Patents by Inventor Jackson Wai
Jackson Wai 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: 12142922Abstract: Techniques to limit electrical power when forming an electrical grid using an active front end unit having an inverter that is coupled to a capacitor (and inductor) that is coupled to an electrical grid. For example, to limit power, the integration of a commanded frequency of the system can be limited to be within a specified phase delta of a measured phase angle of an electrical grid voltage vector. The calculation from power limit to phase delta can be done when the phase of the electrical grid voltage vector has been determined to be accurate and is calculated based on the measured capacitor voltage, grid voltage, and the estimated voltage drop across the output components of the system.Type: GrantFiled: September 1, 2022Date of Patent: November 12, 2024Assignee: Caterpillar Inc.Inventors: Seok-hee Han, Jesse R. Gerdes, Jackson Wai
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Patent number: 12100943Abstract: An apparatus can include an inverter to provide an output N-phase alternating-current to an external component. When N equals two, a phase of the N phases can include an upper gate and a lower gate. The apparatus can also include a current detector configured to detect a phase current magnitude of the output alternating current. The apparatus can also include a controller coupled to the current detector and to the inverter. The controller can generate a gate command for controlling a gate of the inverter. The controller can also determine a value for a current threshold less than a shutoff current threshold for the external component. The controller can provide a protection command to turn off the upper gate of a corresponding phase of the inverter responsive to detecting that the phase current magnitude is greater than the current threshold.Type: GrantFiled: June 1, 2022Date of Patent: September 24, 2024Assignee: Caterpillar Inc.Inventors: Jesse R. Gerdes, Jackson Wai, Seok-hee Han
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Publication number: 20240079870Abstract: Techniques to reduce discontinuities in power, for example, by controlling an electrical power output of an active front end unit during a transition between a first operating mode and a second operating mode. In some examples, to reduce discontinuities, a control unit of the active front end unit can seed the integrator of proportional-integral (PI) controllers that are brought online during the operating mode change with a value that represents the proper state of the current system, such as the measured or calculated value of the component the PI controller is controlling). In other examples, to reduce discontinuities, a control unit of the active front end unit can control reference frame alignment during a transition between a first operating mode and a second operating mode.Type: ApplicationFiled: September 1, 2022Publication date: March 7, 2024Applicant: Caterpillar Inc.Inventors: Seok-hee Han, Jesse R. Gerdes, Jackson Wai
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Publication number: 20240079876Abstract: Techniques to limit electrical power when forming an electrical grid using an active front end unit having an inverter that is coupled to a capacitor (and inductor) that is coupled to an electrical grid. For example, to limit power, the integration of a commanded frequency of the system can be limited to be within a specified phase delta of a measured phase angle of an electrical grid voltage vector. The calculation from power limit to phase delta can be done when the phase of the electrical grid voltage vector has been determined to be accurate and is calculated based on the measured capacitor voltage, grid voltage, and the estimated voltage drop across the output components of the system.Type: ApplicationFiled: September 1, 2022Publication date: March 7, 2024Applicant: Caterpillar Inc.Inventors: Seok-hee Han, Jesse R. Gerdes, Jackson Wai
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Publication number: 20230396054Abstract: An apparatus can include an inverter to provide an output N-phase alternating-current to an external component. When N equals two, a phase of the N phases can include an upper gate and a lower gate. The apparatus can also include a current detector configured to detect a phase current magnitude of the output alternating current. The apparatus can also include a controller coupled to the current detector and to the inverter. The controller can generate a gate command for controlling a gate of the inverter. The controller can also determine a value for a current threshold less than a shutoff current threshold for the external component. The controller can provide a protection command to turn off the upper gate of a corresponding phase of the inverter responsive to detecting that the phase current magnitude is greater than the current threshold.Type: ApplicationFiled: June 1, 2022Publication date: December 7, 2023Applicant: Caterpillar Inc.Inventors: Jesse R. Gerdes, Jackson Wai, Seok-hee Han
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Patent number: 11811344Abstract: A work machine includes a frame, a traction system supporting the frame, a power source mounted on the frame, a switched reluctance motor, an inverter configured to control power to the motor from a power source, and a controller. The controller is configured to receive a signal indicating a desired torque and determine if the desired torque is between an upper threshold and a lower threshold. If the desired torque is between the upper threshold and the lower threshold, pulse width modulation is used to produce a PWM adjusted torque command, and the motor is commanded based on the PWM adjusted torque command. The PWM adjusted torque command is configured to cycle between the upper threshold and the lower threshold to produce the desired torque.Type: GrantFiled: December 23, 2020Date of Patent: November 7, 2023Assignee: Caterpillar Inc.Inventors: Jesse R. Gerdes, Thomas M. Sopko, Carlos E. Nino Baron, Jackson Wai, Ahmed Khalil, Sajan Abdul, Amara Ashfaq, James Michael Thorne
