Patents by Inventor Takamasa Asai

Takamasa Asai 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).

  • Publication number: 20230134710
    Abstract: An electronic control device includes a plurality of circuit blocks and a power supply input circuit. The power supply input circuit supplies power supplied from a first external power supply to the plurality of circuit blocks. The power supply input circuit includes a power supply input terminal, a power supply input line, a plurality of branching lines, a first reverse-current preventing element, and a second reverse-current preventing element. The plurality of branching lines are each connected between a second end portion of the power supply input line and a corresponding one of the plurality of circuit blocks. The first reverse-current preventing element is provided on the power supply input line. The second reverse-current preventing element is provided on the first branching line. The first branching line is connected to the first circuit block.
    Type: Application
    Filed: October 17, 2022
    Publication date: May 4, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masanori IKEUCHI, Takamasa ASAI
  • Patent number: 11527983
    Abstract: An electric power conversion device includes: a first electric power conversion circuit, a current detection circuit, an electric power conversion circuit of field coil excite use, a control circuit, and detector which detects an induced electromotive force generated in the motor generator. In a case where an over current, is detected by the first electric power conversion circuit, the control circuit turns off a switching of a phase of the first electric power conversion circuit from which an over current s detected and a switching of the electric power conversion circuit of field coil excite use. After the value of an induced electromotive force by the motor generator falls below a predetermined value, the control circuit controls to stop a supply of electric power of all phases by the first electric power conversion circuit.
    Type: Grant
    Filed: August 20, 2021
    Date of Patent: December 13, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryo Ute, Hiroyuki Otsuka, Takamasa Asai
  • Publication number: 20220123682
    Abstract: An electric power conversion device includes: a first electric power conversion circuit, a current detection circuit, an electric power conversion circuit of field coil excite use, a control circuit, and detector which detects an induced electromotive force generated in the motor generator. In a case where an over current, is detected by the first electric power conversion circuit, the control circuit turns off a switching of a phase of the first electric power conversion circuit from which an over current s detected and a switching of the electric power conversion circuit of field coil excite use. After the value of an induced electromotive force by the motor generator falls below a predetermined value, the control circuit controls to stop a supply of electric power of all phases by the first electric power conversion circuit.
    Type: Application
    Filed: August 20, 2021
    Publication date: April 21, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryo UTE, Hiroyuki OTSUKA, Takamasa ASAI
  • Patent number: 9793846
    Abstract: A power conversion device has an internal power supply switch and a bias power supply switch connected in parallel with the internal power supply switch, wherein, when an output voltage of an internal power supply circuit is greater than a predetermined value when a power supply is started up, the bias power supply switch opens a current path, and when the power supply is stopped, the step-up power supply circuit is stopped based on a stop signal output by the internal power supply circuit and the internal power supply switch closes the current path, and when the output voltage of the internal power supply circuit becomes lower than a predetermined value, the bias power supply switch closes the current path.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: October 17, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Takamasa Asai
  • Patent number: 9793835
    Abstract: Provided is a power conversion device, including a fault determination unit (11) for determining, based on phase voltages of a polyphase dynamo-electric machine (4) detected by phase voltage detection units (10), a power, earth, or open fault of armature windings of the polyphase dynamo-electric machine (4). The fault determination unit (11) determines, in a state that all power semiconductor switching elements (2) are in an off state and no induction voltage is generated in the armature windings of the polyphase dynamo-electric machine (4), the power fault when all the phase voltages are substantially equal to an anode potential of a DC power supply (3), the earth fault when all the phase voltages are substantially equal to a cathode potential of the DC power supply (3), and the open fault when all the phase voltages are not substantially the same potential.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: October 17, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Takamasa Asai
  • Patent number: 9709631
    Abstract: The present invention relates to a diagnosis apparatus for a field winding type rotating electric machine. The diagnosis apparatus includes an internal power supply circuit having an open fault determination potential, and determines, on the basis of a measurement result of a voltage value of a circuit that includes the field winding in a fault diagnosis condition, that a disconnection has occurred in the circuit when the measurement result is within an open fault determination voltage range including the open fault determination potential, that a power fault has occurred in the circuit when the measurement result is within a power fault determination voltage range including the positive electrode potential, and that an earth fault has occurred in the circuit when the measurement result is within an earth fault determination voltage range including the negative electrode potential.
    Type: Grant
    Filed: July 24, 2013
    Date of Patent: July 18, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Takamasa Asai
  • Patent number: 9680373
    Abstract: The present invention has: a pump capacitor (12), which has one end thereof connected to the source power supply (B) side via a diode (7), and which has the other end thereof connected to two kinds of voltage sources via switches (3, 4); and an output capacitor (13), which has one end there of connected to a high-potential terminal of a pump capacitor via a diode (8), and the other end thereof connected to a source power supply. A filter circuit configured with a resistor (15) and a capacitor (11) is provided between the source power supply and the diode (7).
