Patents by Inventor Ryohhei NAKAO

Ryohhei NAKAO 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: 10807494
    Abstract: The state of internal resistance is appropriately expressed for a battery being energized. A battery management system includes a battery information acquisition section, a voltage calculation section, a current fluctuation amount calculation section 109 and a resistance correction amount calculation section. The battery information acquisition section acquires a voltage value V of a storage battery being energized. The voltage calculation section acquires a predicted battery voltage value Vmodel of the storage battery being energized by a method different from that of the battery information acquisition section. The current fluctuation amount calculation section calculates a current fluctuation amount dI/dt of the storage battery per unit time.
    Type: Grant
    Filed: February 1, 2017
    Date of Patent: October 20, 2020
    Assignee: Vehicle Energy Japan Inc.
    Inventors: Masahiro Yonemoto, Kei Sakabe, Ryohhei Nakao, Keiichiro Ohkawa, Daiki Komatsu
  • Publication number: 20200280204
    Abstract: A battery control device capable of obtaining an allowable charge/discharge current value can further accurately reflect a polarization state of a battery. A battery controller includes a first allowable current value calculation unit, a battery equivalent circuit model, and a correction amount calculation unit. Assuming a non-polarization state, a current limit value of the battery based on an open circuit voltage and upper and lower limit voltages set in the battery, the first allowable current value calculation unit calculates a first allowable current value Imax1. The battery equivalent circuit model estimates a polarization state of the battery when the current limit value is being calculated. The correction unit calculates an allowable current value correction value based on the estimated polarization state for correcting Imax1. A second allowable current value Imax2 which is the corrected first allowable current value is output as an allowable charge/discharge current value of the battery.
    Type: Application
    Filed: May 18, 2020
    Publication date: September 3, 2020
    Applicant: VEHICLE ENERGY JAPAN, INC.
    Inventors: Kei SAKABE, Keiichiro OHKAWA, Takanori YAMAZOE, Ryohhei NAKAO, Masahiro YONEMOTO
  • Patent number: 10680453
    Abstract: A battery control device capable of obtaining an allowable charge/discharge current value can further accurately reflect a polarization state of a battery. A battery controller includes a first allowable current value calculation unit, a battery equivalent circuit model, and a correction amount calculation unit. Assuming a non-polarization state, a current limit value of the battery based on an open circuit voltage and upper and lower limit voltages set in the battery, the first allowable current value calculation unit calculates a first allowable current value Imax1. The battery equivalent circuit model estimates a polarization state of the battery when the current limit value is being calculated. The correction unit calculates an allowable current value correction value based on the estimated polarization state for correcting Imax1. A second allowable current value Imax2 which is the corrected first allowable current value is output as an allowable charge/discharge current value of the battery.
    Type: Grant
    Filed: April 27, 2016
    Date of Patent: June 9, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Kei Sakabe, Keiichiro Ohkawa, Takanori Yamazoe, Ryohhei Nakao, Masahiro Yonemoto
  • Patent number: 10589732
    Abstract: A device for controlling current for charging/discharging a battery with a high accuracy includes a time-point setting unit which calculates a voltage difference by subtracting a calculated open-circuit voltage from a measured closed-circuit voltage, and sets first and second time points, at which an absolute value of the voltage difference becomes equal to or less than a predetermined value and an absolute value of a difference in the open-circuit voltage becomes equal to or less than a predetermined value. The control device further includes a current correction amount calculation unit to obtain the current integral amount, calculate the current error in a detection signal and set the current error as the current correction amount on the basis of the current integral amount and the time from the first time point to the second time point. The current correction unit corrects the detection signal using the current correction amount.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: March 17, 2020
    Assignee: VEHICLE ENERGY JAPAN INC.
    Inventors: Keiichiro Ohkawa, Ryohhei Nakao
  • Publication number: 20190288344
    Abstract: Provided is a battery control device that can achieve an improvement in computation accuracy of an internal resistance and an SOH. The battery control device includes an SOH computation unit which calculates an internal resistance value of a battery, and controls the battery on the basis of the internal resistance value calculated by the SOH computation unit. Then, an internal resistance computing determination unit calculates an index indicating a polarization voltage of the battery, and determines whether the index is equal to or more than a determination threshold. When the internal resistance computing determination unit determines that the index is equal to or more than the determination threshold, the battery is controlled on the basis of the internal resistance value calculated when the index is less than a determination threshold before the determination.
    Type: Application
    Filed: April 7, 2017
    Publication date: September 19, 2019
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Ryohhei NAKAO, Keiichiro OHKAWA
  • Publication number: 20190242948
    Abstract: In an existing permissible current computation algorithm, an excessive current is caused to flow by controlling the battery having a steep change region in the battery characteristic. On the other hand, when the current is reduced and the output is suppressed, the battery performance cannot be sufficiently utilized. Moreover, with countermeasures to increase the number of data points, the amount of data increases and thus can not be installed in the microcomputer.