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Patent number: 11545922Abstract: Power based self-sensing of a rotor position of an SR motor at mid to high speeds and low torque is achieved by an SR motor control system by comparing the motor power to an injection maximum power. A position current pulse is injected to a stator pole in response to the motor power being less than the injection maximum power. An actual stator current created by the position current pulse is compared to an estimated stator current, and a stored estimated rotor position in a memory is updated to a new estimated rotor position if the actual stator current is not equal to the estimated stator current.Type: GrantFiled: January 21, 2021Date of Patent: January 3, 2023Assignee: Caterpillar Inc.Inventors: Jesse Ray Gerdes, James Michael Thorne, Ahmed Khalil, Jackson Wai, Sajan Abdul, Amara Ashfaq
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Patent number: 11515824Abstract: A system and method for torque compensation in a switched reluctance (SR) machine disposed on a machine is disclosed. The system may comprise a SR machine, an inverter and a controller. The controller is in operable communication with the inverter and is configured to determine a commanded main current associated with energization by a main current of a first portion of the plurality of windings for a controlling phase, and determine a commanded parasitic current associated with energization by a parasitic current of a second portion of the windings in a non-controlling phase. The controller is further configured to determine an offset current based on the commanded parasitic current, and determine a target current based on a first sum of the commanded main current and the offset current, and command the inverter to actuate the target current in the first portion of the windings during the controlling phase.Type: GrantFiled: December 21, 2020Date of Patent: November 29, 2022Assignee: Caterpillar Inc.Inventors: Jesse R. Gerdes, Jackson Wai, Ahmed Khalil, James Michael Thorne, Sajan Abdul, Amara Ashfaq
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Publication number: 20220231626Abstract: Power based self-sensing of a rotor position of an SR motor at mid to high speeds and low torque is achieved by an SR motor control system by comparing the motor power to an injection maximum power. A position current pulse is injected to a stator pole in response to the motor power being less than the injection maximum power. An actual stator current created by the position current pulse is compared to an estimated stator current, and a stored estimated rotor position in a memory is updated to a new estimated rotor position if the actual stator current is not equal to the estimated stator current.Type: ApplicationFiled: January 21, 2021Publication date: July 21, 2022Applicant: Caterpillar Inc.Inventors: Jesse Ray Gerdes, James Michael Thorne, Ahmed Khalil, Jackson Wai, Sajan Abdul, Amara Ashfaq
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Publication number: 20220200501Abstract: A work machine includes a frame, a traction system supporting the frame, a power source mounted on the frame, a switched reluctance motor, an inverter configured to control power to the motor from a power source, and a controller. The controller is configured to receive a signal indicating a desired torque and determine if the desired torque is between an upper threshold and a lower threshold. If the desired torque is between the upper threshold and the lower threshold, pulse width modulation is used to produce a PWM adjusted torque command, and the motor is commanded based on the PWM adjusted torque command. The PWM adjusted torque command is configured to cycle between the upper threshold and the lower threshold to produce the desired torque.Type: ApplicationFiled: December 23, 2020Publication date: June 23, 2022Applicant: Caterpillar Inc.Inventors: Jesse R. Gerdes, Thomas M. Sopko, Carlos E. Nino Baron, Jackson Wai, Ahmed Khalil, Sajan Abdul, Amara Ashfaq, James Michael Thorne
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Publication number: 20220200502Abstract: A system and method for torque compensation in a switched reluctance (SR) machine disposed on a machine is disclosed. The system may comprise a SR machine, an inverter and a controller. The controller is in operable communication with the inverter and is configured to determine a commanded main current associated with energization by a main current of a first portion of the plurality of windings for a controlling phase, and determine a commanded parasitic current associated with energization by a parasitic current of a second portion of the windings in a non-controlling phase. The controller is further configured to determine an offset current based on the commanded parasitic current, and determine a target current based on a first sum of the commanded main current and the offset current, and command the inverter to actuate the target current in the first portion of the windings during the controlling phase.Type: ApplicationFiled: December 21, 2020Publication date: June 23, 2022Applicant: Caterpillar Inc.Inventors: Jesse R. Gerdes, Jackson Wai, Ahmed Khalil, James Michael Thorne, Sajan Abdul, Amara Ashfaq
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Patent number: 10938332Abstract: A control system that includes a converter circuit and a control device is disclosed. The converter circuit may be configured to control a phase current of a switched reluctance machine. The control device may be configured to determine an estimated flux based on a bus voltage, a phase voltage, and a mutual voltage. The control device may be configured to determine a flux threshold based on the phase current, and determine a first limit and a second limit relative to the flux threshold. The first limit and the second limit may be scaled relative to the flux threshold based on one or more of the target speed, the load demand, or the bus voltage. The control device may be configured to compare the estimated flux with the first limit, and reset the estimated flux to the second limit based on determining that the estimated flux satisfies the first limit.Type: GrantFiled: October 7, 2019Date of Patent: March 2, 2021Assignee: Caterpillar Inc.Inventors: Ahmed Khalil, James Thorne, Jackson Wai, Amara Ashfaq, Jesse Gerdes
