• The Transactions of the Korean Institute of Electrical Engineers
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• v.38 no.2
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• pp.93-99
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• 1989

This paper describes Sinusoidal Wave-Variable Voltage Variable Fequency (SW-VVVF) system for the high efficiency drive of a 3-phase induction motor. SW-VVVF system consists of a 3-phase 24-pulse converter and a SPWM inverter. The converter with additional 2 tap diode circuits in interphase reactor reduces harmonics in input current. The SPWM inverter consists of an improved PLL system and a V/F controller, which reduces harmonics in output current and performs a high efficiency algorithm by maintaining a constant slip frequency and compensating for the velocity variation of the induction motor with the change of load. Therefore, this system reduces harmonics in input and output currents, and also can drive an induction motor with high efficiency in an economical way. We have proved its utility through experiment.