    Type: Application
    Filed: July 28, 2017
    Publication date: August 8, 2019
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Daiki KOMATSU, Kei SAKABE, Masahiro YONEMOTO, Shin YAMAUCHI, Keiichiro OHKAWA, Ryohhei NAKAO
  • Publication number: 20190207406
    Abstract: Provided is a battery system in which a battery cell does not exceed a use limit temperature, and a time taken for returning to the charging/discharging process is shortened even if a frequency for the battery system to stop a charging/discharging process is reduced and the charging/discharging process is stopped. The battery system disclosed in the invention includes a plurality of battery cells and a control circuit which controls a charging/discharging current of the battery cell. The control circuit performs a plurality of temperature rising estimations on the basis of a battery temperature, a charging/discharging current, and a time width of a time window. The control circuit selects the charging/discharging current corresponding to a temperature rising estimation in which the temperature of the battery cell does not exceed a use limit temperature among the temperature rising estimations.
    Type: Application
    Filed: February 6, 2018
    Publication date: July 4, 2019
    Inventors: Fanny MATTHEY, Shin YAMAUCHI, Kei SAKABE, Ryohhei NAKAO, Daiki KOMATSU, Keiichiro OHKAWA
  • Patent number: 10266063
    Abstract: A battery controller capable of increasing the number of chances of being able to acquire information on a secondary battery storage capacity and a vehicle system having the battery controller mounted thereon are provided. A battery controller 120 mounted on a vehicle system 200 includes a time point setting unit 153 that sets a first time point at which a first voltage difference dVa (=CCVa?OCVa) which is a difference obtained by subtracting a first open-circuit voltage OCVa from a first closed-circuit voltage CCVa is obtained and a second time point at which a second voltage difference dVb (=CCVb?OCVb) which is a difference obtained by subtracting a second open-circuit voltage OCVb from a second closed-circuit voltage CCVb is obtained and an absolute value of the difference from the first voltage difference dVa is equal to or smaller than a predetermined value.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: April 23, 2019
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Keiichiro Ohkawa, Ryohhei Nakao
  • Publication number: 20190023132
    Abstract: The state of internal resistance is appropriately expressed for a battery being energized. A battery management system includes a battery information acquisition section, a voltage calculation section, a current fluctuation amount calculation section 109 and a resistance correction amount calculation section. The battery information acquisition section acquires a voltage value V of a storage battery being energized. The voltage calculation section acquires a predicted battery voltage value Vmodel of the storage battery being energized by a method different from that of the battery information acquisition section. The current fluctuation amount calculation section calculates a current fluctuation amount dI/dt of the storage battery per unit time.
    Type: Application
    Filed: February 1, 2017
    Publication date: January 24, 2019
    Inventors: Masahiro YONEMOTO, Kei SAKABE, Ryohhei NAKAO, Keiichiro OHKAWA, Daiki KOMATSU
  • Publication number: 20180375176
    Abstract: To sufficiently exert charging and discharging performance of a cell while reliably protecting the cell, a battery controller determines ?Vlimit which is a limit value for a difference between a CCV and an OCV of a cell module, which is a secondary cell, and determines at least one of an upper limit voltage and a lower limit voltage of the cell module. An allowable current of the cell module is calculated based on the ?Vlimit and at least one of the upper limit voltage and the lower limit voltage determined in this manner.
    Type: Application
    Filed: December 2, 2016
    Publication date: December 27, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Kei SAKABE, Keiichiro OHKAWA, Ryohhei NAKAO, Masahiro YONEMOTO
  • Publication number: 20180358663
    Abstract: Provided is a battery management device capable of effectively utilizing battery performance while securing battery life. The battery management device includes: a divergence amount calculation unit that calculates a divergence amount between a life target value or a degradation amount target value of a storage battery, which is a secondary battery, and a life prediction value or a degradation amount prediction value according to use history of the storage battery in an arbitrary period; and a limit value change unit that changes charge/discharge limit values for controlling degradation of the storage battery based on the divergence amount. The limit value change unit includes a first limit value calculation unit that calculates a first limit value set that is a combination of the charge/discharge limit values for each of a plurality of types of control parameters that change in correlation with each other based on the divergence amount.
    Type: Application
    Filed: August 8, 2016
    Publication date: December 13, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Masahiro YONEMOTO, Kei SAKABE, Takanori YAMAZOE, Shin YAMAUCHI, Keiichiro OHKAWA, Ryohhei NAKAO
  • Publication number: 20180226824
    Abstract: A battery control device capable of obtaining an allowable charge/discharge current value can further accurately reflect a polarization state of a battery. A battery controller includes a first allowable current value calculation unit, a battery equivalent circuit model, and a correction amount calculation unit. Assuming a non-polarization state, a current limit value of the battery based on an open circuit voltage and upper and lower limit voltages set in the battery, the first allowable current value calculation unit calculates a first allowable current value Imax1. The battery equivalent circuit model estimates a polarization state of the battery when the current limit value is being calculated. The correction unit calculates an allowable current value correction value based on the estimated polarization state for correcting Imax1. A second allowable current value Imax2 which is the corrected first allowable current value is output as an allowable charge/discharge current value of the battery.
