Patents by Inventor Seung Ki Sul
Seung Ki Sul 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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Publication number: 20240088666Abstract: Embodiments of the present application relate to a bidirectional DC/AC power conversion system having multiple DC links, which comprises: a main DC link; at least one auxiliary DC link including at least one of a first auxiliary DC link having a positive terminal connected to a positive terminal of the main DC link and a second auxiliary DC link having a negative terminal connected to a negative terminal of the main DC link; and a plurality of cells connected in series to form one or more legs.Type: ApplicationFiled: November 15, 2021Publication date: March 14, 2024Inventors: Seung-Ki Sul, Sanggi Ko, Shenghui Cui
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Patent number: 11901846Abstract: Embodiments relate to a motor simulator for an inverter under test (IUT), the motor simulator comprising: a voltage follower inverter for at least partially cancelling an output voltage of the IUT; and an output current control unit for controlling an output current of the IUT on the basis of an estimated current of a simulation target motor.Type: GrantFiled: October 15, 2018Date of Patent: February 13, 2024Assignee: PLECKO CO., LTD.Inventors: Seung-Ki Sul, Yong-Cheol Kwon, Yoon-Ro Lee
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Patent number: 11872893Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. A position sensor is adapted to determine a rotor position of the electric motor. The system includes a controller having instructions recorded for determining the rotor position when a sensor fault condition is detected. The controller is adapted to selectively command injection of a voltage signal in a direct magnetic axis in a synchronous reference frame when a motor speed of the electric motor is below a predefined motor speed threshold and the sensor fault condition is detected. The rotor position is estimated based in part on a motor current response to the voltage signal. The voltage signal is defined by an alternating periodic shape having respective constant segments in each of a plurality of control periods, the respective constant segments being discontinuous between the control periods.Type: GrantFiled: April 13, 2022Date of Patent: January 16, 2024Assignees: GM Global Technology Operations LLC, Seoul Nathional UniversityInventors: Anno Yoo, Seung-Ki Sul, Hyung-June Cho
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Publication number: 20230331094Abstract: A propulsion system for a device includes an electric motor configured to generate torque to propel the device. A position sensor is adapted to determine a rotor position of the electric motor. The system includes a controller having instructions recorded for determining the rotor position when a sensor fault condition is detected. The controller is adapted to selectively command injection of a voltage signal in a direct magnetic axis in a synchronous reference frame when a motor speed of the electric motor is below a predefined motor speed threshold and the sensor fault condition is detected. The rotor position is estimated based in part on a motor current response to the voltage signal. The voltage signal is defined by an alternating periodic shape having respective constant segments in each of a plurality of control periods, the respective constant segments being discontinuous between the control periods.Type: ApplicationFiled: April 13, 2022Publication date: October 19, 2023Applicants: GM GLOBAL TECHNOLOGY OPERATIONS LLC, Seoul National UniversityInventors: Anno Yoo, Seung-Ki Sul, Hyung-June Cho
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Patent number: 11387757Abstract: A method for estimating a magnet temperature of a rotor magnet within a rotary electric machine includes, while a rotor of the electric machine is stationary, injecting a high-frequency voltage component onto a control voltage of the electric machine, via a controller, to generate an adjusted voltage command, and extracting a high-frequency component of a resulting current as an extracted high-frequency component. The method also includes calculating an inductance value of the electric machine using the extracted high-frequency component of the resulting current. The magnet temperature is estimated using the calculated inductance value and an angular position of the rotor. The method includes controlling an operation of the electric machine using the estimated magnet temperature. An electric powertrain uses the electric machine and controller noted above.Type: GrantFiled: September 4, 2019Date of Patent: July 12, 2022Assignees: GM Global Technology Operations LLC, Seoul National University R & DB FoundationInventors: Daniel J. Berry, Anno Yoo, Seung Ki Sul, Hyun-Sam Jung
