Patents by Inventor Takayoshi Miki

Takayoshi Miki 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: 20240275376
    Abstract: A control unit of a gate drive circuit applies, between a gate and a source of a switching element, a first voltage so as to turn on the switching element. After transference of drain current of the switching element, the control unit interrupts the first voltage and applies, between the gate and the source of the switching element, a second voltage that is lower than the first voltage and that is higher than a mirror voltage of the switching element. When no short-circuit current is flowing to the switching element, the control unit interrupts the second voltage and applies, between the gate and the source of the switching element, a third voltage higher than the second voltage.
    Type: Application
    Filed: June 16, 2021
    Publication date: August 15, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji NEMOTO, Kohei ONDA, Takayoshi MIKI, Shota MORISAKI
  • Publication number: 20240235542
    Abstract: A semiconductor device is subjected to ON/OFF control by controlling a gate voltage according to a drive control signal (Ssw). In a turn-on operation for charging a gate in response to transition of drive control signal (Ssw) from a first level (0) to a second level (1), a drive signal (Sdr) is set to first level (0) to discharge the gate at a first time (t1) after end of a Miller period (200) of a gate voltage (Vg), thereby providing a voltage drop period (210) in which gate voltage (Vg) temporarily drops. At a second time (t2), drive signal (Sdr) is again set to second level (1) to start charging the gate.
    Type: Application
    Filed: May 25, 2021
    Publication date: July 11, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yasutaka IMAMURA, Yohei MITSUI, Yukihiko WADA, Takayoshi MIKI
  • Patent number: 11984833
    Abstract: An electric vehicle control device includes a first inverter controlling a first group defined by induction motors, and a second inverter controlling a second group defined by induction motors. The first inverter and the induction motors of the first group are connected to each other by a first conductor. The second inverter and the induction motors of the second group are connected by a second conductor. A first length is equal to or less than three times the average value of a second length and a third length. The first length is an inter-center distance between the first conductor and the second conductor, the second length is the maximum length of a conductor portion of the first conductor in the cross section of the first conductor, and the third length is the maximum length of a conductor portion of the second conductor in the cross section of the second conductor.
    Type: Grant
    Filed: August 1, 2019
    Date of Patent: May 14, 2024
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Naoki Nishio, Yasuhiro Shiraki, Takayoshi Miki, Shinsuke Kadoi, Hisanori Yamasaki, Sho Kato, Tetsuo Sugahara
  • Patent number: 11955959
    Abstract: A parallel driving device that drives parallel-connected semiconductor elements includes a control unit and a gate driving circuit. The control unit detects a temperature difference between the semiconductor elements on the basis of detected values by temperature sensors that detect temperatures of the individual semiconductor elements. The control unit generates a control signal for changing the timing at which to turn on a first semiconductor element specified from the semiconductor elements on the basis of the temperature difference. The gate driving circuit generates a first driving signal for driving the semiconductor elements, and generates a second driving signal that is the first driving signal delayed on the basis of the control signal, and applies the second driving signal to the first semiconductor element.
    Type: Grant
    Filed: May 29, 2019
    Date of Patent: April 9, 2024
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yasushi Nakayama, Yoshiko Tamada, Takayoshi Miki, Shota Morisaki, Yukio Nakashima, Kenta Uchida, Keisuke Kimura, Tomonobu Mihara
  • Publication number: 20240006976
    Abstract: A gate drive circuit includes a resistor, a current detector that detects a current flowing through the resistor, and a gate driver. The gate driver applies an electric signal between a gate terminal and a source terminal of a module to drive a switching semiconductor element. One end of the resistor is connected to a drain terminal, the opposite end of the resistor is connected to one end of the current detector, and the opposite end of the current detector is connected to the gate driver. The current detector outputs a detection value of the current to the gate driver, and the gate driver changes a gate drive speed of the switching semiconductor element according to the detection value.
    Type: Application
    Filed: December 24, 2020
    Publication date: January 4, 2024
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinya KURACHI, Takayoshi MIKI, Shota MORISAKI
  • Patent number: 11711025
    Abstract: A power semiconductor module includes at least one upper arm provided between a positive electrode line and a node and including a power semiconductor device and a freewheeling diode connected in parallel, at least one lower arm provided between a negative electrode line and the node and including a power semiconductor device and a freewheeling diode connected in parallel, and a snubber circuit provided between the positive electrode line and the negative electrode line. The snubber circuit includes a snubber capacitor and a snubber resistor connected in series. At least one control terminal outputs a voltage representing the temperature of the snubber resistor or a voltage related to the temperature of the snubber resistor to a driver that drives the power semiconductor device.
