Patents by Inventor Robert D. Lorenz
Robert D. Lorenz 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: 11531075Abstract: An improved system for measuring current within a power semiconductor module is disclosed, where the system is integrated within the power module. The system includes a point field detector sensing a magnetic field resulting from current flowing in one phase of the module. A lead frame conductor may be provided to shape the magnetic field and minimize the influence of cross-coupled magnetic fields from currents conducted in other power semiconductor devices within one phase of the module. Optionally, a second point field detector may be provided at a second location within the module to sense a magnetic field resulting from the current flowing in the same phase of the module. Each phase of the power module includes at least one point field detector. A decoupling circuit is provided to decouple multiple currents flowing within the same phase or to decouple currents flowing within different phases of the power module.Type: GrantFiled: August 9, 2021Date of Patent: December 20, 2022Assignee: Wisconsin Alumni Research FoundationInventors: Robert D. Lorenz, Minhao Sheng, Hiroyuki Nogawa, Yoshinari Ikeda, Eiji Mochizuki
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Publication number: 20210364581Abstract: An improved system for measuring current within a power semiconductor module is disclosed, where the system is integrated within the power module. The system includes a point field detector sensing a magnetic field resulting from current flowing in one phase of the module. A lead frame conductor may be provided to shape the magnetic field and minimize the influence of cross-coupled magnetic fields from currents conducted in other power semiconductor devices within one phase of the module. Optionally, a second point field detector may be provided at a second location within the module to sense a magnetic field resulting from the current flowing in the same phase of the module. Each phase of the power module includes at least one point field detector. A decoupling circuit is provided to decouple multiple currents flowing within the same phase or to decouple currents flowing within different phases of the power module.Type: ApplicationFiled: August 9, 2021Publication date: November 25, 2021Inventors: Robert D. Lorenz, Minhao Sheng, Hiroyuki Nogawa, Yoshinari Ikeda, Eiji Mochizuki
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Patent number: 11085977Abstract: An improved system for measuring current within a power semiconductor module is disclosed, where the system is integrated within the power module. The system includes a point field detector sensing a magnetic field resulting from current flowing in one phase of the module. A lead frame conductor may be provided to shape the magnetic field and minimize the influence of cross-coupled magnetic fields from currents conducted in other power semiconductor devices within one phase of the module. Optionally, a second point field detector may be provided at a second location within the module to sense a magnetic field resulting from the current flowing in the same phase of the module. Each phase of the power module includes at least one point field detector. A decoupling circuit is provided to decouple multiple currents flowing within the same phase or to decouple currents flowing within different phases of the power module.Type: GrantFiled: May 15, 2017Date of Patent: August 10, 2021Assignee: Wisconsin Alumni Research FoundationInventors: Robert D. Lorenz, Minhao Sheng, Hiroyuki Nogawa, Yoshinari Ikeda, Eiji Mochizuki
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Patent number: 11011965Abstract: A permanent magnet synchronous motor includes a stator, a rotor rotatable relative to the stator, and a magnetic structure with a low coercive force magnet and a high coercive force magnet that are arranged magnetically in series with respect to each other to define a pole-pair of the permanent magnet synchronous motor. A magnetization level of the low coercive force magnet is changeable by a stator current pulse such that a stator magnetomotive force at a rated current is equal to or larger than a product of a magnetic field strength for fully magnetizing the low coercive force magnet and a thickness of the low coercive force magnet.Type: GrantFiled: July 31, 2015Date of Patent: May 18, 2021Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Kensuke Sasaki, Takashi Fukushige, Takashi Katou, Apoorva Athavale, Robert D. Lorenz
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Patent number: 10784804Abstract: A magnetization state control method for a variable magnetization machine, the method includes generating a flux linkage vector while changing a magnetization state of the variable magnetization machine such that a trajectory of the flux linkage vector has a curved clockwise trajectory on a dq-axis plane and a magnitude of the flux linkage vector temporally changes, with the dq-axis plane being a synchronous reference frame with a d-axis pointing in a direction of a permanent magnet flux and a q-axis being 90 degrees ahead of the d-axis in a rotational direction of a rotor.Type: GrantFiled: July 31, 2015Date of Patent: September 22, 2020Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Kensuke Sasaki, Takashi Fukushige, Takashi Katou, Brent S. Gagas, Robert D. Lorenz
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Patent number: 10763769Abstract: A controller for a power convertor includes: a torque command value calculation module to calculate a first torque command value to a power convertor; a torque command limit module to receive the first torque command value and generate a second torque command value obtained by correcting the first torque command value so that the first torque command value is limited to a torque limiter range. The torque command limit module sets a width between the upper limit torque value and the lower limit torque value of the torque limiter range to be smaller as a fundamental wave output frequency of the power convertor increases at least in a speed region equal to or higher than a field weakening starting point.Type: GrantFiled: June 29, 2018Date of Patent: September 1, 2020Assignees: Wisconsin Alumni Research Foundation, Toshiba Mitsubishi-Electric Industrial Systems CorporationInventors: Yang Xu, Chikara Morito, Robert D. Lorenz