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Patent number: 11177750Abstract: A motor control apparatus according to one embodiment of the present invention comprises: a current controller for generating a voltage command signal on the basis of a torque command for driving a motor and a fundamental wave current of the motor; a high frequency voltage generator for generating a high frequency voltage signal for injection into the voltage command signal; an inverter for applying a voltage to the motor on the basis of the voltage command signal and the high frequency voltage signal; an angle estimator for generating an estimated angle of a rotor of the motor on an estimated coordinate system on the basis of a current signal of the motor; and a compensator for adding a first compensation signal (icomp) to the current signal (isig), wherein the first compensation signal (icomp) may be related to the torque command and the estimated angle.Type: GrantFiled: September 19, 2018Date of Patent: November 16, 2021Assignee: SEOUL NATIONAL UNIVERSITY R&DB FOUNDATIONInventors: Seung-Ki Sul, Yong-Cheol Kwon, Joohyun Lee
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Patent number: 11038436Abstract: A unit power cell of an inverter system, according to one embodiment of the present invention, comprises: a first leg including first and fourth switching elements, which are connected in series to each other, second and third switching elements, which are connected in series with each other between a connection point of the first and second switching elements and a smoothing unit, and first, second, third and fourth diodes, which are inversely and respectively connected in parallel with the first, second, third and fourth switching elements; and a second leg connected in parallel with the first leg and including fifth and sixth switching elements, which are connected in series to each other, and fifth and sixth diodes, which are inversely and respectively connected in parallel with the fifth and sixth switching elements.Type: GrantFiled: July 18, 2018Date of Patent: June 15, 2021Assignee: LSIS CO., LTD.Inventors: Sung-Guk Ahn, Seung-Ki Sul, Hyun-Sam Jung, Jeong-Mock Yoo
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Publication number: 20210067075Abstract: A method for estimating a magnet temperature of a rotor magnet within a rotary electric machine includes, while a rotor of the electric machine is stationary, injecting a high-frequency voltage component onto a control voltage of the electric machine, via a controller, to generate an adjusted voltage command, and extracting a high-frequency component of a resulting current as an extracted high-frequency component. The method also includes calculating an inductance value of the electric machine using the extracted high-frequency component of the resulting current. The magnet temperature is estimated using the calculated inductance value and an angular position of the rotor. The method includes controlling an operation of the electric machine using the estimated magnet temperature. An electric powertrain uses the electric machine and controller noted above.Type: ApplicationFiled: September 4, 2019Publication date: March 4, 2021Applicants: GM GLOBAL TECHNOLOGY OPERATIONS LLC, Seoul National University R & DB FoundationInventors: Daniel J. Berry, Anno Yoo, Seung Ki Sul, Hyun-Sam Jung
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Publication number: 20210036646Abstract: Embodiments relate to a motor simulator for an inverter under test (IUT), the motor simulator comprising: a voltage follower inverter for at least partially cancelling an output voltage of the IUT; and an output current control unit for controlling an output current of the IUT on the basis of an estimated current of a simulation target motor.Type: ApplicationFiled: October 15, 2018Publication date: February 4, 2021Inventors: Seung-Ki Sul, Yong-Cheol Kwon, Yoon-Ro Lee
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Publication number: 20200366228Abstract: A motor control apparatus according to one embodiment of the present invention comprises: a current controller for generating a voltage command signal on the basis of a torque command for driving a motor and a fundamental wave current of the motor; a high frequency voltage generator for generating a high frequency voltage signal for injection into the voltage command signal; an inverter for applying a voltage to the motor on the basis of the voltage command signal and the high frequency voltage signal; an angle estimator for generating an estimated angle of a rotor of the motor on an estimated coordinate system on the basis of a current signal of the motor; and a compensator for adding a first compensation signal (icomp) to the current signal (isig), wherein the first compensation signal (icomp) may be related to the torque command and the estimated angle.Type: ApplicationFiled: September 19, 2018Publication date: November 19, 2020Inventors: Seung-Ki Sul, Yong-Cheol Kwon, Joohyun Lee