    Type: Grant
    Filed: November 1, 2018
    Date of Patent: July 25, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takeshi Horiguchi, Takayoshi Miki
  • Publication number: 20230223834
    Abstract: A power converting device includes upper-arm and lower-arm gate drive circuits which respectively drive upper-arm and lower-arm semiconductor switching elements and which respectively include upper-arm and lower-arm time point detection circuits for detecting time points at which voltages between main terminals of the upper-arm and lower-arm semiconductor switching elements have crossed respective reference voltages, and a controller including a calculator which calculates a change time point of an inverter output voltage and a PWM command pulse generator which generates, on the basis of information about the time point calculated by the calculator, a PWM command pulse to be given to the upper-arm gate drive circuit and the lower-arm gate drive circuit.
    Type: Application
    Filed: June 17, 2020
    Publication date: July 13, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takayoshi MIKI, Kohei ONDA
  • Publication number: 20220286066
    Abstract: An electric vehicle control device includes a first inverter controlling a first group defined by induction motors, and a second inverter controlling a second group defined by induction motors. The first inverter and the induction motors of the first group are connected to each other by a first conductor. The second inverter and the induction motors of the second group are connected by a second conductor. A first length is equal to or less than three times the average value of a second length and a third length. The first length is an inter-center distance between the first conductor and the second conductor, the second length is the maximum length of a conductor portion of the first conductor in the cross section of the first conductor, and the third length is the maximum length of a conductor portion of the second conductor in the cross section of the second conductor.
    Type: Application
    Filed: August 1, 2019
    Publication date: September 8, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Naoki NISHIO, Yasuhiro SHIRAKI, Takayoshi MIKI, Shinsuke KADOI, Hisanori YAMASAKI, Sho KATO, Tetsuo SUGAHARA
  • Publication number: 20220231595
    Abstract: A parallel driving device that drives parallel-connected semiconductor elements includes a control unit and a gate driving circuit. The control unit detects a temperature difference between the semiconductor elements on the basis of detected values by temperature sensors that detect temperatures of the individual semiconductor elements. The control unit generates a control signal for changing the timing at which to turn on a first semiconductor element specified from the semiconductor elements on the basis of the temperature difference. The gate driving circuit generates a first driving signal for driving the semiconductor elements, and generates a second driving signal that is the first driving signal delayed on the basis of the control signal, and applies the second driving signal to the first semiconductor element.
    Type: Application
    Filed: May 29, 2019
    Publication date: July 21, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yasushi NAKAYAMA, Yoshiko TAMADA, Takayoshi MIKI, Shota MORISAKI, Yukio NAKASHIMA, Kenta UCHIDA, Keisuke KIMURA, Tomonobu MIHARA
  • Patent number: 11128235
    Abstract: A power conversion device includes six semiconductor modules. Each of the six semiconductor modules includes a first terminal (P), a second terminal (N), and a third terminal (AC) on its surface. The first terminals of two semiconductor modules configuring a semiconductor module group of the same phase are arranged to be opposed to each other. A plurality of semiconductor module groups are arranged in a direction perpendicular to an arrangement direction of two semiconductor modules in the semiconductor module group.
    Type: Grant
    Filed: January 27, 2017
    Date of Patent: September 21, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Publication number: 20210135598
    Abstract: A power conversion device includes six semiconductor modules. Each of the six semiconductor modules includes a first terminal (P), a second terminal (N), and a third terminal (AC) on its surface. The first terminals of two semiconductor modules configuring a semiconductor module group of the same phase are arranged to be opposed to each other. A plurality of semiconductor module groups are arranged in a direction perpendicular to an arrangement direction of two semiconductor modules in the semiconductor module group.
    Type: Application
    Filed: January 27, 2017
    Publication date: May 6, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Publication number: 20200395867
    Abstract: A power semiconductor module includes at least one upper arm provided between a positive electrode line and a node and including a power semiconductor device and a freewheeling diode connected in parallel, at least one lower arm provided between a negative electrode line and the node and including a power semiconductor device and a freewheeling diode connected in parallel, and a snubber circuit provided between the positive electrode line and the negative electrode line. The snubber circuit includes a snubber capacitor and a snubber resistor connected in series. At least one control terminal outputs a voltage representing the temperature of the snubber resistor or a voltage related to the temperature of the snubber resistor to a driver that drives the power semiconductor device.
    Type: Application
    Filed: November 1, 2018
    Publication date: December 17, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takeshi HORIGUCHI, Takayoshi MIKI
  • Patent number: 10727729
    Abstract: A power converter includes: a power converter main circuit that includes semiconductor switching elements; gate drive circuits driving the semiconductor switching elements, respectively; and one or a plurality of impedance element groups connected between at least one pair of the gate drive circuits. At least one of the gate drive circuits includes a detector that detects a voltage across the impedance element group, and changes the driving speed of the semiconductor switching elements in accordance with an output of the detector.
