Patents by Inventor Koichi Yahata
Koichi Yahata 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: 8228700Abstract: Connection portions (225UP through 225WP) to which upper arm control terminals (320UU through 320UW) are connected are disposed at a first edge portion of a drive circuit board (22). And connection portions (225UN through 225WN to which lower arm control terminals (320LU through 320LW) are connected are disposed at a second edge portion of the drive circuit board (22). Upper arm implementation regions (227UP through 227WP), lower arm implementation regions (227UN through 227WN), and a low voltage pattern region (228) in which photo-couplers (221U through 221W) are implemented are formed in the board region between these board edge portions. And signal wiring (40U) that transmits a control signal from a photo-coupler (221U) to an implementation region (227UN) is formed in a conductor layer that is a lower layer than the conductor layer in the lower arm implementation region in which the lower arm driver circuit is implemented.Type: GrantFiled: July 30, 2009Date of Patent: July 24, 2012Assignee: Hitachi Automotive Systems, Ltd.Inventors: Koichi Yahata, Masashige Tsuji, Yoshio Akaishi
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Publication number: 20120020136Abstract: A power conversion system according to the present invention includes: an inverter circuit unit that converts a direct current power supplied from a direct current source into an alternating current power, the direct current power being supplied to the inverter circuit through a contactor that conducts and interrupts the direct current; a capacitor that smoothes the direct current power; a discharge circuit unit that is connected to the capacitor in parallel, and that includes a discharge resistor for discharging a charge stored in the capacitor and a switching element for the discharge resistor, being connected in series to the discharge resistor; a voltage detection circuit unit that detects voltage between both terminals of the capacitor; a first discharge control circuit that includes a first microcomputer, and that outputs a control signal to control switching of the switching element for discharging; and a second discharge control circuit that outputs an interruption signal to interrupt the switching elType: ApplicationFiled: February 19, 2010Publication date: January 26, 2012Applicant: Hitachi Automotive Systems. Ltd.Inventors: Yoshio Akaishi, Yasuo Noto, Koichi Yahata, Seiji Funaba, Masashge Tsuji
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Publication number: 20120001574Abstract: According to the present invention, an electrical power conversion system includes: a motor; an inverter circuit that outputs three-phase (U-phase, V-phase, W-phase) alternating currents to the motor; a current sensor that detects each of the three-phase alternating currents; and a control circuit that controls the inverter circuit based on a torque command value and values detected by the current sensor, so that the three-phase alternating currents outputted from the inverter circuit are formed as sine waves; and wherein the control circuit includes: a current component extraction unit that, based on the values detected by the current sensor, for each phase, extracts current components superimposed upon each of three-phase alternating currents; and an AC current abnormality detection unit that detects abnormality of an AC current flowing to the motor, based on the phases of the current components for any two phases among the three-phase alternating currents.Type: ApplicationFiled: June 29, 2011Publication date: January 5, 2012Applicant: Hitachi Automotive Systems, Ltd.Inventors: Yoshio Akaishi, Yasuo Noto, Koichi Yahata, Hirokazu Matsui
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Patent number: 8040088Abstract: A power inverter comprises a power module connected at least to a rotating electric machine, a gate drive circuit board which supplies switching power to the power module, and a rotating electric machine control circuit board which supplies a signal for controlling the waveform of the switching power to the gate drive circuit board. A noise reduction board is formed on a board different from the rotating electric machine control circuit board. The configuration of the noise reduction board is such that various signals for forming a signal for controlling the waveform of the switching power by means of the rotating electric machine control circuit board are inputted through the noise reduction board to the rotating electric machine control circuit board.Type: GrantFiled: June 8, 2009Date of Patent: October 18, 2011Assignee: Hitachi, Ltd.Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
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Publication number: 20110199800Abstract: Connection portions (225UP through 225WP) to which upper arm control terminals (320UU through 320UW) are connected are disposed at a first edge portion of a drive circuit board (22). And connection portions (225UN through 225WN to which lower arm control terminals (320LU through 320LW) are connected are disposed at a second edge portion of the drive circuit board (22). Upper arm implementation regions (227UP through 227WP), lower arm implementation regions (227UN through 227WN), and a low voltage pattern region (228) in which photo-couplers (221U through 221W) are implemented are formed in the board region between these board edge portions. And signal wiring (40U) that transmits a control signal from a photo-coupler (221U) to an implementation region (227UN) is formed in a conductor layer that is a lower layer than the conductor layer in the lower arm implementation region in which the lower arm driver circuit is implemented.Type: ApplicationFiled: July 30, 2009Publication date: August 18, 2011Applicant: Hitachi Automotive Systems, Ltd.Inventors: Koichi Yahata, Masashige Tsuji, Yoshio Akaishi
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Patent number: 7859105Abstract: To provide a power converter equipped with a current detector which is small and can carry out highly accurate current detection, in the power converter equipped with a power module 16 having a power controlling semiconductor element 7 disposed on the power module base 27 with a ceramic substrate 28 interposed, and a control unit 26 for controlling the operation of the power controlling semiconductor element 7, a current detector 40 having a magnetic detecting unit 47 which is disposed in the detection conductor 11, electrically connected to the power controlling semiconductor element 7 and disposed on the power module base 27 with the ceramic substrate 28 interposed, and has a magnetic detecting semiconductor element 43 electrically connected to the control unit 26 is provided in the power module 16; and relative distance between the detection conductor 11 and the power module base 27 is larger than the relative distance between the current detection electrode 42 and the power module base 27.Type: GrantFiled: April 4, 2003Date of Patent: December 28, 2010Assignee: Hitachi, Ltd.Inventors: Kinya Nakatsu, Koichi Yahata, Masato Takahashi, Mitsufumi Iwanaka, Ryuichi Saito, Haruki Hamada
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Patent number: 7719838Abstract: The power inverter includes: a case made of a metal; a first power module provided in the case and including a DC terminal and an AC terminal; a second power module provided in the case and including a DC terminal and an AC terminal; and a cooling formation body for decreasing heat generated from the first and second power modules. The first and second power modules are disposed in a manner such that the DC terminals face each other.Type: GrantFiled: January 25, 2008Date of Patent: May 18, 2010Assignee: Hitachi, Ltd.Inventors: Kenichiro Nakajima, Haruki Hamada, Koichi Yahata, Hideki Homma, Hideyo Suzuki
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Publication number: 20090243524Abstract: A power inverter comprises a power module connected at least to a rotating electric machine, a gate drive circuit board which supplies switching power to the power module, and a rotating electric machine control circuit board which supplies a signal for controlling the waveform of the switching power to the gate drive circuit board. A noise reduction board is formed on a board different from the rotating electric machine control circuit board. The configuration of the noise reduction board is such that various signals for forming a signal for controlling the waveform of the switching power by means of the rotating electric machine control circuit board are inputted through the noise reduction board to the rotating electric machine control circuit board.Type: ApplicationFiled: June 8, 2009Publication date: October 1, 2009Applicant: Hitachi, Ltd.Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
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Patent number: 7561448Abstract: A power inverter comprises a power module connected at least to a rotating electric machine, a gate drive circuit board which supplies switching power to the power module, and a rotating electric machine control circuit board which supplies a signal for controlling the waveform of the switching power to the gate drive circuit board. A noise reduction board is formed on a board different from the rotating electric machine control circuit board. The configuration of the noise reduction board is such that various signals for forming a signal for controlling the waveform of the switching power by means of the rotating electric machine control circuit board are inputted through the noise reduction board to the rotating electric machine control circuit board.Type: GrantFiled: April 5, 2007Date of Patent: July 14, 2009Assignee: Hitachi, Ltd.Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
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Patent number: 7561429Abstract: A power converter unit comprises: a metal casing; a power module mounted in the metal casing and equipped with two or more power semiconductor devices; a metal plate disposed on the power module and fixed to the metal casing; a heat dissipating sheet disposed on the metal plate; and a drive circuit board disposed on the heat dissipating sheet and is equipped with a control circuit for controlling the power semiconductor devices.Type: GrantFiled: November 13, 2007Date of Patent: July 14, 2009Assignee: Hitachi, Ltd.Inventors: Koichi Yahata, Seigo Yukutake, Yoshio Akaishi
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Publication number: 20090002974Abstract: A power converter unit has a metal case; a power module having a plurality of power semiconductor devices that is provided inside the metal case; a gate drive circuit board having a circuit for driving the plurality of the power semiconductor devices that is mounted on the power module; a voltage sensor that is mounted on the gate drive circuit board; a metal plate for electrically connecting the metal case with the gate drive circuit board; screws and soldered parts for fixing the metal plate to the gate drive circuit board; a first wiring that is set up on the gate drive circuit board for electrically connecting the voltage sensor with the soldered parts; and a second wiring that is set up on the gate drive circuit board for electrically connecting the screws and the soldered parts.Type: ApplicationFiled: May 30, 2008Publication date: January 1, 2009Applicant: Hitachi, Ltd.Inventors: Koichi YAHATA, Yoshio Akaishi, Yuuki Takahashi
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Publication number: 20080225487Abstract: The power inverter includes: a case made of a metal; a first power module provided in the case and including a DC terminal and an AC terminal; a second power module provided in the case and including a DC terminal and an AC terminal; and a cooling formation body for decreasing heat generated from the first and second power modules. The first and second power modules are disposed in a manner such that the DC terminals face each other.Type: ApplicationFiled: January 25, 2008Publication date: September 18, 2008Applicant: Hitachi, Ltd.Inventors: Kenichiro NAKAJIMA, Haruki Hamada, Koichi Yahata, Hideki Homma, Hideyo Suziki
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Publication number: 20080112201Abstract: A power converter unit comprises: a metal casing; a power module mounted in the metal casing and equipped with two or more power semiconductor devices; a metal plate disposed on the power module and fixed to the metal casing; a heat dissipating sheet disposed on the metal plate; and a drive circuit board disposed on the heat dissipating sheet and is equipped with a control circuit for controlling the power semiconductor devices.Type: ApplicationFiled: November 13, 2007Publication date: May 15, 2008Applicant: Hitachi, Ltd.Inventors: Koichi YAHATA, Seigo Yukutake, Yoshio Akaishi
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Publication number: 20070246636Abstract: A power inverter comprises a power module connected at least to a rotating electric machine, a gate drive circuit board which supplies switching power to the power module, and a rotating electric machine control circuit board which supplies a signal for controlling the waveform of the switching power to the gate drive circuit board. A noise reduction board is formed on a board different from the rotating electric machine control circuit board. The configuration of the noise reduction board is such that various signals for forming a signal for controlling the waveform of the switching power by means of the rotating electric machine control circuit board are inputted through the noise reduction board to the rotating electric machine control circuit board.Type: ApplicationFiled: April 5, 2007Publication date: October 25, 2007Applicant: Hitachi, Ltd.Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
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Publication number: 20050161809Abstract: To provide a power converter equipped with a current detector which is small and can carry out highly accurate current detection, in the power converter equipped with a power module 16 having a power controlling semiconductor element 7 disposed on the power module base 27 with a ceramic substrate 28 interposed, and a control unit 26 for controlling the operation of the power controlling semiconductor element 7, a current detector 40 having a magnetic detecting unit 47 which is disposed in the detection conductor 11, electrically connected to the power controlling semiconductor element 7 and disposed on the power module base 27 with the ceramic substrate 28 interposed, and has a magnetic detecting semiconductor element 43 electrically connected to the control unit 26 is provided in the power module 16; and relative distance between the detection conductor 11 and the power module base 27 is larger than the relative distance between the current detection electrode 42 and the power module base 27.Type: ApplicationFiled: April 4, 2003Publication date: July 28, 2005Inventors: Kinya Nakatsu, Koichi Yahata, Masato Takahashi, Mitsufumi Iwanaka, Ryuichi Saito, Haruki Hamada