Patents by Inventor Michio Iwahori
Michio Iwahori 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: 9000711Abstract: Provided is a power converter that is capable of ensuring a conduction current without expanding the configuration of a DC voltage conversion circuit such as a DC chopper. Power can be supplied from both a DC chopper and a voltage source rectifier converting AC power into DC power, to a voltage source inverter. The voltage source rectifier has an upper arm part and a lower arm part having switching elements. The voltage source rectifier converts AC power obtained from an alternator into DC power, performs a DC chopper operation using the upper and lower arms thereof and a winding wire of the alternator, and supplies power of a DC power source to the voltage source inverter.Type: GrantFiled: January 25, 2011Date of Patent: April 7, 2015Assignee: Fuji Electric Co., Ltd.Inventor: Michio Iwahori
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Patent number: 8593101Abstract: A power converting device is disclosed that can reduce switching loss occurring in a voltage source inverter that drives an AC motor. It is possible to supply DC power to the voltage source inverter from both a voltage source rectifier, which converts AC power from an AC generator into DC power, and a battery. A first switching circuit is inserted between the voltage source rectifier and the AC generator, and the battery is connected to the output side of the voltage source rectifier. A second switching circuit is inserted between the battery and the voltage source inverter. A third switching circuit and a reactor are inserted in series between the input side of the voltage source inverter and the input side of the voltage source rectifier. At least one of an upper arm and a lower arm of the voltage source rectifier can be chopper controlled.Type: GrantFiled: June 17, 2011Date of Patent: November 26, 2013Assignee: Fuji Electric Co., Ltd.Inventor: Michio Iwahori
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Publication number: 20130002186Abstract: Provided is a power converter that is capable of ensuring a conduction current without expanding the configuration of a DC voltage conversion circuit such as a DC chopper. Power can be supplied from both a DC chopper and a voltage source rectifier converting AC power into DC power, to a voltage source inverter. The voltage source rectifier has an upper arm part and a lower arm part having switching elements. The voltage source rectifier converts AC power obtained from an alternator into DC power, performs a DC chopper operation using the upper and lower arms thereof and a winding wire of the alternator, and supplies power of a DC power source to the voltage source inverter.Type: ApplicationFiled: January 25, 2011Publication date: January 3, 2013Applicant: FUJI ELECTRIC CO., LTD.Inventor: Michio Iwahori
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Patent number: 8212506Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.Type: GrantFiled: October 30, 2009Date of Patent: July 3, 2012Assignee: Fuji Electric Co., Ltd.Inventors: Michio Iwahori, Masakazu Gekinozu
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Patent number: 8183804Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.Type: GrantFiled: October 30, 2009Date of Patent: May 22, 2012Assignee: Fuji Electric Co., Ltd.Inventors: Michio Iwahori, Masakazu Gekinozu
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Publication number: 20110309778Abstract: A power converting device is disclosed that can reduce switching loss occurring in a voltage source inverter that drives an AC motor. It is possible to supply DC power to the voltage source inverter from both a voltage source rectifier, which converts AC power from an AC generator into DC power, and a battery. A first switching circuit is inserted between the voltage source rectifier and the AC generator, and the battery is connected to the output side of the voltage source rectifier. A second switching circuit is inserted between the battery and the voltage source inverter. A third switching circuit and a reactor are inserted in series between the input side of the voltage source inverter and the input side of the voltage source rectifier. At least one of an upper arm and a lower arm of the voltage source rectifier can be chopper controlled.Type: ApplicationFiled: June 17, 2011Publication date: December 22, 2011Applicant: FUJI ELECTRIC CO., LTD.Inventor: Michio Iwahori
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Patent number: 8076897Abstract: In an AC motor driving circuit, a current source rectifier is provided on the output side of an AC generator and an AC motor is connected to the output side of the current source rectifier through a voltage source inverter. Along with this, one of terminals of each of a plurality of bidirectional switches is connected to its corresponding output terminal of the voltage source inverter, the other terminals of a plurality of the bidirectional switches are lumped together to be connected to one of terminals of a storage battery, and the other terminal of the storage battery is connected to one of DC input terminals of the voltage source inverter. This eliminates need for a large capacitor at a DC link and a reactor in a chopper which were previously necessary, by which the AC motor driving circuit is downsized.Type: GrantFiled: May 12, 2009Date of Patent: December 13, 2011Assignee: Fuji Electric Systems Co., Ltd.Inventors: Michio Iwahori, Masakazu Gekinozu