    Type: Application
    Filed: April 27, 2016
    Publication date: August 9, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Kei SAKABE, Keiichiro OHKAWA, Takanori YAMAZOE, Ryohhei NAKAO, Masahiro YONEMOTO
  • Publication number: 20180210036
    Abstract: To perform charge/discharge control of a storage battery at an appropriate timing. In a battery controller, a battery information acquisition unit acquires information on the storage battery. A degradation progression rate calculation unit calculates a degradation progression rate of the storage battery based on the information acquired by the battery information acquisition unit. A limit value setting unit sets a limit value for controlling charge/discharge of the storage battery based on the degradation progression rate calculated by the degradation progression rate calculation unit. A timing determination unit determines a timing at which the limit value needs to be output based on the information acquired by the battery information acquisition unit. A limit value output unit outputs the limit value to a host controller based on the timing determined by the timing determination unit.
    Type: Application
    Filed: August 8, 2016
    Publication date: July 26, 2018
    Inventors: Shin YAMAUCHI, Kei SAKABE, Masahiro YONEMOTO, Takanori YAMAZOE, Keiichiro OHKAWA, Ryohhei NAKAO
  • Publication number: 20180198175
    Abstract: A current of a storage battery is appropriately controlled depending on the situation. In a battery controller, a battery information acquiring unit acquires information on the storage battery. A first allowable current calculating unit calculates a first allowable current of a battery module in accordance with a rated value of a component through which a current flows by charging or discharging of the battery module. A second allowable current calculating unit calculates a second allowable current of the battery module in accordance with an SOC of the battery module on the basis of the information acquired by the battery information acquiring unit. A third allowable current calculating unit calculates a third allowable current of the battery module in accordance with an SOH of the battery module on the basis of the information acquired by the battery information acquiring unit.
    Type: Application
    Filed: August 8, 2016
    Publication date: July 12, 2018
    Inventors: Shin YAMAUCHI, Kei SAKABE, Masahiro YONEMOTO, Takanori YAMAZOE, Keiichiro OHKAWA, Ryohhei NAKAO
  • Publication number: 20180074129
    Abstract: Provided are a battery control device which can estimates an SOC of a battery with a high accuracy, and an electric motor vehicle system. The battery control device (190) includes a feature amount calculation unit (152) which calculates a feature amount indicating a charging/discharging pattern of the battery, a first charging state amount calculation unit (151-1) which calculates a first charging state amount (SOCi) of the battery on the basis of a first battery state amount, a second charging state amount calculation unit (151-2) which calculates a second charging state amount (SOCv) of the battery on the basis of a second battery state amount, and a third charging state amount calculation unit (151-3) which calculates a third charging state amount (SOC(t)) on the basis of the feature amount, the first charging stage amount, the second charging stage amount.
    Type: Application
    Filed: March 16, 2016
    Publication date: March 15, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Ryohhei NAKAO, Keiichiro OHKAWA
  • Publication number: 20180050681
    Abstract: A device for controlling current for charging/discharging a battery with a high accuracy includes a time-point setting unit which calculates a voltage difference by subtracting a calculated open-circuit voltage from a measured closed-circuit voltage, and sets first and second time points, at which an absolute value of the voltage difference becomes equal to or less than a predetermined value and an absolute value of a difference in the open-circuit voltage becomes equal to or less than a predetermined value. The control device further includes a current correction amount calculation unit to obtain the current integral amount, calculate the current error in a detection signal and set the current error as the current correction amount on the basis of the current integral amount and the time from the first time point to the second time point. The current correction unit corrects the detection signal using the current correction amount.
    Type: Application
    Filed: February 26, 2016
    Publication date: February 22, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Keiichiro OHKAWA, Ryohhei NAKAO
  • Publication number: 20180037130
    Abstract: A battery controller capable of increasing the number of chances of being able to acquire information on a secondary battery storage capacity and a vehicle system having the battery controller mounted thereon are provided. A battery controller 120 mounted on a vehicle system 200 includes a time point setting unit 153 that sets a first time point at which a first voltage difference dVa (=CCVa?OCVa) which is a difference obtained by subtracting a first open-circuit voltage OCVa from a first closed-circuit voltage CCVa is obtained and a second time point at which a second voltage difference dVb (=CCVb?OCVb) which is a difference obtained by subtracting a second open-circuit voltage OCVb from a second closed-circuit voltage CCVb is obtained and an absolute value of the difference from the first voltage difference dVa is equal to or smaller than a predetermined value.
    Type: Application
    Filed: February 26, 2016
    Publication date: February 8, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Keiichiro OHKAWA, Ryohhei NAKAO