Patent ID: 6163912
Filing Date: 2000-12-26
Classification: D06F,H02P,Y02B

Abstract:
A washing machine comprising:a three-phase induction motor for driving a rotatable drum or an agitator mounted in said rotatable drum;a controller for independently commanding the torque current component and the exciting current component of primary AC currents supplied to the stator of said three-phase induction motor in accordance with the command rotational angular velocity of said three-phase induction motor and the rotational angular velocity of said three-phase induction motor, and thus changing the magnitude and frequency of each of said primary AC currents thereby to control the rotational angular velocity of said three-phase induction motor; andan angular velocity estimator for estimating the rotational angular velocity of said three-phase induction motor based on at least one of the primary AC current and a primary AC voltage supplied to the stator of said three-phase induction motor and constants unique to said three-phase induction motor.