    Type: Grant
    Filed: April 25, 2013
    Date of Patent: June 13, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Naruki Suetake, Takamasa Asai, Kenichi Fujie
  • Patent number: 9621100
    Abstract: To provide a vehicular AC electric generator provided with a highly reliable electric power conversion unit. A stator of a rotary electric machine is configured to have a plurality of sets of three-phase windings, an electric power conversion unit is configured to have a plurality of sets of three-phase bridge circuits corresponding to the plurality of sets of three-phase windings, each of the three-phase windings of the stator is connected to a DC power supply via the corresponding three-phase bridge circuits of the electric power conversion unit, the plurality of sets of three-phase bridge circuits are controlled to be at different switching timings from each other, and semiconductor switches constituting respective arms in the plurality of sets of three-phase bridge circuits are configured to be one-chip MOSFETs.
    Type: Grant
    Filed: November 22, 2012
    Date of Patent: April 11, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventor: Takamasa Asai
  • Publication number: 20170093311
    Abstract: Provided is a power conversion device, including a fault determination unit (11) for determining, based on phase voltages of a polyphase dynamo-electric machine (4) detected by phase voltage detection units (10), a power, earth, or open fault of armature windings of the polyphase dynamo-electric machine (4). The fault determination unit (11) determines, in a state that all power semiconductor switching elements (2) are in an off state and no induction voltage is generated in the armature windings of the polyphase dynamo-electric machine (4), the power fault when all the phase voltages are substantially equal to an anode potential of a DC power supply (3), the earth fault when all the phase voltages are substantially equal to a cathode potential of the DC power supply (3), and the open fault when all the phase voltages are not substantially the same potential.
    Type: Application
    Filed: December 14, 2016
    Publication date: March 30, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Katsuya TSUJIMOTO, Takamasa ASAI
  • Patent number: 9590554
    Abstract: The present invention relates to a rush current limiting circuit in which a series circuit consisting of an inductor and a resistor for detecting a current is connected between a power source and a first semiconductor switch, in which there is provided a second semiconductor switch whose inter-output-terminal voltage is controlled by the voltage across the series circuit consisting of the inductor and the resistor for detecting a current, and in which the inter-output-terminal voltage of the second semiconductor switch controls the inter-control-terminal voltage of the first semiconductor switch so as to limit a current to a load; the present invention relates also to an electric power converter including the rush current limiting circuit.
    Type: Grant
    Filed: September 27, 2013
    Date of Patent: March 7, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventor: Takamasa Asai
  • Patent number: 9564841
    Abstract: Provided is a power conversion device, including a fault determination unit (11) for determining, based on phase voltages of a polyphase dynamo-electric machine (4) detected by phase voltage detection units (10), a power, earth, or open fault of armature windings of the polyphase dynamo-electric machine (4). The fault determination unit (11) determines, in a state that all power semiconductor switching elements (2) are in an off state and no induction voltage is generated in the armature windings of the polyphase dynamo-electric machine (4), the power fault when all the phase voltages are substantially equal to an anode potential of a DC power supply (3), the earth fault when all the phase voltages are substantially equal to a cathode potential of the DC power supply (3), and the open fault when all the phase voltages are not substantially the same potential.
    Type: Grant
    Filed: November 1, 2012
    Date of Patent: February 7, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Takamasa Asai
  • Publication number: 20170019051
    Abstract: A power conversion device has an internal power supply switch and a bias power supply switch connected in parallel with the internal power supply switch, wherein, when an output voltage of an internal power supply circuit is greater than a predetermined value when a power supply is started up, the bias power supply switch opens a current path, and when the power supply is stopped, the step-up power supply circuit is stopped based on a stop signal output by the internal power supply circuit and the internal power supply switch closes the current path, and when the output voltage of the internal power supply circuit becomes lower than a predetermined value, the bias power supply switch closes the current path.
    Type: Application
    Filed: June 30, 2014
    Publication date: January 19, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Katsuya TSUJIMOTO, Takamasa ASAI
  • Publication number: 20160156302
    Abstract: The present invention relates to a rush current limiting circuit in which a series circuit consisting of an inductor and a resistor for detecting a current is connected between a power source and a first semiconductor switch, in which there is provided a second semiconductor switch whose inter-output-terminal voltage is controlled by the voltage across the series circuit consisting of the inductor and the resistor for detecting a current, and in which the inter-output-terminal voltage of the second semiconductor switch controls the inter-control-terminal voltage of the first semiconductor switch so as to limit a current to a load; the present invention relates also to an electric power converter including the rush current limiting circuit.
    Type: Application
    Filed: September 27, 2013
    Publication date: June 2, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventor: Takamasa ASAI
  • Publication number: 20160146890
    Abstract: The present invention relates to a diagnosis apparatus for a field winding type rotating electric machine. The diagnosis apparatus includes an internal power supply circuit having an open fault determination potential, and determines, on the basis of a measurement result of a voltage value of a circuit that includes the field winding in a fault diagnosis condition, that a disconnection has occurred in the circuit when the measurement result is within an open fault determination voltage range including the open fault determination potential, that a power fault has occurred in the circuit when the measurement result is within a power fault determination voltage range including the positive electrode potential, and that an earth fault has occurred in the circuit when the measurement result is within an earth fault determination voltage range including the negative electrode potential.
