Design of Saturistors for Induction Motor Speed Control

A design method is described for a saturistor which enables the stall current of an induction motor to be restricted to some predetermined value without significant effect on the full-load operation. The design method requires knowledge of the dynamic B¿H loop for the hard magnetic saturistor material. With controlled sinusoidal primary supply voltage and the saturistor connected in the secondary circuit, increased torque at reduced current was obtained during stall.