Patents by Inventor Ji Won Sung

Ji Won Sung has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090047138
    Abstract: An apparatus and method for controlling an operation of a linear compressor by detecting a phase difference inflection point at a time point when a phase difference between a current and a stroke is placed within a certain region, and by recognizing the phase difference infection point as a top dead center (TDC)=O.
    Type: Application
    Filed: December 28, 2006
    Publication date: February 19, 2009
    Inventors: Jae-Yoo Yoo, Ji-Won Sung, Chel-Woong Lee
  • Publication number: 20090010766
    Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed in which a frequency is variably controlled to uniformly maintain a phase difference between current and stroke, a load is determined with a size of frequency at a point of time when the phase difference between the current and the stroke is uniformly maintained, and capacity is varied according to the determined load, to thus improve an operation efficiency. The apparatus for controlling an operation of a reciprocating compressor includes: a control unit for detecting a phase difference between current and stroke and outputting a frequency variable signal or a frequency detect signal based on the detected phase difference; a load detecting unit for detecting a current operation load according to the frequency detect signal; and a stroke reference value determining unit for determining a stroke reference value corresponding to the detected load.
    Type: Application
    Filed: December 28, 2006
    Publication date: January 8, 2009
    Applicant: LG ELECTRONICS INC.
    Inventors: Jae-Yoo Yoo, Ji-Won Sung, Chel-Woong Lee
  • Publication number: 20090004026
    Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed in which a point of inflection with respect to an operation frequency of the reciprocating compressor is detected at a point of time when a phase difference between current and stroke is uniformly maintained, and an operation of the reciprocating compressor is controlled upon recognizing the detected point of inflection with respect to the operation frequency as a point TDC=O. The apparatus for controlling an operation of a reciprocating compressor includes: a control unit for detecting a phase difference between current and stroke and outputting a frequency inflection point detect signal or a frequency variable signal; and a stroke reference value control unit for determining whether a frequency inflection point has been detected or not according to the frequency inflection point detect signal and outputting a stroke reference value control signal based on the determining result.
    Type: Application
    Filed: December 28, 2006
    Publication date: January 1, 2009
    Applicant: LG Electronics Inc.
    Inventors: Jae-Yoo Yoo, Ji-Won Sung, Chel-Woong Lee
  • Patent number: 7468588
    Abstract: The present invention relates to an apparatus and method for controlling operation of a reciprocating compressor. The operating efficiency of the compressor can be improved by performing the steps of: detecting a current and a stroke applied a compressor; a calculating a mechanical resonance frequency by using the detected current and stroke; and determining an operating frequency command value by adding or subtracting the present operating frequency so as to be within a predetermined range of the calculated mechanical resonance frequency and then driving the compressor by the operating frequency command value.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: December 23, 2008
    Assignee: LG Electronics Inc.
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Patent number: 7456592
    Abstract: An apparatus and method for controlling operations of a reciprocating compressor are disclosed. The apparatus includes a compressor control factor detecting unit for detecting a compressor control factor to detect a stroke value corresponding to a point where TDC (Top Dead Center)?0 on the basis of a stroke estimate value of a reciprocating compressor and values of a current and a voltage applied to a motor of the reciprocating compressor; a stroke reference value determining unit for determining a stroke reference value on the basis of the detected compressor control factor; and a controller for varying a voltage applied to the reciprocating compressor according to the determined stroke reference value.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: November 25, 2008
    Assignee: LG Electronics Inc.
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Patent number: 7453229
    Abstract: 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.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: November 18, 2008
    Assignee: LG Electronics Inc.
    Inventors: Chel Woong Lee, Ji-Won Sung
  • Publication number: 20080226465
    Abstract: An operation controlling apparatus for a reciprocating compressor, and a method thereof, which are capable of accurately controlling the reciprocating compressor by sensing a size of a load applied to the reciprocating compressor and a stroke estimation value of the reciprocating compressor and then compensating a parameter of a motor in the reciprocating compressor based upon the sensing, the operation controlling apparatus comprising a controlling unit a controlling unit for comparing a phase difference between a detected current and a stroke with a reference phase difference to determine a size of a load, and outputting, according to the determined size of the load, a compensation control signal to compensate a parameter of a motor and a stroke control signal to control the stroke.
