Patents by Inventor Youhei Kawahara

Youhei Kawahara 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: 9130379
    Abstract: A vehicle power supply system comprises a battery module that includes a plurality of battery cells, battery cell control devices and a signal transmission path through which signals are transmitted. The battery cell control devices comprises a voltage measurement circuit that measures terminal voltages at the battery cells, an abnormality diagnosis circuit that diagnoses an abnormality in the battery cell control device, a timing control circuit that outputs a signal for instructing measurement phase and a signal for instructing diagnosis phase, and a communication circuit that outputs a signal indicating the terminal voltage and a signal based upon a diagnosis result by the abnormality diagnosis circuit.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: September 8, 2015
    Assignees: Hitachi, Ltd., Hitachi Automotive Systems, Ltd.
    Inventors: Kei Sakabe, Akihiko Emori, Akihiko Kudo, Kenji Kubo, Youhei Kawahara, Mutsumi Kikuchi, Tatsumi Yamauchi
  • Patent number: 8947023
    Abstract: In a memory, the surface temperature and the internal resistance of an assembled battery detected under the condition where a difference between the surface and the internal temperature is within a predetermined value are stored, and an internal temperature diagnosis unit that diagnoses whether or not the internal temperature estimated by an internal temperature estimation unit is correct, detects the internal resistance with an internal resistance calculation unit when the internal temperature estimation unit estimates the internal temperature, searches for an internal resistance corresponding to the surface temperature equal to the estimated internal temperature value from among the stored internal resistances, and diagnoses the estimated internal temperature value based upon the result of comparison of a search result of the internal resistance and the internal resistance detected during internal temperature estimation.
    Type: Grant
    Filed: October 14, 2009
    Date of Patent: February 3, 2015
    Assignees: Hitachi, Ltd., Hitachi Automotive Systems, Ltd.
    Inventors: Youhei Kawahara, Akihiko Emori, Akihiko Kudo, Atsuo Suga, Masato Isogai, Kenji Kubo
  • Publication number: 20140239914
    Abstract: A battery controller for charge and discharge control of an assembly battery so that a state of charge of each battery cell forming a battery does not deviate from a predetermined usage range. The battery controller controls an assembly battery comprising a plurality of battery cells. The battery controller calculates an actual average charge state CAVE, an average charge state upper limit value CAVEH, an average charge state lower limit value CAVEL, an average charge state ratio S indicating a position of the actual average charge state CAVE between the average charge state upper limit value CAVEH and the average charge state lower limit value CAVEL, and an assembly battery charge state CPACK based on the actual average charge state CAVE, the average charge state upper limit value CAVEH, the average charge state lower limit value CAVEL, and the average charge state ratio S.
    Type: Application
    Filed: October 6, 2011
    Publication date: August 28, 2014
    Applicant: HITACHI VEHICLE ENERGY, LTD.
    Inventors: Naoyuki Igarashi, Keiichiro Ohkawa, Youhei Kawahara
  • Publication number: 20140217982
    Abstract: To satisfactorily carry out balancing even when balancing control is suspended. It is selected according to a condition which of battery cell information (old state information) by the last balancing stored in a storage device and battery cell information (new state information) acquired during a start of this time is used, and the balancing control is performed.
    Type: Application
    Filed: May 23, 2011
    Publication date: August 7, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Youhei Kawahara, Ryouhei Nakao
  • Patent number: 8798832
    Abstract: An electric storage device including a state detection unit managing and controlling the state of a battery unit, wherein the state detection unit captures an inter-terminal voltage of each of a plurality of batteries measured by a battery management unit in a no-load state where the battery unit is separated from a load, and calculates variation information about the states of charge of the batteries. In addition, the state detection unit, taking into consideration the variation information about the states of charge of the batteries, calculates allowable charge and discharge information required for controlling the charging and discharging of the battery unit in a loaded state where the battery unit is connected to a load and charged or discharged, and outputs the allowable charge and discharge information to a charge and discharge device in the battery unit.
    Type: Grant
    Filed: February 4, 2010
    Date of Patent: August 5, 2014
    Assignees: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd.
