PURPOSE: To permit the generation of a high output torque efficiently, by a method wherein the frequency of an inverter is controlled by the product of a flux correction signal, through which a flux command coincides with a flux detection value, and the angular frequency of the inverter.
CONSTITUTION: A slip angular frequency ωS, operated by a slip operating means 5, is added to a rotation angular frequency command ωR to obtain the angular frequency command ω1 of an inverter 2. On the other hand, a flux operating means 6 operates the flux 0 of an induction motor 4 by the slip angular frequency command ωS and the angular frequency command ω1. A flux correction means 7 outputs a flux correction signal in accordance with a difference between the flux 0 and the flux command R. A voltage command operating means 8 products the flux correction signal by the inverter angular frequency ω1 and outputs an inverter voltage command V1. A PWM signal generating means 9 outputs a PWM control signal in accordance with the angular frequency command ω1 and the voltage command V1.
SUZUKI TOSHIO
UEDA AKITERU
