Patents by Inventor Tatsuhito Nakajima

Tatsuhito Nakajima 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: 20230188030
    Abstract: A power conversion device is provided, and includes a major circuit part, and a control device; the major circuit part includes a power conversion part converting, into AC power, power that is input, and a filter circuit causing the AC power output from the power conversion part to approach a sine wave; the control device controls power conversion by the major circuit part by controlling an operation of the power conversion part; the control device includes an overcurrent suppression controller; the overcurrent suppression controller calculates instantaneous value voltage output command values of the phases of the AC power output from the power conversion part to suppress an overcurrent at the output end of the major circuit part. Accordingly, a power conversion device and a control device of the power conversion device are provided in which the generation of an overcurrent can be suppressed even when a voltage-controlled operation is performed.
    Type: Application
    Filed: March 25, 2021
    Publication date: June 15, 2023
    Applicant: TOSHIBA MITSUBISHI-ELECTRIC INDUSTRIAL SYSTEMS CORPORATION
    Inventors: Tatsuhito NAKAJIMA, Yasuaki MITSUGI, Tomoya KATSUKURA
  • Publication number: 20230170782
    Abstract: A power conversion device is provided, and includes a major circuit part and a control device; the major circuit part includes a power conversion part converting, into AC power, power that is input, and a filter circuit causing the AC power output from the power conversion part to approach a sine wave; the control device controls power conversion by the major circuit part by controlling an operation of the power conversion part; the control device includes an overcurrent suppression controller; the overcurrent suppression controller calculates instantaneous value voltage output command values of the phases of the AC power output from the power conversion part to suppress an overcurrent at the output end of the major circuit part. Accordingly, a power conversion device and a control device of the power conversion device are provided in which the generation of an overcurrent can be suppressed even when a voltage-controlled operation is performed.
    Type: Application
    Filed: March 25, 2021
    Publication date: June 1, 2023
    Applicant: TOSHIBA MITSUBISHI-ELECTRIC INDUSTRIAL SYSTEMS CORPORATION
    Inventors: Takumi NARITA, Tatsuhito NAKAJIMA, Yasuaki MITSUGI, Tomoya KATSUKURA
  • Patent number: 5349522
    Abstract: An AC system having, for example, a voltage source, an inductance and a load has connected thereto an apparatus for controlling the phase and amplitude of the voltage of the system. The instantaneous current and voltage in the AC electrical system are measured and power measurements derived therefrom. The power measurements may be instantaneous real and imaginary power, instantaneous active and reactive power, or active and reactive power averaged over less than one cycle. The power measurements are then used to derive phase related control values, on the basis of which control signals are generated to a converter. The action of the converter in accordance with the control signals thus controls the amplitude and phase of the voltage. By use of power measurements, it is not necessary to measure the phase of the voltage of the AC system.
    Type: Grant
    Filed: June 12, 1992
    Date of Patent: September 20, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Hiroo Konishi, Hironari Kawazoe, Junzo Kawakami, Tomoharu Nakamura, Yukio Tokiwa, Tatsuhito Nakajima