    Type: Grant
    Filed: September 3, 2015
    Date of Patent: July 28, 2020
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Patent number: 10554123
    Abstract: A power converter includes a power module having a positive electrode of a positive-side switching device connected to a first terminal, a negative electrode of the positive-side switching device and a positive electrode of a negative-side switching device connected to a second terminal, and a negative electrode of the negative-side switching device connected to a third terminal. The first terminal is connected to a P terminal of a filter capacitor via a first conductor of a bus bar that is a parallel flat plate conductor. The third terminal is connected to an N terminal of the filter capacitor via a second conductor of the bus bar. The bus bar as the parallel flat plate conductor has an L shape. The second terminal is connected to a load via a conductor bar physically different from the bus bar.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: February 4, 2020
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Publication number: 20190296638
    Abstract: A power converter includes a power module having a positive electrode of a positive-side switching device connected to a first terminal, a negative electrode of the positive-side switching device and a positive electrode of a negative-side switching device connected to a second terminal, and a negative electrode of the negative-side switching device connected to a third terminal. The first terminal is connected to a P terminal of a filter capacitor via a first conductor of a bus bar that is a parallel flat plate conductor. The third terminal is connected to an N terminal of the filter capacitor via a second conductor of the bus bar. The bus bar as the parallel flat plate conductor has an L shape. The second terminal is connected to a load via a conductor bar physically different from the bus bar.
    Type: Application
    Filed: December 14, 2016
    Publication date: September 26, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Patent number: 10411589
    Abstract: A power conversion apparatus includes a main capacitor to store therein DC power, and an inverter circuit to convert the DC power stored in the main capacitor to AC power. The main capacitor and a power semiconductor element that constitutes the inverter circuit are connected to each other by a P-side common wire through which a switching current flows. A switching-current shunt component is connected in parallel to the P-side common wire.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: September 10, 2019
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Patent number: 10312904
    Abstract: A power semiconductor module having switching elements includes: a collector main terminal and a collector auxiliary terminal connected to a collector potential of the switching element; a gate auxiliary terminal connected to a gate potential of the switching element; and an emitter main terminal and an emitter auxiliary terminal connected to an emitter potential of the switching element. A power converter includes a voltage dividing circuit board that generates a divided voltage obtained by dividing a voltage between the collector auxiliary terminal and the emitter auxiliary terminal and transmits to a gate driving circuit. The voltage dividing circuit board is electrically connected to the collector auxiliary terminal and the emitter auxiliary terminal. A gate driving circuit changes a driving speed of the switching element according to the divided voltage.
    Type: Grant
    Filed: September 3, 2015
    Date of Patent: June 4, 2019
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio Nakashima, Takayoshi Miki
  • Publication number: 20190006934
    Abstract: A power converter includes: a power converter main circuit that includes semiconductor switching elements; gate drive circuits driving the semiconductor switching elements, respectively; and one or a plurality of impedance element groups connected between at least one pair of the gate drive circuits. At least one of the gate drive circuits includes a detector that detects a voltage across the impedance element group, and changes the driving speed of the semiconductor switching elements in accordance with an output of the detector.
    Type: Application
    Filed: September 3, 2015
    Publication date: January 3, 2019
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio NAKASHIMA, Takayoshi MIKI
  • Publication number: 20180241389
    Abstract: A power semiconductor module having switching elements includes: a collector main terminal and a collector auxiliary terminal connected to a collector potential of the switching element; a gate auxiliary terminal connected to a gate potential of the switching element; and an emitter main terminal and an emitter auxiliary terminal connected to an emitter potential of the switching element. A power converter includes a voltage dividing circuit board that generates a divided voltage obtained by dividing a voltage between the collector auxiliary terminal and the emitter auxiliary terminal and transmits to a gate driving circuit. The voltage dividing circuit board is electrically connected to the collector auxiliary terminal and the emitter auxiliary terminal. A gate driving circuit changes a driving speed of the switching element according to the divided voltage.
    Type: Application
    Filed: September 3, 2015
    Publication date: August 23, 2018
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yukio NAKASHIMA, Takayoshi MIKI
  • Patent number: 10038438
    Abstract: A driving circuit including: a voltage detector that detects the sum voltage of a positive bias voltage and a negative bias voltage, the negative bias voltage or the positive bias voltage; and a switching element that is connected to the control terminal of a power element and the negative side of a negative-voltage power supply; wherein, when the value of the detection target voltage becomes lower than a voltage setting value or when a voltage between the control terminal and the reference terminal in the power element increases in a state where the value of the detection target voltage is lower than the voltage setting value, the voltage detector turns on the switching element to thereby supply, between the above terminals in the power element, a voltage of 0V or lower.
    Type: Grant
    Filed: May 27, 2015
    Date of Patent: July 31, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kosuke Nakano, Keisuke Iwasawa, Takayoshi Miki, Hiroshi Nakatake