A method of, and apparatus for, operating an induction motor.

摘要

A carrier wave (B) of constant amplitude and frequency, generated by a generator (5), is modulated in multipliers (6 and 6 min ) by respective sinusoidal signals (ea and eb). The resulting modulated signals are applied to stators (La, Lb) of induction motor (1) via power amplifiers (7,7 min ) to drive the motor. The sinusoidal signals (ea, eb) are both of one frequency, which is dependent upon the difference between a commanded speed (Ps) and actual motor speed (Pn). The motor (1) can be driven a very low speed and is suitable for use in a machine tool for driving a workpiece table.