    Inventors: Youhei Kawahara, Kei Sakabe, Akihiko Emori
  • Publication number: 20140184166
    Abstract: A battery control device capable of carrying out current limitation in consideration of constraints on other components than a battery main body is provided. A battery control device according to the invention has an average current table describing an average current allowed for each of plural time window widths, and limits a battery current in accordance with the description.
    Type: Application
    Filed: June 10, 2011
    Publication date: July 3, 2014
    Inventors: Keiichiro Ohkawa, Ryouhei Nakao, Youhei Kawahara
  • Publication number: 20140184236
    Abstract: A battery control apparatus which can calculate a state of charge of a battery with high accuracy is provided. The battery control apparatus of the invention determines whether or not an open circuit voltage of a battery cell is within a high sensitivity range in which the open voltage of the battery cell changes by a specified amount or more with respect to a change in the state of charge of the battery cell, and if within the high sensitivity range, calculates the state of charge by using a previously held correspondence relation table between the state of charge of the battery and the open voltage, and if not within the high sensitivity range, uses a previous state of charge calculation result stored in a storage part.
    Type: Application
    Filed: June 10, 2011
    Publication date: July 3, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Youhei Kawahara, Ryouhei Nakao
  • Publication number: 20140177145
    Abstract: A semiconductor device generates battery state information including information of a capacity that can be extracted from a battery in the case of discharging from a full charge state until a discharge cutoff voltage at a predetermined discharge rate, based on measurement results of battery voltage, current, and temperature. The device calculates a first estimate value of capacity that can be extracted in the case of discharging the battery from the full charge state until the discharge cutoff voltage and calculates a second estimate value of capacity that can be extracted in the case of discharging the battery until a voltage larger than the discharge cutoff voltage. The device corrects the first estimate value based on a difference between a capacity value extracted from the battery by discharging the battery from the full charge state until the voltage larger than the discharge cutoff voltage and the second estimate value.
    Type: Application
    Filed: December 11, 2013
    Publication date: June 26, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Youhei Kawahara, Kenta Kobayashi, Suguru Sasaki, Yusuke Sugawara
  • Publication number: 20140159671
    Abstract: A battery control circuit includes a voltage detection circuit for measuring voltages of electric cells, balancing circuits for balancing the voltages or SOCs of the electric cells, a signal input/output circuit for communicating with the outside, a power supply circuit having two modes: a normal mode and a low consumption mode, and a time management circuit. It receives a signal containing a period of time until the shift of the power supply circuit from the normal mode to the low consumption mode, and stores it in the time management circuit. If a command from the outside has not been sent for a predetermined period of time or when an operation stop command has been sent from the outside, the time management circuit causes the power supply circuit to continuously operate in the normal mode.
    Type: Application
    Filed: December 20, 2013
    Publication date: June 12, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Youhei KAWAHARA, Ryouhei NAKAO, Akihiko KUDO, Akihiko EMORI, Kei SAKABE
  • Patent number: 8736229
    Abstract: A battery control circuit includes a voltage detection circuit for measuring voltages of electric cells, balancing circuits for balancing the voltages or SOCs of the electric cells, a signal input/output circuit for communicating with the outside, a power supply circuit having two modes: a normal mode and a low consumption mode, and a time management circuit. It receives a signal containing a period of time until the shift of the power supply circuit from the normal mode to the low consumption mode, and stores it in the time management circuit. If a command from the outside has not been sent for a predetermined period of time or when an operation stop command has been sent from the outside, the time management circuit causes the power supply circuit to continuously operate in the normal mode.
    Type: Grant
    Filed: June 22, 2011
    Date of Patent: May 27, 2014
    Assignee: Hitachi Vehicle Energy, Ltd.
    Inventors: Youhei Kawahara, Ryouhei Nakao, Akihiko Kudo, Akihiko Emori, Kei Sakabe
  • Publication number: 20140111164
    Abstract: An object of the invention is to provide a battery control apparatus capable of accurately obtaining permissible charging or discharging power in keeping with variation of the internal resistance of a battery. The battery control apparatus of this invention includes an internal resistance table in which the internal resistance value of single cells corresponding to the temperature and state of charge thereof are described in association with each of charging or discharging duration time of the single cells. The battery control apparatus calculates a permissible charging current or a permissible discharging current by using the internal resistance value described in the internal resistance table and controls the charging or discharging of the single cells in accordance with the current value thus obtained.
