Patents by Inventor Hirofumi Akagi
Hirofumi Akagi 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: 10498233Abstract: A bidirectional chopper circuit 1 is provided with: a main power converter 11 having a first switch 21-1 and a second switch 21-2 set up so that one switch is turned off when the other switch is turned on and connected in series with each other so as to line up in a conduction direction when turned on, the terminals on both sides of the main power converter 11 on the opposite sides to the connection sides for the first switch 21-1 and the second switch 21-2 being a pair of first external connection terminals; a plurality of single-phase full-bridge power converters 22-j and a pair of second external connection terminals provided on wiring that branches from wiring connecting the first switch 21-1 and the second switch 21-2 so that one or both are connected in cascade; and an inductor 13 connected in series with the single-phase full-bridge power converters 22-j on wiring that branches from wiring connecting the first switch 21-1 and the second switch 21-2.Type: GrantFiled: March 7, 2016Date of Patent: December 3, 2019Assignees: Tokyo Institute of Technology, Toshiba-Mitsubishi-Electric Industrial Systems CorporationInventors: Hirofumi Akagi, Makoto Hagiwara
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Patent number: 10161516Abstract: A shift control apparatus for a vehicle which has an engine with an exhaust supercharger, and a transmission, if there is a deceleration intention of a driver, compares a target torque and an actual torque, and while the actual torque is higher than the target torque and a difference therebetween is greater than or equal to a predetermined threshold value, controls a speed at which to cause a gear ratio of the transmission to change to the target gear ratio to be slower than at a time of normal shift control.Type: GrantFiled: August 11, 2014Date of Patent: December 25, 2018Assignee: HONDA MOTOR CO., LTD.Inventors: Atsushi Sato, Hirofumi Akagi
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Patent number: 10103645Abstract: This power converter is provided with: three clusters (CLu, CLv, CLw) in which unit cells are cascade-connected; and power supplies of the same kind which are respectively connected to one end of each of the three clusters. Terminals of the three clusters at the side not connected to the power supplies are respectively connected to other ends of the power supplies connected to the other clusters to form a delta-connection configuration. Three connections of the delta-connection configuration are respectively connected to each of the U, V, and W phases of a three-phase alternating current, and power conversion between the power supplies and the three-phase AC is enabled. If DC power supplies (Vdcu, Vdcv, Vdcw) are employed as the power supplies, power conversion between the DC power supplies and the three-phase AC power supplies can be performed.Type: GrantFiled: March 17, 2015Date of Patent: October 16, 2018Assignee: TOKYO INSTITUTE OF TECHNOLOGYInventors: Hirofumi Akagi, Makoto Hagiwara
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Publication number: 20180254699Abstract: A bidirectional chopper circuit 1 is provided with: a main power converter 11 having a first switch 21-1 and a second switch 21-2 set up so that one switch is turned off when the other switch is turned on and connected in series with each other so as to line up in a conduction direction when turned on, the terminals on both sides of the main power converter 11 on the opposite sides to the connection sides for the first switch 21-1 and the second switch 21-2 being a pair of first external connection terminals; a plurality of single-phase full-bridge power converters 22-j and a pair of second external connection terminals provided on wiring that branches from wiring connecting the first switch 21-1 and the second switch 21-2 so that one or both are connected in cascade; and an inductor 13 connected in series with the single-phase full-bridge power converters 22-j on wiring that branches from wiring connecting the first switch 21-1 and the second switch 21-2.Type: ApplicationFiled: March 7, 2016Publication date: September 6, 2018Applicants: Tokyo Institute of Technology, Toshiba-Mitsubishi-Electric Industrial Systems CorporationInventors: Hirofumi Akagi, Makoto Hagiwara
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Publication number: 20170085193Abstract: This power converter is provided with: three clusters (CLu, CLv, CLw) in which unit cells are cascade-connected; and power supplies of the same kind which are respectively connected to one end of each of the three clusters. Terminals of the three clusters at the side not connected to the power supplies are respectively connected to other ends of the power supplies connected to the other clusters to form a delta-connection configuration. Three connections of the delta-connection configuration are respectively connected to each of the U, V, and W phases of a three-phase alternating current, and power conversion between the power supplies and the three-phase AC is enabled. If DC power supplies (Vdcu, Vdcv, Vdcw) are employed as the power supplies, power conversion between the DC power supplies and the three-phase AC power supplies can be performed.Type: ApplicationFiled: March 17, 2015Publication date: March 23, 2017Applicant: TOKYO INSTITUTE OF TECHNOLOGYInventors: Hirofumi Akagi, MAKOTO HAGIWARA
