METHOD OF AND CIRCUIT FOR MEASURING PULSATING COMPONENT OF ELECTROMAGNETIC TORQUE

摘要

A method and circuit for calculating the instantaneous pulsating component of torque for use as a cogging feedback signal to stabilize ac motors at low frequencies. An air gap flux signal is generated by integrating the instantaneous voltage across a stator phase winding during the interval the current in that winding is zero. Pulsating torque is the product of the high pass filtered flux signal and the inverter input or dc link current.