Lg Electronics Inc.

Chel Woong Lee

Jae Yoo Yoo

Min Kyu Hwang

Jae Chun Lee

Hyuk Soo Lee

Jae-Yoo Yoo

Ji Won Sung

Min-Kyu Hwang

Sung Ho Park

Ji-Won Sung

Chan Ho Chun

Chang Oh Kim

Yoo Jae Yoo

Min Gyu Hwang

A method of controlling a refrigerator is provided. The refrigerator may include a main body having a plurality of storage chambers, a plurality of evaporators to independently cool the plurality of storage chambers, and a refrigerant control valve that controls refrigerant flow into the plurality of evaporators. The method may include opening the control valve and allowing refrigerant to flow into at least one of the plurality of evaporators, when an opening integration time of the control valve is greater than a defrost setting time of the evaporator, operating the refrigerator in a defrost mode, and, when a temperature sensed by a defrost sensor of an evaporator being defrosted is greater than return setting temperatures, terminating operation in the defrost mode. In this manner, each evaporator may be defrosted efficiently, and at a point in time at which defrosting is required.

Control method of refrigerator

An apparatus and method are disclosed to control an operation of a reciprocating compressor capable of precisely controlling an operation (stroke) of a reciprocating compressor regardless of a parameter of an internal motor of the reciprocating compressor and a mechanical error of the reciprocating compressor. The apparatus for controlling an operation of a reciprocating compressor which determines a stroke estimate value corresponding to a point when a discharge valve of the reciprocating compressor is opened as a stroke reference value, and controls a voltage applied to the reciprocating compressor according to the determined stroke reference value.

Apparatus for controlling operation of reciprocating compressor and method thereof

An apparatus and method for controlling the operation of a reciprocating compressor are capable of preventing distortion of a current applied to the reciprocating compressor by generating a current amplitude value for compensating a difference value between a stroke reference value of the reciprocating compressor and a stroke estimate value and outputting the current amplitude value in a form of a sine wave to the reciprocating compressor. The apparatus for controlling an operation of a reciprocating compressor generates a current amplitude value for compensating a difference value between a stroke reference value and a stroke estimate value of the reciprocating compressor and outputs the current amplitude value in a sine wave form to the reciprocating compressor.

Apparatus and method for controlling operation of reciprocating compressor

In an apparatus and a method for controlling operation of a compressor, by removing deviation generated by resistance and inductance and removing an error in a stroke estimation value of a compressor, operation of the compressor can be accurately controlled. The apparatus includes a counter electromotive force detector for detecting a counter electromotive force generated at a motor of a compressor. A stroke calculator calculates a stroke estimation value of the compressor on the basis of the counter electromotive force, and a stroke controller controls a stroke of the compressor by varying a voltage applied to the motor on the basis of the calculated stroke estimation value and a stroke reference value.

Apparatus and method for controlling operation of compressor

In a stroke control apparatus of a reciprocating compressor and a method thereof, the stroke control apparatus of the reciprocating compressor includes a reciprocating compressor, a current detecting unit for detecting a current flowing in a motor of the reciprocating compressor, a stroke detecting unit for detecting a piston stroke by using a voltage and a current applied to the motor of the reciprocating compressor, a phase difference detecting unit for detecting a phase difference by receiving the piston stroke from the stroke detecting unit and the motor current from the current detecting unit, an operational frequency determining unit for determining an operational frequency corresponded to an operation region according to the detected phase difference, a frequency/stroke storing unit for storing a piston stroke value by the determined operational frequency, a reference stroke value determining unit for determining a reference stroke value corresponded to the determined operational frequency by using the stroke value pre-stored in the frequency/stroke storing unit, a control unit for comparing the reference stroke value with a present piston stroke value after a certain time point and outputting a stroke control signal according to the comparison result and an inverter for varying an operational frequency and a voltage applied to the motor of the reciprocating compressor according to the stroke control signal of the control unit.

