Patents by Inventor Dal Ho Cheong
Dal Ho Cheong 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).
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Patent number: 7459821Abstract: A PMA (Permanent Magnet Assisted) synRM and a method for imposing a magnetic force thereon. Magnets are inserted into outer flux barriers of a plurality of flux barriers formed along the radius of a rotor, and bridges or slim portions are formed on inner flux barriers at positions corresponding to the positions of the magnets so that the magnetic force is imposed on the magnets through coils. Since the number of the flux barriers is sufficiently increased while the amount of the magnets consumed is decreased, the PMA synRM has increased efficiency and reduced production costs.Type: GrantFiled: January 4, 2005Date of Patent: December 2, 2008Assignee: LG Electronics Inc.Inventors: Dal Ho Cheong, Kyung Hoon Lee, Hyun Hun Shin, June Hee Won, Jae Yoon Oh, Gil Su Lee
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Patent number: 7358694Abstract: An apparatus and method determine a start-up of a sensorless motor. The apparatus includes an elapsed time determination unit, a motor velocity determination unit and an abnormal start-up determination unit. The elapsed time determination unit determines whether a predetermined time has elapsed after a start-up of the motor is initiated. The motor velocity determination unit determines whether a velocity of the motor exceeds a predetermined velocity value when the predetermined time has elapsed. The abnormal start-up determination unit determines that the motor was abnormally started up when the velocity of the motor does not exceed the predetermined value, and an amount of current flowing in the motor does not exceed a predetermined current value.Type: GrantFiled: March 7, 2006Date of Patent: April 15, 2008Assignee: LG Electronics Inc.Inventors: June Hee Won, Dal Ho Cheong, Jae Yoon Oh
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Patent number: 7138777Abstract: A sensorless motor drive apparatus and a method for protecting and controlling the same. The sensorless motor drive apparatus includes a unit for determining the presence or absence of a position estimation error of a rotor contained in a motor using a current value applied to the motor and a position estimation angle of the rotor. Therefore, the sensorless motor drive apparatus determines the presence or absence of the position estimation error of the rotor without using a sensor, so that it reduces production costs, prevents the motor from generating a faulty operation, and prevents a compressor including the motor from being damaged.Type: GrantFiled: January 19, 2005Date of Patent: November 21, 2006Assignee: LG Electronics Inc.Inventors: June Hee Won, Jae Yoon Oh, Gil Su Lee, Dal Ho Cheong, Kyung Hoon Lee
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Patent number: 6831439Abstract: Disclosed are a flux observer and a sensorless control system of a synchronous reluctance motor. The flux observer includes an estimated flux output unit, a measured flux output unit, and a fixed/rotational coordinate converter. The flux observer estimates a flux of a synchronous reluctance motor by removing higher harmonic components of a current in a rotational coordinate system which flows into the motor. The measured flux output unit measures a flux in a fixed coordinate system by combining a voltage in the fixed coordinate system, which is applied to the motor, and a current in the fixed coordinate system, from which higher harmonic components are removed, with the estimated flux outputted from the estimated flux output unit. The fixed/rotational coordinate converter converts the measured flux outputted from the measured flux output unit to a measured flux in the rotational coordinate system.Type: GrantFiled: July 9, 2003Date of Patent: December 14, 2004Assignee: Electronics, Inc.Inventors: June Hee Won, Jae Yoon Oh, Kyung Hoon Lee, Dal Ho Cheong
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Patent number: 6769167Abstract: A rotor for a synchronous reluctance motor of flux barrier type and manufacturing method thereof constructs a rotor for a synchronous reluctance motor by forming a magnetic core steel plate of disc shape on which a shaft hole is formed at center part, and a plurality of flux barrier groups are formed centering around the shaft hole and automatic stacking points are formed; manufacturing a plate stacked body by stacking the core steel plates continuously using the automatic stacking points; disposing end plates on both sides of the plate stacked body; and coupling the end plates and the plate stacked body integrally with each other as inserting a coupling member into the flux barrier groups, whereby the manufacturing process can be made easy and automatic stacking of the core steel plates can be made regardless of the types such as a skew type or a non skew type, and therefore manufacturing cost is reduced and the rotor can be mass produced.Type: GrantFiled: January 15, 2002Date of Patent: August 3, 2004Assignee: LG Electronics Inc.Inventors: Kyung Hun Lee, Jae Yoon Oh, Dal Ho Cheong
