Patents by Inventor Akira Tsubota

Akira Tsubota 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: 11404873
    Abstract: This power system operation assisting device is provided with: a multiple signal frequency specifying unit that uses, as inputs, measured data of an object to be measured and a frequency specifying parameter for calculating a frequency component of the measured data to calculate an oscillation frequency; a generation source candidate calculation unit that uses, as an input, the calculated oscillation frequency to calculate a generation source candidate of an unstable oscillation occurring in a power system; a generation source guarantee test unit that calculates the guarantee test result of the generation source candidate; and a display unit that displays the oscillation frequency, the generation source candidate, and the guarantee test result.
    Type: Grant
    Filed: March 11, 2019
    Date of Patent: August 2, 2022
    Assignee: HITACHI, LTD.
    Inventors: Kenta Kirihara, Akira Tsubota, Yutaka Kokai, Sumito Tobe, Masahiro Yatsu, Hiroo Horii
  • Publication number: 20210126453
    Abstract: This power system operation assisting device is provided with: a multiple signal frequency specifying unit that uses, as inputs, measured data of an object to be measured and a frequency specifying parameter for calculating a frequency component of the measured data to calculate an oscillation frequency; a generation source candidate calculation unit that uses, as an input, the calculated oscillation frequency to calculate a generation source candidate of an unstable oscillation occurring in a power system; a generation source guarantee test unit that calculates the guarantee test result of the generation source candidate; and a display unit that displays the oscillation frequency, the generation source candidate, and the guarantee test result.
    Type: Application
    Filed: March 11, 2019
    Publication date: April 29, 2021
    Inventors: Kenta KIRIHARA, Akira TSUBOTA, Yutaka KOKAI, Sumito TOBE, Masahiro YATSU, Hiroo HORII
  • Patent number: 10461538
    Abstract: A system stabilization control device controls a control instrument within a power system on the basis of measurement information from a plurality of measurement points within the power system. The system stabilization control device includes an equipment information database storing information of system equipment interconnected with the power system; a control priority determining unit determining the control priority of the control instrument on the basis of the information of the system equipment; a control target determining unit determining a control target on the basis of the measurement information from the plurality of measurement points and the control priority; a destabilization time calculating unit calculating destabilization time of the power system from the measurement information from the plurality of measurement points; and a control time determining unit determining control time of the control instrument on the basis of the destabilization time and the information of the system equipment.
    Type: Grant
    Filed: March 4, 2016
    Date of Patent: October 29, 2019
    Assignee: HITACHI, LTD.
    Inventors: Jun Yamazaki, Osamu Tomobe, Eisuke Kuroda, Akira Tsubota, Sumito Tobe, Masahiro Yatsu
  • Publication number: 20190288551
    Abstract: When increasing the efficiency of an aggregation group which is a part of a power system aggregation process, the aggregation group is not optimum and a created aggregation model does not satisfy both low volume of calculations and high analysis accuracy. In order to solve this problem, a power system aggregation device includes: a fitness evaluation function library in which two or more aggregation fitness evaluation functions are stored; and a processing unit which obtains an aggregation fitness from a detailed system model using the aggregation fitness evaluation functions, creates an aggregation group from the aggregation fitness, and creates an aggregation system model from the aggregation group. The processing unit calculates the aggregation fitness of two or more power system model constituent elements using two or more fitness evaluation functions, and creates the aggregation group on the basis of the aggregation fitness of the power system model constituent elements.
    Type: Application
    Filed: July 20, 2017
    Publication date: September 19, 2019
    Inventors: Akira TSUBOTA, Kazutoshi TSUCHIYA, Sumito TOBE, Masahiro YATSU
  • Publication number: 20180054059
    Abstract: A system stabilization control device controls a control instrument within a power system on the basis of measurement information from a plurality of measurement points within the power system. The system stabilization control device includes an equipment information database storing information of system equipment interconnected with the power system; a control priority determining unit determining the control priority of the control instrument on the basis of the information of the system equipment; a control target determining unit determining a control target on the basis of the measurement information from the plurality of measurement points and the control priority; a destabilization time calculating unit calculating destabilization time of the power system from the measurement information from the plurality of measurement points; and a control time determining unit determining control time of the control instrument on the basis of the destabilization time and the information of the system equipment.
    Type: Application
    Filed: March 4, 2016
    Publication date: February 22, 2018
    Applicant: HITACHI, LTD.
    Inventors: Jun YAMAZAKI, Osamu TOMOBE, Eisuke KURODA, Akira TSUBOTA, Sumito TOBE, Masahiro YATSU
  • Patent number: 5287650
    Abstract: The invention enables the rooftop cultivation of turf which can both be walked upon and which also helps prevent temperatures from rising in rooms below the roof by shielding it from the sun. The structured cultivation medium itself comprises three layers of synthetic plastic material, a top layer for turf cultivation, a middle layer to protect the roots and a bottom layer to drain water away. A root blocking waterproofing layer is laid on the surface of the roof slab to waterproof the building and to guard against the downward encroachment of roots. A net is also laid on top of the turf both to prevent it from being damaged by wind and also protect it against concentrated loads.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: February 22, 1994
    Assignee: Asanuma Corporation
    Inventors: Goro Moriguchi, Seiichiro Ishihara, Masatosi Kubo, Akira Tsubota, Takeshi Nakai