Apparatus for controlling compressor, compressor and method for controlling compressor
AssigneeLG Electronics Inc.
InventorsYoungsung Kim, Youngbong Cho, Jaeheung Kim, Hyeongseok Kim
Life of this patent
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Abstract
A compressor control apparatus and method differently compensate for a duty ratio of a control signal during a period in which the compressor performs a compression stroke and a period in which the compressor performs a suction stroke, respectively, to generate the control signal for controlling a compressor.
Claims18
A compressor control apparatus configured to control operation of a compressor, the compressor including a cylinder, a piston configured to reciprocate in the cylinder, and a motor configured to move the piston, the compressor control apparatus comprising:
- an inverter configured to convert power received from an external power source into driving power for driving the motor of the compressor;
- and
- a controller configured to:
- detect at least one of a magnitude of the driving power, a position of the piston of the compressor, or an internal pressure of the cylinder of the compressor,
- generate a pulse width modulation (PWM) control signal for controlling a switching operation of the inverter based on a result of detecting at least one of the magnitude of the driving power, the position of the piston of the compressor, or the internal pressure of the cylinder of the compressor,
- apply a compensation value to a duty ratio of the PWM control signal, the compensation value being varied based on the compressor performing a compression stroke or a suction stroke, and
- apply the PWM control signal to the inverter to control the switching operation of the inverter,
- wherein the controller is configured to:
- decrease the compensation value during a first period of the suction stroke,
- apply a first compensation value to the duty ratio during a first period of the compression stroke, and
- apply a second compensation value to the duty ratio during the first period of the suction stroke, the second compensation value being different from the first compensation value.
A compressor, comprising:
- a cylinder;
- a piston disposed in the cylinder and configured to reciprocate in the cylinder;
- a motor configured to drive a reciprocating movement of the piston in the cylinder;
- a valve configured to control air flow into and out of the cylinder;
- and
- a control apparatus configured to control driving power applied to the motor based on at least one of a level of the driving power applied to the motor, a position of the piston, and an internal pressure of the cylinder,
- wherein the control apparatus is configured to, based on an operating speed of the compressor being less than a preset reference speed, vary a compensation value configured to be applied to a current of the motor during each of a plurality of stroke periods, the plurality of stroke periods being divided according to a change of the internal pressure.
A method of a compressor control apparatus for controlling a compressor, the compressor control apparatus including an inverter configured to convert power received from an external power source into driving power for driving a motor of the compressor, and a controller configured to generate a pulse width modulation (PWM) control signal for controlling a switching operation of the inverter and to apply the PWM control signal to the inverter to control the switching operation, the method comprising:
- comparing an operating speed of the compressor to a preset reference speed;
- based on the operating speed being less than the preset reference speed, determining a stroke period of the compressor based on at least one of a magnitude of the driving power, a position of a piston of the compressor, or an internal pressure of a cylinder of the compressor, the cylinder accommodating a reciprocating movement of the piston therein;
- determining a compensation value corresponding to the determined stroke period among a plurality of reference compensation values that are preset for a plurality of stroke periods, respectively;
- applying the compensation value to a control command for generating the PWM control signal for the determined stroke period;
- and
- generating the PWM control signal according to the control command and applying the PWM control signal to the inverter.
A method of a compressor control apparatus for controlling a compressor, the compressor control apparatus including an inverter configured to convert power received from an external power source into driving power for driving a motor of the compressor, and a controller configured to (i) detect at least one of a magnitude of the driving power, a position of a piston of the compressor, or an internal pressure of a cylinder that accommodates a reciprocating movement of the piston therein, (ii) generate a pulse width modulation (PWM) control signal for controlling a switching operation of the inverter based on a detection result, and (iii) apply the PWM control signal to the inverter to control the switching operation, the method comprising:
- applying a first compensation value to a duty ratio of the PWM control signal during a first period between a rear end time point at which the piston is positioned at a rear end of the cylinder and a time point at which the piston is positioned at an intermediate position;
- applying a second compensation value to the duty ratio during a second period between the time point at which the piston is positioned at the intermediate position and a time point at which a valve of the cylinder is opened, the second compensation value being greater than the first compensation value;
- applying no compensation value to the duty ratio during a period between the time point at which the valve is opened and a time point that is prior to a front end time point at which the piston is positioned at a front end of the cylinder by a predetermined time period;
- applying a third compensation value to the duty ratio during a third period between (i) the time point that is prior to the front end time point by the predetermined time period and (ii) a time point at which discharge of compressed air from the cylinder is ended;
- and
- applying a fourth compensation value to the duty ratio during a fourth period between the time point at which the discharge of compressed air from the cylinder is ended and a time point at which the piston returns to the rear end of the cylinder.
Dependencies are inferred from the claim text.