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Patent number: 8040101Abstract: A current source rectifier is provided at an output of an alternating current generator, an alternating current motor is connected to an output of the rectifier via a voltage source inverter, furthermore, two arms having switching elements connected in inverse parallel to diodes are connected to the output of the rectifier, and one terminal of a direct current power source capable of a power supply and absorption is connected to a midpoint between the arms, while the other terminal thereof is connected to a neutral point of motor coils or generator coils, thereby eliminating a need for a large volumetric reactor in a direct current chopper, achieving a downsizing of the circuit.Type: GrantFiled: January 12, 2009Date of Patent: October 18, 2011Assignees: National University Corporation Nagaoka University of Technology, Fuji Electric Co., Ltd.Inventors: Jun-ichi Itoh, Michio Iwahori, Masakazu Gekinozu
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Publication number: 20100109585Abstract: In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.Type: ApplicationFiled: October 30, 2009Publication date: May 6, 2010Applicant: FUJI ELECTRIC SYSTEMS CO., LTD.Inventors: Michio Iwahori, Masakazu Gekinozu
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Publication number: 20100109587Abstract: In an AC motor driving circuit from an AC power supply and a DC power supply, a matrix converter and a power conversion circuit are provided. The matrix converter is connected between an output of the AC power supply and an input of the AC motor. In the power conversion circuit, switches back-to-back connected to diodes, and bidirectional switches are series-connected, respectively. Connection junctions between the switches and the bidirectional switches are connected to the input phases of the AC motor, respectively. The other terminal of each switch is connected to one terminal of the DC power supply while the other terminal of each bidirectional switch is connected to the other terminal of the DC power supply. In this manner, the number of switches through which electric power passes at the time of operation is reduced so that loss can be reduced. Accordingly, power conversion efficiency can be improved.Type: ApplicationFiled: October 30, 2009Publication date: May 6, 2010Applicant: FUJI ELECTRIC SYSTEMS CO., LTD.Inventors: Michio Iwahori, Masakazu Gekinozu
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Publication number: 20090284200Abstract: In an AC motor driving circuit, a current source rectifier is provided on the output side of an AC generator and an AC motor is connected to the output side of the current source rectifier through a voltage source inverter. Along with this, one of terminals of each of a plurality of bidirectional switches is connected to its corresponding output terminal of the voltage source inverter, the other terminals of a plurality of the bidirectional switches are lumped together to be connected to one of terminals of a storage battery, and the other terminal of the storage battery is connected to one of DC input terminals of the voltage source inverter. This eliminates need for a large capacitor at a DC link and a reactor in a chopper which were previously necessary, by which the AC motor driving circuit is downsized.Type: ApplicationFiled: May 12, 2009Publication date: November 19, 2009Applicant: Fuji Electric Device Technology Co., Ltd.Inventors: Michio Iwahori, Masakazu Gekinozu
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Publication number: 20090206781Abstract: A current source rectifier is provided at an output of an alternating current generator, an alternating current motor is connected to an output of the rectifier via a voltage source inverter, furthermore, two arms having switching elements connected in inverse parallel to diodes are connected to the output of the rectifier, and one terminal of a direct current power source capable of a power supply and absorption is connected to a midpoint between the arms, while the other terminal thereof is connected to a neutral point of motor coils or generator coils, thereby eliminating a need for a large volumetric reactor in a direct current chopper, achieving a downsizing of the circuit.Type: ApplicationFiled: January 12, 2009Publication date: August 20, 2009Applicants: National University Corporation Nagaoka University of Technology, Fuji Electric DeviceTechnology Co., Ltd.Inventors: Jun-ichi Itoh, Michio IWAHORI, Masakazu GEKINOZU