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Single-phase power converter, three-phase two-phase power converter, and three-phase power converter
Patent number: 9496805Abstract: This power converter (1) is provided with: unit cells (11-M) having a semiconductor switch, a DC capacitor (C) and a charge/discharge current I/O terminal; a first arm (12-P) and a second arm (12-N) comprising multiple unit cells (11-M) connected to each other in cascade; an arm connecting unit (13) which has a first terminal to which the first arm (12-P) is connected, a second terminal to which the second arm (12-N) is connected, and a third terminal to which a DC power source is connected; and a transformer (14) which has an AC I/O terminal on the primary side and an intermediate terminal on the secondary side winding, and in which the terminal of the first arm (12-P) and the terminal of the second arm (12-N) are connected to the two end terminals on the secondary winding, and the DC power source (Vdc) is connected to the intermediate terminal.Type: GrantFiled: November 15, 2012Date of Patent: November 15, 2016Assignee: TOKYO INSTITUTE OF TECHNOLOGYInventors: Hirofumi Akagi, Makoto Hagiwara -
Publication number: 20160252180Abstract: A shift control apparatus tor a vehicle which has an engine with an exhaust supercharger, and a transmission, if there is a deceleration intention of a driver, compares a target torque and an actual torque, and while the actual torque is higher than the target torque and a difference therebetween is greater than or equal to a predetermined threshold value, controls a speed at which to cause a gear ratio of the transmission to change to the target gear ratio to be slower than at a time of normal shift control.Type: ApplicationFiled: August 11, 2014Publication date: September 1, 2016Applicant: HONDA MOTOR CO., LTD.Inventors: Atsushi Sato, Hirofumi Akagi
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Patent number: 9379632Abstract: A power converter 100 includes a DC capacitor C, semiconductor switch groups each of which includes semiconductor switches connected in series to each other, bridge-cells 11u-j, 11v-j, and 11w-j each of which includes the DC capacitor C and two semiconductor switch groups connected in parallel to the DC capacitor C, a delta connection unit 10 including delta-connected bridge-cells and a integrated control unit 1 for controlling a circulating current flowing in the delta connection unit such that each of DC-capacitor by-phase average values follows a DC-capacitor three-phase average value, each of the DC-capacitor by-phase average values being obtained by averaging voltage values of the DC capacitors at a corresponding phase of three phases, and the DC-capacitor three-phase average value being obtained by averaging voltage values of the DC capacitors at all of the three phases.Type: GrantFiled: January 18, 2012Date of Patent: June 28, 2016Assignee: Tokyo Institute of TechnologyInventors: Hirofumi Akagi, Makoto Hagiwara
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Publication number: 20140103887Abstract: A power converter 100 includes a DC capacitor C, semiconductor switch groups each of which includes semiconductor switches connected in series to each other, bridge-cells 11u-j, 11v-j, and 11w-j each of which includes the DC capacitor C and two semiconductor switch groups connected in parallel to the DC capacitor C, a delta connection unit 10 including delta-connected bridge-cells and a integrated control unit 1 for controlling a circulating current flowing in the delta connection unit such that each of DC-capacitor by-phase average values follows a DC-capacitor three-phase average value, each of the DC-capacitor by-phase average values being obtained by averaging voltage values of the DC capacitors at a corresponding phase of three phases, and the DC-capacitor three-phase average value being obtained by averaging voltage values of the DC capacitors at all of the three phases.Type: ApplicationFiled: January 18, 2012Publication date: April 17, 2014Inventors: Hirofumi Akagi, Makoto Hagiwara
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Patent number: 8228699Abstract: A power converting apparatus includes three sets of half-bridge inverters connected between output terminals of a solar battery, each of the half-bridge inverters including two series-connected switching devices, single-phase inverters connected to individual AC output lines of the bridge inverters, and two series-connected capacitors dividing a voltage of the solar battery, wherein output terminals of the single-phase inverters are connected to individual phases of a three-phase power system. Each of the half-bridge inverters is operated to output one pulse per half cycle, each of the single-phase inverters is controlled by PWM control operation to make up for a voltage insufficiency from the system voltage, and sums of outputs of the half-bridge inverters and the single-phase inverters are output to the power system.Type: GrantFiled: February 20, 2008Date of Patent: July 24, 2012Assignees: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Akihiko Iwata, Hiroshi Ito, Hirofumi Akagi, Hideaki Fujita, Takushi Jimichi
