Patents by Inventor Katsuya Tsujimoto

Katsuya Tsujimoto 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: 11932111
    Abstract: A rectifier and a vehicle AC generator that can suppress the cost, the rectification loss, and the leakage current from increasing are provided. A rectifier is configured in such a way that in each of n sets, one of a positive electrode side semiconductor device and a negative electrode side semiconductor device is a MOSFET, in such a way that in at least one of the n sets, the other one of the positive electrode side semiconductor device and the negative electrode side semiconductor device is a specific diode, and in such a way that the specific diode is a Schottky barrier diode or a MOS diode, which is a MOSFET whose drain terminal and gate terminal are short-circuited.
    Type: Grant
    Filed: August 3, 2018
    Date of Patent: March 19, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinichiro Minami, Katsuya Tsujimoto, Keiichi Komurasaki, Shingo Inoue
  • Publication number: 20210257888
    Abstract: A rectifier and a vehicle AC generator that can suppress the cost, the rectification loss, and the leakage current from increasing are provided. A rectifier is configured in such a way that in each of n sets, one of a positive electrode side semiconductor device and a negative electrode side semiconductor device is a MOSFET, in such a way that in at least one of the n sets, the other one of the positive electrode side semiconductor device and the negative electrode side semiconductor device is a specific diode, and in such a way that the specific diode is a Schottky barrier diode or a MOS diode, which is a MOSFET whose drain terminal and gate terminal are short-circuited.
    Type: Application
    Filed: August 3, 2018
    Publication date: August 19, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinichiro MINAMI, Katsuya TSUJIMOTO, Keiichi KOMURASAKI, Shingo INOUE
  • Patent number: 10496576
    Abstract: The present invention is an SPI-communication-method communication apparatus that has a plurality of slave communication units for a single master communication unit and an electric power converter utilizing the communication apparatus; the master communication unit outputs communication signals simultaneously to all of the slave communication units and separately reads respective data signals outputted by the slave communication units, in accordance with a priority.
    Type: Grant
    Filed: May 22, 2015
    Date of Patent: December 3, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Isao Tottori, Katsuya Tsujimoto
  • Patent number: 10151605
    Abstract: In a rotation angle detection device for detecting a rotation angle and a rotation speed of a motor generator by using a resolver, a resolver detection accuracy is improved by raising the amplitude or frequency of an excitation signal when the motor generator is performing a driving operation. Furthermore, by reducing the amplitude or frequency of the excitation signal when the motor generator is not performing a driving operation, it is possible to suppress the amount of heat generated by the excitation circuit and the resolver, while maintaining a resolver detection accuracy that enables information about the rotation speed of the motor generator to be obtained.
    Type: Grant
    Filed: November 6, 2014
    Date of Patent: December 11, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenichi Fujie, Katsuya Tsujimoto, Isao Tottori, Naruki Suetake
  • Publication number: 20180267915
    Abstract: The present invention is an SPI-communication-method communication apparatus that has a plurality of slave communication units for a single master communication unit and an electric power converter utilizing the communication apparatus; the master communication unit outputs communication signals simultaneously to all of the slave communication units and separately reads respective data signals outputted by the slave communication units, in accordance with a priority.
    Type: Application
    Filed: May 22, 2015
    Publication date: September 20, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Isao TOTTORI, Katsuya TSUJIMOTO
  • 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: 9780694
    Abstract: Provided is a power converter capable of reliably turning OFF a switching element before turn-OFF of a diode even with a fluctuation in rpm so as not to generate a backflow of a current. The power converter includes a diode ON-interval monitoring unit (18) configured to measure a change rate of a diode ON detection interval signal. When a diode ON detection interval change rate signal (S20) exhibits a decrease on a negative side and is smaller than a predetermined value (an absolute value thereof exceeds a predetermined value), an OFF-timing of the switching element is advanced by a predetermined value or larger, to thereby reliably turn OFF the switching element before the turn-OFF of the diode even with the fluctuation in rpm.