    Type: Application
    Filed: October 18, 2006
    Publication date: September 18, 2008
    Inventors: Hyeung-Ju Kim, Ji-Won Sung, Chang-Oh Kim
  • Publication number: 20080150456
    Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed. The apparatus for controlling an operation of a reciprocating compressor includes: a current phase delay value generating unit that calculates a current phase delay value by using a current stroke and a detected current and outputting the calculated current phase delay value; and a reference current generating unit that delays a reference current based on a difference between the current stroke and a stroke reference value according to the current phase delay value. A phase difference between a current and a pulse width modulation (PWM) voltage is estimated, a phase delay value for compensating the estimated phase difference is calculated, and a reference current is delayed as much as the calculated phase delay value for a certain time to thus remove a current distortion phenomenon.
    Type: Application
    Filed: December 29, 2006
    Publication date: June 26, 2008
    Applicant: LG ELECTRONICS INC.
    Inventors: Kyung-Bum HEO, Jae-Yoo YOO, Ji-Won SUNG
  • Patent number: 7341432
    Abstract: An apparatus and a method for controlling operation of a reciprocating compressor is capable of reducing a stroke estimation error by eliminating an error that occurs due to resistance and inductance of a compressor motor by estimating a stroke with a counter electromotive force induced by a searching coil. Furthermore, by leaving errors of inductance and resistance, among all motor parameters, out of consideration in stroke estimation, a stroke estimation error can be reduced.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: March 11, 2008
    Assignee: LG Electronics Inc.
    Inventors: Ji-Won Sung, Chel-Woong Lee, Jae-Yoo Yoo, Hyuk Lee, Hyung-Jin Kim
  • Patent number: 7335001
    Abstract: An apparatus and a method for controlling an operation of a reciprocating compressor can improve efficiency of a compressor by reconciling an operation frequency with a mechanical resonant frequency. The apparatus includes a mechanical resonant frequency calculating unit for calculating mechanical resonant frequency, using a current applied to a compressor and a stroke; an operation frequency reference value determining unit for determining an operation frequency reference value within a predetermined range of the calculated mechanical resonant frequency; and a controller for comparing the determined operation frequency and a current operation frequency, and then variably controlling an operation frequency of the compressor according to the comparison result, so that stroke feedback or TDC feedback can be controlled more accurately. Accordingly, an operational efficiency of the compressor is improved.
    Type: Grant
    Filed: January 6, 2004
    Date of Patent: February 26, 2008
    Assignee: LG Electronics Inc.
    Inventors: Chel-Woong Lee, Ji-Won Sung, Jae-Yoo Yoo
  • Publication number: 20060251523
    Abstract: 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.
    Type: Application
    Filed: November 7, 2005
    Publication date: November 9, 2006
    Inventors: Chel Lee, Ji-Won Sung
  • Publication number: 20060056979
    Abstract: An apparatus for controlling a compressor includes a stroke calculator for calculating a stroke estimate value of a compressor based on a value of a current applied to a motor of the compressor and a value of a voltage applied to the motor of the compressor; an operation frequency reference determining unit for integrating the stroke estimate value to output an integrated stroke value, detecting a mechanical resonance frequency of the compressor based on the integrated stroke estimate value and the current value, and determining the detected mechanical resonance frequency as an operation frequency reference value; and a controller for varying a current operation frequency of the compressor according to the determined operation frequency reference value.
    Type: Application
    Filed: January 11, 2005
    Publication date: March 16, 2006
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Publication number: 20060056980
    Abstract: An apparatus for controlling an operation of a compressor includes: a back electromotive force calculator for calculating a back electromotive force of a compressor based on a value of a current applied to a motor of the compressor and a value of a voltage applied to the motor of the compressor; an operation frequency reference value determining unit for detecting a mechanical resonance frequency of the compressor based on the back electromotive force value and the current value and determining the detected mechanical resonance frequency as an operation frequency reference value; and a controller for varying an operation frequency of the compressor according to the determined operation frequency reference value.
    Type: Application
    Filed: January 12, 2005
    Publication date: March 16, 2006
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Patent number: 6930462
    Abstract: 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.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: August 16, 2005
    Assignee: LG Electronics Inc.
