Patents by Inventor Hiromitsu OHASHI

Hiromitsu OHASHI 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).

  • Patent number: 11114969
    Abstract: A power converter includes a first inverter, a second inverter, and a switching circuit including first and second switching elements. In a state in which, in the first inverter, potentials at a first node in a high side and a second node in a low side are equal to each other, and potentials at first ends of two-phase windings of n-phase windings with n being an integer of 2 or more are equal to each other, two-phase windings are energized using two legs connected to second ends of the two-phase windings of n legs of the second inverter while performing switching operations on the first and second switching elements of the switching circuit at a predetermined duty ratio.
    Type: Grant
    Filed: March 5, 2018
    Date of Patent: September 7, 2021
    Assignee: NIDEC CORPORATION
    Inventors: Hiromitsu Ohashi, Ahmad Ghaderi
  • Patent number: 11081997
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, a first phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the first inverter, a second phase separation relay circuit to switch between connection and disconnection between the second ends of the windings of each phase and the second inverter, a sub-inverter circuit connectable to the first ends and the second ends of the windings of each phase, a third phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the sub-inverter circuit, and a fourth phase separation relay circuit to switch between connection and disconnection between the second ends of the windings of each phase and the sub-inverter circuit.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: August 3, 2021
    Assignee: NIDEC CORPORATION
    Inventor: Hiromitsu Ohashi
  • Patent number: 11081941
    Abstract: A motor includes a first inverter connected to one end of a winding of each phase and a second inverter connected to another end of the winding of each phase. The first inverter includes a terminal electrically connected to one end of a U-phase winding. The second inverter includes a terminal electrically connected to another end of the U-phase winding. Current output from the terminal of the first inverter and passing through the U-phase winding flows to the terminal of the second inverter. Current output from the terminal of the second inverter and passing through the U-phase winding flows to the terminal of the first inverter. The terminal of the first inverter and the terminal of the second inverter are adjacent to each other.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: August 3, 2021
    Assignee: NIDEC CORPORATION
    Inventors: Yoshiaki Yamashita, Hiromitsu Ohashi
  • Patent number: 10998841
    Abstract: A power conversion device includes a first inverter connected to first ends of m (m is an integer equal to two or more) coil groups, a second inverter connected to second ends of the m coil groups, m?1 separation relay circuits connected between two adjacent coil groups of the m coil groups, m?1 first neutral point relay circuits provided between two adjacent coil groups of the first inverter side of each of the m?1 separation relay circuits, and m?1 second neutral point relay circuits provided between two adjacent coils of the second inverter side of each of the m?1 separation relay circuits.
    Type: Grant
    Filed: January 10, 2018
    Date of Patent: May 4, 2021
    Assignee: NIDEC CORPORATION
    Inventor: Hiromitsu Ohashi
  • Patent number: 10998842
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, a phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the first inverter, a neutral point relay circuit connected to the first ends of the windings of each phase and to switch between connection and disconnection between the first ends of the windings of each phase, a first switching element to switch between connection and disconnection between the second inverter and a power supply, and a second switching element to switch between connection and disconnection between the second inverter and a ground.
    Type: Grant
    Filed: December 22, 2017
    Date of Patent: May 4, 2021
    Assignee: NIDEC CORPORATION
    Inventors: Eiji Wada, Hiromitsu Ohashi
  • Patent number: 10998782
    Abstract: A motor includes a rotor including a rotor core and permanent magnets along an outer periphery of the rotor core, and a stator including windings. Each of the permanent magnets includes a first face in contact with the outer periphery of the rotor core and a second face located outside the first face in a radial direction of the rotor and which faces the stator. In a plan view when the rotor is viewed from a direction parallel to the rotation axis direction of the rotor, the first face includes a linear portion, the second face includes a linear portion parallel to the linear portion of the first face, and a length of the linear portion of the second face is 20% or more and less than 85% of a length of the linear portion of the first face.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: May 4, 2021
    Assignee: Nidec Corporation
    Inventor: Hiromitsu Ohashi
  • Publication number: 20200373867
    Abstract: A motor includes a first inverter electrically connected to a first end of a winding of each phase, and a second inverter electrically connected to a second end of the winding of each phase. Each of the first and second inverters includes low-side switching elements and high-side switching elements. FETs of the first inverter are electrically connected to a first end of a U-phase winding. FETs of the second inverter are electrically connected to a second end of the U-phase winding. At least a portion of a current flowing from one of the FETs of the first inverter to the U-phase winding flows to one of the FETs of the second inverter. One of the FETs of the first inverter and one of the FETs of the second inverter are adjacent to each other.