    Type: Application
    Filed: June 10, 2011
    Publication date: April 24, 2014
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Keiichiro Ohkawa, Ryouhei Nakao, Youhei Kawahara
  • Publication number: 20140042973
    Abstract: An electric storage device includes an assembled battery including a plurality of electric cells connected in series; an assembled battery control unit that estimates internal resistances of the plurality of electric cells, or a magnitude relationship of the internal resistances of the plurality of electric cells; an assembled battery control unit that calculates such a discharge quantity that an SOC after the electric cells have been discharged becomes lower as the internal resistance of the electric cells, which is estimated by the assembled battery control unit, is larger, or as the magnitude relationship of the internal resistances of the electric cells is estimated to be larger by the assembled battery control unit, for each of the electric cells; and electric cell control units that discharge each of the plurality of electric cells on the basis of the discharge quantity calculated by the assembled battery control unit.
    Type: Application
    Filed: April 18, 2011
    Publication date: February 13, 2014
    Applicant: HITACHI VEHICLE ENERGY, LTD.
    Inventors: Youhei Kawahara, Ryouhei Nakao, Akihiko Kudo, Akihiko Emori, Keiichiro Okawa, Yoshinori Aoshima
  • Publication number: 20130320989
    Abstract: A battery states estimation method includes the steps of: measuring an electric current value of a battery B at an electric current value detection section and a terminal voltage value of the battery B at voltage detection section at a time of charge/discharge of the battery; and calculating at least one of such states of the battery as a state of charge (SOC), a state of health (SOH) and a full charge capacity based on the electric current value and the terminal voltage value as measured. When a change in the measured electric current value per second is at a predetermined value or higher, at least one of the SOC, the SOH and the full charge capacity of the battery is calculated based on the electric current values and the terminal voltage values measured during a battery charge/discharge period other than the lapsed period.
    Type: Application
    Filed: March 7, 2011
    Publication date: December 5, 2013
    Applicant: HITACHI, LTD.
    Inventors: Takeshi Inoue, Motoo Futami, Youhei Kawahara, Mitsutoshi Honda
  • Patent number: 8583389
    Abstract: A plurality of resistance value tables of a battery group with respect to temperature and SOC of the assembled battery, which are measured in advance when currents of different change patterns flow in the assembled battery, are stored. A resistance value for the assembled battery is calculated, based upon its voltage and current. From among the plurality of resistance value tables, a resistance value table is selected so that it corresponds to the change pattern of the current flowing in the assembled battery when the voltage and the current of the assembled battery were measured, and a resistance value is searched for from that resistance value table corresponding to the temperature and the SOC of the assembled battery. Then the calculated resistance value and the one from the table are compared to determine the life of the assembled battery.
    Type: Grant
    Filed: January 12, 2010
    Date of Patent: November 12, 2013
    Assignees: Hitachi Vehicle Energy, Ltd., Hitachi, Ltd.
    Inventors: Yoshinori Aoshima, Masahiro Ueda, Youhei Kawahara, Kouji Higashimoto
  • Patent number: 8466708
    Abstract: A state detection device for power supply system comprises: a measurement unit that obtains current, voltage, and temperature at a chargeable and dischargeable power storage unit as measurement values; a storage unit that stores property information of the power storage unit; an arithmetic unit that uses different methods to calculate first and second states of charge for the power storage unit based upon the measurement values and the property information; a conflict detection unit that detects a conflict in an event that a difference between the first state of charge and the second state of charge is equal to or greater than a predetermined threshold; and a correction unit that corrects the property information during charging or discharging of the power storage unit in response to the conflict having been detected by the conflict detection unit.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: June 18, 2013
    Assignees: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd
    Inventors: Youhei Kawahara, Yoshinori Aoshima, Kenichiro Tsuru, Akihiko Kudo, Akihiko Emori, Tatsumi Yamauchi
  • Publication number: 20130106356
    Abstract: In a battery device including a battery pack in which a plurality of cells are connected in series, there are provided a battery control circuit or a battery device capable of eliminating a fluctuation in the voltage or charged state which can occur between the cells, or preventing the cells from being maintained in an over-charged state for a long period. A plurality of cell groups each including a plurality of cells are connected in series to form a battery pack. Cell controller is provided to the respective cell groups operate with electricity supplied from the cell groups allocated thereto so as to monitor and control the state of the cells of the cell group. Battery pack controller controls the cell controller based on information from the plurality of cell controller.
    Type: Application
    Filed: February 28, 2011
    Publication date: May 2, 2013
    Applicant: Hitachi Vehicle Energy, Ltd.
    Inventors: Ryouhei Nakao, Youhei Kawahara, Akihiko Kudou, Akihiko Emori, Kei Sakabe
  • Patent number: 8426047
    Abstract: A multi-series battery control system comprises battery cell groups each having a plurality of serially connected battery cells, a plurality of integrated circuits each disposed in correspondence to one of the battery cell groups and a battery control device that exchanges signals with the individual integrated circuits. Each integrated circuit includes an address setting means that receives a message unique to the integrated circuit, different from messages sent to other integrated circuits, from the battery control device, writes over an initialized address of the integrated circuit with the message and alters the message to a message with which an initialized address of another integrated circuit cannot be overwritten in a step assigned with an ordinal number matching the position of the integrated circuit with regard to the connection order.
    Type: Grant
    Filed: August 19, 2008
    Date of Patent: April 23, 2013
    Assignees: Hitachi, Ltd., Hitachi Vehicle Energy, Ltd.
    Inventors: Akihiko Emori, Youhei Kawahara, Kei Sakabe, Mutsumi Kikuchi, Tatsumi Yamauchi, Akihiko Kudo
  • Publication number: 20130018610
    Abstract: A secondary battery module includes a battery information storage unit for storing electric characteristic information and usage history information of the secondary battery module. A battery information management device and a terminal device respectively include interfaces to be connected to the secondary battery module. The battery information management device is provided with a battery information database. The battery information management device is connected to the terminal device through a communications network. In this way, battery information stored in the battery information storage unit, which is acquired by the battery information management device and the terminal device, is accumulated in the battery information database. Moreover, the battery information management device grades the secondary battery module for reuse based on the battery information and a predetermined threshold.
    Type: Application
    Filed: September 14, 2012
    Publication date: January 17, 2013
    Inventors: Shuko YAMAUCHI, Youhei Kawahara, Akihiko Emori
  • Patent number: 8299757
    Abstract: A secondary battery module includes a battery information storage unit for storing electric characteristic information and usage history information of the secondary battery module. A battery information management device and a terminal device respectively include interfaces to be connected to the secondary battery module. The battery information management device is provided with a battery information database. The battery information management device is connected to the terminal device through a communications network. In this way, battery information stored in the battery information storage unit, which is acquired by the battery information management device and the terminal device, is accumulated in the battery information database. Moreover, the battery information management device grades the secondary battery module for reuse based on the battery information and a predetermined threshold.
    Type: Grant
    Filed: April 8, 2010
    Date of Patent: October 30, 2012
    Assignee: Hitachi Vehicle Energy, Ltd.
    Inventors: Shuko Yamauchi, Youhei Kawahara, Akihiko Emori
  • Publication number: 20120256569
    Abstract: In a memory, the surface temperature and the internal resistance of an assembled battery detected under the condition where a difference between the surface and the internal temperature is within a predetermined value are stored, and an internal temperature diagnosis unit that diagnoses whether or not the internal temperature estimated by an internal temperature estimation unit is correct, detects the internal resistance with an internal resistance calculation unit when the internal temperature estimation unit estimates the internal temperature, searches for an internal resistance corresponding to the surface temperature equal to the estimated internal temperature value from among the stored internal resistances, and diagnoses the estimated internal temperature value based upon the result of comparison of a search result of the internal resistance and the internal resistance detected during internal temperature estimation.
    Type: Application
    Filed: October 14, 2009
    Publication date: October 11, 2012
    Inventors: Youhei Kawahara, Akihiko Emori, Akihiko Kudo, Atsuo Suga, Masato Isogai, Kenji Kubo