Patents by Inventor Nobuaki MUROKI

Nobuaki MUROKI 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: 20230204667
    Abstract: A short-circuit detection device for a rotating electric machine sets an order lower than a fundamental order of a slot harmonic wave as a threshold value, and reduces, among the plurality of frequency components, even-order frequency components having orders higher than the threshold value and odd-order frequency components, converts a plurality of frequency components output from the specific frequency component reduction unit into a voltage signal, generates a difference waveform of voltage signals respectively corresponding to adjacent magnetic poles, detects a short-circuit of a field winding based on a shape of the difference waveform, and estimates a short-circuit position of the field winding, and determines an estimation accuracy of the short-circuit position of the field winding based on a degree of symmetry of a waveform of a maximum wave with respect to a peak angle of the difference waveform serving as a center.
    Type: Application
    Filed: July 8, 2020
    Publication date: June 29, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Publication number: 20220390519
    Abstract: The short-circuit detection device according to the present disclosure includes: a signal acquisition unit configured to acquire, from a magnetic flux detector configured to detect a magnetic flux generated in a gap between a rotor and a stator of a rotary electric machine, one detected signal based on the magnetic flux and set the one detected signal as a first detected signal and a second detected signal; a signal processing unit configured to perform frequency analysis on the first detected signal, and generate and decode a voltage signal simulating a voltage state assumed in a normal case; and a signal comparison unit configured to perform comparison between a decoded signal obtained through the decoding by the signal processing unit and the second detected signal transmitted from the signal acquisition unit, to detect a short-circuit in a field winding of the rotary electric machine.
    Type: Application
    Filed: December 26, 2019
    Publication date: December 8, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Publication number: 20220146593
    Abstract: Provided is a short-circuit detection device including: a signal acquisition unit configured to acquire, from a magnetic flux detector configured to detect a magnetic flux generated in an air gap between a rotor and a stator of a rotating electric machine, a detection signal corresponding to the magnetic flux; a signal processing unit configured to subject the detection signal acquired by the signal acquisition unit to filtering of removing at least one component of odd-order components included in the detection signal, to thereby generate a filtered signal being the detection signal subjected to the filtering; and a short-circuit detection unit configured to detect a short circuit of a field winding through use of the filtered signal generated by the signal processing unit.
    Type: Application
    Filed: April 12, 2019
    Publication date: May 12, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Kenta MOTOYOSHI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Publication number: 20220120822
    Abstract: Provided is a short-circuit detection device configured to detect a short circuit of a field winding wound in a plurality of rotor slots in a rotor of a rotating electric machine, the short-circuit detection device including: a signal conversion unit configured to convert a detection signal in which a circumferential distribution of a magnetic flux of the rotor is detected into an energy equivalent signal corresponding to a circumferential distribution of magnetic energy of the rotor; and a short-circuit detection unit configured to detect a rotor slot in which the short circuit has occurred through use of the energy equivalent signal.
    Type: Application
    Filed: March 12, 2019
    Publication date: April 21, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Patent number: 10840759
    Abstract: In a rotary electric machine, a rotor including a rotor shaft and a rotor main body provided to the rotor shaft. A baffle plate, which is fixed at a plurality of positions to an end portion of the rotor main body in the axial direction, and is configured to define an airflow passage for cooling gas. Further, the baffle plate is segmented into a plurality of baffle segments which are arrayed in a circumferential direction of the rotor. The baffle segments each include an overlapping portion which overlaps an adjacent baffle segment in an axial direction of the rotor.
    Type: Grant
    Filed: October 5, 2017
    Date of Patent: November 17, 2020
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kohei Samata, Takeshi Nakamura, Ryutaro Kawaguchi, Norihiko Hana, Nobuaki Muroki
  • Publication number: 20190348882
    Abstract: In a rotary electric machine, a rotor including a rotor shaft and a rotor main body provided to the rotor shaft. A baffle plate, which is fixed at a plurality of positions to an end portion of the rotor main body in the axial direction, and is configured to define an airflow passage for cooling gas. Further, the baffle plate is segmented into a plurality of baffle segments which are arrayed in a circumferential direction of the rotor. The baffle segments each include an overlapping portion which overlaps an adjacent baffle segment in an axial direction of the rotor.
    Type: Application
    Filed: October 5, 2017
    Publication date: November 14, 2019
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kohei SAMATA, Takeshi NAKAMURA, Ryutaro KAWAGUCHI, Norihiko HANA, Nobuaki MUROKI