A. Furuta et al., Accurate detection of secondary current in shaft hole of induction motors for reliable controls, IEEE MAGNET, 35(5), 1999, pp. 3595-3597
Accurate controls for the speed and the torque of the induction motors (IM)
are realized using the detected secondary current (I-2) signal with the in
verter having a constant ratio of the primary voltage over the driving freq
uency (V-1/f). A, new method for detecting I-2 is presented setting a MI se
nsor head inside a drilled hole through a shaft of an actuator type IM, in
which an almost pure I-2 signal having the slip frequency is stably detecte
d. Accurate and reliable control system for the IM is constructed using the
I-2 feedback loop with the inverter.