Stroke control apparatus of reciprocating compressor and method thereof

An apparatus and a method are disclosed for controlling operation of a compressor capable of greatly decreasing a stroke estimation error of a compressor and controlling operation of the compressor accurately and precisely. The method includes calculating a first stroke estimation value of a compressor on the basis of current, a voltage applied to a motor of a compressor and preset parameters of the motor. Detecting a counter electromotive force of the motor and calculating a second stroke estimation value of the compressor on the basis of the detected counter electromotive force value. Determining a new stroke reference value by comparing the first stroke estimation value with the second stroke estimation value, adding or subtracting a stroke compensation value corresponding to the comparison result to or from a preset stroke reference value, and controlling a stroke of the compressor by varying a voltage applied to the motor on the basis of the determined stroke reference value and the first stroke estimation value.

In an operation control apparatus of a compressor, a current, a voltage an d a TDC, etc. applied to a compressor are detected, a speed and a TDC are constantly controlled so as to place an operation point of the compressor within a high efficiency operation region by using a phase difference between each detected values (for example, a phase difference between the current and the voltage), and an operation frequency is varied according to a load variation, accordingly an operation efficiency of the compressor can be improved.

An apparatus and method for operational control of a reciprocating motor compressor, includes performing an operation of the reciprocating motor compressor precisely and accurately. In addition, with the above apparatus and method, the phase difference between a first speed value of the motor (or first TDC value) and current applied to the motor is detected, the second speed value of the motor at the inflection point of the detected phase value (or second TDC value) is detected and stored as a reference value, and the speed of the motor is controlled on the basis of the reference value and the first speed value of the motor (or the first TDC value).

Apparatus and method for controlling operation of reciprocating motor compressor

In an apparatus and a method for controlling a compressor, by setting a stroke reference value so as to be smaller than a maximum stroke value in a maximum load state and operating the reciprocating compressor stably, damage of a reciprocating compressor can be prevented, a cost in a motor design can be reduced, and a size of a motor can be decreased in designing of the motor.

Apparatus and method for controlling a compressor

Disclosed is a circuit for driving a linear compressor enabling to reduce a cost in detecting voltage and current applied to a linear compressor by decreasing the number of precision resistors. The present invention includes a linear compressor controlling a cooling capacity by varying a stroke through an up-and-down straight-line motion of a piston, an electric circuit part supplying the linear compressor with voltage and current in accordance with a switching signal of an AC switching device through a current detect resistor and the AC switching device wherein a ground terminal is connected between the current detect resistor and linear compressor, a voltage detection unit detecting the voltage applied to the linear compressor by taking the ground terminal as a reference and outputting the detected voltage, a stroke calculation unit receiving the detected current and voltage to calculate the stroke, a speed or an acceleration speed of the linear compressor, and a microcomputer inputting a switching signal for controlling the voltage applied to the linear compressor into the switching device to make a present stroke follow an initial stroke reference.

Circuit for driving linear compressor

An apparatus for detecting shaking of stroke of a linear compressor and a method are provided. A linear compressor mis-operates due to change in an external voltage or noise because the shaking of the stroke is detected by the amounts of change in the stroke or current. In order to solve the above problem, a control apparatus of a compressor includes a stroke/current phase difference calculator for calculating the phase differences of the stroke and current using the stroke and the current, which are determined by the increase and the reduction of the stroke due to the voltage generated by a linear compressor, a phase difference change amount calculator for calculating phase difference change amounts using the calculated phase differences of the stroke and the current, a shaking detector for comparing the calculated phase difference change amounts with a reference value for determining whether the shaking of the stroke is detected, to thus determine the shaking of the stroke, and a stroke controller for receiving a stroke shaking detection signal from the stroke shaking detector and changing the stroke voltage according to the magnitude of the request of cooling capacity, which is determined by the change in load, to thus control the driving of the linear compressor, during the operation of the linear compressor.

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Seoul, South Korea

Chel Woong Lee