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Patent number: 10547261Abstract: A variable magnetization machine control system comprising a controller configured to generate a reversely rotating d-axis/q-axis current vector trajectory during a change in a magnetization state of a variable magnetization machine to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.Type: GrantFiled: August 29, 2014Date of Patent: January 28, 2020Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Takashi Fukushige, Brent S. Gagas, Chen-Yen Yu, Robert D. Lorenz
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Publication number: 20200007058Abstract: A controller for a power convertor includes: a torque command value calculation module to calculate a first torque command value to a power convertor; a torque command limit module to receive the first torque command value and generate a second torque command value obtained by correcting the first torque command value so that the first torque command value is limited to a torque limiter range. The torque command limit module sets a width between the upper limit torque value and the lower limit torque value of the torque limiter range to be smaller as a fundamental wave output frequency of the power convertor increases at least in a speed region equal to or higher than a field weakening starting point.Type: ApplicationFiled: June 29, 2018Publication date: January 2, 2020Applicants: Wisconsin Alumni Research Foundation, Toshiba Mitsubishi-Electric Industrial Systems CorporationInventors: Yang XU, Chikara MORITO, Robert D. LORENZ
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Patent number: 10491065Abstract: A permanent magnet synchronous motor includes a stator with a stator winding, a rotor with a rotor core rotatable relative to the stator, and a magnetic structure with at least one permanent magnet mounted to the rotor core. The magnetic structure produces a magnetic flux that flows between different magnetic poles of the magnetic structure through a main magnetic flux path that passes through the stator winding of the stator via an air gap and a leakage magnetic flux path that is located within the rotor core about an end portion of the permanent magnet near the air gap. The stator, the rotor and the magnetic structure being further configured to satisfy predetermined relationships in regards to the magnetic resistance of the main magnetic flux path and the leakage magnetic flux path, the magnetomotive force of the magnets and the stator.Type: GrantFiled: September 11, 2014Date of Patent: November 26, 2019Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Kensuke Sasaki, Takashi Fukushige, Takashi Kato, Robert D. Lorenz, Apoorva Athavale
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Patent number: 10483892Abstract: A variable magnetization machine control system comprising a controller configured to adjust a d-axis current waveform and a q-axis current waveform in accordance with an operating condition of a variable magnetization machine to generate an adjusted d-axis current waveform and an adjusted q-axis current waveform that provide a driving voltage to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.Type: GrantFiled: August 29, 2014Date of Patent: November 19, 2019Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Takashi Fukushige, Takashi Kato, Brent S. Gagas, Robert D. Lorenz
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Publication number: 20190006971Abstract: A controller includes a torque command value calculation module configured to calculate a torque command based on a speed command of the motor, an output voltage controlling module configured to control an output voltage of the power converter based on the torque command calculated by the torque command value calculation module, a voltage command value correcting module configured to correct a voltage command to the power converter based on a measured output voltage from the power converter, a flux estimation module configured to estimate stator flux and rotor flux of the motor in a subsequent control period based on the voltage command by the voltage command value correcting module and a measured current of the stator and a motor speed estimation module configured to estimate a speed of the motor in a subsequent control period based on the flux estimated by the flux estimation module.Type: ApplicationFiled: June 29, 2017Publication date: January 3, 2019Inventors: Yang Xu, Ryo Iida, Robert D. Lorenz, Yukai Wang
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Patent number: 10171019Abstract: A controller includes a torque command value calculation module configured to calculate a torque command based on a speed command of the motor, an output voltage controlling module configured to control an output voltage of the power converter based on the torque command calculated by the torque command value calculation module, a voltage command value correcting module configured to correct a voltage command to the power converter based on a measured output voltage from the power converter, a flux estimation module configured to estimate stator flux and rotor flux of the motor in a subsequent control period based on the voltage command by the voltage command value correcting module and a measured current of the stator and a motor speed estimation module configured to estimate a speed of the motor in a subsequent control period based on the flux estimated by the flux estimation module.Type: GrantFiled: June 29, 2017Date of Patent: January 1, 2019Assignees: Toshiba Mitsubishi-Electric Industrial Systems Corporation, Wisconsin Alumni Research FoundationInventors: Yang Xu, Ryo Iida, Robert D. Lorenz, Yukai Wang
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Patent number: 10146211Abstract: A variable magnetization machine controller including a hysteresis control component configured to receive an ideal magnetization state signal, output an actual magnetization signal based on the ideal magnetization state signal for control of a variable magnetization machine, and modify the actual magnetization state signal in accordance with an error value between the ideal magnetization state signal and the actual magnetization state signal.Type: GrantFiled: September 12, 2013Date of Patent: December 4, 2018Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Takashi Fukushige, Chen-yen Yu, Robert D. Lorenz
