Patents by Inventor Bojian CAO

Bojian CAO 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: 20240425028
    Abstract: Some embodiments disclosed herein are directed to constraint handling for parameters of electric motors. In particular, embodiments of the present disclosure relate to handling constraints for parameters such as current, voltage, and torque associated with an electric motor. Other embodiments may be disclosed or claimed.
    Type: Application
    Filed: June 26, 2023
    Publication date: December 26, 2024
    Inventors: Lei Hao, Yue-Yun Wang, Bojian Cao, Suresh Gopalakrishnan, Gionata Cimini
  • Patent number: 11926221
    Abstract: A method for controlling transient operation of a variable flux machine (VFM) includes, during a shunt angle transition, receiving a commanded and measured shunt angle when operating in a predetermined operating region, e.g., maximum torque per ampere or field weakening. The method includes calculating d-axis and q-axis delta current terms (?Id and ?Iq) required to maintain an output torque level of the VFM through a duration of the shunt angle transition, then applying the required ?Id and ?Id terms as feed-forward terms to adjust a d-axis current (Id) term and a q-axis current (Iq) term from a respective lookup table. In this manner the controller maintains the output torque level of the VFM during the shunt angle transition. An electric powertrain includes the VFM, a TPIM, and the controller. A PM machine may be controlled by substituting temperature for shunt angle.
    Type: Grant
    Filed: September 24, 2020
    Date of Patent: March 12, 2024
    Assignee: GM Global Technology Operations LLC
    Inventors: Xin Jing, Bojian Cao, Brent S. Gagas
  • Patent number: 11848629
    Abstract: A method and apparatus for electric motor control includes a model predictive controller operating in a d-q reference frame to provide d-q reference frame voltage command signals that counteract a magnetic cross coupling within the motor.
    Type: Grant
    Filed: May 26, 2022
    Date of Patent: December 19, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Yue-Yun Wang, Lei Hao, Ruixing Long, Bojian Cao
  • Publication number: 20230402944
    Abstract: A method and apparatus for electric motor control includes a model predictive controller operating in a d-q reference frame to provide d-q reference frame voltage command signals that counteract a magnetic cross coupling within the motor.
    Type: Application
    Filed: May 26, 2022
    Publication date: December 14, 2023
    Inventors: Yue-Yun Wang, Lei Hao, Ruixing Long, Bojian Cao
  • Publication number: 20230364996
    Abstract: Examples described herein provide a method that includes performing an electrical degradation analysis for a power inverter. The method further includes performing a thermal degradation analysis on the power inverter. The method further includes, responsive to at least one of a result of the electrical degradation analysis being indicative of an electrical issue of the power inverter or a result of the thermal degradation analysis being indicative of a thermal issue of the power inverter, implementing a corrective action for the power inverter.
    Type: Application
    Filed: May 10, 2022
    Publication date: November 16, 2023
    Inventors: Jiyu Zhang, Bojian Cao, Nomar S. Gonzalez Santini, Jeffrey Scott Piasecki, Tanvi Nagarale, Muhammad Hussain Alvi, Rashmi Prasad
  • Patent number: 11689138
    Abstract: A system in a vehicle includes a current regulator to obtain current commands from a controller based on a torque input and provide voltage commands and an inverter to use the voltage commands from the current regulator and direct current (DC) supplied by a battery to provide alternating current (AC). The system also includes an electric traction motor to provide drive power to a transmission of the vehicle based on injection of the AC from the inverter. The current regulator adjusts parameters of a transfer function implemented by the current regulator, based on feedback of an input to and an output from the electric traction motor to achieve the AC corresponding with the torque input in no more than two control cycles.
    Type: Grant
    Filed: July 21, 2021
    Date of Patent: June 27, 2023
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Muhammad Hussain Alvi, Lei Hao, Suresh Gopalakrishnan, Bojian Cao, Vinod Chowdary Peddi
  • Publication number: 20230022957
    Abstract: A system in a vehicle includes a current regulator to obtain current commands from a controller based on a torque input and provide voltage commands and an inverter to use the voltage commands from the current regulator and direct current (DC) supplied by a battery to provide alternating current (AC). The system also includes an electric traction motor to provide drive power to a transmission of the vehicle based on injection of the AC from the inverter. The current regulator adjusts parameters of a transfer function implemented by the current regulator, based on feedback of an input to and an output from the electric traction motor to achieve the AC corresponding with the torque input in no more than two control cycles.
    Type: Application
    Filed: July 21, 2021
    Publication date: January 26, 2023
    Inventors: Muhammad Hussain Alvi, Lei Hao, Suresh Gopalakrishnan, Bojian Cao, Vinod Chowdary Peddi
  • Patent number: 11489471
    Abstract: A diagnostic system includes: a current command module configured to, based on a motor torque request, a motor speed, a direct current (DC) bus voltage, generate a d-axis current command for an electric motor and a q-axis current command for the electric motor; a voltage command module configured to, based on the d-axis current command and the q-axis current command, generate a d-axis voltage command and a q-axis voltage command; a switching control module configured to control switching of an inverter module based on the d-axis voltage command and the q-axis voltage command, where the inverter module is configured to apply power to stator windings of the electric motor from the DC bus; and a fault module configured to selectively indicate that the stator windings of the electric motor are degraded when the d-axis voltage command is less than a predetermined nominal d-axis voltage of the electric motor.