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Patent number: 10897217Abstract: A device may receive a current measurement of a motor identifying a plurality of component currents associated with a plurality of phases. The device may determine a position estimate for the motor based on the plurality of component currents associated with the plurality of phases. The device may control the motor based on the plurality of component currents.Type: GrantFiled: August 21, 2018Date of Patent: January 19, 2021Assignee: Caterpillar Inc.Inventors: Ahmed Khalil, Sam Han, James Thorne, Jesse Gerdes, Jackson Wai, Carlos Nino Baron, Sajan Abdul
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Patent number: 10715052Abstract: An electrical inverter may include a plurality of phase modules to provide a plurality of phase outputs. Two or more of the plurality of phase modules may share a common insulated-gate bipolar transistor.Type: GrantFiled: August 22, 2018Date of Patent: July 14, 2020Assignee: Caterpillar Inc.Inventors: Ahmed Khalil, Jackson Wai, Jesse Gerdes, James Thorne, Amir Saad
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Patent number: 10666182Abstract: A control system for a rotary electric machine includes a controller configured to generate dynamic input current data based upon a dynamic analysis of self flux data, mutual flux data, and saturation scaling factor data. Upon generating a torque request, the controller is configured to determine a desired electrical input based upon the dynamic input current data to generate the desired output torque. The desired electrical input includes a magnitude and duration of an electrical pulse and a desired angular position of the rotor of the rotary electric machine relative to the stator of the machine. The controller determines an angular position of the rotor and generates an operating command to generate the desired electrical input at the desired angular position of the rotor to propel the rotary electric machine and generate the desired output torque. A rotary electric machine and method of operating same are provided.Type: GrantFiled: April 6, 2018Date of Patent: May 26, 2020Assignee: Caterpillar Inc.Inventors: Carlos E. Nino Baron, Ahmed Khalil, Jackson Wai, Jesse R. Gerdes, Sangameshwar Sonth, Amir Saad
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Publication number: 20200067422Abstract: An electrical inverter may include a plurality of phase modules to provide a plurality of phase outputs. Two or more of the plurality of phase modules may share a common insulated-gate bipolar transistor.Type: ApplicationFiled: August 22, 2018Publication date: February 27, 2020Applicant: Caterpillar Inc.Inventors: Ahmed Khalil, Jackson Wai, Jesse Gerdes, James Thorne, Amir Saad
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Publication number: 20200067433Abstract: A device may receive a current measurement of a motor identifying a plurality of component currents associated with a plurality of phases. The device may determine a position estimate for the motor based on the plurality of component currents associated with the plurality of phases. The device may control the motor based on the plurality of component currents.Type: ApplicationFiled: August 21, 2018Publication date: February 27, 2020Applicant: Caterpillar Inc.Inventors: Ahmed KHALIL, Sam HAN, James THORNE, Jesse GERDES, Jackson WAI, Carlos NINO BARON, Sajan ABDUL
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Patent number: 10476421Abstract: A device may select an operation mode based on at least one of a motor speed, a motor transient speed, or a motor power command value. The operation mode may be selected from a group of operation modes including a single pulse mode, a continuous conduction mode, and a variable dwell continuous conduction mode. The device may control a switched reluctance motor using the operation mode.Type: GrantFiled: August 28, 2018Date of Patent: November 12, 2019Assignee: Caterpillar Inc.Inventors: Ahmed Khalil, Carlos Nino Baron, Chad Brewer, Jackson Wai, Yash Bhatia
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Patent number: 10193475Abstract: A method for determining rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may include injecting a test pulse into one or more idle phases of the SR machine, determining a decoupled flux value based at least partially on a total flux value corresponding to the test pulse and a mutual flux value, and determining the rotor position based at least partially on the decoupled flux value.Type: GrantFiled: May 18, 2015Date of Patent: January 29, 2019Assignee: Caterpillar Inc.Inventors: Seok-hee Han, Carlos Nino Baron, Jackson Wai, Ahmed Khalil, Ernesto Inoa, Jesse Gerdes, James Michael Thorne
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Patent number: 10097117Abstract: A control system is provided for an electric machine having a rotor and a stator. The control system has a converter circuit in electrical communication with the stator and a controller in electrical communication with the converter circuit. The controller is configured to receive a first signal indicating a torque applied to or output by the rotor and receive a second signal indicating a rotational speed of the rotor. The controller is also configured to determine at least one characteristic of a pulse signal based on at least one of the first or second signal. The controller is also configured to inject the pulse signal into one or more phases of the stator via the converter circuit according to the determined at least one characteristic. The controller is also configured to determine a position of the rotor based on the injected pulse signal.Type: GrantFiled: December 15, 2016Date of Patent: October 9, 2018Assignee: Caterpillar Inc.Inventors: Ahmed Khalil, Seok-Hee Han, Jackson Wai, Sangameshwar Sonth, Jesse Gerdes, James M. Thorne