction.