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).

  • Patent number: 8228700
    Abstract: 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: Grant
    Filed: July 30, 2009
    Date of Patent: July 24, 2012
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Koichi Yahata, Masashige Tsuji, Yoshio Akaishi
  • Publication number: 20120020136
    Abstract: 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 el
    Type: Application
    Filed: February 19, 2010
    Publication date: January 26, 2012
    Applicant: Hitachi Automotive Systems. Ltd.
    Inventors: Yoshio Akaishi, Yasuo Noto, Koichi Yahata, Seiji Funaba, Masashge Tsuji
  • Publication number: 20120001574
    Abstract: 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: Application
    Filed: June 29, 2011
    Publication date: January 5, 2012
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Yoshio Akaishi, Yasuo Noto, Koichi Yahata, Hirokazu Matsui
  • Patent number: 8040088
    Abstract: 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: Grant
    Filed: June 8, 2009
    Date of Patent: October 18, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
  • Publication number: 20110199800
    Abstract: 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: Application
    Filed: July 30, 2009
    Publication date: August 18, 2011
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Koichi Yahata, Masashige Tsuji, Yoshio Akaishi
  • Patent number: 7859105
    Abstract: 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: Grant
    Filed: April 4, 2003
    Date of Patent: December 28, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kinya Nakatsu, Koichi Yahata, Masato Takahashi, Mitsufumi Iwanaka, Ryuichi Saito, Haruki Hamada
  • Patent number: 7719838
    Abstract: 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: Grant
    Filed: January 25, 2008
    Date of Patent: May 18, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kenichiro Nakajima, Haruki Hamada, Koichi Yahata, Hideki Homma, Hideyo Suzuki
  • Publication number: 20090243524
    Abstract: 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: Application
    Filed: June 8, 2009
    Publication date: October 1, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
  • Patent number: 7561448
    Abstract: 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: Grant
    Filed: April 5, 2007
    Date of Patent: July 14, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
  • Patent number: 7561429
    Abstract: 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: Grant
    Filed: November 13, 2007
    Date of Patent: July 14, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Koichi Yahata, Seigo Yukutake, Yoshio Akaishi
  • Publication number: 20090002974
    Abstract: 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: Application
    Filed: May 30, 2008
    Publication date: January 1, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Koichi YAHATA, Yoshio Akaishi, Yuuki Takahashi
  • Publication number: 20080225487
    Abstract: 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: Application
    Filed: January 25, 2008
    Publication date: September 18, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Kenichiro NAKAJIMA, Haruki Hamada, Koichi Yahata, Hideki Homma, Hideyo Suziki
  • Publication number: 20080112201
    Abstract: 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: Application
    Filed: November 13, 2007
    Publication date: May 15, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Koichi YAHATA, Seigo Yukutake, Yoshio Akaishi
  • Publication number: 20070246636
    Abstract: 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: Application
    Filed: April 5, 2007
    Publication date: October 25, 2007
    Applicant: Hitachi, Ltd.
    Inventors: Hiroshi Katayama, Koichi Yahata, Masashige Tsuji, Takashi Fujimoto, Hiroaki Igarashi
  • Publication number: 20050161809
    Abstract: 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: Application
    Filed: April 4, 2003
    Publication date: July 28, 2005
    Inventors: Kinya Nakatsu, Koichi Yahata, Masato Takahashi, Mitsufumi Iwanaka, Ryuichi Saito, Haruki Hamada