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Patent number: 8154893Abstract: A three-phase inverter circuit including a DC portion including capacitors connected between output terminals of a solar battery and single-phase inverters connected in series with AC output lines of the three-phase inverter circuit that together constitute an inverter section, the inverter section being connected to a three-phase power system. The three-phase inverter circuit outputs a reverse-polarity voltage pulse during a period within each of basic voltage pulses of which pulsewidth corresponds to a half cycle every half cycle of a system voltage. A power burden born by the individual single-phase inverters in each half cycle is made approximately zero and the individual single-phase inverters make a correction for subtracting a common voltage from target output voltages of individual phases during the period when the reverse-polarity voltage pulse is generated.Type: GrantFiled: February 20, 2008Date of Patent: April 10, 2012Assignees: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Akihiko Iwata, Hiroshi Ito, Hirofumi Akagi, Hideaki Fujita, Takushi Jimichi
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Patent number: 8008876Abstract: A hybrid electric vehicle includes, in one example, a motor-generator driven by an engine to generate alternating current, wherein the motor-generator is further configured to start the engine, a motor for driving the vehicle, a diode rectifier to rectify alternating current generated by the motor-generator, an inverter connected to a feed circuit between the diode rectifier and the motor to convert direct current in the feed circuit into alternating current, a power supply connected to a line connecting the diode rectifier with the inverter, a first feed circuit to supply current to the motor to drive the vehicle through the diode rectifier and the inverter in series a second feed circuit to connect the motor-generator with the power supply while bypassing at least the diode rectifier, and an alternating current converter provided in the second feed circuit.Type: GrantFiled: June 23, 2008Date of Patent: August 30, 2011Assignee: Mazda Motor CorporationInventors: Kei Yonemori, Nobuhide Seo, Kohei Saito, Hirofumi Akagi, Hideaki Fujita
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Publication number: 20110128763Abstract: A power converting apparatus is provided with three sets of half-bridge inverters (4a-4c) connected between output terminals of a solar battery (1), each of the half-bridge inverters (4a-4c) including two series-connected switching devices, single-phase inverters (5a-5c) connected to individual AC output lines of the bridge inverters (4a-4c), and two series-connected capacitors (6a, 6b) for dividing a voltage of the solar battery (1), wherein output terminals of the single-phase inverters (5a-5c) are connected to individual phases of a three-phase power system (2). Each of the half-bridge inverters (4a-4c) is operated to output one pulse per half cycle, each of the single-phase inverters (5a-5c) is controlled by PWM control operation to make up for a voltage insufficiency from the system voltage, and sums of outputs of the half-bridge inverters (4a-4c) and the single-phase inverters (5a-5c) are output to the power system (2).Type: ApplicationFiled: February 20, 2008Publication date: June 2, 2011Applicants: Mitsubishi Electric Corporation, Tokyo Institute of TechnologyInventors: Akihiko Iwata, Hiroshi Ito, Hirofumi Akagi, Hideaki Fujita, Takushi Jimichi
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Patent number: 7940018Abstract: A control system and method for a hybrid electric vehicle. One example control system includes a current calculating module to calculate a current, the current being at least one of a current to drive a motor of the vehicle and a current generated by the motor, and a feed controller to selectively implement a first mode when the calculated current is below a predetermined current value and to selectively implement a second mode when the calculated current is more than the predetermined current value, wherein either the first feed circuit or the second feed circuit is used in the first mode and both the first feed circuit and the second feed circuit are used in the second mode.Type: GrantFiled: June 23, 2008Date of Patent: May 10, 2011Assignee: Mazda Motor CorporationInventors: Kei Yonemori, Nobuhide Seo, Kohei Saito, Hirofumi Akagi, Hideaki Fujita
