Application of slip - frequency controlled induction motors for machine tools

The slip-frequency controlled induction motor was applied to machine tools and the desired characteristics have been obtained. The slip-frequency control is performed with the feedback of only the rotor angular velocity, and the position and speed are simultaneously controlled by utilizing the same feedback. Additionally, a method based on currentvoltage control to satisfy the specifications within a wide rotation range was devised for the spindle, and this method has been put to practical use.