    Type: Application
    Filed: March 9, 2018
    Publication date: November 26, 2020
    Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
  • Patent number: 10829147
    Abstract: A power conversion device includes a first inverter connected to a first end of a winding of each phase of a motor, a second inverter connected to a second end of the winding of each phase, and first and second switching circuits. The power conversion device further includes a normal state operation mode in which power conversion is performed by using a first neutral point of the winding of each phase in the second inverter and the first inverter and an abnormal state operation mode in which the power conversion is performed by using a second neutral point of the winding of each phase in the first inverter and the second inverter. An operation mode of the power conversion is switched from the normal state operation mode to the abnormal state operation mode when at least one switch in the first inverter fails.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: November 10, 2020
    Assignee: NIDEC CORPORATION
    Inventor: Hiromitsu Ohashi
  • Publication number: 20200303976
    Abstract: A motor includes a rotor including a rotor core and permanent magnets along an outer periphery of the rotor core, and a stator including windings. Each of the permanent magnets includes a first face in contact with the outer periphery of the rotor core and a second face located outside the first face in a radial direction of the rotor and which faces the stator. In a plan view when the rotor is viewed from a direction parallel to the rotation axis direction of the rotor, the first face includes a linear portion, the second face includes a linear portion parallel to the linear portion of the first face, and a length of the linear portion of the second face is 20% or more and less than 85% of a length of the linear portion of the first face.
    Type: Application
    Filed: April 19, 2017
    Publication date: September 24, 2020
    Applicant: Nidec Corporation
    Inventor: Hiromitsu OHASHI
  • Publication number: 20200295631
    Abstract: A motor includes a first inverter connected to one end of a winding of each phase and a second inverter connected to another end of the winding of each phase. The first inverter includes a terminal electrically connected to one end of a U-phase winding. The second inverter includes a terminal electrically connected to another end of the U-phase winding. Current output from the terminal of the first inverter and passing through the U-phase winding flows to the terminal of the second inverter. Current output from the terminal of the second inverter and passing through the U-phase winding flows to the terminal of the first inverter. The terminal of the first inverter and the terminal of the second inverter are adjacent to each other.
    Type: Application
    Filed: March 9, 2018
    Publication date: September 17, 2020
    Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
  • Patent number: 10742137
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, and a first switching circuit including at least one of a first switch to switch between whether the first inverter and a power supply are connected or disconnected and a second switch to switch between whether the first inverter and a ground are connected or disconnected. The power conversion device has a first operation mode when the motor is driven at a low speed, and a second operation mode when the motor is driven at a high speed.
    Type: Grant
    Filed: March 5, 2019
    Date of Patent: August 11, 2020
    Assignee: NIDEC CORPORATION
    Inventor: Hiromitsu Ohashi
  • Publication number: 20200251966
    Abstract: A motor module includes a motor including n-phase windings where n is 3 or more, a first circuit boar, a first inverter mounted on the first circuit board and connected to the windings, a first passive element group mounted on the first circuit board, a first heat sink in thermal contact with the first circuit board, a second circuit board, a second inverter mounted on the second circuit board and connected to the windings, and a second passive element group mounted on the second circuit board. A first passive element having a highest height in the first passive element group and a second passive element having a highest height in the second passive element group are located between the first circuit board and the second circuit board, and do not overlap each other when viewed along a direction of a rotation axis of a rotor of the motor.
    Type: Application
    Filed: October 5, 2018
    Publication date: August 6, 2020
    Inventors: Shuji ENDO, Hiromitsu OHASHI
  • Publication number: 20200244206
    Abstract: A power converter includes a first inverter, a second inverter, and a switching circuit including first and second switching elements. In a state in which, in the first inverter, potentials at a first node in a high side and a second node in a low side are equal to each other, and potentials at first ends of two-phase windings of n-phase windings with n being an integer of 2 or more are equal to each other, two-phase windings are energized using two legs connected to second ends of the two-phase windings of n legs of the second inverter while performing switching operations on the first and second switching elements of the switching circuit at a predetermined duty ratio.