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Publication number: 20180329002Abstract: An improved system for measuring current within a power semiconductor module is disclosed, where the system is integrated within the power module. The system includes a point field detector sensing a magnetic field resulting from current flowing in one phase of the module. A lead frame conductor may be provided to shape the magnetic field and minimize the influence of cross-coupled magnetic fields from currents conducted in other power semiconductor devices within one phase of the module. Optionally, a second point field detector may be provided at a second location within the module to sense a magnetic field resulting from the current flowing in the same phase of the module. Each phase of the power module includes at least one point field detector. A decoupling circuit is provided to decouple multiple currents flowing within the same phase or to decouple currents flowing within different phases of the power module.Type: ApplicationFiled: May 15, 2017Publication date: November 15, 2018Inventors: Robert D. Lorenz, Minhao Sheng, Hiroyuki Nogawa, Yoshinari Ikeda, Eiji Mochizuki
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Publication number: 20180219504Abstract: A magnetization state control method for a variable magnetization machine, the method includes generating a flux linkage vector while changing a magnetization state of the variable magnetization machine such that a trajectory of the flux linkage vector has a curved clockwise trajectory on a dq-axis plane and a magnitude of the flux linkage vector temporally changes, with the dq-axis plane being a synchronous reference frame with a d-axis pointing in a direction of a permanent magnet flux and a q-axis being 90 degrees ahead of the d-axis in a rotational direction of a rotor.Type: ApplicationFiled: July 31, 2015Publication date: August 2, 2018Inventors: Kensuke SASAKI, Takashi FUKUSHIGE, Takashi KATOU, Brent S. GAGAS, Robert D. LORENZ
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Publication number: 20180219463Abstract: A permanent magnet synchronous motor includes a stator, a rotor rotatable relative to the stator, and a magnetic structure with a low coercive force magnet and a high coercive force magnet that are arranged magnetically in series with respect to each other to define a pole-pair of the permanent magnet synchronous motor. A magnetization level of the low coercive force magnet is changeable by a stator current pulse such that a stator magnetomotive force at a rated current is equal to or larger than a product of a magnetic field strength for fully magnetizing the low coercive force magnet and a thickness of the low coercive force magnet.Type: ApplicationFiled: July 31, 2015Publication date: August 2, 2018Inventors: Kensuke SASAKI, Takashi FUKUSHIGE, Takashi KATOU, Apoorva ATHAVALE, Robert D. LORENZ
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Publication number: 20170288586Abstract: A variable magnetization machine control system comprising a controller configured to adjust a d-axis current waveform and a q-axis current waveform in accordance with an operating condition of a variable magnetization machine to generate an adjusted d-axis current waveform and an adjusted q-axis current waveform that provide a driving voltage to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.Type: ApplicationFiled: August 29, 2014Publication date: October 5, 2017Inventors: Takashi FUKUSHIGE, Takashi KATO, Brent S. GAGAS, Robert D. LORENZ
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Publication number: 20170279392Abstract: A variable magnetization machine control system comprising a controller configured to generate a reversely rotating d-axis/q-axis current vector trajectory during a change in a magnetization state of a variable magnetization machine to drive the variable magnetization machine at a predetermined speed while maintaining the driving voltage below a predetermined maximum magnitude.Type: ApplicationFiled: August 29, 2014Publication date: September 28, 2017Inventors: Takashi FUKUSHIGE, Brent S. GAGAS, Chen-Yen YU, Robert D. LORENZ
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Publication number: 20170279322Abstract: A permanent magnet synchronous motor includes a stator with a stator winding, a rotor with a rotor core rotatable relative to the stator, and a magnetic structure with at least one permanent magnet mounted to the rotor core. The magnetic structure produces a magnetic flux that flows between different magnetic poles of the magnetic structure through a main magnetic flux path that passes through the stator winding of the stator via an air gap and a leakage magnetic flux path that is located within the rotor core about an end portion of the permanent magnet near the air gap. The stator, the rotor and the magnetic structure being further configured to satisfy predetermined relationships in regards to the magnetic resistance of the main magnetic flux path and the leakage magnetic flux path, the magnetomotive force of the magnets and the stator.Type: ApplicationFiled: September 11, 2014Publication date: September 28, 2017Inventors: Kensuke SASAKI, Takashi FUKUSHIGE, Takashi KATO, Robert D. LORENZ, Apoorva ATHAVALE
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Patent number: 9647583Abstract: A variable magnetization machine controller has a current command module, a magnetization module and a reducing current module. The current command module computes a vector current command in a dq axis based on a torque command. The magnetization module applies a magnetization control pulse to a d-axis current of the vector current command. Thus, the reducing current module applies a reducing current to a q-axis current of the vector current command based on the torque command and one of an estimated torque of the variable magnetization machine and a measured torque of the variable magnetization machine.Type: GrantFiled: June 28, 2013Date of Patent: May 9, 2017Assignees: Nissan Motor Co., Ltd., Wisconsin Alumni Research FoundationInventors: Takashi Fukushige, Chen-yen Yu, Robert D. Lorenz