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Publication number: 20100014335Abstract: A three-phase inverter circuit (4) of which DC portion is smoothing capacitors (3) connected between output terminals of a solar battery (1) and single-phase inverters (5a-5c) connected in series with AC output lines of the three-phase inverter circuit (4) together constitute an inverter section, and this inverter section is connected to a three-phase power system (2). The three-phase inverter circuit (4) outputs a reverse-polarity voltage pulse (10ua) during a period within each of basic voltage pulses of which pulsewidth corresponds to a half cycle every half cycle of a system voltage. A power burden born by the individual single-phase inverters (5a-5c) in each half cycle is made approximately zero and the individual single-phase inverters (5a-5c) make a correction for subtracting a common voltage (Vo) from target output voltages of individual phases during the period when the reverse-polarity voltage pulse (10ua) is generated.Type: ApplicationFiled: February 20, 2008Publication date: January 21, 2010Applicants: MITSUBISHI ELECTRIC CORPORATION, TOKYO INSTITUTE OF TECHNOLOGYInventors: Akihiko Iwata, Hiroshi Ito, Hirofumi Akagi, Hideaki Fujita, Takushi Jimichi
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Patent number: 7606052Abstract: A filter device that suppresses electromagnetic interference generated in an alternating current circuit connected to a power converter with an alternating current output includes: a common mode choke connected to between any one terminal at an input side, an output side, or a direct current link of the power converter and input terminals of the alternating current circuit; and a connecting element that connects an outgoing line from a neutral point of the alternating current circuit to a reference potential point having little potential variation at an upstream of the common mode choke.Type: GrantFiled: March 14, 2003Date of Patent: October 20, 2009Assignee: Tokyo Institute of TechnologyInventor: Hirofumi Akagi
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Publication number: 20080315817Abstract: A control system and method for a hybrid electric vehicle. One example control system includes a current calculating module to calculate a current, the current being at least one of a current to drive a motor of the vehicle and a current generated by the motor, and a feed controller to selectively implement a first mode when the calculated current is below a predetermined current value and to selectively implement a second mode when the calculated current is more than the predetermined current value, wherein either the first feed circuit or the second feed circuit is used in the first mode and both the first feed circuit and the second feed circuit are used in the second mode.Type: ApplicationFiled: June 23, 2008Publication date: December 25, 2008Applicant: MAZDA MOTOR CORPORATIONInventors: Kei Yonemori, Nobuhide Seo, Kohei Saito, Hirofumi Akagi, Hideaki Fujita
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Publication number: 20080315803Abstract: A hybrid electric vehicle includes, in one example, a motor-generator driven by an engine to generate alternating current, wherein the motor-generator is further configured to start the engine, a motor for driving the vehicle, a diode rectifier to rectify alternating current generated by the motor-generator, an inverter connected to a feed circuit between the diode rectifier and the motor to convert direct current in the feed circuit into alternating current, a power supply connected to a line connecting the diode rectifier with the inverter, a first feed circuit to supply current to the motor to drive the vehicle through the diode rectifier and the inverter in series a second feed circuit to connect the motor-generator with the power supply while bypassing at least the diode rectifier, and an alternating current converter provided in the second feed circuit.Type: ApplicationFiled: June 23, 2008Publication date: December 25, 2008Applicant: MAZDA MOTOR CORPORATIONInventors: Kei Yonemori, Nobuhide Seo, Kohei Saito, Hirofumi Akagi, Hideaki Fujita
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Publication number: 20060233000Abstract: The invention provides a bidirectional power converter, that can be connected directly to an AC system without interposing a transformer, that is small in size, light in weight, inexpensive to manufacture, and capable of regenerative operation, and also provides a motor drive equipped with such a power converter and a BTB system and a grid-linking inverter system each comprising such a power converter.Type: ApplicationFiled: March 8, 2004Publication date: October 19, 2006Inventor: Hirofumi Akagi
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Publication number: 20060227483Abstract: A filter device that suppresses electromagnetic interference generated in an alternating current circuit connected to a power converter with an alternating current output. This filter device includes: a common mode choke connected to between any one terminal at an input side, an output side, or a direct current link of the power converter and input terminals of the alternating current circuit; and a connecting means that connects an outgoing line from a neutral point of the alternating current circuit to a reference potential point having little potential variation at an upstream of the common mode choke.Type: ApplicationFiled: March 14, 2003Publication date: October 12, 2006Inventor: Hirofumi Akagi