    Type: Application
    Filed: March 5, 2018
    Publication date: July 30, 2020
    Inventors: Hiromitsu OHASHI, Ahmad GHADERI
  • Publication number: 20200059189
    Abstract: A power conversion device includes a first inverter connected to first ends of the first coil group, a second inverter connected to first ends of the second coil group, a separation relay circuit connected to second ends of the first coil group and second ends of the second coil group to switch between connection and disconnection of the first and second coil groups, a first neutral point relay circuit connected to the second ends of the first coil group to switch between connection and disconnection of the second ends of the first coil group, and a second neutral point relay circuit connected to the second ends of the second coil group to switch between connection and disconnection of the second ends of the second coil group.
    Type: Application
    Filed: January 10, 2018
    Publication date: February 20, 2020
    Inventor: Hiromitsu OHASHI
  • Publication number: 20190372500
    Abstract: A power conversion device includes a first inverter connected to first ends of m (m is an integer equal to two or more) coil groups, a second inverter connected to second ends of the m coil groups, m?1 separation relay circuits connected between two adjacent coil groups of the m coil groups, m?1 first neutral point relay circuits provided between two adjacent coil groups of the first inverter side of each of the m?1 separation relay circuits, and m?1 second neutral point relay circuits provided between two adjacent coils of the second inverter side of each of the m?1 separation relay circuits.
    Type: Application
    Filed: January 10, 2018
    Publication date: December 5, 2019
    Inventor: Hiromitsu OHASHI
  • Publication number: 20190372502
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, a first phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the first inverter, a second phase separation relay circuit to switch between connection and disconnection between the second ends of the windings of each phase and the second inverter, a sub-inverter circuit connectable to the first ends and the second ends of the windings of each phase, a third phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the sub-inverter circuit, and a fourth phase separation relay circuit to switch between connection and disconnection between the second ends of the windings of each phase and the sub-inverter circuit.
    Type: Application
    Filed: December 26, 2017
    Publication date: December 5, 2019
    Inventor: Hiromitsu OHASHI
  • Publication number: 20190372501
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, a phase separation relay circuit to switch between connection and disconnection between the first ends of the windings of each phase and the first inverter, a neutral point relay circuit connected to the first ends of the windings of each phase and to switch between connection and disconnection between the first ends of the windings of each phase, a first switching element to switch between connection and disconnection between the second inverter and a power supply, and a second switching element to switch between connection and disconnection between the second inverter and a ground.
    Type: Application
    Filed: December 22, 2017
    Publication date: December 5, 2019
    Inventors: Eiji WADA, Hiromitsu OHASHI
  • Publication number: 20190315388
    Abstract: A power conversion device includes a first converter connected to first ends of windings of each phase of a motor, a second converter connected to second ends of the windings of each phase, and a switching circuit used to define a neutral point in the windings of each phase on the first inverter side. At least one of a plurality of switches included in the first inverter has a first current capacity, and a plurality of switches included in the second inverter have a second current capacity that is greater than the first current capacity.
    Type: Application
    Filed: March 5, 2019
    Publication date: October 17, 2019
    Inventor: Hiromitsu OHASHI
  • Publication number: 20190210640
    Abstract: A power conversion device includes a first inverter connected to a first end of a winding of each phase of a motor, a second inverter connected to a second end of the winding of each phase, and first and second switching circuits. The power conversion device further includes a normal state operation mode in which power conversion is performed by using a first neutral point of the winding of each phase in the second inverter and the first inverter and an abnormal state operation mode in which the power conversion is performed by using a second neutral point of the winding of each phase in the first inverter and the second inverter. An operation mode of the power conversion is switched from the normal state operation mode to the abnormal state operation mode when at least one switch in the first inverter fails.
    Type: Application
    Filed: September 15, 2017
    Publication date: July 11, 2019
    Inventor: Hiromitsu OHASHI
  • Publication number: 20190199239
    Abstract: A power conversion device includes a first inverter connected to first ends of windings of each phase of a motor, a second inverter connected to second ends of the windings of each phase, and a first switching circuit including at least one of a first switch to switch between whether the first inverter and a power supply are connected or disconnected and a second switch to switch between whether the first inverter and a ground are connected or disconnected. The power conversion device has a first operation mode when the motor is driven at a low speed, and a second operation mode when the motor is driven at a high speed.
    Type: Application
    Filed: March 5, 2019
    Publication date: June 27, 2019
    Inventor: Hiromitsu OHASHI