Lg Electronics Inc.

Soon-Bae Yang

Tae-Kyung Kim

Tae-Won Kim

Sung-Min Park

Tae-kyoung Kim

Kwan-Yuhl Cho

A method and an apparatus for detecting a laundry weight of a washing machine can correctly detect a laundry weight of a washing machine. To this end, a motor of a washing machine is driven at a first speed and then at a second speed, and a laundry weight is detected on the basis of a value of a first current for driving the motor at the first speed and a value of a second current for driving the motor at the second speed.

Method and apparatus for detecting laundry weight of washing machine

Disclosed is a method of controlling drive speed of a motor operating in overload conditions. The method includes the steps of: driving the motor at a predetermined reference speed; detecting phase voltage and phase current applied to the motor; determining whether or not the motor is operating in overload conditions based on the detected phase voltage and phase current; and controlling the motor according to whether or not the motor is operating in overload conditions. Accordingly, the present invention can prevent occurrence of over-current due to the instantaneous acceleration of the motor to a predetermined initial speed.

Method of controlling motor drive speed

A lead-angle control device according to the present invention includes: a space voltage vector controller calculating effective vector application times necessary for obtaining output voltage vectors of an inverter from stationary-coordinate-system instruction voltage components; a lead-angle compensator comparing the sum of the effective vector application times with a sampling period, and generating lead-angle compensation values; a speed controller generating an instruction current for compensating an error caused by a difference between an instruction speed and a current speed; an instruction current generator which generates a rotating-coordinate-system instruction current component by extracting a lead-angle component at a point where maximum torque-per-ampere can be obtained from the magnitude of the instruction current and performing a mathematical calculation on the magnitude of the instruction current and a lead-angle component; and an instruction voltage generator generating a stationary-coordinate-system instruction voltage component from the rotating-coordinate-system instruction current component.

Lead-angle control method and device for operating permanent magnet synchronous motor in flux weakening regions

An output control apparatus for a linear compressor and a method of the same are disclosed. In the conventional art, when controlling an output of the linear compressor using a stroke, it is possible to implement a constant stroke. However, since the intermediate position of the piston is varied, it is impossible to constantly implement a top dead point. Therefore, an output control of the linear compressor is difficult, and a higher efficiency is not easily implemented. In addition, there is a problem for constantly controlling an output of the linear compressor. Therefore, in the present invention, the timing when the piston and discharge valve collide with each other is determined, and a certain degree of stroke is determined as a control reference stroke based on the thusly determined stroke for thereby controlling the stroke and driving a linear compressor, and then the linear compressor is driven by controlling the stroke, so that it is possible control an output having no deviation in accordance with the system, whereby a higher efficiency operation is implemented irrespective of the size of the load.

Output control apparatus for linear compressor and method of the same

A linear compressor operating apparatus includes a rectifying and filtering unit for converting an alternating current into a direct current, an inverter for inverting the direct current outputted from the rectifying and filtering unit into a desired frequency alternating current for operating a linear compressor in accordance with the alternating current outputted from the inverter, a position sensor for detecting a position of a piston of the linear compressor and outputting a position signal in accordance with said detection, a current detector for detecting the current running through the linear compressor, and a controller for receiving a current signal outputted from the current detector and a position signal outputted from the position sensor and outputting a pulse width modulating signal to control the inverter. The apparatus obtains a constant value of an interval which determines the efficiency of the linear compressor, regardless of a load thereof and optimizes a phase angle between the driving current and the compressor piston.

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Seoul, South Korea

Soon-Bae Yang