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Patent number: 6735284Abstract: The present invention relates to a system and a method for controlling a motor. A rotation/fixed coordinates converter converts a reference magnetic flux voltage and a reference torque voltage of a rotation coordinates system into data of a fixed coordinates system, and outputs the data to the three-phase voltage generator. A fixed/rotation coordinates converter converts a three-phase current applied from the inverter to the motor into a two-phase current. An estimation unit estimates a rotation angle and rotor speed of the motor upon receiving currents applied to the fixed/rotation coordinates converter. A control block receives the estimated rotation angle and the estimated speed from the estimation unit, and outputs the reference magnetic flux voltage and the reference torque voltage of the motor to the rotation/fixed coordinates converter to compensate an error caused by loads generated when driving the motor.Type: GrantFiled: April 14, 2003Date of Patent: May 11, 2004Assignee: LG Electronics Inc.Inventors: Dal Ho Cheong, June Hee Won, Jae Yoon Oh, Kyung Hoon Lee
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Publication number: 20040070364Abstract: The present invention relates to a system and a method for controlling a motor. A rotation/fixed coordinates converter converts a reference magnetic flux voltage and a reference torque voltage of a rotation coordinates system into data of a fixed coordinates system, and outputs the data to the three-phase voltage generator. A fixed/rotation coordinates converter converts a three-phase current applied from the inverter to the motor into a two-phase current. An estimation unit estimates a rotation angle and rotor speed of the motor upon receiving currents applied to the fixed/rotation coordinates converter. A control block receives the estimated rotation angle and the estimated speed from the estimation unit, and outputs the reference magnetic flux voltage and the reference torque voltage of the motor to the rotation/fixed coordinates converter to compensate an error caused by loads generated when driving the motor.Type: ApplicationFiled: April 14, 2003Publication date: April 15, 2004Applicant: LG Electronics Inc.Inventors: Dal Ho Cheong, June Hee Won, Jae Yoon Oh, Kyung Hoon Lee
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Publication number: 20040061472Abstract: Disclosed are a flux observer and a sensorless control system of a synchronous reluctance motor. The flux observer includes an estimated flux output unit, a measured flux output unit, and a fixed/rotational coordinate converter. The flux observer estimates a flux of a synchronous reluctance motor by removing higher harmonic components of a current in a rotational coordinate system which flows into the motor. The measured flux output unit measures a flux in a fixed coordinate system by combining a voltage in the fixed coordinate system, which is applied to the motor, and a current in the fixed coordinate system, from which higher harmonic components are removed, with the estimated flux outputted from the estimated flux output unit. The fixed/rotational coordinate converter converts the measured flux outputted from the measured flux output unit to a measured flux in the rotational coordinate system.Type: ApplicationFiled: July 9, 2003Publication date: April 1, 2004Applicant: LG Electronics Inc.Inventors: June Hee Won, Jae Yoon Oh, Kyung Hoon Lee, Dal Ho Cheong
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Patent number: 6646409Abstract: An apparatus for controlling the rotation speed of a motor, which is capable of controlling the rotation speed and the torque of the motor by detecting the input voltage and the input current of the motor without using a sensor for detecting the position of the rotor of the motor, is provided.Type: GrantFiled: January 8, 2002Date of Patent: November 11, 2003Assignee: LG Electronics Inc.Inventors: June Hee Won, Dal Ho Cheong, Jae Yoon Oh, Kyung Hoon Lee