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Publication number: 20200228028Abstract: A unit power cell of an inverter system, according to one embodiment of the present invention, comprises: a first leg including first and fourth switching elements, which are connected in series to each other, second and third switching elements, which are connected in series with each other between a connection point of the first and second switching elements and a smoothing unit, and first, second, third and fourth diodes, which are inversely and respectively connected in parallel with the first, second, third and fourth switching elements; and a second leg connected in parallel with the first leg and including fifth and sixth switching elements, which are connected in series to each other, and fifth and sixth diodes, which are inversely and respectively connected in parallel with the fifth and sixth switching elements.Type: ApplicationFiled: July 18, 2018Publication date: July 16, 2020Inventors: Sung-Guk AHN, Seung-Ki SUL, Hyun-Sam JUNG, Jeong-Mock YOO
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Patent number: 10164435Abstract: A reactive power compensator includes a plurality of phase clusters each including plurality of cells and a controller configured to control the plurality of phase clusters. The controller performs control to generate an offset signal through phasor transformation based on respective voltage values and current values of the plurality of phase clusters and to compensate for energy errors between the plurality of phase clusters based on the generated offset signal.Type: GrantFiled: January 12, 2018Date of Patent: December 25, 2018Assignee: LSIS CO., LTD.Inventors: Yong Ho Chung, Gum Tae Son, Seung Ki Sul, Jae Jung Jung, Joon Hee Lee
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Patent number: 10122173Abstract: A reactive power compensator includes a plurality of phase clusters each including a plurality of cells, and a controller configured to control the plurality of phase clusters. When an energy error is generated in each of the plurality of phase clusters, the controller performs control to compensate for the energy error by generating an offset signal having a zero sequence component based on an error energy value of each of the plurality of phase clusters.Type: GrantFiled: June 7, 2017Date of Patent: November 6, 2018Assignee: LSIS CO., LTD.Inventors: Yong Ho Chung, Gum Tae Son, Seung Ki Sul, Jae Jung Jung, Joon Hee Lee
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Publication number: 20180212430Abstract: A reactive power compensator includes a plurality of phase clusters each including plurality of cells and a controller configured to control the plurality of phase clusters. The controller performs control to generate an offset signal through phasor transformation based on respective voltage values and current values of the plurality of phase clusters and to compensate for energy errors between the plurality of phase clusters based on the generated offset signal.Type: ApplicationFiled: January 12, 2018Publication date: July 26, 2018Inventors: Yong Ho CHUNG, Gum Tae SON, Seung Ki SUL, Jae Jung JUNG, Joon Hee LEE
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Publication number: 20180205228Abstract: A reactive power compensator includes a plurality of phase clusters each including a plurality of cells, and a controller configured to control the plurality of phase clusters. When an energy error is generated in each of the plurality of phase clusters, the controller performs control to compensate for the energy error by generating an offset signal having a zero sequence component based on an error energy value of each of the plurality of phase clusters.Type: ApplicationFiled: June 7, 2017Publication date: July 19, 2018Applicants: LSIS CO., LTD., Seoul National University R&DB FOUNDATIONInventors: Yong Ho CHUNG, Gum Tae SON, Seung Ki SUL, Jae Jung JUNG, Joon Hee LEE
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Publication number: 20180183336Abstract: Disclosed herein is an apparatus for controlling DC link voltage in power cells of a medium-voltage inverter. The apparatus controls DC link voltage in single-phase I/O power cells in the medium-voltage inverter, by way of using a first average power based on a positive sequence voltage and a positive sequence current to output a first DC link voltage reference for controlling the average value of the DC link voltages, and using a second average power based on a negative sequence voltage and a positive sequence current or a positive sequence voltage and a negative sequence current to output a second DC link voltage reference for controlling an interphase DC link voltage.Type: ApplicationFiled: November 1, 2017Publication date: June 28, 2018Inventors: Jong-Je PARK, Seung-Ki SUL, Jeong-Mock YOO, Hyun-Sam JUNG
