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.