    Inventors: Jae Yoo Yoo, Chel Woong Lee, Ji Won Sung, Hyuk Lee
  • Publication number: 20050158178
    Abstract: Disclosed are an apparatus and a method for controlling an operation of a reciprocating compressor which can improve operational efficiency of the reciprocating compressor. The apparatus for controlling the operation of the reciprocating compressor includes a resonance frequency operation unit for operating a mechanical resonance frequency of the reciprocating compressor, an operating frequency reference value generation unit for comparing the operated mechanical resonance frequency with a current operating frequency of the reciprocating compressor, and generating an operating frequency reference value according to the comparison result, and a controller for controlling a motor of the reciprocating compressor according to the generated operating frequency reference value.
    Type: Application
    Filed: December 23, 2004
    Publication date: July 21, 2005
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung, Hyung-Jin Kim
  • Publication number: 20050137722
    Abstract: An apparatus and method for controlling operations of a reciprocating compressor are disclosed. The apparatus includes a compressor control factor detecting unit for detecting a compressor control factor to detect a stroke value corresponding to a point where TDC (Top Dead Center)?0 on the basis of a stroke estimate value of a reciprocating compressor and values of a current and a voltage applied to a motor of the reciprocating compressor; a stroke reference value determining unit for determining a stroke reference value on the basis of the detected compressor control factor; and a controller for varying a voltage applied to the reciprocating compressor according to the determined stroke reference value.
    Type: Application
    Filed: September 21, 2004
    Publication date: June 23, 2005
    Inventors: Jae-Yoo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Publication number: 20050111987
    Abstract: The present invention relates to an apparatus and method for controlling operation of a reciprocating compressor. The operating efficiency of the compressor can be improved by performing the steps of: detecting a current and a stroke applied a compressor; a calculating a mechanical resonance frequency by using the detected current and stroke; and determining an operating frequency command value by adding or subtracting the present operating frequency so as to be within a predetermined range of the calculated mechanical resonance frequency and then driving the compressor by the operating frequency command value.
    Type: Application
    Filed: November 17, 2004
    Publication date: May 26, 2005
    Applicant: LG Electronics Inc.
    Inventors: Jae-Woo Yoo, Chel-Woong Lee, Ji-Won Sung
  • Publication number: 20040239266
    Abstract: An apparatus and a method for controlling an operation of a reciprocating compressor can improve efficiency of a compressor by reconciling an operation frequency with a mechanical resonant frequency. The apparatus includes a mechanical resonant frequency calculating unit for calculating mechanical resonant frequency, using a current applied to a compressor and a stroke; an operation frequency reference value determining unit for determining an operation frequency reference value within a predetermined range of the calculated mechanical resonant frequency; and a controller for comparing the determined operation frequency and a current operation frequency, and then variably controlling an operation frequency of the compressor according to the comparison result, so that stroke feedback or TDC feedback can be controlled more accurately. Accordingly, an operational efficiency of the compressor is improved.
    Type: Application
    Filed: January 6, 2004
    Publication date: December 2, 2004
    Inventors: Chel-Woong Lee, Ji-Won Sung, Jae-Yoo Yoo
  • Patent number: 6815922
    Abstract: 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.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: November 9, 2004
    Assignee: LG Electronics Inc.
    Inventors: Jae Yoo Yoo, Chel Woong Lee, Ji Won Sung, Hyuk Lee
  • Publication number: 20040071556
    Abstract: An apparatus and a method for controlling operation of a reciprocating compressor is capable of reducing a stroke estimation error by eliminating an error that occurs due to resistance and inductance of a compressor motor by estimating a stroke with a counter electromotive force induced by a searching coil. Furthermore, by leaving errors of inductance and resistance, among all motor parameters, out of consideration in stroke estimation, a stroke estimation error can be reduced.
    Type: Application
    Filed: September 24, 2003
    Publication date: April 15, 2004
    Applicant: LG Electronics Inc.
    Inventors: Ji-Won Sung, Chel-Woong Lee, Jae-Yoo Yoo, Hyuk Lee, Hyung-Jin Kim