Brushless motor and washing machine provided with same

    公开(公告)号:US09973138B2

    公开(公告)日:2018-05-15

    申请号:US15328334

    申请日:2015-09-02

    摘要: A brushless motor includes: a motor including a stator around which a winding wire is wound and a rotor holding a permanent magnet; a motor control microcomputer; an inverter circuit in which a power element is incorporated and controls an amount of a voltage applied to the winding wire; a temperature detecting element which detects a temperature of the power element; and a current detecting element which detects a power supply current or a current of the winding wire. A first current limit value is defined by current limit value which is set such that a junction temperature of the power element does not exceed a predetermined value, the brushless motor sets a second current limit value which is higher than the first current limit value, and the brushless motor operates, based on the second current limit value only in a predetermined period after start-up of the brushless motor.

    Motor drive device and brushless motor

    公开(公告)号:US09929683B2

    公开(公告)日:2018-03-27

    申请号:US15328149

    申请日:2015-08-28

    CPC分类号: H02P6/18 H02P21/24 H02P27/06

    摘要: Provided is a motor drive device which performs switching, with respect to a synchronous motor including a stator around which a motor winding is wound and a rotor holding a permanent magnet, from a synchronous operation in which the synchronous motor is synchronously driven to position-sensorless vector control in which a current supplied to the motor winding is controlled based on a position of the rotor. During the synchronous operation, the present motor drive device calculates, by estimation, an induced voltage error based on the detected current and voltage, performs control of an amplitude of a current instruction such that an error, of a target induced voltage, calculated based on an estimated induced voltage and based on an internal angle becomes equal to the induced voltage error, and switches the mode to the sensorless mode after the error is reduced to be within a range of a predetermined value. Further, by gradually reducing the current instruction during the synchronous operation, the absolute value of the induced voltage error is reduced to be within a range of the predetermined value.