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Patent number: 6525497Abstract: Disclosed are a phase distortion compensating apparatus and method for reducing a torque ripple in a 3-phase motor using four switching elements, which are capable of adjusting respective switching times of phase voltages, to be supplied to the 3-phase motor by an inverter including the switching elements, based on a voltage difference between upper and lower DC link capacitors respectively adapted to supply voltages to the inverter, thereby reducing a torque ripple generated in the motor.Type: GrantFiled: March 21, 2001Date of Patent: February 25, 2003Assignee: LG Electronics Inc.Inventors: Dong Myung Lee, Jae Yoon Oh, Dal Ho Cheong
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Publication number: 20030025475Abstract: An apparatus for controlling the rotation speed of a motor, which is capable of controlling the rotation speed and the torque of the motor by detecting the input voltage and the input current of the motor without using a sensor for detecting the position of the rotor of the motor, is provided.Type: ApplicationFiled: January 8, 2002Publication date: February 6, 2003Applicant: LG Electronics Inc.Inventors: June Hee Won, Dal Ho Cheong, Jae Yoon Oh, Kyung Hoon Lee
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Publication number: 20030020351Abstract: A rotor for a synchronous reluctance motor of flux barrier type and manufacturing method thereof constructs a rotor for a synchronous reluctance motor by forming a magnetic core steel plate of disc shape on which a shaft hole is formed at center part, and a plurality of flux barrier groups are formed centering around the shaft hole and automatic stacking points are formed; manufacturing a plate stacked body by stacking the core steel plates continuously using the automatic stacking points; disposing end plates on both sides of the plate stacked body; and coupling the end plates and the plate stacked body integrally with each other as inserting a coupling member into the flux barrier groups, whereby the manufacturing process can be made easy and automatic stacking of the core steel plates can be made regardless of the types such as a skew type or a non skew type, and therefore manufacturing cost is reduced and the rotor can be mass produced.Type: ApplicationFiled: January 15, 2002Publication date: January 30, 2003Applicant: LG Electronics Inc.Inventors: Kyung Hun Lee, Jae Yoon Oh, Dal Ho Cheong
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Patent number: 6388903Abstract: Disclosed are a voltage compensating apparatus and method for a 3-phase inverter using four switches, to compensate for a severe distortion of a 3-phase application voltage due to a voltage ripple.Type: GrantFiled: May 10, 2001Date of Patent: May 14, 2002Assignee: LG Electronics Inc.Inventors: Dong Myung Lee, Jae Yoon Oh, Dal Ho Cheong, Soon Bae Yang
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Publication number: 20020053891Abstract: Disclosed are a phase distortion compensating apparatus and method for reducing a torque ripple in a 3-phase motor using four switching elements, which are capable of adjusting respective switching times of phase voltages, to be supplied to the 3-phase motor by an inverter including the switching elements, based on a voltage difference between upper and lower DC link capacitors respectively adapted to supply voltages to the inverter, thereby reducing a torque ripple generated in the motor.Type: ApplicationFiled: March 21, 2001Publication date: May 9, 2002Inventors: Dong Myung Lee, Jae Yoon Oh, Dal Ho Cheong
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Publication number: 20020012255Abstract: Disclosed are a voltage compensating apparatus and method for a 3-phase inverter using four switches, to compensate for a severe distortion of a 3-phase application voltage due to a voltage ripple.Type: ApplicationFiled: May 10, 2001Publication date: January 31, 2002Inventors: Dong Myung Lee, Jae Yoon Oh, Dal Ho Cheong, Soon Bae Yang
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Patent number: 5682634Abstract: This invention relates to a method and apparatus for controlling the speed of a washing machine motor by varying the number of revolutions and changing direction of rotation of the motor to control the water current of the washing machine. The invention detects the actual speed of the washing machine motor at every half cycle of ordinary use power frequency, determines speed error by comparing the detected actual speed with an ordered speed, determines a speed state from the speed error, calculates a proportional integration value according to the determined speed state, and scales the calculated proportional compensation value into an angular value. The washing machine's motor speed is controlled using the scaled angular value.Type: GrantFiled: November 16, 1994Date of Patent: November 4, 1997Assignee: Goldstar Co., Ltd.Inventors: Dal Ho Cheong, Doo Whan Sang