SUPPRESSION OF TORQUE MODULATION IN ELECTRIC MOTOR DRIVE SYSTEMS BY FREQUENCY CONTROL

摘要

An electric motor is supplied voltage having a continually varying frequency to obviate cyclic torque pulsations or torque modulation observed to cause vibrations in the motor and load. An AC alternator is connected through a frequency changer with an induction motor in a controlled slip motor drive system including a continually varying slip frequency signal to shift the slip frequency in relation to a nominal value to prevent cyclic torque pulsations. The slip frequency is varied at a rate such that the rotor and load operate at the nominal slip, being incapable of following the changes in input frequency.