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Patent number: 10008937Abstract: Disclosed herein is an apparatus for controlling DC link voltage in power cells of a medium-voltage inverter. The apparatus controls DC link voltage in single-phase I/O power cells in the medium-voltage inverter, by way of using a first average power based on a positive sequence voltage and a positive sequence current to output a first DC link voltage reference for controlling the average value of the DC link voltages, and using a second average power based on a negative sequence voltage and a positive sequence current or a positive sequence voltage and a negative sequence current to output a second DC link voltage reference for controlling an interphase DC link voltage.Type: GrantFiled: November 1, 2017Date of Patent: June 26, 2018Assignee: LSIS CO., LTD.Inventors: Jong-Je Park, Seung-Ki Sul, Jeong-Mock Yoo, Hyun-Sam Jung
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Patent number: 9954475Abstract: A motor driving apparatus includes a rectifying circuit to rectify an AC power supplied from an external AC power source, one pair of film capacitors to output a DC voltage and a neutral point voltage by removing a ripple of a voltage rectified by the AC-DC conversion unit, a 3-level inverter to supply a driving current to a motor using the DC voltage applied from the DC link unit, and a control module to control the 3-level inverter. The control module includes a motor speed control module to control the rotation of the motor, a DC voltage control module to stabilize the DC voltage, a neutral point voltage control module to stabilize the neutral point voltage, and a stabilizing voltage limiting module to control the DC voltage control module and the neutral point voltage control module according to an output of the motor speed control module.Type: GrantFiled: March 14, 2016Date of Patent: April 24, 2018Assignees: SAMSUNG ELECTRONICS CO., LTD., SEOUL NATIONAL UNIVERSITY R&DB FOUNDATIONInventors: Je Hyung Cho, Seung-Ki Sul, Se Hwa Choe, Han Sol Seo
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Publication number: 20180083550Abstract: The present disclosure relates a modular multi-level converter (MMC) including two arms including different types of sub modules according to the respective arms, two sub controllers corresponding to the two arms, respectively and configured to separately control the two arms, respectively, and a central controller configured to determine a switching operation condition of the sub module and to output a switching signal corresponding to the switching operation condition to each of the two sub controllers, wherein the two sub controllers control the respective corresponding arms based on the switching signal and, upon receiving a voltage change switching signal for controlling a voltage applied to one of the two arms, change the voltage applied to one of the two arms based on the voltage change switching signal.Type: ApplicationFiled: March 30, 2017Publication date: March 22, 2018Inventors: Yong-Ho CHUNG, Gum-Tae SON, Seung-KI SUL, Jae-Jung JUNG, Sheng-hui CUI
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Patent number: 9819294Abstract: An inverter control apparatus and a control method thereof are provided. The inverter control apparatus and a control method thereof stably operate a three-phase motor using a capacitor having a small capacitance for a DC link. The inverter control apparatus includes a current sensor to sense an output current of the inverter, a voltage sensor to sense a DC-link voltage of the inverter, and a controller to generate an average of a periodically varying rotor based q-axis current boundary value based on the output current and the DC-link voltage to generate a current reference on the basis of the average of the rotor based q-axis current boundary value, and to drive a three-phase motor based on the current reference. Stabilized variable speed control of a motor by using a small-capacitance capacitor for a DC link of an inverter is performed and reliability of an inverter circuit improved.Type: GrantFiled: September 2, 2015Date of Patent: November 14, 2017Assignees: SAMSUNG ELECTRONICS CO., LTD., SNU R&DB FOUNDATIONInventors: Young Jae Park, Han Sol Seo, Bodrov Alexey, Seung Ki Sul, Hyun-Sam Jung, Seung-Jun Chee