Patent ID: 8294411
Filing Date: 2012-10-23
Classification: H02P

Abstract:
1. A sensorless induction motor control device, which has a function of correcting a slip frequency of a sensorless induction motor, for controlling a induction motor by estimating said slip frequency from a current flowing through windings included in said sensorless induction motor; wherein a Q-phase current command is calculated based on a difference between a speed estimation value, which is calculated using an estimation value of said slip frequency, and an externally supplied speed command and a D-phase voltage command and a Q-phase voltage command, which are used for controlling a voltage applied to said sensorless induction motor, are calculated using a Q-phase current command, characterized in that said sensorless induction motor control device comprises: an ideal voltage command determination unit for determining an ideal voltage command using said speed command and said Q-phase current command; an actual voltage command calculation unit for calculating an actual voltage command using a D-phase voltage command and said Q-phase voltage command; and a slip frequency correction unit for comparing said ideal voltage command with said actual voltage command and changing said estimation value of said slip frequency to smaller if said actual voltage command is smaller than said ideal voltage command.