    Type: Grant
    Filed: December 16, 2019
    Date of Patent: November 1, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Jiyu Zhang, Siddharth Ballal, Lei Hao, Wesley G. Zanardelli, Bojian Cao
  • Patent number: 11316391
    Abstract: A method for controlling transient operation of a rotary electric machine in an electric powertrain or other electrical system includes, during a shunt angle transition occurring during a maximum torque per ampere (MTPA) control region, determining an estimated output torque of the electric machine via a torque estimation block using d-axis and q-axis current commands and an additional value, i.e., an actual shunt angle or a machine temperature. The method includes subtracting the estimated output torque from a commanded output torque to derive an adjusted commanded torque value or torque error, and calculating, from the torque error, a delta d-axis current command and a delta q-axis current command. The method includes adjusting d-axis and q-axis current commands using the delta commands to produce adjusted d-axis and q-axis current commands, which are then used as closed-loop feedback control terms by the torque estimation block.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: April 26, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Xin Jing, Bojian Cao, Brent S. Gagas
  • Publication number: 20220089034
    Abstract: A method for controlling transient operation of a variable flux machine (VFM) includes, during a shunt angle transition, receiving a commanded and measured shunt angle when operating in a predetermined operating region, e.g., maximum torque per ampere or field weakening. The method includes calculating d-axis and q-axis delta current terms (?Id and ?Iq) required to maintain an output torque level of the VFM through a duration of the shunt angle transition, then applying the required ?Id and ?Id terms as feed-forward terms to adjust a d-axis current (Id) term and a q-axis current (Iq) term from a respective lookup table. In this manner the controller maintains the output torque level of the VFM during the shunt angle transition. An electric powertrain includes the VFM, a TPIM, and the controller. A PM machine may be controlled by substituting temperature for shunt angle.
    Type: Application
    Filed: September 24, 2020
    Publication date: March 24, 2022
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Xin Jing, Bojian Cao, Brent S. Gagas
  • Patent number: 11133771
    Abstract: An electric drive system of a vehicle comprises a motor, a position sensor, an inverter, sensors to sense current and voltage supplied to the motor, and a controller to control the motor by controlling the inverter based on data from the position sensor and the sensors and a torque command. The controller estimates a motor torque using a motor model, calculates the motor torque, and generates a first state of health for the electric drive system based on a difference between the estimated and calculated motor torques. The controller generates, in response to the first state of health being less than or equal to a first threshold, a second state of health for at least one of the position sensor, the sensors, and the motor, and determines whether one of the position sensor, the sensors, and the motor is faulty based on the first and second states of health.
    Type: Grant
    Filed: December 4, 2019
    Date of Patent: September 28, 2021
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Jiyu Zhang, Siddharth Ballal, Lei Hao, Wesley G. Zanardelli, Bojian Cao, Mutasim Salman
  • Publication number: 20210273505
    Abstract: A method for controlling transient operation of a rotary electric machine in an electric powertrain or other electrical system includes, during a shunt angle transition occurring during a maximum torque per ampere (MTPA) control region, determining an estimated output torque of the electric machine via a torque estimation block using d-axis and q-axis current commands and an additional value, i.e., an actual shunt angle or a machine temperature. The method includes subtracting the estimated output torque from a commanded output torque to derive an adjusted commanded torque value or torque error, and calculating, from the torque error, a delta d-axis current command and a delta q-axis current command. The method includes adjusting d-axis and q-axis current commands using the delta commands to produce adjusted d-axis and q-axis current commands, which are then used as closed-loop feedback control terms by the torque estimation block.
    Type: Application
    Filed: March 2, 2020
    Publication date: September 2, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Xin Jing, Bojian Cao, Brent S. Gagas
  • Publication number: 20210184610
    Abstract: A diagnostic system includes: a current command module configured to, based on a motor torque request, a motor speed, a direct current (DC) bus voltage, generate a d-axis current command for an electric motor and a q-axis current command for the electric motor; a voltage command module configured to, based on the d-axis current command and the q-axis current command, generate a d-axis voltage command and a q-axis voltage command; a switching control module configured to control switching of an inverter module based on the d-axis voltage command and the q-axis voltage command, where the inverter module is configured to apply power to stator windings of the electric motor from the DC bus; and a fault module configured to selectively indicate that the stator windings of the electric motor are degraded when the d-axis voltage command is less than a predetermined nominal d-axis voltage of the electric motor.
    Type: Application
    Filed: December 16, 2019
    Publication date: June 17, 2021
    Inventors: Jiyu ZHANG, Siddharth BALLAL, Lei HAO, Wesley G. ZANARDELLI, Bojian CAO
  • Publication number: 20210175835
    Abstract: An electric drive system of a vehicle comprises a motor, a position sensor, an inverter, sensors to sense current and voltage supplied to the motor, and a controller to control the motor by controlling the inverter based on data from the position sensor and the sensors and a torque command. The controller estimates a motor torque using a motor model, calculates the motor torque, and generates a first state of health for the electric drive system based on a difference between the estimated and calculated motor torques. The controller generates, in response to the first state of health being less than or equal to a first threshold, a second state of health for at least one of the position sensor, the sensors, and the motor, and determines whether one of the position sensor, the sensors, and the motor is faulty based on the first and second states of health.
    Type: Application
    Filed: December 4, 2019
    Publication date: June 10, 2021
    Inventors: Jiyu ZHANG, Siddharth BALLAL, Lei HAO, Wesley G. ZANARDELLI, Bojian CAO, Mutasim SALMAN