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).
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Publication number: 20230198452Abstract: A power conversion apparatus includes a first inverter connected to one end of each of the respective phase windings of a motor, a second inverter connected to another end of each of the respective phase windings, and a control circuit that controls the operations of the first and second inverters. The control circuit controls, based on a third-order component of the magnetic flux of a permanent magnet of a rotor and a third-order component of a current supplied to an A-phase winding, a sixth-order component of a radial force acting on teeth of a stator.Type: ApplicationFiled: January 25, 2019Publication date: June 22, 2023Inventors: Hiromitsu OHASHI, Kaori NABESHI
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Patent number: 11469700Abstract: 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: GrantFiled: March 9, 2018Date of Patent: October 11, 2022Assignee: NIDEC CORPORATIONInventors: Yoshiaki Yamashita, Hiromitsu Ohashi
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Patent number: 11420672Abstract: 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: GrantFiled: March 5, 2019Date of Patent: August 23, 2022Assignee: NIDEC CORPORATIONInventor: Hiromitsu Ohashi
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Publication number: 20220173671Abstract: In an aspect of a power conversion device that converts power from a power source to supply the converted power to a motor, the power conversion device includes an inverter connected to a winding of the motor and including a first switching element that generates heat in association with an operation of power control and a second switching element that generates more heat than the first switching element in association with an operation of power control, and a substrate on which the first switching element and the second switching element are mounted, wherein a first element group including one or a plurality of the first switching elements and a second element group including one or a plurality of the second switching elements are alternately mounted on the substrate.Type: ApplicationFiled: March 25, 2020Publication date: June 2, 2022Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
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Publication number: 20220166361Abstract: A power converter that converts power from a power source and supplies the converted power to a motor includes an inverter connected to a winding of the motor and including switches that generate heat along with power control operation, and a substrate on which the switches are mounted. A first switch of the switches is mounted in a first region on the substrate, and a second switch that generates more heat than the first switch is mounted in a second region having a higher heat dissipation than a heat dissipation of the first region.Type: ApplicationFiled: February 18, 2020Publication date: May 26, 2022Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
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Publication number: 20220014136Abstract: A motor includes: coil groups of n phases (n is an integer of three or more); a first inverter connected to one ends of the coil groups of n phases; a second inverter connected to the other ends of the coil groups of n phases; a stator around which the coil groups of n phases are wound; and a rotor that can rotate relative to the stator. At least one coil group of the coil groups of n phases includes a first sub coil group including a first coil and a second coil connected in series, and a second sub coil group including a third coil and a fourth coil connected in series. The first sub coil group and the second sub coil group are connected in parallel.Type: ApplicationFiled: October 29, 2019Publication date: January 13, 2022Inventor: Hiromitsu OHASHI
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Patent number: 11114969Abstract: 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: GrantFiled: March 5, 2018Date of Patent: September 7, 2021Assignee: NIDEC CORPORATIONInventors: Hiromitsu Ohashi, Ahmad Ghaderi
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Patent number: 11081997Abstract: 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: GrantFiled: December 26, 2017Date of Patent: August 3, 2021Assignee: NIDEC CORPORATIONInventor: Hiromitsu Ohashi
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Patent number: 11081941Abstract: 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: GrantFiled: March 9, 2018Date of Patent: August 3, 2021Assignee: NIDEC CORPORATIONInventors: Yoshiaki Yamashita, Hiromitsu Ohashi
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Patent number: 10998782Abstract: 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: GrantFiled: April 19, 2017Date of Patent: May 4, 2021Assignee: Nidec CorporationInventor: Hiromitsu Ohashi
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Patent number: 10998842Abstract: 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: GrantFiled: December 22, 2017Date of Patent: May 4, 2021Assignee: NIDEC CORPORATIONInventors: Eiji Wada, Hiromitsu Ohashi
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Patent number: 10998841Abstract: 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: GrantFiled: January 10, 2018Date of Patent: May 4, 2021Assignee: NIDEC CORPORATIONInventor: Hiromitsu Ohashi
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Publication number: 20200373867Abstract: 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: ApplicationFiled: March 9, 2018Publication date: November 26, 2020Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
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Patent number: 10829147Abstract: 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: GrantFiled: September 15, 2017Date of Patent: November 10, 2020Assignee: NIDEC CORPORATIONInventor: Hiromitsu Ohashi
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Publication number: 20200303976Abstract: 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: ApplicationFiled: April 19, 2017Publication date: September 24, 2020Applicant: Nidec CorporationInventor: Hiromitsu OHASHI
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Publication number: 20200295631Abstract: 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: ApplicationFiled: March 9, 2018Publication date: September 17, 2020Inventors: Yoshiaki YAMASHITA, Hiromitsu OHASHI
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Patent number: 10742137Abstract: 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: GrantFiled: March 5, 2019Date of Patent: August 11, 2020Assignee: NIDEC CORPORATIONInventor: Hiromitsu Ohashi
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Publication number: 20200251966Abstract: 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: ApplicationFiled: October 5, 2018Publication date: August 6, 2020Inventors: Shuji ENDO, Hiromitsu OHASHI
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Publication number: 20200244206Abstract: 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: ApplicationFiled: March 5, 2018Publication date: July 30, 2020Inventors: Hiromitsu OHASHI, Ahmad GHADERI
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Publication number: 20200059189Abstract: 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: ApplicationFiled: January 10, 2018Publication date: February 20, 2020Inventor: Hiromitsu OHASHI