Lg Electronics Inc.

Kwan Yuhl Cho

Tae Kyoung Kim

Soon Bae Yang

Dong Myung Lee

Hak Woon Kim

An apparatus and method for determining the presence or absence in a motor lock error in a sensorless motor. The method includes the steps of: driving the sensorless motor; determining whether or not a predetermined time elapses after the sensorless motor has been driven; measuring a current applied to the sensorless motor after the lapse of the predetermined time; calculating a difference between the measured current with a predetermined reference current; and determining the presence or absence of a motor lock error in the sensorless motor by determining whether the determined difference is equal to or higher than a predetermined reference difference, so that it quickly determines the presence or absence of a motor lock error in the sensorless motor without using a sensor and prevents an overcurrent from flowing in the sensorless motor, resulting in the prevention of a faulty operation or damage to the sensorless motor.

Apparatus and method for determining whether motor lock error occurs in sensorless motor

An apparatus for sensing a laundry amount in a washing machine includes: a rectifier; an inverter receiving a DC voltage and converting it to a three-phase AC voltage, a BLDC motor driven by the three-phase AC voltage from the inverter, a rotor position detector detecting the position of a rotor of the BLDC motor; a microcomputer outputting a control signal for controlling a switching operation of the inverter according to the position detect signal of the rotor position detector and a current control signal; a gate driving unit receiving the control signal from the microcomputer and outputting a gate drive signal to the inverter; a torque command generator generating a torque command signal corresponding to a speed set by a user; a torque controller operating the torque command signal from the torque command generator and outputting a q-axis current command signal; a current controller outputting the current control signal according to the q-axis current command signal from the torque controller and a d-axis current command signal; a speed detector detecting a driving speed of the BLDC motor according to the position detect signal of the rotor position detector; a laundry amount sensor comparing the speed detect signal from the speed detector with a previously stored reference speed and sensing a laundry amount; and a current command unit applying the d-axis current command signal to the current controller according to the speed detect signal from the speed detector.

Apparatus and method for sensing laundry amount in a washing machine

An apparatus for detecting a rotor position in a brushless direct current (BLDC) motor, in which a rotor position can be detected by a virtual neutral point voltage and current of one phase in a motor. The number of circuits required for the rotor position detection is reduced to save the production cost and reduce the space occupied by a position detecting circuit.

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Seoul, South Korea

Kwan Yuhl Cho