    Type: Grant
    Filed: April 7, 2014
    Date of Patent: October 3, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Junji Tada, Kenichi Akita, Katsuya Tsujimoto, Keiichi Komurasaki
  • Publication number: 20170276515
    Abstract: In a rotation angle detection device for detecting a rotation angle and a rotation speed of a motor generator by using a resolver, a resolver detection accuracy is improved by raising the amplitude or frequency of an excitation signal when the motor generator is performing a driving operation. Furthermore, by reducing the amplitude or frequency of the excitation signal when the motor generator is not performing a driving operation, it is possible to suppress the amount of heat generated by the excitation circuit and the resolver, while maintaining a resolver detection accuracy that enables information about the rotation speed of the motor generator to be obtained.
    Type: Application
    Filed: November 6, 2014
    Publication date: September 28, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kenichi FUJIE, Katsuya TSUJIMOTO, Isao TOTTORI, Naruki SUETAKE
  • 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
  • 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: 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: 20170005593
    Abstract: Provided is a power converter capable of reliably turning OFF a switching element before turn-OFF of a diode even with a fluctuation in rpm so as not to generate a backflow of a current. The power converter includes a diode ON-interval monitoring unit (18) configured to measure a change rate of a diode ON detection interval signal. When a diode ON detection interval change rate signal (S20) exhibits a decrease on a negative side and is smaller than a predetermined value (an absolute value thereof exceeds a predetermined value), an OFF-timing of the switching element is advanced by a predetermined value or larger, to thereby reliably turn OFF the switching element before the turn-OFF of the diode even with the fluctuation in rpm.
    Type: Application
    Filed: April 7, 2014
    Publication date: January 5, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Junji TADA, Kenichi AKITA, Katsuya TSUJIMOTO, Keiichi KOMURASAKI
  • 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: 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
  • 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: 8704400
    Abstract: A vehicle power converter including a plurality of switching elements having diodes connected thereto in parallel and constituting a multi-phase bridge circuit and a controller for conducting the switching element corresponding to each diode in synchronization with a conduction state of the diode concerned to perform synchronous rectification and is connected between a power generator-motor driven from the external to generate multi-phase AC power and DC equipment, further includes a load state detecting unit for detecting a load state of the power generator-motor when the multi-phase AC power occurs, wherein a shift from diode rectification to synchronous rectification or a shift from the synchronous rectification to the diode rectification is carried out in accordance with an output of the load state detecting unit.
    Type: Grant
    Filed: November 2, 2009
    Date of Patent: April 22, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenji Nakajima, Kenichi Akita, Masato Mori, Mitsunori Tabata, Katsuya Tsujimoto
  • Patent number: 8450983
    Abstract: A microcomputer that exercises driving control and power-generation control over a motor generator unit and a power-generation maintaining unit that, separately from the power-generation control exercised by the microcomputer, maintains a power-generation process performed by the motor generator unit are provided. While the microcomputer is operating normally, the power-generation maintaining unit allows the microcomputer to exercise the power-generation control. When an abnormality has occurred in the microcomputer, the power-generation maintaining unit acts as a backup or secondary controller to maintain the power-generation process performed by the motor generator unit, in an autonomous manner independently of the microcomputer.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: May 28, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroshi Gokan, Naruki Suetake, Katsuya Tsujimoto
  • Patent number: 8292778
    Abstract: The idle-stop restart control system includes: a sensorless synchronous motor-generator which operates as a generator and a starting motor; an induced-signal detecting circuit for detecting an induced signal output from an armature winding; a field drive circuit for controlling energization of a field winding; and a restart control circuit output, to the field drive circuit, a drive signal for controlling the energization of the field winding to amplify the induced signal while calculating the number of revolutions and an angular position of a rotor based on the detected induced signal when an engine stop command is input and a level of the detected induced signal is equal to or less than a predetermined value and output the drive signal for controlling the energization of the armature winding to restart the engine based on the calculated number of revolutions and angular position of the rotor when a restart command is input.
    Type: Grant
    Filed: March 2, 2010
    Date of Patent: October 23, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tetsushi Watanabe, Masaaki Taruya, Katsuya Tsujimoto