Torque Sensors for Induction Motors Using Amorphous Microcore Field Sensors

Abstract

The authors describe the use of amorphous core sensors as a means of achieving precision vector control in induction motors. This type of sensor detects a magnetic field proportional to the secondary current I 2 flowing in the rotor end rings to determine the current I 2 and electric torque. Eight sensor cores are placed around the rotor, reducing the effect of mechanical vibrations. Good output linearity was obtained, and the feasibility of constructing a precision vector control system with a torque feedback loop was demonstrated.