Patents by Inventor Kohei MAJIMA

Kohei MAJIMA 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).

  • Short circuit detection device, and short circuit detection method for rotating electric machine
    Patent number: 11695366
    Abstract: Provided are a short circuit state analyzer to compare difference value when the AC excitation current is applied at a first frequency with a threshold value, to estimate a short circuit resistance from the difference value based on data indicating a relationship between the short circuit resistance and the difference value at the first frequency when the difference value is smaller than the threshold value, to cause an excitation power supply to apply the AC excitation current to the field windings at a second frequency lower than the first frequency when the difference value is equal to or greater than the threshold value, and to estimate the short circuit resistance from a difference value obtained by the AC excitation current at the second frequency based on data indicating a relationship between the short circuit resistance and the difference value at the second frequency.
    Type: Grant
    Filed: January 27, 2020
    Date of Patent: July 4, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yuji Takizawa, Haruyuki Kometani, Ryosuke Kawashima, Kohei Majima, Susumu Maeda
  • SHORT CIRCUIT DETECTION DEVICE, AND SHORT CIRCUIT DETECTION METHOD FOR ROTATING ELECTRIC MACHINE
    Publication number: 20220376645
    Abstract: Provided are a short circuit state analyzer to compare difference value when the AC excitation current is applied at a first frequency with a threshold value, to estimate a short circuit resistance from the difference value based on data indicating a relationship between the short circuit resistance and the difference value at the first frequency when the difference value is smaller than the threshold value, to cause an excitation power supply to apply the AC excitation current to the field windings at a second frequency lower than the first frequency when the difference value is equal to or greater than the threshold value, and to estimate the short circuit resistance from a difference value obtained by the AC excitation current at the second frequency based on data indicating a relationship between the short circuit resistance and the difference value at the second frequency.
    Type: Application
    Filed: January 27, 2020
    Publication date: November 24, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Ryosuke KAWASHIMA, Kohei MAJIMA, Susumu MAEDA