    Type: Application
    Filed: July 24, 2013
    Publication date: May 26, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Katsuya TSUJIMOTO, Takamasa ASAI
  • Publication number: 20150318783
    Abstract: The present invention has: a pump capacitor (12), which has one end thereof connected to the source power supply (B) side via a diode (7), and which has the other end thereof connected to two kinds of voltage sources via switches (3, 4); and an output capacitor (13), which has one end there of connected to a high-potential terminal of a pump capacitor via a diode (8), and the other end thereof connected to a source power supply. A filter circuit configured with a resistor (15) and a capacitor (11) is provided between the source power supply and the diode (7).
    Type: Application
    Filed: April 25, 2013
    Publication date: November 5, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Naruki SUETAKE, Takamasa ASAI, Kenichi FUJIE
  • Publication number: 20150280623
    Abstract: Provided is a power conversion device, including a fault determination unit (11) for determining, based on phase voltages of a polyphase dynamo-electric machine (4) detected by phase voltage detection units (10), a power, earth, or open fault of armature windings of the polyphase dynamo-electric machine (4). The fault determination unit (11) determines, in a state that all power semiconductor switching elements (2) are in an off state and no induction voltage is generated in the armature windings of the polyphase dynamo-electric machine (4), the power fault when all the phase voltages are substantially equal to an anode potential of a DC power supply (3), the earth fault when all the phase voltages are substantially equal to a cathode potential of the DC power supply (3), and the open fault when all the phase voltages are not substantially the same potential.
    Type: Application
    Filed: November 1, 2012
    Publication date: October 1, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Takamasa Asai
  • Publication number: 20150188479
    Abstract: To provide a vehicular AC electric generator provided with a highly reliable electric power conversion unit. A stator of a rotary electric machine is configured to have a plurality of sets of three-phase windings, an electric power conversion unit is configured to have a plurality of sets of three-phase bridge circuits corresponding to the plurality of sets of three-phase windings, each of the three-phase windings of the stator is connected to a DC power supply via the corresponding three-phase bridge circuits of the electric power conversion unit, the plurality of sets of three-phase bridge circuits are controlled to be at different switching timings from each other, and semiconductor switches constituting respective arms in the plurality of sets of three-phase bridge circuits are configured to be one-chip MOSFETs.
    Type: Application
    Filed: November 22, 2012
    Publication date: July 2, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventor: Takamasa Asai
  • Patent number: 8901865
    Abstract: A current limiting device includes a switching portion, a reflux portion connected to a connection point of the switching portion and an output terminal, and supplying a current to a motor generator while the switching portion is cutting off the current, a current measurement portion that measures the current flowing from the output terminal to the motor generator, and a current control portion that controls the switching portion to switch ON/OFF according to a current value measured by the current measurement portion. When the motor generator is motor-driven using electric power of a condenser, the current control portion limits the current to the motor generator by controlling the switching portion to switch ON/OFF in a case where the measured current value is equal to or exceeds a predetermined current value.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: December 2, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Shogo Matsuoka, Katsuya Tsujimoto, Takamasa Asai
  • Patent number: 8797768
    Abstract: Provided is a power conversion device capable of detecting a short circuit failure and protecting from the same securely. The power conversion device includes: a three-phase bridge type power conversion circuit including a semiconductor switch including a first main terminal, a second main terminal, and a control terminal; a control circuit for controlling an operation of the semiconductor switch; and a voltage detection circuit for monitoring a voltage between DC terminals of the power conversion circuit, in which the control circuit has a protection function of turning off the semiconductor switch if the voltage between the DC terminals of the power conversion circuit, which is detected by the voltage detection circuit, is lower than a predetermined value for a predetermined period of time or longer.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: August 5, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventor: Takamasa Asai
  • Publication number: 20110234127
    Abstract: A current limiting device for vehicle includes a switching portion that passes/cuts off a current from an input terminal to an output terminal, a reflux portion that is connected to a connection point of the switching portion and the output terminal and supplies a current to a motor generator while the switching portion is cutting off the current, a current measurement portion that measures the current flowing from the output terminal to the motor generator, and a current control portion that controls the switching portion to switch ON/OFF according to a current value measured by the current measurement portion. When the motor generator is motor-driven using electric power of a condenser, the current control portion limits the current to the motor generator by controlling the switching portion to switch ON/OFF in a case where the measured current value is equal to or exceeds a predetermined current value.
    Type: Application
    Filed: October 8, 2010
    Publication date: September 29, 2011
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Shogo Matsuoka, Katsuya Tsujimoto, Takamasa Asai