Two-phase motor drive using static frequency-doubler amplifiers

A variable-speed drive is described in which a 2-phase induction motor is energized by power modulators of the frequency-doubler type. The system provides continuous and reversible control of motor torque. In comparison with similar drives using conventional magnetic amplifiers this system has the advantages of simplicity, high efficiency, inherent zero stability, and reasonably flat torque-speed characteristics. Both steady-state and transient characteristics of the drive are described and analyzed.