Speed Control of a Single-Frame Cascade Induction Motor with Slip-Power Pump Back

This paper describes an analytical and experimental study of a self-cascade single-frame brushless induction motor, using a rectifier- inverter to control speed by slip-power pump back to the line. Steady- state analyses of asynchronous and synchronous performance and test results of a special machine wound for the study are presented. The effect of machine parameters, windings, and construction is discussed. The performance and rating of the brushless cascade machine are found to be equivalent to the slip-ring induction motor or wound-field synchronous machine built into the same frame.